粉细砂地层单层暗挖车站工法比选研究

Comparison and Selection of Construction Methods for Single-layer Mined Station in Silty Sand Stratum

为研究粉细砂地层单层暗挖车站柱洞法施工时地表沉降规律,采用注浆试验、数值分析与现场监控量测相结合的方式进行研究,并通过分析柱洞法在粉细砂地层设计及施工中存在的问题,提出一种在粉细砂地层单层暗挖车站的优化设计方案。结果表明:1)注浆加固对粉细砂的含水量、黏聚力、内摩擦角、压缩模量均有明显的改善;2)粉细砂地层柱洞法施工地表沉降大、沉降槽宽度大;3)柱洞法施工时存在施工空间狭小、边跨施工沉降量大、综合接地施工困难等问题;4)优化后的单层暗挖施工方案具有沉降量小、可机械化施工、节约工期、施工方便等优点。

In order to study the ground settlement law during the construction of the single-layer mined station in silty sand layer by column-hole method,the method of grouting test,numerical analysis and on-site monitoring and measurement are combined and adopted.The problems in design and construction of column-hole method in silty sand layer are analyzed,and an optimized design method is put forward.The results show that:(1)The grouting reinforcement can significantly improve the moisture content,cohesion,internal friction angle and compression modulus of silty sand layer.(2)The ground settlement and settlement groove induced by column-hole method are large in silty sand layer.(3)Problems such as narrow construction space,large side-span construction settlement,and difficulty in comprehensive grounding construction exist in column-hole method construction.(4)The optimized single-layer mining construction scheme are characterized by small settlement,mechanized construction,time saving and convenient construction.