基坑工程降水对复合地基变形的影响

Discuss on issues about composite foundation settlement caused by groundwater lowering

由深基坑工程土方开挖引起的周围土体水平位移和竖向位移通常与基坑降水引起的变形耦合在一起,使得降水引起的土体变形研究变得复杂。选取郑州市数十例基坑工程支护结构实测变形很小的降水工程,用稳定流理论分析降水引起的沉降范围;然后,以半理论、半统计方法研究了降水引起的地基变形的计算方法。由于土体结构复杂,且准确的参数确定尚有困难,建议的沉降计算方法还有一定的局限性。

Usually the composite foundation settlement consists of two parts: one results from the excavation of pit, the other is caused by the groundwater lowering. It is difficult to separate one from the other. Dozens of practical cases, whose deformation of pit retaining system are small enough, are studied in detail by the principle of stable flow theory. The radius of settlement crateriform is determined first, then, the maximum settle calcuation formula is put forwards. Calibration by typical project analysis shows the condition for the suggested formula.