爆炸载荷下顺层台阶边坡渐进破坏规律数值分析

NUMERICAL STUDY ON THE PROGRESSIVE FAILURE MECHANISM OF BEDDING STEP SLOPE UNDER EXPLOSIVE LOAD

在连续–非连续单元方法(continuum-discontinuum element method,CDEM)框架中引入了岩体损伤破裂模型及爆生气体绝热膨胀模型,开展了爆炸载荷下顺层台阶边坡渐进破坏过程的数值分析,探讨了爆破距离、结构面产状、结构面强度等因素对边坡顺层结构面破坏特征的影响规律。结果表明,爆破作用下,顺层结构面将发生拉剪复合型破坏,结构面倾角越大、结构面强度越低、爆破距离越小,顺层边坡越容易出现失稳破坏。相较于爆破距离,结构面强度对结构面破裂面积的影响更大,随着结构面强度的增大,破裂面积迅速减小。

Based on the framework of continuum-discontinuum element method(CDEM),the rock damage fracture model and explosion gas adiabatic expansion model are introduced.The numerical analysis of progressive failure process of bedding step slope under explosive load is carried out,and the influence of blasting distance,structural plane occurrence and structural plane strength on the failure characteristics of bedding step slope is discussed.The results show that under the action of blasting the tensile-shear composite failure will occur on the bedding structural plane.The larger the structural plane dip angle is,the lower the structural plane strength should be,and the smaller the blasting distance is,the greater the probability of failure of bedding slope will be.Compared with the blasting distance,the strength of structural plane has a greater influence on the fracture area.With the increase of strength,the fracture area decreases rapidly.