Development and Application of OpenSees for a RC Frame in Fire

Speaker: Jian Zhang

1 Fire Following Earthquake

San Francisco earthquake, 1906 Kobe earthquake, 1995

Fire following an earthquake is an important factor causing damage to buildings and life-line structuresIt is important to understand the behaviour of structures subjected to post-earthquake fires.

2 Experiment in India 

3000

1500

1300

Raft top Raft top

500

Ventilationopening

Fire level/Topof beam

Typical column,300 x 300

Plinth beam,230 x 230

Footing,1100 x 1100 x 500

Bricked box container filledwith sand with fuel tray on top

(level with the top of beam)

Roof slab120 thk

Roof beam230 x 230

Steel framingsystem

Simulated gravityloading of 2nd and 3rdabove floor

Superimposed live loadon floor 1

Extendedcolumn

Reactionwall

4300

5000

Hydraulicjack

Thermocouples at fivedifferent elevation levelsin three plan locations offire compartment

Understanding of the mechanics of the response of earthquake damagedstructures subjected to fire

Understanding behaviour of structural materials subjected to fire after damage and to develop constitutive laws for programming into computational models

3 OpenSees- An open source, object oriented software framework

Development

Thermal action (thermal load) Material Section-Force deformation Element

Test the new modulesModelling an experiment

Steel frame (ZSR1) tested and analyzed by Rubert0 100 200 300 400 500 600

0.005

0.010

0.015

0.020

0.025

0.030

0.035

0.040

0.045

Model, U1, with St 37 Model, U2, with St 37 Tested, U1 Tested, U2

u1

u2

Temperature of the left bay (ºC)

Dis

plac

emen

t (m

)

-100 -80 -60 -40 -20 0 20 40 60 80 100

-300

-200

-100

0

100

200

300

Rea

ctio

n Lo

ad (k

N)

Horizontal Displacement (mm)

node 1

0 200 400 600 800 1000-20

-15

-10

-5

0

5

10

15

Hor

izon

tal d

ispl

acem

ent (

mm

)

Temperature at the edge of the beam toward fire (C)

node 1 node 2

0 200 400 600 800 1000-6

-4

-2

0

2

4

6

8

10

Mid

-spa

n de

flect

ion

(mm

)

Temperature at the edge of the beam toward fire (C)

node 3

4 Modelling the experiment