This paper outlines a methodology to assess the seismic drift of reinforced concrete buildings with limited structural and geotechnical information. Based on the latest and the most advanced research on predicting pot...This paper outlines a methodology to assess the seismic drift of reinforced concrete buildings with limited structural and geotechnical information. Based on the latest and the most advanced research on predicting potential near-field and far field earthquakes affecting Hong Kong, the engineering response spectra for both rock and soil sites are derived. A new step-by-step procedure for displacement-based seismic hazard assessment of building structures is proposed to determine the maximum inter-storey drift demand for reinforced concrete buildings. The primary information required for this assessment is only the depth of the soft soil above bedrock and the height of the building. This procedure is further extended to assess the maximum chord rotation angle demand for the coupling beam of coupled shear wall or frame wall structures, which may be very critical when subjected to earthquake forces. An example is provided to illustrate calibration of the assessment procedure by using actual engineering structural models.展开更多
Due to excessive displacements of tall buildings occasioned by lateral loads, lateral load resisting systems are usually provided to curtail the load effect. The resistance may be offered by Frame Action, Shear Walls,...Due to excessive displacements of tall buildings occasioned by lateral loads, lateral load resisting systems are usually provided to curtail the load effect. The resistance may be offered by Frame Action, Shear Walls, or combined Walls and Frames (also known as Dual System). In this study, finite element based software, ETABS, was used to generate and analyse three-dimensional building models for the assessment of the relative effectiveness of the various lateral load resisting systems. Three models were used, one each for the three resisting systems. Each model consisted of three samples representing three different building heights of 45 m, 75 m, and 99 m. Wind Design Spreadsheet complying with the appropriate British Standards was used to compute preliminary wind load coefficients using the wind speed values from the relevant wind isopleth map of Nigeria as primary data. Lateral wind load was then applied at floor levels of each of the building samples. Each building sample was subjected to three-dimensional analysis for the determination of both the lateral displacements of storey tops and interstorey drifts. The results of the work showed that the dual system was the most efficient lateral-load resisting system based on deflection criterion, as they yielded the least values for lateral displacements and inter-storey drifts. The moment frame was the least stiff of the resisting systems, yielding the highest values of both the lateral displacement and the inter-storey drift.展开更多
The present study investigates the vulnerability assessment of the prototype revised Mandatory Rule of Thumb(MRT)buildings initially designed and detailed for three storeys bare frame building;later modified through v...The present study investigates the vulnerability assessment of the prototype revised Mandatory Rule of Thumb(MRT)buildings initially designed and detailed for three storeys bare frame building;later modified through variable number of storeys(three,four,and five)and different arrangement of infill walls(bare frame,soft-storey,irregular infilled,and fully infilled).The application of infill walls increases the fundamental frequencies,stiffness,and maximum strength capacity,but reduces the deformation capability than the bare frame building.The vulnerability was also reduced through infill walls,where the probability of exceeding partial-collapse and collapse damage reduced by 80% and 50%,respectively.Furthermore,the increased in storeys(three to five)also increases the failure probability,such that partial-collapse and collapse for fully infilled increases by almost 55% and 80%,respectively.All obtained results and discussions concluded that the structural sections and details assigned for MRT building is not sufficient if considered as bare frame and soft-storey.And increase in number of storeys causes building highly vulnerable although the infill walls were considered.展开更多
基金the Research Grants Council of Hong Kong Under Project No. HKU 7023/99E and HKU 7002/00EThe Ministry of Science and Technology of PRC and The Bureau of Science and Technology of Guangzhou Under Project No. 2004CCA03300 and No.2004Z1-E0051
文摘This paper outlines a methodology to assess the seismic drift of reinforced concrete buildings with limited structural and geotechnical information. Based on the latest and the most advanced research on predicting potential near-field and far field earthquakes affecting Hong Kong, the engineering response spectra for both rock and soil sites are derived. A new step-by-step procedure for displacement-based seismic hazard assessment of building structures is proposed to determine the maximum inter-storey drift demand for reinforced concrete buildings. The primary information required for this assessment is only the depth of the soft soil above bedrock and the height of the building. This procedure is further extended to assess the maximum chord rotation angle demand for the coupling beam of coupled shear wall or frame wall structures, which may be very critical when subjected to earthquake forces. An example is provided to illustrate calibration of the assessment procedure by using actual engineering structural models.
文摘Due to excessive displacements of tall buildings occasioned by lateral loads, lateral load resisting systems are usually provided to curtail the load effect. The resistance may be offered by Frame Action, Shear Walls, or combined Walls and Frames (also known as Dual System). In this study, finite element based software, ETABS, was used to generate and analyse three-dimensional building models for the assessment of the relative effectiveness of the various lateral load resisting systems. Three models were used, one each for the three resisting systems. Each model consisted of three samples representing three different building heights of 45 m, 75 m, and 99 m. Wind Design Spreadsheet complying with the appropriate British Standards was used to compute preliminary wind load coefficients using the wind speed values from the relevant wind isopleth map of Nigeria as primary data. Lateral wind load was then applied at floor levels of each of the building samples. Each building sample was subjected to three-dimensional analysis for the determination of both the lateral displacements of storey tops and interstorey drifts. The results of the work showed that the dual system was the most efficient lateral-load resisting system based on deflection criterion, as they yielded the least values for lateral displacements and inter-storey drifts. The moment frame was the least stiff of the resisting systems, yielding the highest values of both the lateral displacement and the inter-storey drift.
文摘The present study investigates the vulnerability assessment of the prototype revised Mandatory Rule of Thumb(MRT)buildings initially designed and detailed for three storeys bare frame building;later modified through variable number of storeys(three,four,and five)and different arrangement of infill walls(bare frame,soft-storey,irregular infilled,and fully infilled).The application of infill walls increases the fundamental frequencies,stiffness,and maximum strength capacity,but reduces the deformation capability than the bare frame building.The vulnerability was also reduced through infill walls,where the probability of exceeding partial-collapse and collapse damage reduced by 80% and 50%,respectively.Furthermore,the increased in storeys(three to five)also increases the failure probability,such that partial-collapse and collapse for fully infilled increases by almost 55% and 80%,respectively.All obtained results and discussions concluded that the structural sections and details assigned for MRT building is not sufficient if considered as bare frame and soft-storey.And increase in number of storeys causes building highly vulnerable although the infill walls were considered.
