Research On The Anchorage Mechanism Of Bolt Under The Loading Of Pullout

At present, used bolt to reinforce the unstable rock or soil have become a very important technology in geotechnical engineering, which can make full use of geotechnical potential. With the acceleration of China’s modernization, anchorage technology have been widely used in mining, utilities, transportation, military and other fields, the research of rock anchorage technology have irreplaceable significance on social and economical value. So far, the design of geotechnical anchors were mainly relied on experience or engineering analogy method in domestic and international, the research works of mechanism that the bolt in geotechnical consolidation were not yet in-depth. For this, in this thesis, first to analysis the theory of deformation and failure when the bolt under the effect of external loading, then, to study the variation of shear stress of bolt-mortar and mortar-rock mass interface when the anchor bolt under the static and dynamic loading with numerical simulation. In order to fully explore the working mechanism of the bolt, discussed the ultimate uplift capacity formula of bolt which expansion in the head.Based on a large number of research studies, the study contents in this thesis as follows:(1)Access to a large anchorage research literatures, describe the types of anchors and basic mechanics, then proposed contents and purpose in this paper.(2) According to the established mathematical model of the interface of the anchoring and surrounding soil turn into softening when under the loading of pullout, to analysis the axial force and displacement of anchor when the soil which vicinity to the interface was in the state of elastic, plastic and slip. The theoretical formula of the critical loose pullout load of anchors was derived.(3)Used FLAC3D to simulation the transfer law of force when the bolt respectively under static and dynamic loading, study the axial force and deformation at the different positions of the bolt, as well as the distribution of interfacial shear stress on the anchorage. (4)To analysis the failure surface of soil when the bolt that expansion in the head under different loads, derivation the unity equations of surface destruction and ultimate uplift capacity.