土石混合体地层中基坑开挖对邻近既有隧道影响模型试验研究

为解决土石混合体地层中基坑开挖引起的隧道响应问题,采用非相似试验方法展开研究,土石混合体地层不连续的特性导致其中进行的基坑开挖对邻近既有隧道的影响更为复杂。针对土石混合体地层中基坑开挖对邻近既有隧道的影响问题,采用自主设计的非相似性模型试验模拟隧道旁基坑开挖过程,研究地层含石率w 对基坑开挖引起的隧道结构响应的影响规律。研究结果表明: 含石率w 的上升使得受开挖引起的隧道弯矩变化量的逐步下降;含石率在w<60%、w =60%及w =90%时,隧道管片周围土压力受开挖引起的变化呈现不同规律;当0%

Model Test Study on Influences of Deep Foundation Pit on Adjacent Tunnel in Soil-Rock Mixtures

The dissimilar test method is carried out for tunnel response induced by foundation pit excavation in soil-rock mixtures. The discontinuous characteristics of the mixtures complicate the influence of foundation pit excavation on adjacent tunnel. Meanwhile, the influence of rock content w on the tunnel response induced by foundation pit excavation is studied. The experimental results show that: (1) An increase in w would decrease the tunnel segment moment. (2) Variations of earth pressures around tunnel lining show different laws in the cases of w<60%,w =60% and w = 90%. (3) When 0%< w ≤ 60%, the increase of rock content cannot reduce the variation on deformation and displacement of tunnel segment; however, the variation on deformation and displacement of tunnel segment can be effective controlled in the case of w = 90%.