us 290 doing more with less people - texas a&m university · us 290 comprised of vertical...

TTI Short Course 2014 - TxDOT Houston District Bridge

Michael E. Carlson, P.E. TxDOT Houston District Bridge Design

US 290 DOING MORE WITH LESS


THE US 290 CORRIDOR


US 290 – DOING MORE WITH LESS

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Table Revised: 11/6/2013 Added C-2 Details: 9/26/2014

July 2014

Williams Brothers

Construction Co.

$49 million*



13 Total Segments (Approx. 38 Miles) Our Design Began Late 2009 Foresaw Compressed Letting Schedule HNTB is the Project Management Coordinator. Provided Bridge Layouts By a Variety of Consultants Layouts Were Created In-House In Later Segments

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ABOUT TxDOT HOUSTON DISTRICT BRIDGE

US 290 INTRODUCTION & SCOPE

Currently 23 Total Employees – 14 P.Es (10 P.Es designing) – 4 Cad Operators – BRINSAP Personnel & Administrative

33 Employees Back in August 2006 (When J.C. Liu Retired) 2/3 the Staff, Staff is Less Experienced, & Every Job is Now a Rush Job. 14 People Involved When US 290 Design Began



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Segment CSJ Type * # of Bridges Let Date Winning Bid (Millions) * Total Bridge Sheets

Seg K (2) 0271-14-217 Recon 20 May-11 $151.6 1423

Seg G (6) 0050-09-071 Recon 9 Sep-12 $110.4 326

Seg J1 (1) 0271-14-228 Recon 10 Oct-12 $107.0 966

Seg F (7) 0050-08-086 Widen 12 Mar-13 $58.0 341

Seg E (8) 0050-08-087 Recon 6 Apr-13 $135.4 427

Seg H (5) 0050-09-070 Recon 16 Apr-13 $153.3 457

Seg I (4) 0050-09-069 Recon 11 May-13 $142.8 333

Seg J2 (3) 0271-14-213 Recon 6 Nov-13 $151.6 380

Seg D (9) 0050-06-081 Widen 12 Nov-13 $85.2 268

Seg C (10) 0050-06-080 Widen 5 (C1 & C2) Jul-14 (C1) $45.6 (C1) 137 (C1 & C2)

Seg B (11) 0050-06-079 Widen 6

Seg A (12) 0114-12-007 Widen 14

* Includes Only Bridges Designed By & Signed & Sealed Sheets Provided By TxDOT Houston District Bridge Foundation Layout Redlines Provided By By TxDOT Houston District Bridge, However Signed & Sealed By Consultants

Total of 5058 Bridge Sheets

Total of $1.1 Billion


US 290 Corridor – Compressed Schedule By Segment


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0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

2010 2011 2012 2013 2014

% D

esig

n Ti

me

Design Year (Fiscal Year)

Seg K

Seg 6

Seg J1

Seg 7

Seg 8

Seg 5

Seg 4

Seg J2

Seg 9

Seg 10

Seg 11

Seg 12


HOW DID WE DO IT? Changing the Responsibilities & Division of Work Amongst Personnel.


The Traditional Way We Design Bridges

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District Bridge Engineer

Assigns New Bridge to Team

Team Leader A Project Manager

Team Leader C Project Manager

Coordinates with other designers outside of bridge & distributes work amongst designers within bridge. Supports team personnel.

Design Engineer

Does majority of design, works with EITs and CAD Operators.

Cad Operator

Does drafting for majority of the bridge details.

Design Engineer or EIT

Team Leader B Project Manager


The Mass Production Design of Bridges

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District Bridge Engineer

Design Engineer BGS

Cad Operator Substructure

Design Engineer Concrete

Superstructure

Team Leader Project Manager

Design Engineer Substructure

Design Engineer Foundations

Design Engineer Steel Superstructure

Design Engineer / EIT Quantities

Cad Operator Superstucture

Cad Operator Steel

Design Engineer Support / Other

BGS is created as soon as Bridge layouts are confirmed

Coordination begins to create superstructure design sheets.

Steel superstructures require the most design and detailing time.

A specific engineer and CAD operator is designated to this task.

As soon as the superstructure is laid out, substructure engineers begin coordinating with CAD operators to produce sheets.

Foundation loading is calculated and documented for Geotech engineers.

Foundations are designed and detailed.

Team Leader coordinates with PMC, assigns work loads, and offers design support.

Quantities are calculated and tabulated for the entire bridge and are inserted on design sheets.



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Mass Production Pros

Encourages Standardization For Each Design Element – Greatly Increases Speed of Design, Drafting, & Later Calculations – Provides Consistency That Aids Contractor Later During Construction. – Provides Consistency of Architectural Elements.

Reduces Redesign of Similar Elements – Designs Can Be Grouped and Re-Referenced – A Similar Design May Already Exist on Another Bridge.

Pull and Document the Previous Design. – Make a Library.

As the Library Grows Design Becomes Even More Efficient.



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Mass Production Challenges

Requires Complete Bridge Layouts Increased Collaboration Between Multiple Engineers / CAD Operators CAD File Ownership Concerns Increased Burnout Amongst Personnel Engineers Become “Rusty” on Designing Elements Outside Their Mass

Production Task


STANDARDIZE Architecture, Design, & Detailing.


Houston Area Green Ribbon Project

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Developed with the Katy Freeway Reconstruction.

Comprised of 4 Schemes – Vertical Scheme – Horizontal Scheme – Wave Scheme – Interchange Scheme

(Similar to Horizontal Scheme with more robust structural elements)


Houston Area Green Ribbon Project

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US 290 comprised of Vertical Scheme & Interchange Scheme Columns Standardizes Use of Inverted-T Caps, U-Beams, and Steel Tub Girders. Architectural Details & Rustication is Defined.

Green Ribbon Requirements

We Went One Step Further…

Encouraged standardization of engineering details through standardization of architectural elements.

Standardized Inverted-T Cap Dimensions Throughout. U54 Beams Used Throughout Reconstructed

Areas Unless Steel Tubs Required. Column Details Were All Standardized

and a Library was Developed. Footing Details Were All Standardized

and a Library was Developed.


Standardizing Designs

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Engineer is encouraged to adapt methods of increasing design efficiency when faced with hundreds of elements to design.

Engineer is encouraged to tabularize results or create a library of previous designs.

Engineer is encouraged to pull previous designs for other similar elements.

Design Engineer Pros

CAD Operator Pros

Drafting takes a long time. Encouraged to reuse as much as possible.

Using existing goby's prevents missing callouts and notes.

CAD Operator becomes more familiar with details can catch dimension errors.


CHANGE PRIORITIES Changing the Priority and Order of Work.


Prioritize Your Work

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Start drawing sheets before design. Some sheet may not need to be drawn to the perfect scale.

As long as dimensions and callouts are correct. Minimize down time.

Manage Employee Work Loads

Be Smart With Your Redlines Breakdown and simplify redlines between CAD Operator and Engineer. Make sure one element is perfect then copy to minimize having to

make the same change later to multiple elements.

What Really Needs to Be Shown on the Plans Eliminate repeated design information on different sheets. Can it be built with what is provided? Minimizes the locations of revisions if something changes.


WORK SMARTER Let The Computer Do The Heavy Lifting.


Let the Computer Do the Heavy Lifting

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The Biggest Waste of Time For Engineers & CAD Operators…

DATA MANAGEMENT!



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Let standardization work for you. Engineer is automatically encouraged to make tools to enhance

productivity while designing hundred of similar elements Design spreadsheets to require as little tampering as possible but also so

they can be easily modified for different situations. One tool is not required to do everything. Simplify each tool. Improve your tools when downtime permits between jobs. When possible, design tools to work together. Design tools that require inputs only once.

Design Spreadsheet Tools Smartly



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Use Axiom importer as much as possible for all data (bar tables, etc) Design your tools around Axiom. However….

– This requires cooperation between Engineers and CAD Operators. – Originally this was a challenge as CAD Operators were concerned of allowing others access to drawings. – Everyone is happier now.

Do Not 10 Key!



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BGS output format is very predicable. Spreadsheet Visual Basic macros developed in house. Extract bearing seat elevations, bearing taper reports, slab data, & beam

data from BGS outputs. Tabulation of quantities summarized Working to be even more Axiom friendly Results in major decrease of time and reduction of errors.

Example: BGS Extractors

Factoid:

Is This Really Necessary? – Connector C (Located In Segment J1) Connects 2 Lanes of IH-10 Traffic to US 290

Westbound. – It is 95 Spans Long (11,690ft). – Would you like to copy and paste all that BGS output data to summarize you EQ sheet?



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Example: BGS Extractors



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This “Excels” with standardization. Setup for direct Axiom from calculations to CAD bar table. Revised, and revised again to be easily adaptable for different bents. Easily adopt to bents with similar rebar details.

Change the length, skew, bar spacing and go on… Does not require re-drawing of bent that changed slightly.

A disadvantage of Bentley Rebar. Resulted in a major decrease of time and reduction of errors.

Example: Rebar Quantity Tables

Factoid: No Errors!

– No substantial quantity errors have been found since letting using these tools. – There have been very limited field change orders resulting from these techniques.



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Example: Rebar Quantity Tables



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Library of columns & footings developed for Green Ribbon. Every footing and column used along the corridor has a unique name.

Aka: Footing DSF-2, or Column Type A is always the same no matter what segment of US 290 you are on.

Footing dimensions, quantities are looked up from the master library. Column and foundation spreadsheets are setup to require very little

modification and are formatted the same to allow data to be easily migrated between each spreadsheet.

Fully Axiom supported. Resulted in a major decrease of time and reduction of errors.

Example: Column & Foundation Tables



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Example: Column Tables



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Example: Foundation Tables



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Example: Foundation Tables



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We had to design many, many, many U-Beams…. How to Design U-Beams (We started this before PGSuper)….

– Run BGS 2 Times. – Compute LLDF using Bridge Division Spreadsheets. – Compute your loadings due to dead loads. – Create a PSTRS14 Input file – Run PSTRS14 – Use a spreadsheet to compute drops and slab section depths with BGS and PSTRS14 output data. – Run BGS one last time.

…..And it better all have satisfied the design requirements, otherwise start from the top again.

How long should it take an engineer to perform the tasks after creating BGS for a 20 span 28’ wide connector?

Superstructure U-Beam Design



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We can do it in less than 10 minutes. Remember the biggest waste of time is data management so let the

computer do the heavy lifting. Envisioned by John F. Corbett back in 2001. Revived and improved upon back in 2009, and again in 2014. Automatically integrates BGS, LLDF, PSTRS14, and Bearing Drop data.

– Automatically Imports BGS LS2 Data (# of Beams, Beam Lengths, Spacing's & Skews. – Provides user capable automatic calculation and distribution of dead loads such as

railings, medians, sidewalks, and haunch weights. – Automatically calculates LLDF using Bridge Division spreadsheets for each beam using

exact BGS output data. – Automatically creates and runs PSTRS14 input files – Automatically imports PSTRS14 outputs such as number of strands, f’ci, f’c, deflections

and cambers. – Automatically calculates bearing drops and slab depth sections. – Automatically summarizes BGS drops and slab depth sections.

Example: Corbett Automatic Superstructure Design



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SOFTWARE New Software Used.


Software

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Uses beam element finite element modeling Allowed for a quick cap design or CAP18 check. Program includes load combinations, no need to spend hours specifying. Program includes wind loading, and breaking forces, along with dead load

and HL-93 automatic calculation. Quick and easy calculation of single column foundation loadings. Basic post-tensioning capabilities. Allowed for quick special designs: irregular footings, straddle bents,

eccentric Bents, & unsymmetrical bents. A model can take 15-30 minutes to develop versus a week to develop a

STAAD model. Very reasonable software cost to TxDOT. http://www.viathor.com

Viathor VBent


Software

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Viathor Vbent Example: Single Column Bent

Model Inputs - Deck - Cap - Reinforcing


Software

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Model Inputs - Column - Foundation - Reinforcing - Live Loads


Software

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Reports - Summary - Cap Flexure - Foundation

Loads


Software

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Viathor Vbent Example: Single Column Ecc. Post Tensioned


Software

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Viathor Vbent Example: Straddle Caps


RESULTS Conclusions & Results.


US 290 Corridor – Timesheet Billed Engineering Hours / Signed Bridge Sheet


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Average 21Hrs / Sheet

15.7

37.3

17.6 19.2

15.6

20.2

25.5 25.9

11.4

21.6

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

Seg K (2) Seg G (6) Seg J1(1)

Seg F (7) Seg E (8) Seg H (5) Seg I (4) Seg J2 (3) Seg D (9) Seg C(10)

Seg B(11)

Seg A(12)

Bill

ed H

rs (F

unct

ions

164

& 1

70)

Per S

igne

d &

Sea

led

Brid

ge S

heet

US 290 Job Segment - In Order of Lettings (2011-2014)

US 290 Corridor - Timesheet Billed Engineering Hours / Signed Bridge Sheet TxDOT Houston District Bridge Design

Currently in Design



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Segment CSJ Type * # of Bridges * Total Hrs * Total Bridge Sheets * Hrs / Sheet

Seg K (2) 0271-14-217 Recon 20 22,330 1,423 15.69

Seg G (6) 0050-09-071 Recon 9 12,168 326 37.33

Seg J1 (1) 0271-14-228 Recon 10 16,983 966 17.58

Seg F (7) 0050-08-086 Widen 12 6,549 341 19.21

Seg E (8) 0050-08-087 Recon 6 6,657 427 15.59

Seg H (5) 0050-09-070 Recon 16 9,239 457 20.22

Seg I (4) 0050-09-069 Recon 11 8,487 333 25.49

Seg J2 (3) 0271-14-213 Recon 6 9,828 380 25.86

Seg D (9) 0050-06-081 Widen 12 3,062 268 11.43

Seg C (10) 0050-06-080 Widen 5 2,953 137 21.55

Seg B (11) 0050-06-079 Widen 6

Seg A (12) 0114-12-007 Widen 14

* Includes Only Bridges Designed By & Signed & Sealed Sheets Provided By TxDOT Houston District Bridge Foundation Layout Redlines Provided By By TxDOT Houston District Bridge, However Signed & Sealed By Consultants


THANK YOU US 290 - DOING MORE WITH LESS

Michael E. Carlson, P.E TxDOT Houston District Bridge Design [email protected] 713-802-5366

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