摘要：
In order to simulate the dynamic response of discontinuous structural plane or interface under seismic load,a new 3-D interface elastoplastic model is established within the elastoplastic framework,in which the effects of strain rate and plastic damage on the strength of the interface are comprehensively considered.In the elastic phase,the process of the non-linear strain of the interface is described with hyperbolic function.In the plastic phase,the effects of strain rate and damage on the strength of the interface are considered,while the Mohr Coulomb criterion with stretch cutoff limit is revised and the solving process of the plastic strain increment is deduced based on the plastic consistency condition.Compared with the relevant experimental data,the reasonability of the model is verified.Through putting the model into the relevant finite element calculation program and applying it to the numerical calculation for typical underground project,the result shows that compared with the equivalent continuum model,the principal stress of the beam calculated by the model is decreased by about 7％ with long anchor-rod for bearing more load,while the deformation of the beam is increased by 1 ～ 2 mm,which is indicated that the existence of the interface reduces the constraint effect from the surrounding rock on the rock-anchored beam,thus decreases its stability under the seismic load.%为了模拟非连续结构面、接触面等在地震荷载作用下的动力响应,在弹塑性框架内建立了一种新的三维接触面弹塑性模型,该模型能够综合考虑应变率和塑性损伤对接触面强度的影响.在弹性阶段,采用双曲线函数来描述接触面的非线性应变过程.在塑性阶段,考虑了应变率和损伤对接触面强度的影响,对带拉伸截止限的莫尔库伦准则进行了修正,并且基于塑性一致性条件,推导了塑性应变增量的求解过程.通过与试验数据对比,验证了模型的合理性.将该模型写入到有限元计算程序中,并应用于典型地下工程数值计算,结果表明:与等效连续模型相比,该模型计算的梁体主应力减小了约7.6％,长锚杆承担了更多的荷载;梁体变形量增加了1 ～2 mm,说明接触面的存在减小了围岩对岩锚梁的约束作用,降低了其在地震荷载作用下的稳定性.
