软土地区管幕群顶管施工地面沉降监测与分析

Monitoring and analysis of ground settlement during pipe roof construction of pipe-jacking groups in soft soil areas

依托上海14号线桂桥路站管幕段实例工程,对管幕群顶管顶进施工过程地面沉降情况进行监测,分析群顶管施工对地面沉降的影响,在此过程中对本工程采用水土分算或合算进行讨论。根据顶进过程实际工况和监测数据,分析管幕群顶管施工影响地面的原因,提出相应控制措施。结果表明:①管幕群顶管施工引起最大地面沉降出现在始发井出加固区区域;②在本工程中采用水土合算计算正面土压力较为符合实际情况;③管幕群顶管施工过程中影响地面变形的因素主要包括前舱压力、顶进速度、洞门止水、管壁摩擦和同步注浆等方面。

Based on the example project of the pipe roof section of Guiqiao Road Station on Shanghai Line 14,the ground settlement of the pipe roof is monitored during pipe-jacking construction process.At the same time,the influences of pipe-jacking group construction on the ground settlement are analyzed,and the methods for calculating the water pressure and soil pressure are discussed.According to the actual working conditions and the monitoring data of the jacking process,the reasons for the influences of the pipe-jacking construction on the ground are analyzed,and the corresponding control measures are proposed.Some conclusions are drawn as follows:(1)The maximum ground settlement caused by the pile jacking construction occurs in the area outside the reinforcement zone.(2)The calculation of the frontal soil pressure using water and soil is more in line with the actual situation in this project.(3)The factors affecting the ground deformation during the pipe jacking construction process mainly include the front cabin pressure,the jacking speed,the tightness of the hole,the pipe friction and the synchronous grouting.