地下厂房岩锚梁接触面非线性有限元模拟方法

针对地下厂房岩锚梁与围岩接触问题，分别构建了模拟岩锚梁与围岩接触面非线性特征的有限元数学模型和力学模型。在Desai薄层单元基础上，推导了岩锚梁接触面单元有限元形式；结合非线性弹性理论和弹塑性理论，提出了岩锚梁接触面三维非线性力学模型，该力学模型能够模拟岩锚梁接触面弹性阶段的非线性现象和塑性阶段的损伤软化现象。针对岩锚梁接触面闭合、张开、剪切滑动等变形特征，提出了考虑接触面粘结、开裂、滑移现象的分段式抗滑安全系数。详细地论述了本文提出模型的有限元迭代方法，并据此编写了有限元程序。将本文模型应用于某地下厂房岩锚梁有限元分析计算中，应用效果良好。

Nonlinear Finite Element Simulation Method for Contact Face of Rock-anchored Beam and Surrounding Rock in Underground House

For the contact problem of rock-anchored beam and surrounding rock of underground powerhouse, the finite element mathematical model and mechanical model are established to simulate the nonlinear characteristics of the contact surface of rock anchor beam and surrounding rock. Based on Desai thin-layer element, the finite element form of contact element is derived in this paper; Combined with nonlinear elastic theory and elastic plasticity theory, a three-dimensional nonlinear mechanical model of contact face, which can simulate the nonlinear phenomena on elastic stage and damage softening phenomena on plastic stage of contact element, is proposed. In view of the deformation characteristics of contact elements such as closing, opening and shearing slip, a segmented safety factor, with the bonding, cracking and slip phenomenas of contact face are considered, is proposed. The finite element iteration method of the model is discussed in detail, and the finite element program is compiled accordingly. The proposed model is applied to finite element analysis calculation of rock-anchored beam in an underground powerhouse, and shows good application effect.