Study On Anchor Behavior Of The Large And Deeply Embedded Anchor Device

Shaking table test is the most direct and effective method for structural seismic research.Lately there has been a trend towards building shaking table.Anchor bolts are often used for the connection of actuators to concrete foundation,but anchor bolts are usually embedded deeply and headed with large end plate in concrete with the trend for shaking table to be large.Besides,the distance between anchor bolts are close,resulting in a group effect consequently.Concrete foundation is under fatigue load continuously which have an effect on anchor behavior.However,it’s not sufficient that the research on anchor behavior under the circumstance as I mentioned above.In this paper,an anchor device for actuators of shaking table is proposed.The finite element software ABAQUS is used to build numerical models and research anchor behavior of the device.The main research work include:(1)In this paper,the failure mode and ultimate bearing capacity of the anchor device consisted of bolt and sleeve under tension were studied firstly.The influence of buried depth,anchor end plate and sleeve size on tensile capacity under concrete cone failure was analyzed.The formula for bearing capacity of concrete cone failure was fitted.The design formula for the bearing capacity of end plate failure and bolt failure was proposed respectively at the same time based on the analysis of the stress state.The ultimate tensile bearing capacity of the anchor device was the minimum value of bearing capacity of three failure modes mentioned above.(2)Based on the research results of single anchor,the effect of anchor space,embedment depth and the size of end plate and sleeve on the bearing capacity of anchor group were further studied.The failure mode of group anchor was analyzed.The calculation model of group anchor bearing capacity was proposed based on the ideal projected area of cone damage of single anchor,the real projected area of damage and the tensile capacity of single anchor.(3)Finally,the existing concrete fatigue test results were used to establish a unified S-N curve based on the stress space failure criterion.The fatigue life of concrete was predicted and parameter was analysed based on the secondary development of ABAQUS.The fatigue constitutive model of concrete after arbitrary load cycle was established.The residual bearing capacity of the structure under fatigue history was calculated.