论文部分内容阅读
新建隧道施工对近接隧道的影响,一直是隧道设计和施工中必须考虑的问题,但现阶段对此还没有一致的认识。为了进一步研究新建隧道施工对近接隧道影响机理,设计了能够模拟隧道分步开挖的室内模型试验装置,并用该试验装置进行了砂土地层中新建隧道施工引起近接水平平行隧道位移的试验研究。试验重点研究了两平行隧道间净距、埋深对既有隧道位移的影响。通过对试验结果分析,得到了既有隧道拱顶和靠近新建隧道一侧拱腰部位的位移发展规律。试验结果分析表明,新建隧道开挖会对既有平行隧道结构产生侧向挤压效应,隧道埋深和净距对既有隧道的位移都有影响,但隧道间净距变化对位移量的影响更大。当隧道间净距大于2倍隧道直径时,新建隧道开挖对既有水平平行隧道位移的影响非常小。研究成果可为砂土地层中近距离平行隧道设计和施工提供参考。
The impact of the new tunnel construction on the next tunnel has always been a problem that must be considered in the design and construction of the tunnel. However, there is no consensus on this at this stage. In order to further study the influence mechanism of the newly built tunnel on the adjacent tunnel, an indoor model test device capable of simulating the tunneling step by step was designed. The experimental device was used to test the displacement of the parallel tunnel near the horizontal due to the construction of the new tunnel in the sand stratum. The experiment focuses on the influence of the clearance between two parallel tunnels and the buried depth on the displacement of existing tunnels. Through the analysis of test results, the law of displacement development of existing tunnel arch and the arch waist near the new tunnel is obtained. The test results show that the new tunnel excavation will have a lateral squeezing effect on the existing parallel tunnel structure. The influence of tunnel depth and clearance on the displacement of existing tunnels is affected. However, the influence of the change of clearance between tunnels on the displacement Bigger When the clearance between tunnels is more than 2 times the tunnel diameter, the impact of the new tunnel excavation on the displacement of the existing horizontal parallel tunnels is very small. The research results can provide reference for the design and construction of close parallel tunnels in sand stratum.