盾构隧道小近距下穿既有隧道施工技术研究

在盾构隧道小净距下穿既有隧道,未对既有隧道内及周边进行加固的情况下,利用FLAC3D有限差分程序模拟计算了地表、既有隧道的沉降变形及二者间的土层最大主应力,参考数值计算的结果优化了盾构施工参数,当施工进入盾构隧道对既有隧道的影响范围内时对既有隧道进行自动化监测,根据监测结果进一步调整盾构推进参数,使得盾构隧道安全、快速通过了既有隧道,取得了良好的社会和经济效益。

Study on the construction technology of short-distance shield tunnel under-crossing existing tunnel

Under the condition of short-distance shield tunnel under-crossing existing tunnel without reinforcing existing internal tunnel and surroundings,using FLAC3D finite difference program,the paper simulates and calculates the subsidence deformation of surface and existing tunnel and the maximum stress between the two layers,optimizes the shield construction parameters according to numerical calculation.When the shield tunnel construction is within the influential domain of the existing tunnel,the automatic monitoring is set out for existing tunnel.According to the monitoring results,it further adjusts shield parameters,so as to make the shield tunnel fast crossing existing tunnel.As a result,it achieves great social and economic benefits.