numerical analaysis of fire in a 24 story structure

7/28/2019 Numerical Analaysis of Fire in a 24 Story Structure

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ANALYSIS OF WIND LOADING ONMULTISTOREY STRUCTURE

Christian ZimmermanDaniel Brand

Mohamad JamalMonzer Moutasallem


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INTRODUCTION


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6m by 6m CentrallyLocated Shear Wall

24 Storey Building

50m by 50m


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Monzer and I (Mohamad) Theory

Daniel

Method

Christian

Discussion of Results


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WIND


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+ Positive Pressure + - Negative Pressure -


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Shear Wall


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Distortion and Grading in strand7


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METHOD


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Step 1: Create initial nodes and elements for

column


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6.25m 6.25m12.5m 12.5m 12.5m

12.5m

Step 2: Copy columns by increment


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Step 3: Connect columns with plate elements


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6.25m

6.25m

12.5m

12.5m

12.5m

Step 4: Copy rows by increment


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Step 5: Copy rows to create grid


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Step 6: Remove corner column and delete

exterior plate element


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Step 7: Create floor slab mesh with Quad4


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Step 8: Subdivide floor slab and beam mesh


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Step 9: Delete slab mesh in location of shear

core


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Step 10: Create beam element on the interior

perimeter of shear core


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Step 11: Extrude beam by increment


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Step 12: Subdivide shear core


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Step 13: Extrude column nodes by increment


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Step 14: Add restraints at the base of column dx,

dy, dz and rz (torsion) to simulate a pin joint


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Step 15: Define material properties & geometry


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Step 16: Create load cases and add gravity


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Step 17: Add live load


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Step 18: Run linear static solver to determine if

model is working and if reasonable results


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Step 19: Remove restraints, copy levels and add

restrains on bottom and test


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Step 20: Add wind load and test

Wind = -(z+4)*(12.5)*(1.2/24)


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Step 21: Create raft mesh by Quad4, extrude by

increment and define material property


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Step 22: Remove column restraints, add raft

restraints and test


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Step 23: Create soil mesh by Quad4, extrude by

increment and define material property


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Step 24: Remove raft restraints, add soil

restraints and test


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Step 25: Create 24 floors, update wind load as well as raftdepth and refined soil and raft mesh further into 3x3x3


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RESULTS & DISCUSSION


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Gravity Load Soil settlement due to self

weight

Differential displacement

relative to initial position

Small displacement in shear coredue to interior beams carrying

load


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Live Load Similar loading pattern within

structure to gravity case

No soil settlement beyond raft

slab as live load


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Wind Load

No soil settlement as with live load

Key consideration is now x

displacement


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Wind Load

Both uplift and settlement

occurring in both raft and

floor slabs

No soil cohesion results in raftslab lifting independently

Shear Core acting like

Cantilever


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Combination Load

Gravity and live loads overcome uplift due towind loading (no +ve plate displacement)

Soil settlement dependent on gravity loading

hence similar results (brick displacement)

Horizontal displacement only dependent onwind loading hence similar results


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THANK YOU

ANY QUESTIONS?

numerical analaysis of fire in a 24 story structure

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