摘要
考虑岩层与土层力学性质的差异,提出利用复变函数与随机介质理论联合求解复合地层隧道开挖引起的地表沉降计算方法。首先利用复变函数获得岩层在上部土层自重荷载和隧道发生非均匀变形条件下的解析解,并获得岩土分界面沉降变形,将其与分界面围成的区域视为“不等厚层开挖”,随后运用随机介质理论,获得地表沉降值。通过2个复合地层隧道开挖的实例,分析岩土分层与不分层所得计算结果与实测值的差异,结果表明:相比将岩土层视为一种介质的计算方法,岩土分层的计算结果与实测值的吻合度明显得到提高。此外,考虑隧道不同收敛变形模式、上覆岩土层软硬比及软土层不同影响角对地层变形的影响,得出隧道收敛变形对地层变形影响较大,对地表的影响范围较小;上覆岩土层软硬比对地层变形和影响范围均有较大的影响;土层影响角越大,地表变形越大,地表影响范围随之减小。
Taking mechanical property differences of rock and soil layers into consideration,a method of calculating ground settlement caused by tunnel excavation in composite strata by means of uniting complex variable function and stochastic medium theory is proposed.Firstly,via complex variable function the analytical solution of rock strata under the conditions of self-weight of upper soil layer and non-uniform deformation of tunnel can be obtained,and the settlement deformation of rock-soil interface is gotten,and regard the area surrounded by the interface as“unequal thickness excavation”.Then,with the use of stochastic medium theory,surface settlement value is calculated.By summing up two examples of tunnel excavation in composite strata and analyzing the differences between calculated results and measured values,it can be noted that the agreement between calculated results and measured values of geotechnical stratification method is obviously better than the calculation method considering rock and soil layers as medium.In addition,it is concluded that the tunnel convergent deformation influences strata deformation more and surface less by considering the influence of different tunnel convergent deformation modes,soft-hard ratio of overlying strata and influence angles of soft soil on strata deformation.The soft-hard ratio of overlying strata has a great influence on strata deformation and influence zone.The larger the influence angle of soil layer is,the larger surface deformation will go,and the influence zone of ground surface will reduce with it.
作者
杨海涛
晏莉
严志伟
张文杰
YANG Haitao;YAN Li;YAN Zhiwei;ZHANG Wenjie(School of Civil Engineering,Changsha University of Science and Technology,Changsha 410114,China;Key Laboratory of Tunnel Engineering Ministry of Education,Southwest Jiaotong University,Chengdu 610031,China)
出处
《自然灾害学报》
CSCD
北大核心
2023年第6期185-196,共12页
Journal of Natural Disasters
基金
国家自然科学基金项目(51408067)
湖南省教育厅优秀青年项目(18B136)
长沙理工大学桥梁与隧道工程重点学科基金项目(10ZDXK06)
长沙理工大学桥梁工程领域开放基金项目(15KC03)。
关键词
复合地层
隧道开挖
复变函数
随机介质
土体变形
composite strata
tunnel excavation
complex variable function
random medium
soil deformation
