建筑物抗浮设防水位及浮力的计算

Calculation of Water Level for Prevention of Up-Floating and Buoyancy of Buildings

高层建筑地下停车场、地下商店、下沉式广场以及城市公共管廊等近年来在城市中大量兴建,其特征是"超补偿式基础",建筑面积大,基坑开挖深,挖土卸载大,而结构自身荷载相对较小,在地下水位较高时,抗浮成了重要问题。而抗浮设计是一个复杂的综合性课题,国家标准对如何确定抗浮设防水位的规定是原则性和指导性的,其取值过高或过低将直接影响地下工程的经济性和安全性[1,2,3]。本文对几本标准对地下水抗浮计算原则、地方标准抗浮设防水位确定方法进行阐述和对比,结合一些学者的研究成果和观点对抗浮设防水位的确定方法及水头折减等问题进行探讨。

High-rise buildings underground parking lot, underground shops,sunken square and city public corridor have been numerously built in the city in recent years, which is characterized by 'super-compensation foundation',large building area,depth excavation of foundation pit,large excavation unloading,and the structure itself is relatively small load; when the groundwater level is high,anti-floating has become an important issue. However the anti-floating design is a complex and comprehensive project,the national standard on how to determine the anti-floating water level requirements are principle and guidance,if the value is too high or too low, it will directly affect the economical efficiency and safety of underground engineering. This paper expounds and compares several national standards for groundwater anti-floating calculation principle and the determination method of local standard for water level for prevention of up-floating,combines with some scholars' research results and views against the determination method water level for prevention of up-floating and waterhead reduction issues.