不同埋深下类矩形与圆形隧道施工诱发土体变形透明土试验对比研究  

Comparative Experimental Study on Deformation of Transparent Soil Induced by Construction of Quasi-rectangular and Circular Tunnels at Different Buried Depths

作　　者：杨明辉[1] 肖建勋 杨涛[1] YANG Minghui;XIAO Jianxun;YANG Tao(College of Civil Engineering,Hunan University,Changsha 410082,China)

机构地区：[1]湖南大学土木工程学院,湖南长沙410082

出　　处：《湖南大学学报（自然科学版）》2024年第9期66-75,共10页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(51678230);河南省交通科技计划项目(2021J7)。

摘　　要：类矩形隧道因其内部空间优势在工程中逐步得到推广,但其施工引发周边土层变化规律与常规圆形隧道的差异尚缺乏深入研究,且该差异与隧道埋深紧密相关.为此自主设计组装了类矩形与圆形隧道开挖装置,以透明土模拟周边土层,并采用粒子图像测速(PIV)技术精准测定土层变形,对不同埋深下等面积类矩形与圆形隧道动态开挖过程中诱发上覆土体变化规律进行了深入分析.试验对比结果表明,两类隧道引发上覆土层变形的滑裂面基本一致,大致符合太沙基理论的竖直滑动面假定,滑裂角θ约等于45°+φ/2;不同埋深情况下,圆形隧道上覆土层竖向变形始终保持“V”型的正态分布,即存在最大值,而类矩形隧道随着地层深度的增加,上覆土层变形由“V”型转变为“W”型,即存在多个沉降最值,表明该类隧道比圆形隧道地层变形更为均匀,且在相同埋深情况下类矩形隧道开挖引发的地表沉降最大沉降值小于圆形隧道,该现象在浅埋状态下尤为明显,二者差异随着埋深增大逐渐缩小,该结论可为施工方案设计选择提供参考.The quasi-rectangular tunnel has gradually gained popularized in engineering because of its space advantages.However,there is a lack of in-depth research on the differences between quasi-rectangular and circular tunnels in the surrounding soil layer changes,which are closely related to the buried depth of tunnels.The quasirectangular and circular tunnel excavation devices were independently designed and assembled,and transparent soil was used to simulate the surrounding soil layers.Particle image velocimetry(PIV)was used to accurately measure the deformation of the soil layer,and the law of soil deformation induced by the dynamic construction of quasirectangular and circular tunnels at different buried depths was analyzed.Experimental comparison results elucidate that the sliding surfaces of the soil deformation induced by the two types of tunnels are basically the same,which roughly conforms to the vertical sliding surface assumption of Terzaghi’s theory.The sliding angle(θ)is approximately equal to 45°+φ/2.The vertical deformation of the overlying soil layer of the circular tunnel always maintains a“V”shaped normal distribution at different buried depths,indicating the presence of a maximum value.The vertical deformation of the overlying soil layer of the quasi-rectangular tunnel changes from a“V”shape to a“W”shape as the depth of the formation increases,indicating the existence of multiple maximum settlements.This suggests that rectangular tunnels result in more uniform ground deformations compared to circular tunnels.Under the same burial depth,the maximum surface settlement induced by the excavation of similar rectangular tunnels is smaller than that of circular tunnels,especially in shallow burial conditions.The difference between both two gradually decreases with the increase of buried depth.These findings can serve as references for the design and selection of construction schemes.

关 键 词：类矩形隧道 土体变形 透明土 PIV技术 

分 类 号：TU411.93[建筑科学—岩土工程]