新建隧道下穿施工对既有铁路的影响研究

隧道施工时势必会引起周围地层移动，当隧道下穿既有铁路施工时，就会引起既有铁路路基的不均匀沉降，影响铁路正常运营。以某新建地铁区间隧道下穿铁路的工程实例为研究对象，利用MIDAS GTS数值模拟软件对施工过程进行模拟分析。重点分析了隧道利用半断面深孔注浆时，不同的注浆半径对地层所起到的加固效果。在保证施工及运营安全又经济合理的前提下，提出合理的注浆加固范围（半径），并提出保证铁路正常运行的针对性措施。

Study on Effect of Underneath Construction of New Tunnel on Existing Railway

It is inevitable that tunnel construction will cause certain terrain movement nearby. Tunnel passing underneath existing railway can lead to uneven subgrade settlement, affecting the normal operation of the railway. Taking the underneath railway in a new metro region as the object of study, MIDAS GTS software for numerical simulation is used to analyze the construction process, which focuses on the reinforcement effect of different grouting radius on terrain when half-section deep-hole grouting is adopted for the tunnel. On the premise of safe construction and operation, as well as economical rationality, the reasonable grouting range (radius) for reinforcement and the measures ensuring normal operation are proposed.