design, construction, and nonlinear dynamic analysis of three
TRANSCRIPT
Report Number CCEER-09-03
Construction and Nonlinear Dynamic Analysis of Three Bridge Bents Used in a Bridge System Test
David Hillis
M. "Saiid" Saiidi
____________________________________________
Center for Civil Engineering Earthquake Research Department of Civil Engineering/258
University of Nevada Reno, NV 89557
August 2009
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Acknowledgements The research presented in this report was sponsored by the National Science Foundation
through NEES award number CMS-0420347 and CMMI-0650935. The authors thank
UNR students Hoon Choi, Carlos Cruz, Sarira Motaref, Ashkan Vosooghi, Arash Esmaili,
Danielle Smith, Amir Reza Shoja-Taheri, and Milad Oliaee for their assistance at various
stages of the project. Thanks are also due Patrick Laplace, Paul Lucas, and Chad Lyttle
for their dedicated help in the UNR structures lab. Dr. M. Sadrossadat Zadeh and Dr.
Won Lee are thanked for their helpful advice with the analytical modeling. Gratitude is
due BarSplice Products Inc. for donating the mechanical connectors and Mike Pagano at
Avar for assistance with post-tensioning. Konrad Eriksen and Tung Ng of Dynamic
Isolation Systems are thanked for fabricating the isolators used in two of the columns.
Special appreciation goes to Don Newman at Scott Meeks and Sons and Ed Little of
Surface Systems for building the piers. Karin Saxon is thanked for her careful editing of
the report. Enduring support of Christina and Kiana Hillis played an important role
enabling the first author to work on this project. This report is based on a special project
report prepared by the first author under the supervision of the second author.
iii
Abstract
During major earthquakes that have occurred in the United States and around the world a
common issue that has been observed in bridges and viaducts is the severe localized
damage often accompanied by significant residual column displacements. The use of
innovative design and materials in individual bridge columns has been shown to improve
seismic performance by reducing the residual displacement. This report presents
information about the design, construction and nonlinear dynamic analysis of three bridge
bents used in a bridge system test. Each individual bent contained one of three different
bent details: the use of Shape Memory Alloy and Engineered Cementitious Composites,
Unbonded Post Tensioned Columns, and Isolator Built in Columns. Analytical evaluation
of individual columns showed significant reduction in the residual displacement.
Extensive pre-test analytical modeling was conducted using OpenSEES prior to finalizing
the column height and bridge model configuration to achieve a comparable lateral drift
ratio. When working with innovative design and materials many differences and logistic
issues associated with construction were identified. However, the construction of the
bents used in the bridge model was successful. These bents were then used in a quarter
scale four span bridge tested at the University of Nevada, Reno.
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Table of Contents Chapter 1 – Introduction
1.1 Introduction …………………………………………………………............ 1 1.2 Previous Work ……………………………………………………………… 2 1.3 Objectives and Scope ………………………………………………………. 3
Chapter 2 – Design of Bents
2.1 Introduction ………………………………………………………………… 4 2.2 Design of Bents …………………………………………………………….. 4 2.2.1 Shape Memory Alloy and Engineered Cementitious Composite Bent ….. 5 2.2.2 Post-Tensioned Bent ……………………………………………………… 6 2.2.3 Built in Isolator (ISO) …………………………………………………….. 7 2.3 Material Testing …………………………………………………………… 12
CH 3 - Construction of Bents
3.1 Introduction ……………………………………………………………….. 15 3.2 Cast-in-Place Construction …………………………………………..……. 15 3.3 SMA and ECC Bent Construction ………………………………….…...… 16 3.4 PT Bent Construction …………………………………………….….......... 17 3.5 ISO Bent Construction ……………………………………………………. 18
Chapter 4 OpenSEES Modeling and Results
4.1 Introduction ……………………………………………………………...… 19 4.2 Isolator Bearing Bent (ISO Bent) ………………………………………..... 20 4.3 Post-Tensioned Bent ……………………………………………………..... 20 4.4 SMA/ECC Bent …………………………………………………………… 21 4.5 Cyclic Load Analysis of Single Columns………………………………….. 21 4.6 Location of Bents in Bridge Model ……………………………………….. 22
Chapter 5 Summary and Conclusions
5.1 Summary…………………………………………………………………... 25 5.2 Conclusions……………..………………………………………………….. 26
References …………………………………………………………………………...... 27 Tables …………………………………………………………………………………. 29
Figures ………………………………………………………………………………… 30
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List of Tables Table 4.1 –Cases of Bent Arrangements to be Analyzed ……………………………... 29 Table 4.2 –Maximum and Minimum Displacement Results ………………………….. 29
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List of Figures Figure 2.1 – Cross Section of Built in Isolator Column ………………………………. 30 Figure 2.2 – Displacement and Compression Area in Rubber ………………………… 30 Figure 2.3 – Mechanical Connection Testing Preparation …………………………….. 31 Figure 2.4 – Mechanical Connection Testing Assembled with Labels……………...… 31 Figure 2.5 – Mechanical Connection Testing Setup …………………………………... 32 Figure 2.6 – Bar Rupture During Test of S-1 ………………………………………..... 32 Figure 2.7 – Mechanical Connection Testing Results ………………………………… 33 Figure 2.8 – Transverse Reinforcement Stress vs. Strain ……………………………... 33 Figure 2.9– SMA Stress vs. Strain at a Maximum of 6.8% Strain ………………......... 34 Figure 2.10– SMA Stress vs. Strain at a Maximum of 6.9% Strain…………………… 34 Figure 2.11– Column Longitudinal Bars Stress vs. Strain ……………………………..35 Figure 3.1 – Construction Pad is Cleared to Begin Construction ……………………... 36 Figure 3.2 – Footing Formwork ……………………………………………………….. 36 Figure 3.3 – Bottom Footing Steel is Placed ………………………………………….. 36 Figure 3.4 – Column Cage is Placed Into Footing …………………………………….. 37 Figure 3.5 – Top Footing Steel is Placed ……………………………………………… 37 Figure 3.6 – Concrete Pour for Footings……………………………………….………. 38 Figure 3.7 – Platform Construction …………………………………………………… 38 Figure 3.8 – Sono-Tube Placement and Bent Cap Formwork ………………………… 39 Figure 3.9 – Form Removal After 12 Days …………………………………………… 39 Figure 3.10 – Column and Bent Cap Concrete Pour ………………………………….. 40 Figure 3.11 – Form Removal After 12 Days ………………………………………….. 41 Figure 3.12 – Preparing SMA Bars and Mechanical Connectors ……………………... 41 Figure 3.13 – SMA Bars and Mechanical Connectors in Column Cage ……………… 42 Figure 3.14 – SMA-ECC Column and Recess Formwork …………………………….. 42 Figure 3.15 – Placement of ECC ……………………………………………………… 43 Figure 3.16 – Sono-Tube Placement During ECC Column Pour ……………………... 43 Figure 3.17 – Placement of Bottom Recess in PT Bent ………………………………..44 Figure 3.18 – Placement of PT Duct …………………………………………………... 44 Figure 3.19 – PT Duct During Column and Bent Cap Concrete Pour …..…………….. 45 Figure 3.20 – Duct Exiting Bent Cap Through Recess ………………………………... 45 Figure 3.21 – Recess Formwork Removal…………………….……………………….. 46 Figure 3.22 – Placement of Longitudinal Bars Through Isolator ……………………... 46 Figure 3.23 – Placement of Lower Transverse Steel in ISO Bent …………………….. 47 Figure 3.24 – Placement of Rubber Sleeves …………………….…………………….. 47 Figure 3.25 – Placement of Upper Transverse Steel in ISO Bent …………………….. 48 Figure 3.26 – Placement of Lower Transverse Steel in ISO Bent at Isolator-Concrete Interface……………………………………………………………………. 48 Figure 3.27 – Movement of ISO Bent ……………………………………………..….. 49 Figure 3.28 – Placement of ISO Bent Into Footing …………………………………… 49 Figure 3.29 – Finished Reinforcement Placement in ISO Bent ………………………. 50 Figure 4.1 – Spline Model of 4-Span Bridge ………………………………………….. 51 Figure 4.2 – Single Column Model …………………….…….……………………….. 52
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Figure 4.3 – Post Tensioned Column Force vs. Displacement ……….………………... 53 Figure 4.4 – Post Tensioned Column and Conventional Column Force vs. ……………… Displacement Bridge ……………………………………………………… 53 Figure 4.5 – Shape Memory Alloy and ECC Column Force vs. Displacement ………... 54 Figure 4.6 – Shape Memory Alloy and ECC Column and Conventional Column Force vs. Displacement Results …………………………………………... 54 Figure 4.7 – Built in Isolator Column Force vs. Displacement Results ………………. 55 Figure 4.8 – Built in Isolator Column and Conventional Column Force vs. Displacement …………………………………………………………….. 55 Figure 4.9 – Case 1 Displacement Histories ………………….…………………………56 Figure 4.10 – Case 2 Displacement Histories …….……….…….………………………56 Figure 4.11 – Case 3 Displacement Histories …….……….…….………………………57 Figure 4.12 – Case 4 Displacement Histories …….……….…….………………………57 Figure 4.13 – Case 5 Displacement Histories …….……….…….………………………58 Figure 4.14 – Case 6 Displacement Histories ……….…….…….………………………58 Figure 4.15 – Case 1 Delimited Displacement Histories …….…………….……………59 Figure 4.16 – Case 2 Delimited Displacement Histories .………….……………………59 Figure 4.17 – Case 3 Delimited Displacement Histories ….…….………………………60 Figure 4.18 – Case 4 Delimited Displacement Histories ……..…………………………60 Figure 4.19 – Case 5 Delimited Displacement Histories …….….………………………61 Figure 4.20 – Case 6 Delimited Displacement Histories …….….………………………61 Figure 4.21 – Pinching 4 Material Parameters - Image Obtained from the OpenSEES Online Manual ……………………………………………………………. 62
Chapter 1 – Introduction 1.1 Introduction
During major earthquakes that have occurred in the United States and around the world a
common issue that has been observed in bridges and viaducts is the severe localized
damage often accompanied by significant residual column displacements. This
displacement is usually caused by yielding of the longitudinal reinforcement in the
columns to dissipate the seismic energy. Many bridges and viaducts could be closed if a
large residual displacement exists. The closure of any infrastructure after a seismic event
will prohibit the flow of emergency response vehicles, impact the regional economy, and
will have a substantial cost to replace or repair the structure. The use of innovative
design and materials in columns may improve seismic performance, so that bridges and
viaducts could remain serviceable. These new concepts have been either dynamically or
cyclically tested at a component level and have shown potential; however, no system
testing has been conducted to evaluate their interaction with one another and other
components of bridges.
An extensive study to determine the effectiveness of innovative materials to drastically
improve the seismic bridge response has been in progress through funding by the
National Science Foundation grant under the Network for Earthquake Engineering
Simulation Research. The project consists of many components some of which involve
shake table testing of a series of 110-ft models of four-span bridges. Analytical models
were developed to simulate a large scale bridge under dynamic loading with and without
the innovative designs and material. The bridge specimen that is the subject of this report
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consists of three different bent details, one with shape memory alloy (SMA) and
engineered cementitious composites, unbonded post tensioned columns, and columns
incorporating an elastomeric pad (isolator). These details are intended to minimize
residual displacements. The piers incorporating SMA and built-in pad are expected to
have minimal damage in the plastic hinges. The study presented in this report includes
design and construction of the piers and the computer modeling of the bridge model using
program OpenSEES.
1.2 Previous Work
The use of innovative design and materials in columns has been shown to improve the
seismic performance of reinforced concrete bridge columns. The details to be used
consist of shape memory alloy and engineered cementitious composites (ECC), unbonded
post tensioned columns, and isolator built in columns. The placement of superelastic
shape memory alloy (SMA) bars in the plastic hinge region has shown to reduce residual
displacement in reinforced concrete (RC) beams and columns under cyclic loading
(Saiidi, et al., 2007; Saiidi, et al., 2009) and dynamic testing (Saiidi and Wang, 2006).
Engineered cementitious composites used in columns have shown to drastically increase
the ductility when compared to conventional concrete. (Li, 2005) Similar results were
observed by utilizing an unbonded post tensioned column detail (Sakai, 2004), and the
Isolator Built-in Column (Kawashima, 2004). The details previously listed were all tested
on structural components. Previous research reviewed of bridge system testing included a
four span bridge tested at the University of Nevada, Reno (Nelson and Saiidi, 2007), and
a two span bridge (Johnson, et al., 2008). Other relevant work included modeling
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research preformed on bridge systems (Sadrossadat-Zadeh and Saiidi, 2007) and
component modeling (Lee and Billington, 2007).
1.3 Objectives and Scope
The objective of the research presented in this report was to design, construct and
conduct pretest analysis of a four-span bridge utilizing innovative materials in the lower
column plastic hinges while using conventional reinforced concrete in the upper plastic
hinges. The ultimate objective of this part of the project was to compare the performance
of different innovative details relative to each other and relative to conventional
reinforced concrete construction. The criteria to judge the performance was the residual
displacement and damage. The pretest analytical modeling was carried out using
program OpenSEES (Marzzoni, et al., 2006) and was aimed at finding appropriate
location for different piers so they experience equal transverse displacement demand.
4
Chapter 2 – Design of Bents
2.1 Introduction
The piers discussed in this chapter are to be utilized in a 4-span bridge test conducted at
the Center for Civil Engineering Earthquake Research at the University of Nevada, Reno.
The template for this testing setup has been used in previous studies [Nelson et al.]. In
the first bridge tested by Nelson et al., the bents height varied to create bridge symmetry
in the structure. This type of construction is very common when bridges span uneven
topography. The bents were constructed to be one-quarter scale using conventional
materials. Scaling was necessary due to the limited capacity of the shake tables. The
bents were constructed to conform to the National Cooperative Highway Research
Program (NCHRP) 12-49 recommendations [NCHRP] when possible. For the second
bridge test the impact of using innovative materials and design is to be studied. Since
these designs are innovative, design codes do not exist for them but the provisions of
NCHRP 12-49 was used to the extent possible. Some deviation from the code was
necessary
2.2 Design of Bents
The columns chosen for this test incorporate shape memory alloy (SMA) and engineered
cementitious composite (ECC) [Obrien], unbonded post-tensioned construction [Sakai],
and built in isolator construction (ISO) [Kawashima]. All of these methods have been
researched on limited basis in structural components. The results have been promising as
they significantly reduce the residual displacement after seismic loading. For the next
phase of this research project, these methods will be tested in a bridge system. The
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general design of these bents was based on previous research conducted at the University
of Nevada [Nelson].
2.2.1 Shape Memory Alloy and Engineered Cementitious Composite Bent
The selected SMA material in this project was Nitinol (Nickel Titanium Naval Ordnance
Laboratory) for its superelastic properties. The hypothesis was that by using the SMA as
the longitudinal reinforcement the column would have self-centering characteristics.
It was desired to maintain the same flexural capacity and longitudinal steel ratio used in
the previous testing. The previous specimen used 16 - # 3 bars. Each #3 bar has a cross
sectional area of .11 in^2. Therefore the total area of longitudinal steel used in previous
testing was 1.76in^2. To maintain the total area from previous studies 9 - # 4 bars were
chosen to be used in this column. Therefore the total area of longitudinal steel used in
this specimen was 1.80 in^2. Given that the nominal yield stress in the SMA that was
ordered was the same as that of steel reinforcement, placing the same amount of
reinforcement area would lead to comparable moment capacities for the steel and SMA-
reinforced columns. The SMA bars are to be placed in the lower plastic hinge region of
the columns. The longitudinal bars in columns are required to be continuous, however
this is too cost prohibitive when utilizing SMA. For this reason, it was determined to cut
the standard rebar and splice in the SMA using mechanical connectors. In previous
testing the SMA, bars were machined to have threading on the ends and use a mechanical
union. The machining process was found to be very difficult and expensive. For this
specimen a product from Bar Splice Products Inc. was chosen. The Zap Screwlok Type 2
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connector was chosen for evaluation. The Type 2 connector will force failure into the bar
rather than the connector. A series of tests were completed on different configurations of
size and the number of connecting bolts per bar, Figure 2.5 through Figure 2.7. The final
product chosen was for a #4 bar and had 3 bolts per side. To ensure uniform compression
from the bolts, they are designed to twist the head of the bolt off when proper torque is
achieved, Figure 2.3 and Figure 2.4. The transverse reinforcement consisted of W2.9
(0.192 in Wire) spaced at 1.25 in, and it was the same as that used in the conventional
bridge model.
2.2.2 Post-Tensioned Bent
The post tensioned (PT) column design was based on research conducted by Sakai and
Mahin. This column will be constructed similarly to the conventional construction, with
the exception of a post tensioning duct placed through the center of the column. Then a
post tensioning rod will be placed inside the duct and stressed in tension to apply the PT
force. To maintain a similar total amount of longitudinal steel; half of the total
longitudinal steel area made up the column cage and the other half was the total area of
the PT rod. For this bent 8 #3 bars were selected for the column cage reinforcement and a
PT rod size of 1 in diameter was selected. This rod has a minimum yield strength of 150
ksi and a cross sectional area of .85 in^2. The total longitudinal steel area per column for
this bent was 1.73 in^2. From a literature search, various ranges of the PT force were
found. It was decided that an initial value of 60% of the yield force would be used in this
bent, which was a value of 70.8 kips. This topic will be discussed again in Chapter 4.
7
2.2.3 Built in Isolator (ISO)
The initial isolator built in column design was based on work completed by Kawashima.
For this method variations of rubber layers being placed at the column-footing interface
were tested. Some of the variations included different rubber thickness, the addition of
upper and lower steel plates, the addition of post tensioning, presence of steel shims, and
the anchorage of the steel plated into the concrete. This design method gave a good
estimate for the total rubber thickness to be used, however the final design was based on
elastomeric bearing design guidelines. The design method used in previous research by
Kawashima (Figure 2.1-2.2) is outlined below:
)1.1(Eqtd
r=ε
Where: rε = Compressive Strain in Rubber d = Displacement of Rubber t = Thickness of Rubber dr = Displacement in Rubber H = Height θ = Rotation For this specimen w = 12 in. x = The Distance to the Neutral Axis w = The Width of the Rubber Since θ is relatively small compared to the height:
)2.1(EqH
Hd r θθ=
⋅≅
)3.1(Eqwx
=α
8
Where: α = The Compression to Width Ratio Since )4.1(Eqxd θ⋅=
From Eq. 1.2 it can be shown:
)5.1(Eqwx ⋅=α
Therefore: tw
tx
td
rθαθε ⋅⋅
=>⋅
=>=)( )6.1()( Eq
tw
rθαε ⋅⋅
=
Now consider the yield strength of rubber vs concrete:
rσ < < ccσ Eq (1.7) Where: rσ = Stress on Rubber
ccσ = Stress on Concrete
Since the rubber is much more ductile than the concrete, we expect the column deformation to be concentrated in the rubber. To determine the minimum thickness of the rubber Equation 1.6 can be rearranged to
give the following:
)8.1()(min Eqwt
rεθα ⋅⋅
=
Since we do not know the value of the strain in the rubber, we must estimate a value. We do not want the strain to be such that strain hardening becomes significant. So assume that:
2.1. tor ≅ε
If we were to assume:
→> 3.2. torε This would result in significant strain hardening.
Also, an estimate of the α value must be assumed. So assume that:
5.3. to≅α is reasonable.
9
Now minimize and maximize Equation 1.8 to obtain a range of minimum rubber
thicknesses.
Maximum tmin occurs when 5.=α and 1.=rε for a drift of 7%, we get the value
inwtr
⋅≅⋅⋅
=⋅⋅
= 2.41.
07.)125(.)(min ε
θα
Minimum tmin occurs when 3.=α and 2.=rε for a drift of 7% we get the value
inwtr
⋅≅⋅⋅
=⋅⋅
= 3.12.
07.)123(.)(min ε
θα
From the method used above the thickness of the rubber should be between 1.3 to 4.2
inches. It was decided a value of 3.0 inches would be used as the total rubber preliminary
thickness. Further, the equation for Ec described in Mechanics of low shape factor
elastomeric seismic isolation building, Ian D. Aiken, James M. Kelly, Fredrick F.
Tajirian, Report No. UCB/EERC-89/13 November 1989 was also considered. The Final
Design Method is as follows:
We can describe the procedure of Elastomeric bearing design as below:
1. Calculate Potential Shape factor based on geometry assuming layer thickness
2. Determine target drift ratio
3. Calculate EC and Eb
4. Find Kθ =M/θ and determine Tr (Total rubber thickness)
5. Assume maximum moment at rubber level is the column capacity from Extract
Analysis
6. Verify capacity of isolator is greater than column capacity
10
1.) Calculate Potential Shape Factor
Sπ
d2
⎛⎜⎝
⎞⎟⎠
2⋅ 9π
Holed( )2
⎡⎢⎣
⎤⎥⎦
2
⋅− πPipeHoled( )
2
⎡⎢⎣
⎤⎥⎦
2
⋅−
2 π⋅ d⋅ .5⋅ t⋅:= S 13.36= is > 3 ok
2.) Target Drift Ratio
θm .1 rad⋅:= About 10% Drift
Determine Maximum Bending Moment Capacity
Given Parameters
Gr 120lb
in 2⋅:= d 12 in⋅:= t .2 in⋅:= Hole d
58
in⋅:= Tr 3.0 in⋅:=
E 400lb
in 2⋅:= PipeHole d 3.5 in⋅:= I π
d 4
64⋅:= I 1017.88 in 4.00
=
Assumptions: The isolator has Tr of 3.0 inches Column Diameter is 12 in There are 9 - 5/8 in holes for the longitudinal bars to pass through
S = Shape Factor = Plan Area/Area of Perimeter Free to Buldge
I = Moment of Inertia = π*d4/64
θm = maximum design rotation (rad)
Ec = effective modulus of elastomeric bearing in compression = 5.6*G*S 2 **If s>3
G = Shear modulus (ksi)
Tr = Total Elastomer Thickness
t = Layer Elastomer Thickness
d = column diameter
Assumptions: The isolator has Tr of 3.0 inches Column Diameter is 12 in There are 9 - 5/8 in holes for the longituidnal bars to pass through
11
From the calculations above we observe the design parameters to be utilized in the model.
Upon several trial analyses and final review, it was decided the bearing would have the
following properties:
Axial Load Capacity – 150 Kips
Maximum Rotation - .4 Radians
Compression Stiffness – 2200 Kips/in
2 - 1” A36 Plates (Upper and Lower )
18 - .20” Thick Rubber Layers
17 - 12 GA. Steel Shims
Outer Diameter – 12.0”
G = 0.1 ksi
E = 0.4 ksi
Ec = 107 ksi
Eb = 300 ksi
3. Calculate Ec and Eb
5. From Extract Analysis the Maximum Moment Capacity is 801,000 in*lb
6. Verify the Maximum Moment Capacity is Greater than demand
This value is greater than Maximum Moment
4. Calculate
Eb E 123
S2⋅+⎛⎜
⎝⎞⎟⎠
⋅:= Eb 47981.18lb
in2.00=
Kθ EbI
Tr⋅:= Kθ 16279629.98in lb⋅=
M Kθ θm⋅:=M 1627963.00in lb⋅=
Ec 5.6 Gr⋅ S2⋅:= Ec 119904.57
lb
in2.00=
12
The total height of the bearing is 7.378”. Also for anchorage into the concrete 4 – 1”
diameter by 10” long bolts were threaded into the upper and lower plate. Since the
longitudinal bars are to be continuous; holes were required in the bearing were the
longitudinal bars are to pass through. Further, a mandrel was required through the center
of the bearing so the PT duct may pass through the center. The mandrel was a 3” X-
Strong Pipe, A53 GR. B. These requirements increased the complexity of the
manufacturing; however, the final product delivered and installed with no difficulties.
The mandrel, although allowed the PT duct to pass though the center of the column,
provided resistance to shear forces at the column isolator, and column-footing interfaces.
2.3 Material Testing
Prior to the start of construction, and during, the material components were tested to
verify the properties. The materials tested were the SMA Bars, Transverse Column
Reinforcement, Longitudinal Reinforcement, Footing Concrete, Column Concrete, ECC
Concrete, and Bent Cap Reinforcement. From the test the following was determined:
Transverse Column Reinforcement (See Figure 2.8) Average Yield 58.1 ksi Ultimate Average 71.8 ksi Shape Memory Alloy (See Figure 2.9 and 2.10) Average Yield 62.4 ksi Ultimate Average 121.7 ksi Transverse Column Reinforcement (See Figure 2.11) Average Yield 70.1 ksi Ultimate Average 96.9 ksi
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Bent Cap Reinforcement Average Yield 63.8 ksi Ultimate Average 86.5 ksi Footing Concrete
7 Day lb psi ksi Sample 1 83125 2939.9 2.9 Sample 2 90265 3192.5 3.2 Sample 3 96045 3396.9 3.4 Average 89812 3176.4 3.2
28 Day lb psi ksi Sample 1 155265 5491.4 5.5 Sample 2 152110 5379.8 5.4 Sample 3 145950 5161.9 5.2 Average 151108 5344.4 5.3
Column Concrete
7 Day lb psi ksi Sample 1 102190 3614.2 3.6 Sample 2 92575 3274.2 3.3 Sample 3 89310 3158.7 3.2 Average 94692 3349.0 3.3
28 Day lb psi ksi Sample 1 142410 5036.7 5.0 Sample 2 129920 4595.0 4.6 Sample 3 148935 5267.5 5.3 Sample 4 146225 5171.7 5.2 Average 141873 5017.7 5.0
ECC Concrete West Column
7 Day lb psi ksi Sample 1 28345 4010.0 4.0 Sample 2 31230 4418.1 4.4 Average 29788 4214.1 4.2
14
14 Day lb psi ksi Sample 1 34695 4908.3 4.9 Sample 2 37215 5264.8 5.3 Average 35955 5086.6 5.1
28 Day lb psi ksi Sample 1 51415 7273.7 7.3 Sample 2 49141 6952.0 7.0 Sample 3 49987 7071.7 7.1 Average 50181 7099.2 7.1
East Column
7 Day lb psi ksi Sample 1 36523 5167.0 5.2 Sample 2 33230 4701.1 4.7 Average 34877 4934.0 4.9
14 Day lb psi ksi Sample 1 57584 8146.5 8.1 Sample 2 48645 6881.9 6.9 Average 53115 7514.2 7.5
28 Day lb psi ksi Sample 1 64115 9070.4 9.1 Sample 2 69425 9821.6 9.8 Sample 3 67311 9522.6 9.5 Average 66950 9471.5 9.5
15
CH 3 - Construction of Bents 3.1 Introduction
This chapter describes the construction process and material properties obtained from the
material tests conducted at UNR.
3.2 Cast-in-Place Construction
All bents followed the same general construction procedure of construction. First, the
footing formwork construction was completed. After the form was constructed the
bottom layer of footing bars were placed. Then the column cage was tied, and then
placed on top of the bottom rebar in the footing. Then the upper rebar mat was placed
and tied. At this point, the footing steel and column steel was complete so the first of two
concrete pours was completed. This pour placed concrete to the top of the footing.
Turnbuckles were placed to ensure the column was plum and that the column cage would
not move during construction. To access the top of the column and bent cap a temporary
construction platform was built. When this platform construction was completed, the
turnbuckles were removed and a sono-tube was lowered from the top of the platform
down and around the column. A sono-tube is a cylindrical cardboard form that was
removed when the concrete has cured. Next, a form for each bent cap was constructed on
the platform, but it was not securely fastened. It was not securely fastened because it was
expected to be repositioned during the placement of the bent cap reinforcement. Next,
the bent cap steel was placed; the bent cap formwork was repositioned. Finally, the
second concrete pour was completed. During all concrete pours slump was tested, and
concrete cylinders were made for future testing. Construction photographs taken during
the construction process described above can be seen in Figures 3.1-3.11.
16
The method described is the necessary procedure for conventional construction; however,
there were many differences and logistic issues associated with innovative design and
materials. These individual deviations will be discussed below.
3.3 SMA and ECC Bent Construction
The differences in the construction of the SMA and ECC bents were additional formwork,
one ECC column pour for the bottom portion of the column, one standard concrete pour
for the remaining column and bent cap, and construction complications due to the SMA
bars. Additional formwork at the column – footing interface was placed during this bent
construction. In previous testing, it was observed, at the column-footing interface, the
ECC column would crack and essentially rock on the conventional concrete footing. It
was determined for this specimen a recess would be constructed below the interface and
be filled with ECC during the bottom portion of the column pour. This formwork was
placed prior to the footing pour and removed prior to the ECC pour. The formwork was
14" x 14" x 6" below the column footing interface.
In the region of the mechanical connectors the column cage diameter increased by
approximately 1/2”. This made the column cover concrete much thinner in this region.
Since the cover concrete was reduced placement of the sono-tube was critical in this bent.
The sono-tube also had to be cut into two pieces per bent. This was because the ECC
was made in batches and placed by hand. No vibration was done per the contractors
recommendations. Another unique feature of the SMA bent was the connection of the
17
SMA bars to the longitudinal steel reinforcement. The steel bars first had to be bent by
the fabricator and delivered to the site. The bars were then cut for attachment of the
mechanical connectors and the SMA bars. After the SMA, bars and connectors were
installed, the fabricator returned to the site to tie the column cage. These proved to be
difficult. The difficulties came from the smooth SMA bars and the mechanical
connectors themselves. Since the SMA bars were smooth, they did not provide sufficient
friction with the spirals and the column cage tended to twist. These columns had to be
unassembled and retied to ensure that the longitudinal bars were perpendicular to the
footing. See Figures 3.12-3.16 for additional details.
3.4 PT Bent Construction
The PT bent followed the standard construction procedure outlined above with the
addition of more steps. The steps necessary were the addition of formwork for a recess,
placement of the PT duct, and recess formwork removal. The additional formwork was
needed to create a recess for the post tension rod bearing plates and nuts. This formwork
consisted of 6" x 6" x 6" boxes made of plywood, which were placed in the footing and
bent cap. The boxes were placed in the bottom of the footing and the top of the bent cap
at the center of the column. Furthermore, once the footing and column cages were placed
the post-tension duct was placed. The duct ran from the bottom box to the top box of the
bent cap. Since this duct and formwork must be vertical and located directly in the center
of the column, their placement was critical. Once the concrete was poured and had cured
the recess forms were removed. See Figures 3.17-3.21 for additional details.
18
3.5 ISO Bent Construction
The ISO bent construction started with the formwork and bottom footing steel being
placed. Then the bearing was placed on a construction table and the longitudinal bars
were passed through the holes in the bearing. When the bars were in place, they were
temporarily fixed to a rebar hoop to prevent the legs from twisting out of position. Next,
8" rubber sleeves were slipped over the longitudinal bars and positioned above and below
the bearing. These sleeve provided the longitudinal bars above and below the bearing to
be unbonded, this allowed the bars to develop the necessary strain without rupture. Next,
the transverse steel coil was tied into position. It was necessary to tie the transverse steel
in two separate sections, above and below the bearing since it could not be continuous.
Once the transverse steel was in place, the column cage was lifted with a forklift and
moved into position onto the bottom footing steel. Further, the upper footing steel was
placed and tied into position. Next, the post tension duct was placed through the mandrel
and tied into position on the wooden recesses. For the remaining construction, the
procedure was followed described in Section 3.2. Figures 3.22-3.29 show the details
specific to this bent.
19
Chapter 4 OpenSEES Modeling and Results
4.1 Introduction
The pre-test finite element modeling completed for this project was performed using the
computer program Open System for Earthquake Engineering Simulation (OPENSEES)
(Mazzoni, et al., 2006). The general framework for developing this model is similar to
most finite element programs. The main components of the model are nodes, elements,
sections, and materials. Fiber elements were used to model the plastic hinges. The
plastic hinge length was assumed to be 1.5 times the column diameter. All of the
elements and materials were chosen from the standard library of commands. The model
developed for the innovative bridge model was based on the model of a conventional
bridge model used in a previous study [Sadrossadat-Zadeh, 2007]. This previous model
is well documented and provided a base model to expand on. Some of this model's bridge
components including the abutments, bent cap-superstructure connection, etc. were
unchanged. The components of the model that needed to be expanded were the shape
memory alloy (SMA) / engineered cementitious composite (ECC), PT, and Built in
Isolator construction (ISO) bent properties.
Individual models were developed for a single column representing each of the three
different types of bents. This process of developing the individual models, then
combining the individual column models into the full bridge model proved to be
beneficial because it allowed for understanding the modeling process on a simple
20
structure before it was implemented in the entire bridge model. Once completed the final
model consisted of over 100 nodes. A spline model can be seen in Figure 4.1.
4.2 Isolator Bearing Bent (ISO Bent)
The first step in modeling the ISO Bent was to define the node locations at the top and
bottom of the bearing in the model and then to define the materials and section properties.
The locations of the nodes were based on the geometry of the structure, located at the
center of mass of the bearing at the column-footing interface and the bottom of the
bearing. The bearing properties were used in the Pinching 4 Material defined in
OpenSEES. Pinching 4 Material is a hysteretic shape material. The user defines the
slopes of transition to match the material property being modeled (Fig. 4.21). The
elastomeric bearing was modeled as a homogeneous mass with non-isotropic properties.
Uniaxial element testing was conducted on individual elements to ensure the correct
material properties were defined. These individual models contained cantilever type
sections that were uniform in cross section. The elements were then loaded in tension and
compression for specified displacements. Then a correlation between the analytical
model and test results were made, resulting in a element that preformed similar to
documented results.
4.3 Post-Tensioned Bent
The PT Bent model was based on work completed by Dr. Lee ( Lee, 2007). For this
column a hole was modeled at the column center and extruded down the entire length of
the column. This void represented the duct for the post tensioning rod to be passed
21
through. Also, a co-rotational steel element was placed in the center, this was the element
type chosen for the rod itself. A co-rotational element will bend with the column to
ensure the PT rod is always at the center of the duct, and does not come in contact with
the concrete. Initially it was assumed that the strain would be approximately uniform
along the length since the rod was unbounded. This issue will be discussed later in this
chapter.
4.4 SMA/ECC Bent
The SMA Bent also required the Pinching 4 material Type for SMA bars. The ECC was
not modeled any differently from the standard concrete since the compressive strength
specified was uniform. For the SMA the material parameters were modified many times
until the uniaxial modeling test produced similar results to actual SMA material tests, as
seen in chapter 2.
4.5 Cyclic Load Analysis of Single Columns
As previously discussed individual column models were developed and combined into
the full bridge model after reasonable results for each column had been obtained. The
columns were in cantilever form with a diameter of 12 in and a height of 72 in, the same
dimensions as the proposed specimens. These column models were analyzed for cyclic
displacement and where all displacement controlled. They were pushed to a maximum
positive and negative displacements of 7.2 inches, or 10% drift, in 10 equal increments.
The column model is shown in Figure 4.2. The results for each column individual model
can be seen in Figures 4.3, 4.5, and 4.7. Also, results of the individual models are shown
22
in comparison to a conventional reinforced concrete column of the same lateral load
strength in Figures 4.4, 4.6, and 4.8. These force-displacement plots show a significant
reduction in residual drift in the advanced material/details columns compared to the
conventional columns. Once these models were developed the individual model
parameters were implemented into the full bridge model.
4.6 Location of Bents in Bridge Model
One of the objectives of the project was to determine the relative performance of the
three innovative details that were introduced in this project. It was important that the
bents in the bridge model were subjected to comparable seismic demands. Different
performance criteria may be used to define the seismic demand. It was decided to use the
lateral displacement as the deciding criterion. Because the bents were geometrically the
same, by placing similar displacement demands, the demand drift ratios would be
comparable. The drift ratio is considered to be one of the best indicators of the seismic
demand or performance. However, initially since the lower plastic hinges in the columns
used very different materials and details, it was uncertain if the bridge superstructure
would experience significant in-plane rotation. In-plane rotation would lead to different
lateral displacements at different bents and would prevent direct comparison of different
details. The stiffness of each bent was considered to avoid in-plane rotation. Therefore
either the column heights could be changed or possibly arranging the bents in such a way
that this rotation could be avoided, or some combination of both. After the column
elements were implemented in the full bridge model, 18 full bridge models were
developed. The models were in three main categories with column height s of 60 in, 72
23
in, and 84 in. In each of these column height categories six different combinations of
bent locations were evaluated. These cases are shown in Table 4.1.
From these three different column height categories it was determined that column
heights of 72 in would be used to ensure a similar loading would be placed on each. Since
the loading is similar, an evaluation could be performed on each column and in
comparison to each other.
Next each of the six different bent location cases were reviewed to determine if the in-
plane rotation could be minimized. The displacement histories vs. Time results of the six
cases of the 72in columns can be seen in Figures 4.9-4.12. The motion used was the
Century City record of the 1994 Northridge earthquake and was applied in two horizontal
directions. The conventional construction four span bridge also utilized this motion in
the transverse direction only during testing. By using the same motion and similar
dimensions, this bridge's performance can be compared to its conventional counterpart.
From an initial inspection cases 3, 5, and 6 appeared favorable, but needed further review.
Figures 4.13-4.16 present the most critical 10 seconds of results from the responses so the
maximum and minimum displacements could be further reviewed. Table 4.2 lists the
maximum, minimum, lateral displacement, and standard deviation. From review of the
standard deviations it was determined that case 5 would be chosen for the four-span
bridge model because it had the lowest standard deviation in the lateral displacement at
the top of the column for all three bents. Cases 3 and 5 were very close in the observed
model results; this is possibly because the two cases have the inverse of bent positions.
24
However, it is interesting to note the other inverse cases did not have similar model
results. This modeling effort provided sufficient information that the column heights
would be constant while essentially eliminating the possible in-plane rotation.
25
Chapter 5 Summary and Conclusions
5.1 Summary
An extensive study to determine the effectiveness of innovative materials and details to
significantly improve the seismic bridge response has been in progress through funding
by the National Science Foundation grant under the Network for Earthquake Engineering
Simulation Research. The project consists of many components some of which involve
shake table testing of a series of 110-ft models of four-span bridges. One of the bridge
models uses advanced materials. This report presents information about the design and
construction of innovative bents and nonlinear dynamic analysis of the bridge prior to the
test.
The quarter scale bridge components were constructed utilizing three different details at
the plastic hinges: shape memory alloy (SMA) and engineered cementitious composites
(ECC), unbonded post tensioned columns, and isolator built in columns. These details
were used at the bottom column plastic hinges.
Extensive pre-test analytical modeling was conducted using OpenSEES prior to finalizing
the bridge model configuration. These models were developed to simulate the response
of a large scale bridge under dynamic loading. Different bent locations and heights were
attempted and an optimal bridge configuration was identified that placed comparable
lateral displacement demands on the bent.
26
5.2 Conclusions
1. The construction of the bents of the bridge model each utilizing a different advanced
detail and/or material was successful
2. The analytical evaluation of individual columns showed significant reduction in the
residual displacement as intended.
3. Various elements of OpenSEES were successfully implemented in the model of the
full bridge.
4. The OpenSEES model was effectively used to determine an optimal bridge
configuration in which different bents experienced comparable drift ratios.
27
References
1. Fischer, G., Li, V.C., " Deformation behavior of fiber-reinforced polymer reinforced
engineered cementitious composite (ECC) flexural members under reversed cyclic loading conditions", ACI Structural Journal, v 100, n 1, p 25-35, January/February 2003
2. Johnson, N., Saiidi, M., and Sanders, D., “Large-Scale Experimental and Analytical Studies of a Two-Span Reinforced Concrete Bridge System,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-06-02, March 2006.
3. Johnson, N., T. Ranf, M. Saiidi, D. Sanders, and M. Eberhard, “Seismic Testing of A Two-Span Reinforced Concrete Bridge,” Journal of Bridge Engineering, ASCE, Vol. 13, No. 2, March-April 2008, pp. 173-182.
4. Kawashima, K., and G. Yamagishi, “Development of a Rubber Layer Built-In RC Columns”, Proc. Structural and Earthquake Engineering, JSCE, 752/I-66, 43-62, 2004
5. Lee, W and Billington, S., "Simulation and performance-based earthquake engineering assessment of self-centering post-tensioned concrete bridge systems", Stanford University, June 2007
6. Li, V. C., "Engineered Cementitious Composites", Proceedings of ConMat'05, Vancouver, Canada, Aug. 22-24, 2005.
7. Mander, J. B., M. J. N. Priestley, et al. (1988). "Theoretical Stress-Strain Model for Confined Concrete." Journal of Structural Engineering 114(8): 1804-1826.
8. Mazzoni, S., McKenna, F., et al. (2006). "Open System for Earthquake Engineering Simulation User Command-Language Manual."
9. Nelson, R. and Saiidi, M, “Experimental Evaluation of Performance of Conventional Bridge Systems,” Center for Civil Engineering Earthquake Research, CCEER 07-04, October 2007
10. O'Brien, M., M. Saiidi, and M. Sadrossadat-Zadeh, "A Study of Concrete Bridge Columns Using Innovative Materials Subjected to Cyclic Loading," Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-07-1, January 2007.
11. Sadrossadat-Zadeh, M. and Saiidi, M., "Analytical Study of NEESR-SG 4-Span Bridge Model Using OpenSees," Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-07-03, January 2007.
28
12. Saiidi, M. S. and H. Wang (2005). "A study of RC Columns with Shape Memory Alloy and Engineered Cementitious Composites." CCEER-05-01.
13. Saiidi, M., and H. Wang, “An Exploratory Study of Seismic Response of Concrete Columns with Shape Memory Alloys Reinforcement,” American Concrete Institute, ACI Structural Journal, Vol. 103, No. 3, May-June 2006, pp. 436-443.
14. Saiidi, M., M. Zadeh, C. Ayoub, and A. Itani, “A Pilot Study of Behavior of Concrete Beams Reinforced with Shape Memory Alloys,” Journal of Materials in Civil Engineering, ASCE, Vol. 19, No. 6, June 2007, pp. 454-461.
15. Saiidi, M., M. O’Brien, and M. Zadeh, “Cyclic Response of Concrete Bridge Columns Using Superelastic Nitinol and Bendable Concrete,” American Concrete Institute, ACI Structural Journal, Vol. 106, No. 1, January-February 2009, pp. 69-77.
16. Sakai, J. and S. Mahin, “Analytical Investigations of New Methods for Reducing Residual Displacements of Reinforced Concrete Bridge Columns”, Pacific Earthquake Engineering Research Center, PEER 2004/02, August 2004.
29
-------------------------------------------------- | | | | | | | | | | | | = = =
Bent Height 72" 72" 72' Case1 PT ISO SMA Case2 SMA ISO PT Case3 SMA PT ISO Case4 ISO SMA PT Case5 ISO PT SMA Case6 PT SMA ISO
South Middle North
Min Max Min Max Min Max Standard Deviation
Case 1 -2.07213 3.94637 -2.43222 4.7393 -3.18002 5.73331 Lateral Displacement 6.0185 7.17152 8.91333 1.46Case 2 -1.33504 5.5961 -2.50362 5.37188 -3.85315 5.2404 Lateral Displacement 6.93114 7.8755 9.09355 1.08Case 3 -2.55302 4.86429 -2.61138 4.93037 -2.89319 5.07817 Lateral Displacement 7.41731 7.54175 7.97136 0.30Case 4 -2.11553 5.05671 -2.66562 4.96334 -3.75893 4.98833 Lateral Displacement 7.17224 7.62896 8.74726 0.81Case 5 -2.89052 5.12251 -2.66404 4.91779 -2.65387 4.78658 Lateral Displacement 8.01303 7.58183 7.44045 0.29Case 6 -3.31732 5.3273 -2.96573 5.05543 -2.79243 4.83085 Lateral Displacement 8.64462 8.02116 7.62328 0.51
Table 4.2 –Maximum and Minimum Displacement Results
Table 4.1 –Cases of Bent Arrangements to be Analyzed
30
W
t
Upper andLower SteelPlatedr
X
dr
W
Figure 2.1 – Cross Section of Built in Isolator Column
Figure 2.2 – Displacement and Compression Area in Rubber
31
Figure 2.3 – Mechanical Connection Testing Preparation
Figure 2.4 – Mechanical Connection Testing Assembled with Labels
32
Figure 2.5 – Mechanical Connection Testing Setup
Figure 2.6 – Bar Rupture During Test of S-1
33
Figure 2.7 – Mechanical Connection Testing Results
Figure 2.8 – Transverse Reinforcement Stress vs. Strain
34
Figure 2.9– SMA Stress vs. Strain at a Maximum of 6.8% Strain
Figure 2.10– SMA Stress vs. Strain at a Maximum of 6.9% Strain
35
Figure 2.11– Column Longitudinal Bars Stress vs. Strain
36
Figure 3.1 – Construction Pad is Cleared to Begin Construction
Figure 3.3 – Bottom Footing Steel is Placed
Figure 3.2 – Footing Formwork
37
Figure 3.4 – Column Cage is Placed Into Footing
Figure 3.3 – Bottom Footing Steel is Placed
38
Figure 3.5 – Top Footing Steel is Placed
Figure 3.6 – Concrete Pour for Footings
39
Figure 3.7 – Platform Construction
Figure 3.8 – Sono-Tube Placement and Bent Cap Formwork
40
Figure 3.9 – Form Removal After 12 Days
Figure 3.10 – Column and Bent Cap Concrete Pour
41
Figure 3.12 – Preparing SMA Bars and Mechanical Connectors
Figure 3.11 – Form Removal After 12 Days
42
Figure 3.16 – Sono-Tube Placement During ECC Column Pour
Figure 3.13 – SMA Bars and Mechanical Connectors in Column Cage
Figure 3.14 – SMA-ECC Column and Recess Formwork
43
Figure 3.15 – Placement of ECC
44
Figure 3.17 – Placement of Bottom Recess in PT Bent
Figure 3.18 – Placement of PT Duct
45
Figure 3.19 – PT Duct During Column and Bent Cap Concrete Pour
Figure 3.20 – Duct Exiting Bent Cap Through Recess
46
Figure 3.21 – Recess Formwork Removal
Figure 3.22 – Placement of Longitudinal Bars Through Isolator
47
Figure 3.23 – Placement of Lower Transverse Steel ISO Bent
Figure 3.24 – Placement of Rubber Sleeves
48
Figure 3.25 – Placement of Upper Transverse Steel in ISO Bent
Figure 3.26 – Placement of Lower Transverse Steel in ISO Bent at Isolator-Concrete Interface
49
Figure 3.27 – Movement of ISO Bent
Figure 3.28 – Placement of ISO Bent Into Footing
50
Figure 3.29 – Finished Reinforcement Placement in ISO Bent
51
Figure 4.1 – Spline Model of 4-Span Bridge
52
Figure 4.2 – Single Column Model
Fixed Boundary
53
Figure 4.4 – Post Tensioned Column and Conventional Column Force vs. Displacement Bridge
Figure 4.3 – Post Tensioned Column Force vs. Displacement Bridge
54
Figure 4.5 – Shape Memory Alloy and ECC Column Force vs. Displacement Results
Figure 4.6 – Shape Memory Alloy and ECC Column and Conventional Column Force vs. Displacement Results
55
Figure 4.7 – Built in Isolator Column Force vs. Displacement Results
Figure 4.8 – Built in Isolator Column and Conventional Column Force vs. Displacement Results
56
Figure 4.9 – Case 1 Displacement Histories Results
Figure 4.10 – Case 2 Displacement Histories Results
57
Figure 4.11 – Case 3 Displacement Histories Results
Figure 4.12 – Case 4 Displacement Histories Results
58
Figure 4.13 – Case 5 Displacement Histories
Figure 4.14 – Case 6 Displacement Histories
59
Figure 4.15 – Case 1 Delimited Displacement Histories
Figure 4.16 – Case 2 Delimited Displacement Histories
60
Figure 4.17 – Case 3 Delimited Displacement Histories Results
Figure 4.18 – Case 4 Delimited Displacement Histories Results
61
Figure 4.19 – Case 5 Delimited Displacement Histories Results
Figure 4.20 – Case 6 Delimited Displacement Histories Results
62
Figure 4.21 – Pinching 4 Material Parameters - Image Obtained from the OpenSEES Online Manual
63
List of CCEER Publications Report No. Publication CCEER-84-1 Saiidi, M., and R. Lawver, "User's Manual for LZAK-C64, A Computer Program to
Implement the Q-Model on Commodore 64," Civil Engineering Department, Report No. CCEER-84-1, University of Nevada, Reno, January 1984.
CCEER-84-1 Douglas, B., Norris, G., Saiidi, M., Dodd, L., Richardson, J. and Reid, W., "Simple
Bridge Models for Earthquakes and Test Data," Civil Engineering Department, Report No. CCEER-84-1 Reprint, University of Nevada, Reno, January 1984.
CCEER-84-2 Douglas, B. and T. Iwasaki, "Proceedings of the First USA-Japan Bridge Engineering
Workshop," held at the Public Works Research Institute, Tsukuba, Japan, Civil Engineering Department, Report No. CCEER-84-2, University of Nevada, Reno, April 1984.
CCEER-84-3 Saiidi, M., J. Hart, and B. Douglas, "Inelastic Static and Dynamic Analysis of Short R/C
Bridges Subjected to Lateral Loads," Civil Engineering Department, Report No. CCEER-84-3, University of Nevada, Reno, July 1984.
CCEER-84-4 Douglas, B., "A Proposed Plan for a National Bridge Engineering Laboratory," Civil
Engineering Department, Report No. CCEER-84-4, University of Nevada, Reno, December 1984.
CCEER-85-1 Norris, G. and P. Abdollaholiaee, "Laterally Loaded Pile Response: Studies with the
Strain Wedge Model," Civil Engineering Department, Report No. CCEER-85-1, University of Nevada, Reno, April 1985.
CCEER-86-1 Ghusn, G. and M. Saiidi, "A Simple Hysteretic Element for Biaxial Bending of R/C in
NEABS-86," Civil Engineering Department, Report No. CCEER-86-1, University of Nevada, Reno, July 1986.
CCEER-86-2 Saiidi, M., R. Lawver, and J. Hart, "User's Manual of ISADAB and SIBA, Computer
Programs for Nonlinear Transverse Analysis of Highway Bridges Subjected to Static and Dynamic Lateral Loads," Civil Engineering Department, Report No. CCEER-86-2, University of Nevada, Reno, September 1986.
CCEER-87-1 Siddharthan, R., "Dynamic Effective Stress Response of Surface and Embedded Footings
in Sand," Civil engineering Department, Report No. CCEER-86-2, University of Nevada, Reno, June 1987.
CCEER-87-2 Norris, G. and R. Sack, "Lateral and Rotational Stiffness of Pile Groups for Seismic
Analysis of Highway Bridges," Civil Engineering Department, Report No. CCEER-87-2, University of Nevada, Reno, June 1987.
CCEER-88-1 Orie, J. and M. Saiidi, "A Preliminary Study of One-Way Reinforced Concrete Pier
Hinges Subjected to Shear and Flexure," Civil Engineering Department, Report No. CCEER-88-1, University of Nevada, Reno, January 1988.
CCEER-88-2 Orie, D., M. Saiidi, and B. Douglas, "A Micro-CAD System for Seismic Design of
Regular Highway Bridges," Civil Engineering Department, Report No. CCEER-88-2, University of Nevada, Reno, June 1988.
Reprin
64
CCEER-88-3 Orie, D. and M. Saiidi, "User's Manual for Micro-SARB, a Microcomputer Program for Seismic Analysis of Regular Highway Bridges," Civil Engineering Department, Report No. CCEER-88-3, University of Nevada, Reno, October 1988.
CCEER-89-1 Douglas, B., M. Saiidi, R. Hayes, and G. Holcomb, "A Comprehensive Study of the
Loads and Pressures Exerted on Wall Forms by the Placement of Concrete," Civil Engineering Department, Report No. CCEER-89-1, University of Nevada, Reno, February 1989.
CCEER-89-2 Richardson, J. and B. Douglas, "Dynamic Response Analysis of the Dominion Road
Bridge Test Data," Civil Engineering Department, Report No. CCEER-89-2, University of Nevada, Reno, March 1989.
CCEER-89-2 Vrontinos, S., M. Saiidi, and B. Douglas, "A Simple Model to Predict the Ultimate
Response of R/C Beams with Concrete Overlays," Civil Engineering Department, Report NO. CCEER-89-2, University of Nevada, Reno, June 1989.
CCEER-89-3 Ebrahimpour, A. and P. Jagadish, "Statistical Modeling of Bridge Traffic Loads - A Case
Study," Civil Engineering Department, Report No. CCEER-89-3, University of Nevada, Reno, December 1989.
CCEER-89-4 Shields, J. and M. Saiidi, "Direct Field Measurement of Prestress Losses in Box Girder
Bridges," Civil Engineering Department, Report No. CCEER-89-4, University of Nevada, Reno, December 1989.
CCEER-90-1 Saiidi, M., E. Maragakis, G. Ghusn, Y. Jiang, and D. Schwartz, "Survey and Evaluation
of Nevada's Transportation Infrastructure, Task 7.2 - Highway Bridges, Final Report," Civil Engineering Department, Report No. CCEER 90-1, University of Nevada, Reno, October 1990.
CCEER-90-2 Abdel-Ghaffar, S., E. Maragakis, and M. Saiidi, "Analysis of the Response of Reinforced
Concrete Structures During the Whittier Earthquake 1987," Civil Engineering Department, Report No. CCEER 90-2, University of Nevada, Reno, October 1990.
CCEER-91-1 Saiidi, M., E. Hwang, E. Maragakis, and B. Douglas, "Dynamic Testing and the Analysis
of the Flamingo Road Interchange," Civil Engineering Department, Report No. CCEER-91-1, University of Nevada, Reno, February 1991.
CCEER-91-2 Norris, G., R. Siddharthan, Z. Zafir, S. Abdel-Ghaffar, and P. Gowda, "Soil-Foundation-
Structure Behavior at the Oakland Outer Harbor Wharf," Civil Engineering Department, Report No. CCEER-91-2, University of Nevada, Reno, July 1991.
CCEER-91-3 Norris, G., "Seismic Lateral and Rotational Pile Foundation Stiffnesses at Cypress," Civil
Engineering Department, Report No. CCEER-91-3, University of Nevada, Reno, August 1991.
CCEER-91-4 O'Connor, D. and M. Saiidi, "A Study of Protective Overlays for Highway Bridge Decks
in Nevada, with Emphasis on Polyester-Styrene Polymer Concrete," Civil Engineering Department, Report No. CCEER-91-4, University of Nevada, Reno, October 1991.
CCEER-91-5 O'Connor, D.N. and M. Saiidi, "Laboratory Studies of Polyester-Styrene Polymer
Concrete Engineering Properties," Civil Engineering Department, Report No. CCEER-91-5, University of Nevada, Reno, November 1991.
65
CCEER-92-1 Straw, D.L. and M. Saiidi, "Scale Model Testing of One-Way Reinforced Concrete Pier Hinges Subject to Combined Axial Force, Shear and Flexure," edited by D.N. O'Connor, Civil Engineering Department, Report No. CCEER-92-1, University of Nevada, Reno, March 1992.
CCEER-92-2 Wehbe, N., M. Saiidi, and F. Gordaninejad, "Basic Behavior of Composite Sections
Made of Concrete Slabs and Graphite Epoxy Beams," Civil Engineering Department, Report No. CCEER-92-2, University of Nevada, Reno, August 1992.
CCEER-92-3 Saiidi, M. and E. Hutchens, "A Study of Prestress Changes in A Post-Tensioned Bridge
During the First 30 Months," Civil Engineering Department, Report No. CCEER-92-3, University of Nevada, Reno, April 1992.
CCEER-92-4 Saiidi, M., B. Douglas, S. Feng, E. Hwang, and E. Maragakis, "Effects of Axial Force on
Frequency of Prestressed Concrete Bridges," Civil Engineering Department, Report No. CCEER-92-4, University of Nevada, Reno, August 1992.
CCEER-92-5 Siddharthan, R., and Z. Zafir, "Response of Layered Deposits to Traveling Surface
Pressure Waves," Civil Engineering Department, Report No. CCEER-92-5, University of Nevada, Reno, September 1992.
CCEER-92-6 Norris, G., and Z. Zafir, "Liquefaction and Residual Strength of Loose Sands from
Drained Triaxial Tests," Civil Engineering Department, Report No. CCEER-92-6, University of Nevada, Reno, September 1992.
CCEER-92-6-A Norris, G., Siddharthan, R., Zafir, Z. and Madhu, R. "Liquefaction and Residual Strength
of Sands from Drained Triaxial Tests," Civil Engineering Department, Report No. CCEER-92-6-A, University of Nevada, Reno, September 1992.
CCEER-92-7 Douglas, B., "Some Thoughts Regarding the Improvement of the University of Nevada,
Reno's National Academic Standing," Civil Engineering Department, Report No. CCEER-92-7, University of Nevada, Reno, September 1992.
CCEER-92-8 Saiidi, M., E. Maragakis, and S. Feng, "An Evaluation of the Current Caltrans Seismic
Restrainer Design Method," Civil Engineering Department, Report No. CCEER-92-8, University of Nevada, Reno, October 1992.
CCEER-92-9 O'Connor, D., M. Saiidi, and E. Maragakis, "Effect of Hinge Restrainers on the Response
of the Madrone Drive Undercrossing During the Loma Prieta Earthquake," Civil Engineering Department, Report No. CCEER-92-9, University of Nevada, Reno, February 1993.
CCEER-92-10 O'Connor, D., and M. Saiidi, "Laboratory Studies of Polyester Concrete: Compressive
Strength at Elevated Temperatures and Following Temperature Cycling, Bond Strength to Portland Cement Concrete, and Modulus of Elasticity," Civil Engineering Department, Report No. CCEER-92-10, University of Nevada, Reno, February 1993.
CCEER-92-11 Wehbe, N., M. Saiidi, and D. O'Connor, "Economic Impact of Passage of Spent Fuel
Traffic on Two Bridges in Northeast Nevada," Civil Engineering Department, Report No. CCEER-92-11, University of Nevada, Reno, December 1992.
CCEER-93-1 Jiang, Y., and M. Saiidi, "Behavior, Design, and Retrofit of Reinforced Concrete One-
way Bridge Column Hinges," edited by D. O'Connor, Civil Engineering Department, Report No. CCEER-93-1, University of Nevada, Reno, March 1993.
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CCEER-93-2 Abdel-Ghaffar, S., E. Maragakis, and M. Saiidi, "Evaluation of the Response of the Aptos Creek Bridge During the 1989 Loma Prieta Earthquake," Civil Engineering Department, Report No. CCEER-93-2, University of Nevada, Reno, June 1993.
CCEER-93-3 Sanders, D.H., B.M. Douglas, and T.L. Martin, "Seismic Retrofit Prioritization of Nevada
Bridges," Civil Engineering Department, Report No. CCEER-93-3, University of Nevada, Reno, July 1993.
CCEER-93-4 Abdel-Ghaffar, S., E. Maragakis, and M. Saiidi, "Performance of Hinge Restrainers in the
Huntington Avenue Overhead During the 1989 Loma Prieta Earthquake," Civil Engineering Department, Report No. CCEER-93-4, University of Nevada, Reno, June 1993 (in final preparation).
CCEER-93-5 Maragakis, E., M. Saiidi, S. Feng, and L. Flournoy, "Effects of Hinge Restrainers on the
Response of the San Gregorio Bridge during the Loma Prieta Earthquake," (in final preparation) Civil Engineering Department, Report No. CCEER-93-5, University of Nevada, Reno.
CCEER-93-6 Saiidi, M., E. Maragakis, S. Abdel-Ghaffar, S. Feng, and D. O'Connor, "Response of
Bridge Hinge Restrainers during Earthquakes -Field Performance, Analysis, and Design," Civil Engineering Department, Report No. CCEER-93-6, University of Nevada, Reno, May 1993.
CCEER-93-7 Wehbe, N., Saiidi, M., Maragakis, E., and Sanders, D., "Adequacy of Three Highway
Structures in Southern Nevada for Spent Fuel Transportation, Civil Engineering Department, Report No. CCEER-93-7, University of Nevada, Reno, August 1993.
CCEER-93-8 Roybal, J., Sanders, D.H., and Maragakis, E., "Vulnerability Assessment of Masonry in
the Reno-Carson City Urban Corridor," Civil Engineering Department, Report No. CCEER-93-8, University of Nevada, Reno, May 1993.
CCEER-93-9 Zafir, Z. and Siddharthan, R., "MOVLOAD: A Program to Determine the Behavior of
Nonlinear Horizontally Layered Medium Under Moving Load," Civil Engineering Department, Report No. CCEER-93-9, University of Nevada, Reno, August 1993.
CCEER-93-10 O'Connor, D.N., Saiidi, M., and Maragakis, E.A., "A Study of Bridge Column Seismic
Damage Susceptibility at the Interstate 80/U.S. 395 Interchange in Reno, Nevada," Civil Engineering Department, Report No. CCEER-93-10, University of Nevada, Reno, October 1993.
CCEER-94-1 Maragakis, E., B. Douglas, and E. Abdelwahed, "Preliminary Dynamic Analysis of a
Railroad Bridge," Report CCEER-94-1, January 1994. CCEER-94-2 Douglas, B.M., Maragakis, E.A., and Feng, S., "Stiffness Evaluation of Pile Foundation
of Cazenovia Creek Overpass," Civil Engineering Department, Report No. CCEER-94-2, University of Nevada, Reno, March 1994.
CCEER-94-3 Douglas, B.M., Maragakis, E.A., and Feng, S., "Summary of Pretest Analysis of
Cazenovia Creek Bridge," Civil Engineering Department, Report No. CCEER-94-3, University of Nevada, Reno, April 1994.
CCEER-94-4 Norris, G.M., Madhu, R., Valceschini, R., and Ashour, M., "Liquefaction and Residual
Strength of Loose Sands from Drained Triaxial Tests," Report 2, Vol. 1&2, Civil Engineering Department, Report No. CCEER-94-4, University of Nevada, Reno, August 1994.
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CCEER-94-5 Saiidi, M., Hutchens, E., and Gardella, D., "Prestress Losses in a Post-Tensioned R/C Box Girder Bridge in Southern Nevada," Civil Engineering Department, CCEER-94-5, University of Nevada, Reno, August 1994.
CCEER-95-1 Siddharthan, R., El-Gamal, M., and Maragakis, E.A., "Nonlinear Bridge Abutment ,
Verification, and Design Curves," Civil Engineering Department, CCEER-95-1, University of Nevada, Reno, January 1995.
CCEER-95-2 Ashour, M. and Norris, G., "Liquefaction and Undrained Response Evaluation of Sands
from Drained Formulation," Civil Engineering Department, Report No. CCEER-95-2, University of Nevada, Reno, February 1995.
CCEER-95-3 Wehbe, N., Saiidi, M., Sanders, D. and Douglas, B., “Ductility of Rectangular Reinforced
Concrete Bridge Columns with Moderate Confinement, “Civil Engineering Department, Report No. CCEER-95-3, University of Nevada, Reno, July 1995.
CCEER-95-4 Martin, T.., Saiidi, M. and Sanders, D., “Seismic Retrofit of Column-Pier Cap
Connections in Bridges in Northern Nevada,” Civil Engineering Department, Report No. CCEER-95-4, University of Nevada, Reno, August 1995.
CCEER-95-5 Darwish, I., Saiidi, M. and Sanders, D., “Experimental Study of Seismic
Susceptibility Column-Footing Connections in Bridges in Northern Nevada,” Civil Engineering Department, Report No. CCEER-95-5, University of Nevada, Reno, September 1995.
CCEER-95-6 Griffin, G., Saiidi, M. and Maragakis, E., “Nonlinear Seismic Response of
Isolated Bridges and Effects of Pier Ductility Demand,” Civil Engineering Department, Report No. CCEER-95-6, University of Nevada, Reno, November 1995.
CCEER-95-7 Acharya, S.., Saiidi, M. and Sanders, D., “Seismic Retrofit of Bridge
Footings and Column-Footing Connections,” Civil Engineering Department, Report No. CCEER-95-7, University of Nevada, Reno, November 1995.
CCEER-95-8 Maragakis, E., Douglas, B., and Sandirasegaram, U., “Full-Scale Field
Resonance Tests of a Railway Bridge,” A Report to the Association of American Railroads, Civil Engineering Department, Report No. CCEER-95-8, University of Nevada, Reno, December 1995.
CCEER-95-9 Douglas, B., Maragakis, E. and Feng, S., “System Identification Studies on Cazenovia Creek Overpass,” Report for the National Center for Earthquake Engineering Research, Civil Engineering Department, Report No. CCEER-95-9, University of Nevada, Reno, October 1995.
CCEER-96-1 El-Gamal, M.E. and Siddharthan, R.V., “Programs to Computer Translational Stiffness of Seat-Type Bridge Abutment,” Civil Engineering Department, Report No. CCEER-96-1, University of Nevada, Reno, March 1996.
CCEER-96-2 Labia, Y., Saiidi, M. and Douglas, B., “Evaluation and Repair of Full-
Scale Prestressed Concrete Box Girders,” A Report to the National Science Foundation, Research Grant CMS-9201908, Civil Engineering Department, Report No. CCEER-96-2, University of Nevada, Reno, May 1996.
CCEER-96-3 Darwish, I., Saiidi, M. and Sanders, D., “Seismic Retrofit of R/C Oblong
Tapered Bridge Columns with Inadequate Bar Anchorage in Columns and Footings,” A Report to the Nevada Department of Transportation, Civil Engineering Department, Report No. CCEER-96-3, University of Nevada, Reno, May 1996.
68
CCEER-96-4 Ashour, M., Pilling, R., Norris, G. and Perez, H., “The Prediction of
Lateral Load Behavior of Single Piles and Pile Groups Using the Strain Wedge Model,” A Report to the California Department of Transportation, Civil Engineering Department, Report No. CCEER-96-4, University of Nevada, Reno, June 1996.
CCEER-97-1-A Rimal, P. and Itani, A. “Sensitivity Analysis of Fatigue Evaluations of Steel Bridges”, Center for Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada Report No. CCEER-97-1-A, September, 1997.
CCEER-97-1-B Maragakis, E., Douglas, B., and Sandirasegaram, U. “Full-Scale Field Resonance Tests
of a Railway Bridge,” A Report to the Association of American Railroads, Civil Engineering Department, University of Nevada, Reno, May, 1996.
CCEER-97-2 Wehbe, N., Saiidi, M., and D. Sanders, "Effect of Confinement and Flares on the Seismic
Performance of Reinforced Concrete Bridge Columns," Civil Engineering Department, Report No. CCEER-97-2, University of Nevada, Reno, September 1997.
CCEER-97-3 Darwish, I., M. Saiidi, G. Norris, and E. Maragakis, “Determination of In-Situ Footing
Stiffness Using Full-Scale Dynamic Field Testing,” A Report to the Nevada Department of Transportation, Structural Design Division, Carson City, Nevada, Report No. CCEER-97-3, University of Nevada, Reno, October 1997.
CCEER-97-4-A Itani, A. “Cyclic Behavior of Richmond-San Rafael Tower Links,”
Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-97-4, August 1997.
CCEER-97-4-B Wehbe, N., and M. Saiidi, “User’s manual for RCMC v. 1.2 : A
Computer Program for Moment-Curvature Analysis of Confined and Unconfined Reinforced Concrete Sections,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-97-4, November, 1997.
CCEER-97-5 Isakovic, T., M. Saiidi, and A. Itani, “Influence of new Bridge Configurations on Seismic Performance,” Department of Civil Engineering, University of Nevada, Reno, Report No. CCEER-97-5, September, 1997.
CCEER-98-1 Itani, A., Vesco, T. and Dietrich, A., “Cyclic Behavior of “as Built” Laced Members
With End Gusset Plates on the San Francisco Bay Bridge” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada Report No. CCEER-98-1, March, 1998.
CCEER-98-2 G. Norris and M. Ashour, “Liquefaction and Undrained Response Evaluation of Sands
from Drained Formulation.” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-98-2, May, 1998.
CCEER-98-3 Qingbin, Chen, B. M. Douglas, E. Maragakis, and I. G. Buckle, "Extraction of Nonlinear
Hysteretic Properties of Seismically Isolated Bridges from Quick-Release Field Tests", Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-98-3, June, 1998.
CCEER-98-4 Maragakis, E., B. M. Douglas, and C. Qingbin, "Full-Scale Field Capacity Tests of a
Railway Bridge", Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-98-4, June, 1998.
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CCEER-98-5 Itani, A., Douglas, B., and Woodgate, J., “Cyclic Behavior of Richmond-San Rafael Retrofitted Tower Leg”. Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno. Report No. CCEER-98-5, June 1998
CCEER-98-6 Moore, R., Saiidi, M., and Itani, A., “Seismic Behavior of New Bridges with Skew and
Curvature”. Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno. Report No. CCEER-98-6, October, 1998.
CCEER-98-7 Itani, A and Dietrich, A, “Cyclic Behavior of Double Gusset Plate Connections”, Center
for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-98-5, December, 1998.
CCEER-99-1 Caywood, C., M. Saiidi, and D. Sanders, “Seismic Retrofit of Flared Bridge Columns
with Steel Jackets,” Civil Engineering Department, University of Nevada, Reno, Report No. CCEER-99-1, February 1999.
CCEER-99-2 Mangoba, N., M. Mayberry, and M. Saiidi, “Prestress Loss in Four Box Girder Bridges in
Northern Nevada,” Civil Engineering Department, University of Nevada, Reno, Report No. CCEER-99-2, March 1999.
CCEER-99-3 Abo-Shadi, N., M. Saiidi, and D. Sanders, "Seismic Response of Bridge Pier Walls in
the Weak Direction", Civil Engineering Department, University of Nevada, Reno, Report No. CCEER-99-3, April 1999.
CCEER-99-4 Buzick, A., and M. Saiidi, "Shear Strength and Shear Fatigue Behavior of Full-Scale
Prestressed Concrete Box Girders", Civil Engineering Department, University of Nevada, Reno, Report No. CCEER-99-4, April 1999.
CCEER-99-5 Randall, M., M. Saiidi, E. Maragakis and T. Isakovic, "Restrainer Design Procedures For
Multi-Span Simply-Supported Bridges", Civil Engineering Department, University of Nevada, Reno, Report No. CCEER-99-5, April 1999.
CCEER-99-6 Wehbe, N. and M. Saiidi, "User's Manual for RCMC v. 1.2, A Computer Program for
Moment-Curvature Analysis of Confined and Unconfined Reinforced Concrete Sections", Civil Engineering Department, University of Nevada, Reno, Report No. CCEER-99-6, May 1999.
CCEER-99-7 Burda, J. and A. Itani, “Studies of Seismic Behavior of Steel Base Plates,” Civil
Engineering Department, University of Nevada, Reno, Report No. CCEER-99-7, May 1999.
CCEER-99-8 Ashour, M. and G. Norris, “Refinement of the Strain Wedge Model Program,” Civil
Engineering Department, University of Nevada, Reno, Report No. CCEER-99-8, March 1999.
CCEER-99-9 Dietrich, A., and A. Itani, “Cyclic Behavior of Laced and Perforated Steel Members on
the San Francisco-Oakland Bay Bridge,” Civil Engineering Department, University, Reno, Report No. CCEER-99-9, December 1999.
CCEER 99-10 Itani, A., A. Dietrich, “Cyclic Behavior of Built Up Steel Members and their
Connections,” Civil Engineering Department, University of Nevada, Reno, Report No. CCEER-99-10, December 1999.
CCEER 99-10-A Itani, A., E. Maragakis and P. He, “Fatigue Behavior of Riveted Open Deck Railroad
Bridge Girders,” Civil Engineering Department, University of Nevada, Reno, Report No. CCEER-99-10-A, August 1999.
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CCEER 99-11 Itani, A., J. Woodgate, “Axial and Rotational Ductility of Built Up Structural Steel
Members,” Civil Engineering Department, University of Nevada, Reno, Report No. CCEER-99-11, December 1999.
CCEER-99-12 Sgambelluri, M., Sanders, D.H., and Saiidi, M.S., “Behavior of One-Way Reinforced
Concrete Bridge Column Hinges in the Weak Direction,” Department of Civil Engineering, University of Nevada, Reno, Report No. CCEER-99-12, December 1999.
CCEER-99-13 Laplace, P., Sanders, D.H., Douglas, B, and Saiidi, M, “Shake Table Testing of Flexure
Dominated Reinforced Concrete Bridge Columns”, Department of Civil Engineering, University of Nevada, Reno, Report No. CCEER-99-13, December 1999.
CCEER-99-14 Ahmad M. Itani, Jose A. Zepeda, and Elizabeth A. Ware "Cyclic Behavior of Steel
Moment Frame Connections for the Moscone Center Expansion,” Department of Civil Engineering, University of Nevada, Reno, Report No. CCEER-99-14, December 1999.
CCEER 00-1 Ashour, M., and Norris, G. “Undrained Lateral Pile and Pile Group Response in
Saturated Sand”, Civil Engineering Department, University of Nevada, Reno, Report No. CCEER-00-1, May 1999. January 2000.
CCEER 00-2 Saiidi, M. and Wehbe, N., “A Comparison of Confinement Requirements in Different
Codes for Rectangular, Circular, and Double-Spiral RC Bridge Columns,” Civil Engineering Department, University of Nevada, Reno, Report No. CCEER-00-2, January 2000.
CCEER 00-3 McElhaney, B., M. Saiidi, and D. Sanders, “Shake Table Testing of Flared Bridge
Columns With Steel Jacket Retrofit,” Civil Engineering Department, University of Nevada, Reno, Report No. CCEER-00-3, January 2000.
CCEER 00-4 Martinovic, F., M. Saiidi, D. Sanders, and F. Gordaninejad, “Dynamic Testing of Non-
Prismatic Reinforced Concrete Bridge Columns Retrofitted with FRP Jackets,” Civil Engineering Department, University of Nevada, Reno, Report No. CCEER-00-4, January 2000.
CCEER 00-5 Itani, A., and M. Saiidi, “Seismic Evaluation of Steel Joints for UCLA Center for Health
Science Westwood Replacement Hospital,” Civil Engineering Department, University of Nevada, Reno, Report No. CCEER-00-5, February 2000.
CCEER 00-6 Will, J. and D. Sanders, “High Performance Concrete Using Nevada Aggregates,” Civil
Engineering Department, University of Nevada, Reno, Report No. CCEER-00-6, May 2000.
CCEER 00-7 French, C., and M. Saiidi, “A Comparison of Static and Dynamic Performance of Models
of Flared Bridge Columns,” Civil Engineering Department, University of Nevada, Reno, Report No. CCEER-00-7, October 2000.
CCEER 00-8 Itani, A., H. Sedarat, “Seismic Analysis of the AISI LRFD Design
Example of Steel Highway Bridges,” Civil Engineering Department, University of Nevada, Reno, Report No. CCEER 00-08, November 2000.
CCEER 00-9 Moore, J., D. Sanders, and M. Saiidi, “Shake Table Testing of 1960’s Two
Column Bent with Hinges Bases,“ Civil Engineering Department, University of Nevada, Reno, Report No. CCEER 00-09, December 2000.
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CCEER 00-10 Asthana, M., D. Sanders, and M. Saiidi, “One-Way Reinforced Concrete Bridge Column Hinges in the Weak Direction,“ Civil Engineering Department, University of Nevada, Reno, Report No. CCEER 00-10, April 2001.
CCEER 01-1 Ah Sha, H., D. Sanders, M. Saiidi, “Early Age Shrinkage and Cracking of Nevada
Concrete Bridge Decks, “Civil Engineering Department, University of Nevada, Reno, Report No. CCEER 01-01, May 2001.
CCEER 01-2 Ashour, M. and G. Norris, “Pile Group program for Full Material Modeling an
Progressive Failure.” Civil Engineering Department, University of Nevada, Reno, Report No. CCEER 01-02, July 2001.
CCEER 01-3 Itani, A., C. Lanaud, and P. Dusicka, “Non-Linear Finite Element Analysis of Built-Up
Shear Links.” Civil Engineering Department, University of Nevada, Reno, Report No. CCEER 01-03, July 2001.
CCEER 01-4 Saiidi, M., J. Mortensen, and F. Martinovic, “Analysis and Retrofit of Fixed Flared
Columns with Glass Fiber-Reinforced Plastic Jacketing,” Civil Engineering Department, University of Nevada, Reno, Report No. CCEER 01-4, August 2001
CCEER 01-5 Saiidi, M., A. Itani, I. Buckle, and Z. Cheng,” Performance of A Full-Scale Two-Story
Wood Frame Structure Supported on Ever-Level Isolators,” Civil Engineering Department, University of Nevada, Reno, Report No. CCEER 01-5, October 2001
CCEER 01-6 Laplace, P., D. Sanders, and M. Saiidi, “Experimental Study and Analysis
of Retrofitted Flexure and Shear Dominated Circular Reinforced Concrete Bridge Columns Subjected to Shake Table Excitation, “Civil Engineering Department, University of Nevada, Reno, Report No. CCEER 01-6, June 2001.
CCEER 01-7 Reppi, F., and D. Sanders, “Removal and Replacement of Cast-in-Place,
Post-tensioned, Box Girder Bridge, “Civil Engineering Department, University of Nevada, Reno, Report No. CCEER 01-7, December 2001.
CCEER 02-1 Pulido, C., M. Saiidi, D. Sanders, and A. Itani, ”Seismic Performance and Retrofitting of
Reinforced Concrete Bridge Bents,” Civil Engineering Department, University of Nevada, Reno, Report No. CCEER 02-1, January 2002.
CCEER 02-2 Yang, Q., M. Saiidi, H. Wang, and A. Itani, ”Influence of Ground Motion Incoherency on
Earthquake Response of Multi-Support Structures,” Civil Engineering Department, University of Nevada, Reno, Report No. CCEER 02-2, May 2002.
CCEER 02-3 M. Saiidi, B. Gopalakrishnan, E. Reinhardt, and R. Siddharthan, A Preliminary Study of
Shake Table Response of A Two-Column Bridge Bent on Flexible Footings Civil Engineering Department, University of Nevada, Reno, Report No. CCEER 02-03, June 2002.
CCEER 02-4 Not Published CCEER 02-5 Banghart, A., Sanders, D., Saiidi, M., “Evaluation of Concrete Mixes for Filling the Steel
Arches in the Galena Creek Bridge,” Civil Engineering Department, University of Nevada, Reno, Report No. CCEER 02-05, June 2002.
CCEER 02-6 Dusicka, P., Itani, A., Buckle, I. G., “Cyclic Behavior of Shear Links and Tower Shaft
Assembly of San Francisco – Oakland Bay Bridge Tower” Civil Engineering Department, University of Nevada, Reno, Report No. CCEER 02-06, July 2002.
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CCEER 02-7 Mortensen, J., and M. Saiidi, “A Performance-Based Design Method for Confinement in Circular Columns," Civil Engineering Department, University of Nevada, Reno, Report No. CCEER 02-07, November 2002.
CCEER 03-1 Wehbe, N., and M. Saiidi, “User’s manual for SPMC v. 1.0 : A Computer Program for
Moment-Curvature Analysis of Reinforced Concrete Sections with Interlocking Spirals,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-03-1, May, 2003.
CCEER 03-2 Wehbe, N., and M. Saiidi, “User’s manual for RCMC v. 2.0 : A Computer Program for
Moment-Curvature Analysis of Confined and Unconfined Reinforced Concrete Sections,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-03-2, June, 2003.
CCEER 03-3 Nada, H., D. Sanders, and M. Saiidi, “Seismic Performance of RC Bridge Frames with
Architectural-Flared Columns,” Civil Engineering Department, University of Nevada, Reno, Report No. CCEER 03-3, January 2003.
CCEER 03-4 Reinhardt, E., M. Saiidi, and R. Siddharthan, “Seismic Performance of a
CFRP/ Concrete Bridge Bent on Flexible Footings." Civil Engineering Department, University of Nevada, Reno. Report No. CCEER 03-4, August 2003.
CCEER 03-5 Johnson, N., M. Saiidi, A. Itani, and S. Ladkany, “Seismic Retrofit of Octagonal
Columns with Pedestal and One-Way Hinge at the Base,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, and Report No. CCEER-03-5, August 2003.
CCEER 03-6 Mortensen, C., M. Saiidi, and S. Ladkany, “Creep and Shrinkage Losses in Highly
Variable Climates,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-03-6, September 2003.
CCEER 03- 7 Ayoub, C., M. Saiidi, and A. Itani, “A Study of Shape-Memory-Alloy-Reinforced Beams
and Cubes,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-03-7, October 2003.
CCEER 03-8 Chandane, S., D. Sanders, and M. Saiidi, "Static and Dynamic Performance of RC Bridge
Bents with Architectural-Flared Columns," Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-03-8, November 2003.
CCEER 04-1 Olaegbe, C., and Saiidi, M., "Effect of Loading History on Shake Table Performance of
A Two-Column Bent with Infill Wall," Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-04-1, January 2004.
CCEER 04-2 Johnson, R., Maragakis, E., Saiidi, M., and DesRoches, R., “Experimental Evaluation of
Seismic Performance of SMA Bridge Restrainers,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-04-2, February 2004.
CCEER 04-3 Moustafa, K., Sanders, D., and Saiidi, M., "Impact of Aspect Ratio on Two-Column Bent
Seismic Performance," Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-04-3, February 2004.
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CCEER 04-4 Maragakis, E., Saiidi, M., Sanchez-Camargo, F., and Elfass, S., “Seismic Performance of
Bridge Restrainers At In-Span Hinges,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-04-4, March 2004.
CCEER 04-5 Ashour, M., Norris, G. and Elfass, S., “Analysis of Laterally Loaded Long or
Intermediate Drilled Shafts of Small or Large Diameter in Layered Soil,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-04-5, June 2004.
CCEER 04-6 Correal, J., Saiidi, M. and Sanders, D., “Seismic Performance of RC Bridge Columns
Reinforced with Two Interlocking Spirals,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-04-6, August 2004.
CCEER 04-7 Dusicka, P., Itani, A. and Buckle, I., ”Cyclic Response and Low Cycle Fatigue
Characteristics of Plate Steels,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-04-7, November 2004.
CCEER 04-8 Dusicka, P., Itani, A. and Buckle, I., ” Built-up Shear Links as Energy Dissipaters for
Seismic Protection of Bridges,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-04-8, November 2004.
CCEER 04-9 Sureshkumar, K., Saiidi, S., Itani, A. and Ladkany, S., “Seismic Retrofit of Two-Column
Bents with Diamond Shape Columns,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-04-9, November 2004.
CCEER 05-1 Wang, H. and Saiidi, S., “A Study of RC Columns with Shape Memory Alloy and
Engineered Cementitious Composites,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-05-1, January 2005.
CCEER 05-2 Johnson, R., Saiidi, S. and Maragakis, E., "A Study of Fiber Reinforced Plastics for
Seismic Bridge Restrainers," Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-05-2, January 2005.
CCEER 05-3 Carden, L.P., Itani, A.M., Buckle, I.G, "Seismic Load Path in Steel Girder Bridge
Superstructures,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-05-3, January 2005.
CCEER 05-4 Carden, L.P., Itani, A.M., Buckle, I.G, "Seismic Performance of Steel Girder Bridge
Superstructures with Ductile End Cross Frames and Seismic Isolation,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-05-4, January 2005.
CCEER 05-5 Goodwin, E., Maragakis, M., Itani, A. and Luo, S., "Experimental Evaluation of the
Seismic Performance of Hospital Piping Subassemblies,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-05-5, February 2005.
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CCEER 05-6 Zadeh M. S., Saiidi, S, Itani, A. and Ladkany, S., "Seismic Vulnerability Evaluation and Retrofit Design of Las Vegas Downtown Viaduct,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-05-6, February 2005.
CCEER 05-7 Phan, V., Saiidi, S. and Anderson, J., “Near Fault (Near Field) Ground Motion Effects on
Reinforced Concrete Bridge Columns” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-05-7, August 2005.
CCEER 05-8 Carden, L., Itani, A. and Laplace, P., “Performance of Steel Props at the UNR Fire
Science Academy subjected to Repeated Fire” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-05-8, August 2005.
CCEER 05-9 Yamashita, R. and Sanders, D., “Shake Table Testing and an Analytical Study of
Unbonded Prestressed Hollow Concrete Column Constructed with Precast Segments” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-05-9, August 2005.
CCEER 05-10 Not Published CCEER 05-11 Carden, L., Itani., A., and Peckan, G., “Recommendations for the Design of Beams and
Posts in Bridge Falsework,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-05-11, October 2005.
CCEER 06-01 Cheng, Z., Saiidi, M., and Sanders, D., “Development of a Seismic Design Method for
Reinforced Concrete Two-Way Bridge Column Hinges,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-06-01, February 2006.
CCEER 06-02 Johnson, N., Saiidi, M., and Sanders, D., “Large-Scale Experimental and Analytical
Studies of a Two-Span Reinforced Concrete Bridge System,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-06-02, March 2006.
CCEER 06-03 Saiidi, M., Ghasemi, H. and Tiras, A., “Seismic Design and Retrofit of Highway Bridges,”
Proceedings, Second US-Turkey Workshop, Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-06-03, May 2006.
CCEER 07-01 O'Brien, M., Saiidi, M. and Sadrossadat-Zadeh, M., “A Study of Concrete Bridge
Columns Using Innovative Materials Subjected to Cyclic Loading,” Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-07-01, January 2007.
CCEER 07-02 Sadrossadat-Zadeh, M. and Saiidi, M., "Effect of Strain rate on Stress-Strain Properties
and Yield Propagation in Steel Reinforcing Bars," Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-07-02, January 2007.
CCEER 07-03 Sadrossadat-Zadeh, M. and Saiidi, M., " Analytical Study of NEESR-SG 4-Span Bridge
Model Using OpenSees," Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-07-03, January 2007.
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CCEER 07-04 Nelson, R., Saiidi, M. and Zadeh, S., "Experimental Evaluation of Performance of
Conventional Bridge Systems," Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-07-04, October 2007.
CCEER 07-05 Bahen, N. and Sanders, D., "Strut-and-Tie Modeling for Disturbed Regions in Structural
Concrete Members with Emphasis on Deep Beams," Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-07-05, December 2007.
CCEER 07-06 Choi, H., Saiidi, M. and Somerville, P., "Effects of Near-Fault Ground Motion and Fault-
Rupture on the Seismic Response of Reinforced Concrete Bridges," Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-07-06, December 2007.
CCEER 07-07 Ashour M. and Norris, G., "Report and User Manual on Strain Wedge Model Computer
Program for Files and Large Diameter Shafts with LRFD Procedure," Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-07-07, October 2007.
CCEER 08-01 Doyle, K. and Saiidi, M., "Seismic Response of Telescopic Pipe Pin Connections,"
Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-08-01, February 2008.
CCEER 08-02 Taylor, M. and Sanders, D., "Seismic Time History Analysis and Instrumentation of the
Galena Creek Bridge," Center for Civil Engineering Earthquake Research, Department of Civil Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-08-02, April 2008.
CCEER 08-03 Abdel-Mohti, A. and Pekcan, G., "Seismic Response Assessment and Recommendations
for the Design of Skewed Post-Tensioned Concrete Box-Girder Highway Bridges," Center for Civil Engineering Earthquake Research, Department of Civil and Environmental Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-08-03, September 2008.
CCEER 08-04 Saiidi, M., Ghasemi, H. and Hook, J., “Long Term Bridge Performance
Monitoring, Assessment & Management,” Proceedings, FHWA/NSF Workshop on Future Directions,” Center for Civil Engineering Earthquake Research, Department of Civil and Environmental Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-08-04, September 2008.
CCEER 09-01 Brown, A., and Saiidi, M., “Investigation of Near-Fault Ground Motion Effects on
Substandard Bridge Columns and Bents,” Center for Civil Engineering Earthquake Research, Department of Civil and Environmental Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-09-01, July 2009.
CCEER 09-02 Linke, C., Pekcan, G., and Itani, A., “Detailing of Seismically Resilient Special Truss
Moment Frames,” Center for Civil Engineering Earthquake Research, Department of Civil and Environmental Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-09-02, August 2009.
CCEER 09-03 Hills, D., and Saiidi, M., “Design, Construction, and Nonlinear Dynamic Analysis of
Three Bridge Bents Used in a Bridge System Test,” Center for Civil Engineering Earthquake Research, Department of Civil and Environmental Engineering, University of Nevada, Reno, Nevada, Report No. CCEER-09-03, August 2009.