共同管沟深基坑现场变形监测与数值模拟分析

为了分析共同管沟深基坑边坡的变形规律及其对邻近建筑物的影响作用，以三星深基坑工程为例，采用数值模拟分析并进行现场变形监测验证。结果表明:降水措施对深基坑开挖引起的水平位移作用不大，而对竖向位移作用较大；随着深基坑开挖深度的不断加大，边坡土体的水平位移和竖向位移总体呈现增大的趋势，最大水平位移值表现为从坡脚向坡脚上方移动；原地下水位线以上所开挖边坡的最大竖向位移都发生在坡脚处，采用降水措施后，原地下水位线以下所开挖边坡的最大竖向位移出现在原地下水位附近。现场变形监测与数值模拟计算结果吻合度较高，说明土体参数的选取合理。研究成果可提升城市共同管沟深基坑建设安全设计及施工水平、降低工程风险损失。

Field monitoring and numerical simulation analysis on deformation of deep foundation pit for utility tunnel

In order to analyze the deformation law of deep foundation pit slop for utility tunnel and the influence on adjacent buildings, taking the deep foundation pit construction project of Samsung as example, the numerical simulation analysis was carried out, and the field monitoring of deformation was conducted for validation. The results showed that dewatering measures had a little influence on the horizontal displacement caused by excavation of deep foundation pit and great influence on the vertical displacement. The horizontal and vertical displacement of slope soil generally presented an increasing trend with the increasing excavation depth of deep foundation pit. The maximum value of horizontal displacement manifested as moving upward from the toe of slope. Above the initial groundwater level, the maximum vertical displacement of slope occurred at the toe of slope, and under the initial groundwater level, the maximum vertical displacement of slope appeared around the initial groundwater level when dewatering. The results of field monitoring and numerical simulation of deformation had a high goodness of fit, which showed that the selection of soil parameters was reasonable. It can enhance the safety design and construction level of deep foundation pit for urban utility tunnel, and reduce the risk loss of project.