软土地区超高层建筑岩土工程关键问题及沉降控制研究

Research on key problems of geotechnical engineering and settlement control of super-high-rise buildings in soft soil area

以上海中心大厦为例,对软土地区超高层建筑桩型选择、桩基承载力计算、沉降计算参数取值及沉降计算等岩土工程关键技术问题进行了总结和研究。超高层荷载大,对桩基承载力要求高,桩型选择需结合周边环境、桩基承载力要求、施工可行性等因素综合考虑后确定,软土地区超高层建筑采用后注浆大直径超长灌注桩是适宜的。超高层建筑基础沉降要求高,需结合地层条件、结构特点、荷载分布情况、周边环境等因素综合考虑,确定沉降计算参数及计算方法。经采用多种计算方法进行沉降预测,塔楼沉降量估算值为75~120 mm,最终实测总沉降量约100 mm,有限元法的预测结果与实测值更为吻合,其中结构封顶时沉降量占最终沉降量的90%左右,沉降变形主要发生在工程建设期间。

Drawing on the Shanghai Tower as a case study,this article delves into critical geotechnical considerations for super-highrise buildings constructed on soft soil,encompassing pile type selection,bearing capacity calculation,settlement calculation,and more.Given the substantial loads exerted by super-high-rise structures,pile bearing capacity assumes paramount importance.The selection of pile types necessitates a thorough evaluation,weighing factors such as environmental conditions,load-bearing requirements,and construction feasibility.In soft-soil regions,large-diameter and super-long bored piles with delayed-grouting emerge as the preferred choice.Given the stringent settlement requirements for super-high-rise buildings,settlement calculations demand meticulous attention,encompassing variables such as strata conditions,structural attributes,load distribution,and environmental factors.By adopting several different methods,the calculated value of settlement of the tower ranges from 75 to 120mm,while the measured value is around 100mm.Comparatively,predictions from finite element method(FEM)exhibit greater alignment with measured values,the settlement at the period of structural capping accounted for about 90%of the total settlement,and the foundation settlement mainly occurred during the construction.