By independently designing experimental model, the experiments of bolt pullout were carried out to study the rule of mechanics transfer on anchorage system. The digital speckle correlation method and the strain measurement were used to measure the deformation of experimental model in the process of bolt drawing. The characteristics of the bolt force transfer, deformation field evolution on anchorage system, the interface deformation evolution between anchorage agent and surrounding rock were analyzed. The evolution characteristics of anchorage agent displacement, surrounding rock displacement, and the relative displacement of both were studied. The results show that: The vertical strain of bolt decreased with increasing distance from anchor end. The evolution characteristics of axial force different value between two adjacent points corresponded to the friction type of the interface between bolt and anchorage agent. The deformation of anchorage system was mainly concentrated on the interface between anchorage agent and surrounding rock. The deformation concentrated area of anchorage system extended from the anchor end to the deep part along the anchorage direction with the drawingforce increased. The interface deformation evolution trend between anchorage agent and surrounding rock was monotonically decreased along the anchorage direction during initial drawing stage. With the drawing force increased, it increased firstly and then decreased along the anchorage direction, and the maximum deformation value was fixed at the location of some anchorage depth near anchorage end. The displacement evolution characteristics of anchor agent and the surrounding rock were the same. The anchor agent and the surrounding rock went through elastic deformation stage, plastic deformation and propagation stage, deformation springback stage. The relative displacement evolution rate of both was related to displacement evolution stage of them.
Journal of Mining & Safety Engineering
bolt pull-out experimental
digital speckle correlation methods