盾构下穿既有铁路股道地基沉降控制与加固研究

Research on Ground Settlement Control and Ground Stabilization While Shield underneath pass Existing Railway Track

随着轨道交通在城市建设中的飞速发展,盾构下穿城市其他重要建构筑物的情况屡见不鲜,为施工带来极大的难度与挑战。通过对南宁市轨道交通3号线盾构隧道下穿铁路股道现场调研,基于Peck公式对轨道沉降进行理论计算,同时,借助有限差分软件FLAC3D验证了轨道沉降计算值的准确性。参考《铁路线路维修规则》(铁运<2006>146号)给出的轨道沉降容许值,发现无加固措施时的轨道沉降不能满足要求。结合国内类似工程的施工案例,通过对适用性、施工工艺与难度、施工周期、施工对环境的影响、加固效果、造价这6个方面的综合比选,选择D型便梁加固+洞内注浆的加固措施,并通过有限元软件SAP2000进行D型便梁的验算,确保便梁的设计满足使用要求,研究思路对其它类似工程具有一定的指导意义。

With the rapid development of rail traffic in urban construction,it is common for a shield to cross under other important structures, which brings great difficulty and challenge to the construction. The paper investigated the site of the railway track under shield tunnel of no.3 rail transit in Nanning and calculated the ground settlement using Peck formula. At the same time,the finite-difference software FLAC3 Dwas used to prove the accuracy of the calculating result. Compared with Railway Line Maintenance Rules（ railway transport 2006146） and found that it can＇t meet the requirement of track settlement without reinforcement. Combining the construction cases of similar projects in China and considering applicability,Construction technology and difficulty,construction period,effect on environment,reinforcement effect and cost,the stabilization measure that combining type D beam with grouting in hole was chosen. Through the finite element software SAP2000,the numerical simulation calculation is carried out to check type D beam and ensure that the beam is designed to meet the use requirements. The research has certain guiding significance to other similar projects.