粉细砂地层单层暗挖车站工法比选研究

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。

Comparison and Selection of Construction Methods forSingle layer Mined Station in Silty Sand Stratum

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. 