邻近隧道及周围地层受深基坑开挖影响的现场监测研究

发布时间：2018-12-27 11:35

【摘要】：深大基坑施工诱发的运营隧道变形以及周围土体沉降等施工问题,在我国城市轨道交通施工安全控制和风险评估中受到日益关注。文章基于上海市交响乐团在建基坑工程,结合运营隧道以及基坑围护结构监测数据,分析了基坑不同开挖阶段周边地表沉降、地下连续墙变形、运营隧道收敛变形以及竖向位移的规律和特点。实测结果表明:周边地表总体呈下沉趋势,大致呈抛物线型分布;坑外土体侧斜和围护墙体侧移具有基本相同的变化规律,且均向基坑内侧移,开挖深度对土体侧移的影响并不是简单的线性关系;隧道的水平附加收敛表现为向外拉伸,随基坑开挖的进行,收敛变形增幅明显;隧道净沉降曲线与基坑周围土层、围护结构变形曲线的变化趋势具有较好的一致性;地下连续墙两侧SMW工法加固可有效控制隧道、坑外地表以及地下连续墙的变形。研究成果可为正确制定软土城区基坑施工对邻近地铁隧道的保护措施提供一定的理论依据。
[Abstract]:The construction problems such as tunnel deformation and soil settlement caused by deep and large foundation pit construction have been paid more and more attention in the construction safety control and risk assessment of urban rail transit in China. Based on the foundation pit project under construction by Shanghai Symphony Orchestra, combined with the monitoring data of tunnel operation and foundation pit enclosure structure, this paper analyzes the ground subsidence and deformation of underground continuous wall in different excavation stages of foundation pit. The law and characteristics of convergent deformation and vertical displacement of operating tunnel. The measured results show that the surface of the surrounding surface is in a general subsidence trend, which is approximately parabolic distribution. The lateral displacement of the soil outside the pit and the retaining wall have the same variation law, and they all move to the inside of the foundation pit. The influence of excavation depth on the lateral displacement of soil is not a simple linear relationship. The horizontal additional convergence of the tunnel is shown as outward extension, and with the excavation of the foundation pit, the increase of convergence deformation is obvious, the net settlement curve of the tunnel is consistent with the deformation curve of the surrounding soil layer of the foundation pit and the deformation curve of the enclosure structure has a good consistency. The deformation of tunnel, pit surface and underground continuous wall can be effectively controlled by SMW method on both sides of underground continuous wall. The research results can provide certain theoretical basis for correctly formulating the protection measures for adjacent subway tunnels in the construction of foundation pit in soft soil urban area.
【作者单位】：上海理工大学环境与建筑学院;国土资源部丘陵山地地质灾害防治重点实验室;华东建筑设计研究院有限公司;
【基金】：上海自然科学基金项目(15ZR1429400) 国土资源部丘陵山地地质灾害防治重点实验室课题(2015k005)
【分类号】：U456.3

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