Ubc Seismic Calculations

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Seismic Calculations for UBC 1997 Static Process for Regular Buildings

Dear ETABS users, this is coolest bliss and in this tutorial we will solve an exam

then well compare it with ETABS. Remember, it is a very simple example, just

ETABS new users.

In the following pages, you will see some pictures and notes.

To understand this example, you will need at hand following things:-

1- UBC Seismic Calculation Sheet; CB Seis Ver 2.0 Download it.

Excel-2007 Format or Excel-2003 Format

If you want Visual Basic .EXE file download it from here.

2- UBC-97 Code (Chapter 16)

3- ETABS (Version 9.5.0)

And of course, A GOOD BRAIN.:-)


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We will

with the

*2D mo

*24ft wi

*12ft hig


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24x24

Bays


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2-Select

beam

option

3-Draw beam from

grid B to grid C as

shown

4-Select

draw

column

option

5-Draw 2

columns

here.


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1-Select

elevation

shortcut. 2-Goto

Elevation


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Selectthis line

and

delete.


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Goto this

option


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Make self weight multiplier "ZE

neglect self weights.


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Select MASS SOURCE

OPTION


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1-Select "FROM LOADS" beca

put any additional mass in this

no self weight...We will only pu

select this option.

2-Enter these v

because we wa

seismic weight

DL + 25% LL(See UBC code


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Select all 4

"4 LINES

SELECTED"


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Put 2 kip/ft as DL towards

GRAVITY. Other values should

be as shown.


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Keep all other

options same as

that of DL in

previous step and

put 1 kip/ft as LIVE

LOAD


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Goto DEFINE>STATIC LO

and define two new cases

1-EQX as QUAKE accordin

and

2-EQY as QUAKE accordin


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For EQX put all

values as shown in

form


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Similarly for EQY...everything same,

except the direction....

(YOU CAN EVEN OMIT THIS EQY

LOAD CASE because we will run

our model as 2D only in XZdirection.

Our model coordinates...

XY...as 2D


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Cl


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UNCHECK

DYNAMIC &

PDELTA

OPTIONS..

Sel

XZ


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SAVEYOUR

MODEL


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RUNANALYSIS


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DEFLECT

EQX

1-

sh

be


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Select

STORY

SHEARS


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12 ft

For each storey

DL = 2x24 = 48 KIP

and

LL = 1x24 = 24 KIP

Before going to next step. Fill all

in this sheet

Note

these

two

values


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Forget

about TOP

& BOTTOM

location..

they are

same in this

example

compare THICK RED CIRCLE storey

shears with excel sheet...storey

shear...they are same!


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Compare!

Display>Story Response Plots


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Check story shear this time


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Show reactions

for EQX


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This time...check

storey moment with

EXCEL SHEET


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1-Right

click on

oint

Value of DELTA S.you have to put this

value in excel sheetStory drift ratio = St

drift / Story Height


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This is the

value of delta

S.


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This is

the valueof story

drift ratio


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Building Location: Pasrur, District Sialkot, Pakistan

Seismic Zone: II-B Soil Profile Type: SD

Seismic Zone Factor Z: 0.2

Seismic Coefficients

Ca: 0.28 Na: 0

Cv: 0.4 Nv: 0

No. of Storeys: 4 Importance Factor: 1

Building Height: 48 Ct : 0.02

Building Period: 0.36 Response Factor: 5.5

Building Dead Load: 192 Building Live Load: 96

Seismic Weight, W = 1 x DL + 0.25 x LL = 216

Eq 30-4: 43 Design Base Shear: 27

Eq 30-5: 27 Ft: 0

Eq 30-6: 7

Example-1

30-Sep-10

UBC Seismic CalculationsPrepared By: coolest bliss Job:

SITE DATA

BUILDING DATA

LOADING

BASE SHEAR

Checked By: - Date:

CB Seis. Ver 1.0

In ut data rinted from excel sheet


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CB Seis. Ver 1.0

Building / Frame Data

Height

h

Dead

Load

DL

Live Load

LL

Seismic

Weight

wx

Total

Height

hx

wx.hx

Lateral

Force

Fx

Storey

Shear

Vx

s Overturning

Moment

Storey

Drift

Drift

Limit

ft kip kip kip ft kip-ft kip kip in kip-ft in in

48.00 192 96 216 6480 27.49 82

Storey 1 12.00 48 24 54 12.00 648 2.75 27 0.40396 660 0.40396 3.60 OK 0.00281

Storey 2 12.00 48 24 54 24.00 1296 5.50 25 0.62030 363 0.21635 3.60 OK 0.00150

Storey 3 12.00 48 24 54 36.00 1944 8.25 19 0.76972 132 0.14942 3.60 OK 0.00104

Storey 4 12.00 48 24 54 48.00 2592 11.00 11 0.85990 0 0.09018 3.60 OK 0.00063

Storey

Drift

Ratio

UBC Seismic Calculationscoolest bliss

-

Example-1

30-Sep-10

Job:

Date:

Prepared By:

Checked By:

LevelDrift

Check

Calculate


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file:///C|/Documents%20and%20Settings/waseem.sarwar/Desktop/New%20Folder/Static.txt

ETABS v9.5.0 File:STATIC Units:Kip-ft September 30, 2010 9:21 PAGE 1

PROJECT INFORMATION

Company Name = Omrania & Associates


S T O R Y D A T A

STORY SIMILAR TO HEIGHT ELEVATION

STORY4 None 12.000 48.000

STORY3 STORY4 12.000 36.000

STORY2 STORY4 12.000 24.000

STORY1 STORY4 12.000 12.000

BASE None 0.000


S T A T I C L O A D C A S E S

STATIC CASE AUTO LAT SELF WT NOTIONAL NOTIONAL

CASE TYPE LOAD MULTIPLIER FACTOR DIRECTION

DEAD DEAD N/A 0.0000

LIVE LIVE N/A 0.0000

EQX QUAKE UBC97 0.0000

EQY QUAKE UBC97 0.0000


A U T O S E I S M I C U B C 9 7

Case: EQX

AUTO SEISMIC INPUT DATA

Direction: XTypical Eccentricity = 5%

file:///C|/Documents%20and%20Settings/waseem.sarwar/Desktop/New%20Folder/Static.txt (1 of 6) [9/30/2010 11:12:36 AM]


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Eccentricity Overrides: No

Period Calculation: Program Calculated

Ct = 0.02 (in feet units)

Top Story: STORY4Bottom Story: BASE

R = 5.5

I = 1

hn = 48.000 (Building Height)

Soil Profile Type = SD

Z = 0.2

Ca = 0.2800

Cv = 0.4000

AUTO SEISMIC CALCULATION FORMULAS

Ta = Ct (hn^(3/4))

If Z >= 0.35 (Zone 4) then: If Tetabs


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V (Eqn 4) = 0.0465W

V Used = 0.1273W = 27.49

Ft Used = 0.00

AUTO SEISMIC STORY FORCES

STORY FX FY FZ MX MY MZ

STORY4 11.00 0.00 0.00 0.000 0.000 -527.825

STORY3 8.25 0.00 0.00 0.000 0.000 -395.869

STORY2 5.50 0.00 0.00 0.000 0.000 -263.913

STORY1 2.75 0.00 0.00 0.000 0.000 -131.956


A U T O S E I S M I C U B C 9 7

Case: EQY

AUTO SEISMIC INPUT DATA

Direction: Y

Typical Eccentricity = 5%

Eccentricity Overrides: No

Period Calculation: Program Calculated

Ct = 0.02 (in feet units)

Top Story: STORY4Bottom Story: BASE

R = 5.5

I = 1

hn = 48.000 (Building Height)

Soil Profile Type = SD

Z = 0.2

Ca = 0.2800Cv = 0.4000



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AUTO SEISMIC CALCULATION FORMULAS

Ta = Ct (hn^(3/4))

If Z >= 0.35 (Zone 4) then: If Tetabs


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M A S S S O U R C E D A T A

MASS LATERAL LUMP MASS

FROM MASS ONLY AT STORIES

Loads Yes Yes

M A S S S O U R C E L O A D S

LOAD MULTIPLIER

DEAD 1.0000

LIVE 0.2500


A S S E M B L E D P O I N T M A S S E S

STORY UX UY UZ RX RY RZ

STORY4 1.678E+00 1.678E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00

STORY3 1.678E+00 1.678E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00

STORY2 1.678E+00 1.678E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00

STORY1 1.678E+00 1.678E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00

BASE 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00

Totals 6.713E+00 6.713E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00


MODAL INFORMATION

Modal Analysis not done.


TOTAL REACTIVE FORCES (RECOVERED LOADS) AT ORIGIN

LOAD FX FY FZ MX MY MZ



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DEAD 4.441E-16 0.000E+00 1.920E+02 9.216E+03 -6.912E+03 -1.421E-14

LIVE 2.220E-16 0.000E+00 9.600E+01 4.608E+03 -3.456E+03 -7.105E-15

EQX -2.749E+01 0.000E+00 0.000E+00 0.000E+00 -9.897E+02 1.320E+03

EQY 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00


S T O R Y F O R C E S

STORY LOAD P VX VY T MX MY

STORY4 EQX 1.776E-15 -1.100E+01 0.000E+00 5.278E+02 5.684E-14 -1.320E+02

STORY3 EQX 3.020E-14 -1.924E+01 0.000E+00 9.237E+02 1.478E-12 -3.629E+02

STORY2 EQX 2.132E-14 -2.474E+01 0.000E+00 1.188E+03 9.095E-13 -6.598E+02

STORY1 EQX 0.000E+00 -2.749E+01 0.000E+00 1.320E+03 0.000E+00 -9.897E+02

STORY4 EQY 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00

STORY3 EQY 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00

STORY2 EQY 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00

STORY1 EQY 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00


STORY DRIFTS

STORY DIRECTION LOAD MAX DRIFT

STORY4 X EQX 1/1597

STORY3 X EQX 1/964

STORY2 X EQX 1/666

STORY1 X EQX 1/356

Ubc Seismic Calculations

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