地下建筑抗浮设计新方法——消除浮力法的工程实践与探讨

Engineering practice and discussion on a new anti-floating design method of underground buildings

传统地下建筑抗浮设计大多采用被动抗浮模式,需要设置大量的抗拔桩或相当数量的压重来平衡基底的水浮力,不仅建造成本高,而且对施工和使用期间抗浮水位的取值很敏感,要求数据比较准确,当偶遇暴雨引发的洪涝灾害时,往往容易发生地下室上浮等安全事故。针对传统地下建筑抗浮设计存在成本高、事故多等缺点,本文提出新的抗浮设计方法——消除浮力法,通过在基坑周边设置隔水构件,以及在基底利用反滤层排水,从而对基底渗流水采用疏堵结合的措施,有效消除基底水浮力,该方法属于主动抗浮模式。经过理论分析,消除浮力法不需要抗拔桩或大量压重就能有效解决地下室抗浮的难题。该方法概念清晰、受力明确、安全可靠、经济合理、简便实用,具有很好的工程实际应用价值,并且已经在实际工程中取得了非常好的应用效果。

The traditional anti-floating method of underground buildings mostly adopts passive anti-floating mode. This requires a large number of uplift piles or a considerable amount of weight to balance the water buoyancy at the bottom of the foundation pit. This traditional method is not only expensive, but also sensitive to the anti-floating water level during construction and running. At the same time, the anti-floating water level needs to be accurately determined. When encountering rainstorms, security incidents such as basement floating are often prone to occur. Due to the disadvantages of high cost and potential risks in the traditional anti-floating method of underground buildings, this paper proposes a new anti-floating design method: the method of eliminating buoyancy. In this method, a water blocking member is arranged around the foundation pit, and a reverse filter layer is used on the base to drain water. A combination of dredging and blocking measures is adopted for the seepage water of the basement to effectively eliminate the buoyancy of the basement water. Different from the traditional method, this method is a kind of active anti-floating mode. After theoretical analysis,the eliminating buoyancy method can effectively solve the problem of basement anti-floating without using anti-uplift piles or a large amount of weight. This method has many advantages, such as cost-saving and reliable, simple and practical, and has good practical application in civil engineering. It has achieved very good results in practical projects.