承压水作用下条形基坑坑底整体加固厚度研究

在承压水作用下的基坑工程中常面临着坑底突涌问题,传统的突涌分析方法只考虑了坑底隔水层土重的影响,而忽略了该土层的抗剪强度对坑底抗突涌的作用,尤其对于坑底在加固后具有强度较之原状土已大大提高的水泥土时,其结果显得更加过于保守。通过对基坑突涌分析的简化假设并结合工程实例,讨论了用水泥搅拌桩对条形基坑进行整体加固时,用同时控制水泥土的抗剪和抗隆起双重指标来确定所需加固厚度的方法,还提出通过同时考虑降水,以适当减少加固厚度,实现方案的最优化,并给出了使用该方法的建议和适用范围。

Study on the Thickness of Entirety Stabilization in the Bottom of Strip Pit under Confined Water Pressure

Under the confined water pressure, how to control bottom piping in the foundation pit engineering becomes a common problem. Traditional analysis method only involves the gravity of the upper impermeable stratum while shear strength of it is ignored, which leads the result to be too conservative, especially when foundation pit bottom is consolidated by cemented soil whose strength is far more than the original soil. Based on simplified assumption of bottom piping analysis and practical project, the method to establish the suitable thickness of entirety stabilization by cement mix pile is studied in this paper, which considers both shear resistance and heave resistance. It also presents that using dewatering method can properly reduce the stabilization thickness at the same time to get the optimized scheme. Meanwhile, some advice and the applicable range are given about the method.