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SEISMIC ANALYSIS ON SACS

Monday, 17th February 2014

By: FJ


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INTRODUCTIONS

The method of this analysis using Engineering Dynamic Inc. SACS Program has been used to

determine the structuresNatural Period. The resultingMode ShapesandMass Matrixare used in

theResponse Analysis. The Response Analysis generates all the loads for the Seismic Analysis.

Earthquake load consist of two analysis, e.g.:

Strength Level Earthquake(SLE) 100 years event

Ductility/Rare Level Earthquake(DLE/RLE) 800 years event

The differences are the value of Peak Ground Acceleration (PGA) and Pseudo Spectrum Velocity

(PSV).

INTRODUCTION


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SACINP.S1

Basic model using sacinp.opr

No AMOD

Basic CDM using inplace

Line up the similar load

LCOMB consist of basic load with additional

GX and GY (for superelement)

LCSEL according to LCOMB

No environmental load

Only one WOR# Dead Load

Water depth using MSL

PSIINP.S1

Basic soil data using psiinp.opr

PutPILSUP AVG(combined ESEX and ESEY)

FOUNDATION LINEARIZATION

Initial Load

INPUT

INPUT


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OUTPUT

Superelement file dynsef.s1

psilist.s1 (check structure base shear)

FOUNDATION LINEARIZATION

For initial load

factor use 1.0

Soil stiffness generated based on 2 directions of lateral SACS

generated self weight are used to average out the soil

stiffness for use in dynamic analysis

INPUT SACS (SACINP.S1)

SOIL DATA


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SACINP.S2

Basic model using sacinp.s1

Fix LCOMB for mass of the structure

No Selfweight

No WOR# Dead Load

Fixity 222000 (Leg/edge of Deck)

DYNSEF.S1

Use for superlement of the structure

DYNINP.S2

Put DYNOPT for mass calculation and mode shape


Put DYNOPT2 for structural density = 110 % x 490.0 pcf

DYNAMIC ANALYSIS

INPUT


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DYNAMIC ANALYSIS

Increase structural

density 110 %

DYNINP.S2

INPUT SACS (SACINP.S2)


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OUTPUT

dynmod.s2

dynmass.s2

dynlist.s2 (check natural period/frequency and mass participation >90%)

DYNAMIC ANALYSIS

> 90 %


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DYRINP.S3


Damping Value 5%

Directionally factor X = Y = 100% (1.00), Z = 50 % (0.5)

Include PGA and PSV based on return event (SLE 100 years or DLE 800 years).

DYNMOD.S2

Use for structure modes shape

DYNMASS.S2

Use for structure mass

PSICSF.S1

Use for common solution file

EARTHQUAKE

INPUT


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Earthquake load components, i.e.:

1. Peak Ground Acceleration (PGA)

2. Period and Pseudo Spectrum Velocity (PSV)

3. Damping Ratio

4. Mudline Elevation

5. Directional Factor

OUTPUT

dyrcsf.s3

dyrlist.s3

EARTHQUAKE

PGA 0.216 G

Dumping Ratio 5 %

Mudline 49.0 ft

T (second)Region A

PSV (in/sec/g)

0.030 1.845

0.050 3.075

0.125 15.238

0.500 60.952

5.000 60.952

10.000 30.476

5

2

14

3

INPUT DYRINP.S3


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Iteration of base shear betweenStep 1with base shear atStep 3.

ITERATION

DYRLIST.S3

PSILIST.S1

OUTPUT


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PSTINP.S4

Put AMOD for load case 1 and 2

Increase AMOD 1.700

DYRCSF.S3

Common solution file for earthquake loads

OUTPUT

pstlst.s4

Consider UC member greater than 1.00 (UC < 1.0)

A. ELEMENT STRESS / CODE CHECK

POST PROCESSING

Basic Allowable Stress

Modification

INPUT


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B. JOINT PUNCHING SHEAR

POST PROCESSING

JCINP.S4

Put AMOD for load case 3 and 4

Increase AMOD 1.700

DYRCSF.S3

Common solution file for earthquake loads

OUTPUT

jcnlst.s5

Consider Punching Shear greater than 1.00 (Load UC < 1.0)

Basic Allowable Stress

Modification

INPUT


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MISCELLANEOUS

PILINP.S6

Basic model using sacinp.s1

LCOMB consist of response from each pile/leg

(taken from element stress member detail)

LCSEL only for pile response (PILE)

Increase AMOD 1.700

PSIINP.OPR

Original soil data using psiinp.opr

PILE ANALYSIS

INPUT


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MISCELLANEOUS

OUTPUT

psilist.s6

Consider Safety Factor Pile greater than 1.0 (SF > 1.0)

Consider Pile Below Mudline Stress Ratio greater than 1.0 (UC < 1.0)

PILE ANALYSIS

Taken from member stress analysis for each pile head

PILE INPUT (SACINP.PIL)


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MISCELLANEOUS

CONCLUSION

Member Unity Checks Ratio (UC < 1.0)

Joint Punching Shear Ratio (Load UC < 1.0)

Safety Factor of Pile (SF > 1.0)

Pile Below Mudline Stress Ratio (UC < 1.0)

F I N

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