The Structural Design of Tall and Special Buildings

UY, B; DAS, S

doi: 10.1002/(SICI)1099-1794(199703)6:1<1::AID-TAL78>3.0.CO;2-Kpmid: N/A

This paper considers the time dependent effects of creep and shrinkage of concrete in a fabricated steel box column typically used in tall building construction. The effects of creep and shrinkage on the behaviour of the steel box are considered using the age adjusted effective modulus method. The analysis has been undertaken to include incremental loading to simulate the construction of individual floor levels in a building. A parametric study has been developed to consider the effects of various material and geometric properties as well as the number of constructed levels of the building. A study of the strain and stress distribution is undertaken and a numerical model for the determination of the axial shortening is developed. Recommendations for further research to be undertaken including full‐scale experiments and material property testing are suggested in order to augment the minimal research data available. © 1997 John Wiley & Sons, Ltd.

PARK, HYO SEON; PARK, CHIL LIM

doi: 10.1002/(SICI)1099-1794(199703)6:1<23::AID-TAL80>3.0.CO;2-1pmid: N/A

The use of displacement participation factors obtained by the unit load method provides an effective drift control tool for high‐rise buildings. Structural sensitivity coefficients and displacement participation factors for members in a structure with respect to the lateral displacement to be controlled are computed and used for identifying active members and their corresponding displacement components. The drift control method using the displacement participation factors with a variable linking strategy is formulated into an optimization problem to determine the amount of material to be modified. Using the drift control method, a structural design model for a high‐rise building is proposed and applied to one verifying example and two moment resisting frames. Time consuming trial‐and‐error processes related to the structural design of a high‐rise building is avoided by the proposed structural design model. As demonstrated in the examples, the maximum lateral displacements of the examples are reduced by 57·05, 40·0 and 16·36% without changing the total weights of the structures. © 1997 John Wiley & Sons, Ltd.

HART, GARY C.; HUANG, SAMPSON C.; LOBO, ROY F.; JAIN, ANURAG; VAN WINKLE, MATTHEW

doi: 10.1002/(SICI)1099-1794(199703)6:1<37::AID-TAL83>3.0.CO;2-Mpmid: N/A

This paper presents the response of steel moment resisting frames with damage to their welded connections for two repair options: (1) reweld only; and (2) reweld and strengthen connection. Two different nonlinear dynamic analysis programs are used to research the effect of repairing and strengthening these weld failures and also for predicting the expected building response assuming that the connection is not repaired. The effect on response is studied for connections where weld failure reduces the capacity to 50, 20 and 5% of the original moment capacity. The frames selected for the research are in a real building damaged during the Northridge earthquake. They are subjected to an ensemble of artificial earthquake records that have an equal probability of occurring at the site for comparative studies. © 1997 John Wiley & Sons, Ltd.

KAPPOS, ANDREAS J.

doi: 10.1002/(SICI)1099-1794(199703)6:1<59::AID-TAL85>3.0.CO;2-8pmid: N/A

Two regular R/C ten‐storey buildings, a frame and a dual (frame + wall) structure are designed and detailed to the 1985 CEB Seismic Code and to the 1995 Eurocode 8, for a design acceleration of 0·25g and the medium ductility level. The two designs are first compared in terms of cost of materials; then their inelastic response to a number of accelerograms normalized to various earthquake intensities, corresponding to different limit states, is analysed. The resulting demands on each building for each earthquake intensity are checked against the corresponding capacities both at the member and at the storey level, thus allowing an assessment of their seismic performance to be made. A superior performance is found in the Eurocode designed structures, especially the frame structure, which is characterized by adequate drift control even under the maximum credible (‘survival’) earthquake; however, a significant difference in the seismic reliability of column critical regions and the remaining parts of the stuctures has to be pointed out. © 1997 John Wiley & Sons, Ltd.