盾构富水砂层中穿越低矮建筑群施工技术研究

Study on Construction Technology of Crossing Low-rise Buildings in Shield Water-rich Sand Layer

针对南昌轨道交通2号线一期工程七标盾构隧道工程施工过程中,因穿越老旧低矮建筑群而可能出现的地面沉降和房屋坍塌问题,就富水砂层盾构下穿建筑物风险进行分析,并基于盾构前期掘进过程中的掘进参数、地表沉降等的统计情况,从盾构下穿建筑物期间的掘进参数控制、通过后控制措施等方面进行分析,提出针对性的控制措施。对盾构通过前后建构筑物沉降监测分析可知:地表沉降累计值最大为13.1mm,实现地面累计沉降值小于20mm的目标,盾构施工过程中未对原有房屋结构质量产生明显影响。

In the construction process of the seven-standard shield tunnel of the first phase of Nanchang Rail Transit Line 2, the groundwater subsidence and house collapse caused by the passage of the old low-rise buildings will be under the shield of the rich sand layer. The risk analysis of the building is carried out, and based on the statistics of the excavation parameters and surface settlement during the tunneling process, the excavation parameter control and the post-control measures during the tunneling of the shield are analyzed.Control measures. According to the monitoring analysis of the shield construction through the front and rear structures, the cumulative value of surface settlement is 13.1 mm, and the target of the ground settlement is less than 20 mm. The construction of the shield does not have a significant impact on the structural quality of the original building.