砂卵石地层下盾构过浅覆土路段施工技术

Construction Measures of the Shield through Shallow Covering Section under Sandy Gravel Formation

以成都地铁区间隧道的工程为例,阐述了富水砂卵地层条件下盾构机通过浅覆土路段地层破坏机理,同时用有限元软件plaxis进行了数值模拟分析,研究发现盾构机过浅覆土路段对地层扰动性较大,施工安全系数低,必须采取加固土体、改善盾构掘进参数等一系列施工安全性的控制措施。

Based on the tunnel project of Chengdu metro section, the failure mechanism of the shield through shallow covering section under water-rich sandy gravel formation is elaborated in detail and the numerical simulation analysis is done by finite element software plaxis. The result shows that, when the shield passing through shallow covering section, it will cause heavy disturbance and low construction safety factors. Therefore, the controlling measures for construction safety such as soil mass consolidation, parameters of shield driving improvement and so on must be taken.