Abstract:
In order to study the drawing interface mechanical properties of threaded steel bolt and the drawing failure process of anchor structure, on the basis of bolt tensile test and numerical simulation, the symmetrical plane model of threaded steel bolt anchorage is established by using finite element software ABAQUS. Based on the interface bond damage model, the whole process of drawing failure of threaded steel bolt is numerically simulated. The results show that: the numerical simulation can restore the tensile fracture process of the real bolt. Different from the tensile fracture characteristics of round steel, the tensile fracture orientation of the bolt is parallel to the inclination angle of the rib; the variation law of load displacement curves of bolts with different rib spacings show that the smaller the rib spacing of bolts, the better the anchorage bearing performance, and the existence of bolt transverse rib can not only improve the bonding contact area, but also increase the mechanical biting force; with the increase of the pull-out load, the rock mass gradually fails from the front end to the back end in a funnel-like manner, and the interface damage and shear stress peak gradually move to the deep part of the anchorage. The damage of bolt, rock mass or interface will cause the fluctuation of load-displacement curve of bolt. The more severe the damage is, the more obvious the fluctuation of load displacement curve is.