全长粘结式锚杆加固节理边坡的动静态位移响应

Response of dynamic and static displacements of jointed slope reinforced by wholly grouted bolts

锚杆通常被作为表面粗糙的轴力杆单元进行分析,但在节理边坡加固中,由于节理面的错动,同时考虑锚杆的轴向和横向作用显得更加合理。通过理论分析,建立锚杆三弹簧单元的力学特征模型和变形特征模型,对其受力和变形进行全面分析;运用拉格朗日元数值方法(FLAC3D),建立以理想弹塑性本构Mohr-Coulomb准则为基础的节理边坡模型,应用三弹簧锚杆单元,对其锚固前后的动静态位移响应进行模拟。结果表明:节理面锚固处理后,岩体的刚度得到提高;边坡各部位的位移减小,节理两侧位移的突变值变小;锚杆对节理的上下盘岩体起到有效的拉结作用,抑制了两盘之间的较大变形位移,有利于边坡稳定。

Bolt is often analyzed as spar element with rough surface, which can only endure stress along the axial direction. But when it applied to jointed slope, it is more reasonable to consider both the axial and lateral effect of bolt due to the moving of joint plane. The models of mechanical characteristics with three springs and deformation characteristics are founded for bolt according to the theoretical analysis. In these models, the stress and deformation of bolt can be fully analyzed; in order to reflect the differences of dynamic and static displacements effect of jointed mass between the states of bolting and unbolting, the numerical calculation models of slopes are founded based on the perfect elastoplastic constitutive model, Mohr-Coulomb criterion, by numerical simulation technique of fast Lagrangian analysis of continua in 3D （FLAC3D）. In the numerical simulations, the bolt element with three springs is applied. The analysis result shows that after bolting in jointed plane, the stiffness of rock mass is improved; the displacement of slope becomes smaller; the mutation magnitude of displacement beside joint plane becomes smaller; bolt system exerts the tensile effect for the upper and lower rock mass, and reduces the displacement in the joint plane, which is good to the slope stability.