关于基础设计中地下水浮力问题的思考

Thoughts on uplift pressure of underground water in foundation design

在参阅文献的基础上,对抗浮设防水位、地下水浮力计算的部分地方经验进行了汇总对比,指出要对勘察建议的抗浮设计参数作必要的判断与调整。结合工程案例分析,建议应结合具体情况考虑采用被动抗浮措施还是主动抗浮措施,并尽可能了解施工阶段和使用阶段抗浮稳定的各种工况,进而有针对性地采取结构抗浮措施。探讨了抗拔构件设计中安全系数取值、裂缝验算等重要问题。分析了地下水位变化对天然地基、复合地基和桩基安全度的影响,指出沿海地区的高层建筑往往具备利用有利水浮力的条件,补充了合理利用地下水浮力的具体设计建议。

Based on relevant publications, experiences in difference areas were summarized and compared about anti-floating fortification groundwater level and evaluation of uplift pressure of underground water. Parameters from geotechnicalinvestigation report were recommended to be carefully verified before considering anti-floating strategies. Based on casestudies, it was suggested that the use of passive anti-floating measures or active anti-floating measures should be combinedwith the specific circumstances. All potential anti-floating loading cases in construction stage and service stage should betaken into account to carry out proper anti-floating measures accordingly. Important issues in uplift component design werediscussed, such as safety factor and crack calculation. Impacts of groundwater level change on safety degree of naturalsubgrade, composite foundation and pile foundation were demonstrated. It was pointed out that high-rise buildings in thecoastal area could take the advantage of beneficial uplift pressure. Detailed design suggestions on the reasonable utilizationof groundwater uplift pressure were given.