复合岩土地层隧道开挖引起土体变形的计算方法.

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. [ABSTRACT FROM AUTHOR]