西北地区地铁基坑降水对周围环境影响的计算方法

Study on calculation method of effect of subway foundation pit dewatering on surrounding environment in northwest China

为保证西北地区地铁建设的顺利进行,通过对西安和兰州的地铁车站深基坑降水工程进行研究分析,总结地铁车站深基坑降水引发基坑周围地面沉降变形的附加沉降估算公式和考虑渗流力作用的沉降计算公式,并结合实际工程对两种理论计算结果与实测沉降结果进行对比分析.结果表明:附加沉降估算公式的计算结果相对于实测沉降结果偏保守,应代入经验系数使结果更符合实际情况;考虑渗流力作用的沉降计算公式相比于附加沉降估算公式在精度上有很大提高,与实测沉降结果较为接近,可作为西北地区地铁基坑降水对周围环境影响的计算公式.

In order to ensure the smooth construction of subway in northwest China,the deep foundation pit dewatering projects of subway stations in Xi’an and Lanzhou are studied and analyzed,and the additional settlement estimation formula for the ground settlement deformation around the foundation pit caused by the deep foundation pit dewatering of the subway station is summarized and the seepage is considered.The settlement calculation formula under the action of force,combined with the actual project,compares the two theoretical calculation results with the measured settlement results.The results show that the calculation results of the additional settlement estimation formula are conservative compared to the actual measured settlement results,and empirical coefficients should be brought in to make the results to match the actual situation better.The accuracy of settlement calculation formula considering the seepage force is greatly improved in comparison with the additional settlement estimation formula,and it is closer to the measured settlement results,which can be used as a calculation formula for the impact of dewatering on the surrounding environment of subway foundation pits in the northwestern region.