圆砾及粉砂地层盾构下穿重要建(构)筑物施工技术研究

昆明市轨道交通首期工程得胜桥站—环城南路站区间主要地质条件为圆砾及粉砂地层，盾构需下穿文物保护建筑、老旧民房等重要建（构）筑物。通过减小刀盘直径、增大开口率、采用三步注浆模式、控制掘进参数、模拟试验段掘进等措施成功穿越了各重大风险源。实施结果表明:既有的建（构）筑物沉降量可控。

Study on Construction Technology of Shield Tunneling Beneath Important Buildings(Structures) in Cobble and Silty Sand Strata

The interval from Deshengqiao Station to South Ring Road Station of the phase I works of Kunming urban rail transit bears the major geological condition of cobble and silty sand strata. The shield tunneling needs to cross under some important buildings(structures), such as heritage buildings or old house. The following measures, reducing the cutter head diameter, increasing the opening ratio, adopting a three-step grouting mode, controlling the tunneling parameters, and simulating the tunneling in test section, crossed the major risk sources successfully. The result of implementation shows that the existing buildings (structures) subsidence is controllable.