南京市某综合管廊工程基坑监测分析

在综合管廊建设过程中,常面临开挖基坑失稳问题;而钢板桩支护由于自身施工快速、隔水性好等良好性能,能够保证开挖临空面不会失稳破坏;因此在基坑支护领域得到了广泛应用。结合南京市某综合管廊工程,针对工程中采用的钢板桩加二道钢支撑支护方式,开展了管廊基坑监测工作,获取了管廊基坑的深层土体水平位移、地面沉降量、钢支撑轴力等监测值。研究结果表明,从第二道支撑底往下开挖至基坑底的过程中土体水平位移变化量最大,水平位移最大值出现在地表;地面沉降量随着基坑开挖而增大,沉降速率逐渐减小;钢支撑的轴力值第二道支撑大于第一道,并受开挖速度及支撑架设时间等因素影响。研究成果可为相关管廊工程的设计、施工、监测提供工程借鉴。

The analysis of excavation monitoring for the utility tunnel project in Nanjing

The instability of excavation pit often happens in the construction of utility tunnel. The steel sheet pile can ensure the stability of excavation surface for its good performance of quick implement and waterproof. Thus it has been widely applied in the supporting system for foundation pit. The supporting pattern of steel sheet pile and two steel supports are used in the utility tunnel project of Nanjing. The data of horizontal displacement of depths soil, ground settlement, axial force of steel support were measured for the utility tunnel excavation based on the project The results show that the horizontal displacement of soil from the second support to the bottom of excavation is the largest, the maximum of horizontal displacement for soil is at the surface; ground subsidence increases with the process of excavation and subsidence rate gradually decreases. Axial force of the second steel support is greater than the first steel support. Axial force is affected by many factors such as the speed of excavation, the time when steel supports were set up and so on. This paper can provide good reference for the design, construction and monitoring of the related utility tunnel project.