下穿建筑物土压平衡盾构土仓土压力参数研究

采用现场监测和理论分析相结合的方法,对盾构穿越既有建筑过程中控制沉降措施进行了分析,分析结果表明：盾构开挖时,土仓土压应该大于开挖前地层侧向土压力的理论值,在本工程中,通过现场试验和监测,得出土压系数取实测侧压力系数的1.2~1.3倍时,盾构开挖时地表沉降达到较好的控制。当盾构穿越既有建筑物时,应考虑建筑物附加应力对地应力的影响,调整土仓中土压参数。从现场监测结果表明,调整前后地表沉降量有较显著的变化。

Study on Earth Pressure Parameters of Chamber of the Slurry Balance Shield Passing Under Structures

By combining the field monitoring and the theoretic analysis,the measures of settlement control are analysed when shield tunnel excavating under the structure,and the following results are obtained.Firstly,considering the settlement control,the earth pressure of chamber should be higher than the measured lateral earth pressure before excavation.In this paper,by means of field testing and field monitoring,it is found that settlement control is reasonable when earth pressure of chamber is 1.2~1.3 times the me...