Seismic Aspects Of Foundation Analysis For High-Rise Buildings

[[abstract]]建築物耐震分析為地震帶地區結構設計之重要工作，建築物基礎與土壤於地震情況之行為及分析更為上部結構安全之基石。本文主要探討以基樁為高層建築物基礎於地震力作用下之分析模式，於一般建築物之基樁基礎建議採用擬靜態方法(Pseudo-Static Analysis)分析，並配合上部結構地震橫力求取與樁基礎之非線性分析方法(包括t-z曲線與p-y曲線等方法)進行。另建築物於地震力作用下因土壤液化導致基礎沉陷，或無液化現象之土壤於地震情況下發生壓縮沉陷，其沉陷量評估亦於本文中討論。文中亦舉實際案例說明建築物基礎於地震情況下之分析考慮。[[abstract]]Dynamic structural analysis is important and necessary for buildings at seismic area. Also, analysis of foundation and soil subjected to seismic forces is considered fundamental for safety of superstructure of buildings. This paper focuses primarily on the methodology of seismic analysis of piles for supporting high-rise buildings. Pseudo-static approach is recommended for analysis of piles subjected to seismic forces. Lateral forces on superstructure induced by seismic activity are taken into account along with nonlinear analysis of soil surrounding the piles, including t-z curves and p-y curves. On the other hand, liquefaction of foundation soils, which may result in settlement, may be triggered under seismic conditions. Dynamic settlement may also take place even for soils with no liquefaction. Methodologies for evaluation of seismic settlements are discussed in this paper. Finally, case studies for seismic analysis of foundation piles and for evaluation of seismic settlement for buildings are discussed