Progressive Collapse of Steel Frames 47

0 10 20 30 40 50 60

Load (Kn/mm

2

)

50

45

40

35

25

20

15

10

5

0

Max. Deflection in mm

Deflection (mm) fro

experimental test

Deflection (mm) from analysis

Figure 29. The maximum lateral deflection for internal co-

lumn removed from the analysis and experimental test.

tion would be measured and get around 35 - 36 mm.

7. Conclusions

Nonlinear finite element models investigating the progre-

ssive collapse of steel frames have been developed and

reported in this paper. The finite element models have

accounted for the nonlinear material of the steel frames

and the nonlinear geometry was also considered. The

investigated steel frames had different geometries and

different damping ratios. Overall, the paper addresses

how multistory frames would behave when subjected to

local damage or loss of a main structural carrying

element. The history behavior of the steel frames defor-

mations and failure modes were investigated and

discussed in this paper. The nonlinear finite element

models accented the nonlinear material and geometry

behavior of the steel frames. The study has shown that:

By increasing damping ratios in dynamic analysis the

maximum lateral deflection decreased for all frames.

The progressive collapse potential decreased as the

number of story increased since more structural mem-

bers participate in resisting progressive collapse.

The nonlinear dynamic analysis method provided a

realistic representation of the progressive collapse be-

havior.

The increase only in the girder size for the purpose of

preventing progressive collapse may result in weak

story when the building is subject to seismic load.

The formation of weak story can be prevented by in-

creasing the column size in such a way that the strong

column-weak beam requirement is satisfied.

The maximum lateral deflection obtained for internal

column-removed case using the 3D-model was slightly

higher (within 2%) than that obtained for internal column-

removed case using the 2D-model.

REFERENCES

[1] R. E. Mc Connel and S. J. Kelly, “Structural Aspects of

Progressive Collapse of Warehouse Racking,” The Struc-

tural Engineer, Vol. 61A, No. 11, 1983, pp. 343-347.

[2] F. Casciati and L. Faravelli, “Progressive Failure for

Seismic Reliability Analysis,” Engineering Structures,

Vol. 6, No. 2, 1984, pp. 97-103.

http://dx.doi.org/10.1016/0141-0296(84)90002-6

[3] A. J. Pretlove, “Dynamic Effects in Fail-Safe Structural

Design,” Proceedings, International Conference on Steel

Structures: Recent Advances and their Application to De-

sign, Budva, 1986, pp. 749-757.

[4] J. L. Gross and W. Mcguire, “Progressive Collapse Re-

sistant Design,” Journal of Structural Engineering, Vol.

109, No. 1, 1983, pp. 1-15.

[5] R. M. Bennett, “Formulation for Probability of Progres-

sive Collapse,” Structural Safety, Vol. 5, No. 1, 1988, pp.

67-77. http://dx.doi.org/10.1016/0167-4730(88)90006-9

[6] A. J. Pretlove, M. Ramsden and A. G. Atkins, “Dynamic

Effects in Progressive Failure of Structures,” Interna-

tional Journal of Impact Engineering, Vol. 11, No. 4,

1991, pp. 539-546.

[7] E. M. Smith, “Alternate Path Analysis of Space Trusses

for Progressive Collapse,” Journal of Structural Engi-

neering, Vol. 114, No. 9, 1988, pp. 1978-1999.

http://dx.doi.org/10.1061/(ASCE)0733-9445(1988)114:9(

1978)

[8] R. B. Malla and B. B. Nalluri, “Dynamic Effects of

Member Failure on Response of Truss Type Space Struc-

ture,” Journal of Spacecrafts and Rockets, Vol. 32, No. 3,

1995, pp. 545-551. http://dx.doi.org/10.2514/3.26649

[9] K. Abedi and G. A. R. Parke, “Progressive Collapse of

Single-Layer Braced Domes” International Journal of

Space Structures, Vol. 11, No. 3, 1996, pp. 291-306.

[10] J. R. Gilmour and K. S. Virdi, “Numerical Modeling of

the Progressive Collapse of Framed Structures as a Result

of Impact or Explosion,” 2nd International PhD Sympo-

sium in Civil Engineering, 1998.

[11] G. Kaewkulchai and E. B. Williamson, “Dynamic Be-

havior of Planar Frames during Progressive Collapse”.

16th ASCE Engineering Mechanics Conference, Univer-

sity of Washington, Seattle, 2003.

[12] G. Kaewkulchai and E. B. Williamson, “Beam Element

Formulation and Solution Procedures for Dynamic Pro-

gressive Collapse Analysis,” Computers and Structures,

Vol. 82, No. 7-8, 2004, pp. 639-651.

http://dx.doi.org/10.1016/j.compstruc.2003.12.001

[13] K. Khandelwal and S. El-Tawil, “Collapse Behavior of

Steel Special Moment Resisting Frame Connections,”

Journal of Performance of Constructed Facilities, Vol.

113, No. 5, 2007, pp. 646-665.

[14] J. Kim and J. Park, “Design of Steel Frames Considering

Progressive Collapse,” Steel and Composite Structures,

Vol. 8, No. 1, 2008, pp. 85-98.

http://dx.doi.org/10.12989/scs.2008.8.1.085

[15] GSA, “Progressive Collapse Analysis and Design Guide-

lines for New Federal Office Buildings and Major Mod-

ernization Projects,” The US General Services Admini-

stration, 2003.

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