层状岩体深埋长隧道锚杆支护优化设计

层状岩体是地下工程中经常遇到的一种岩体，力学性质具有明显的各向异性。选择合适的屈服准则和强度参数变化规律，结合各向异性弹性本构方程，获得横观各向同性弹塑性本构关系，利用该本构模型对共和隧道锚杆支护方案进行数值计算。首先考虑地应力、岩性的影响，从围岩的变形、破坏形式、塑性区及锚杆拉力的大小等方面改进、优化支护设计方案；其次从实际工程出发，考虑施工难度、工程造价等因素的影响，得到改进方案Ⅰ效果较理想，通过试验段现场监测确定改进方案I。本构模型对计算结果的影响很大，正确模型的计算结果可以为实际工程提供科学依据。

Optimum design of rock bolts supporting long-deep tunnel in layered surrounding rock mass

Layered rock mass is a kind of common rock mass in underground engineering, and its mechanical properties often take on distinct anisotropy. Selecting appropriate yield function and suitable strength parameters variable law, combining elastic constitutive function of anisotropy, then elastoplastic constitutive function of anisotropy is obtained. Gonghe tunnel is numerically modeled by utilizing this constitutive function. Firstly considered the influence of crustal stress and rock property, support design scheme is modified and optimized from these aspects such as deformation of surrounding rock mass, style of failure, magnitude of yield field and bolts tension; secondly considered the influence of construction difficulty and engineering cost from the actual project, it is concluded that the modified design I is better. Modified scheme I is even adopted in the process of tunnel construction. So constitutive model has great effect on the result of calculation, calculation result of appropriate model can provide scientific proof for the actual project.