Factors Influencing Seismic Behavior Of Adhesive Anchor Groups

In recent years, post anchorage technology has been widely applied in our country,and the connection technology not only involves the safety of structures, and if theimportant equipment in lifeline engineering structures has anchorage destruction,incalculable disaster also can happen. In addition, most studies in the field of anchorbolt force situation are for single anchor bolt under simple load, and the performancestudy of anchor group under complicated stress condition research is less. Based on theabove analysis, this paper research content is of great significance to guide theengineering practice and theoretical research.Specific work includes the following aspects:(1) ABAQUS finite element simulation software which is used in this paper ispowerful, and it can handle a variety of nonlinear problem. So, this paper uses thissoftware to simulate test. The effective method of simulation of bond slip is found inthis paper. In this paper, to simulate the anchor bolt thread embedding into chemicalbinder which represents effective simulation of the mechanical interlocking, simplyand effectively the bond-slip action between the bolt and concrete comes true.(2)In this paper, from the study of test simulation of bending shear with differentspacing and edge distance of anchor group, writer adopted finite element analysissoftware ABAQUS respectively on two groups of specimens to simulate bending sheartest and studied the mechanic performance, failure pattern and how anchor spacing andedge distance affect the above two factors. In addition, critical edge distance andanchor spacing are gained, which is the same as the former results perfectly.(3) ABAQUS finite element software is used to simulate low reversed cyclicloading experiment. Cycling loading cases after the destruction of the anchor nodesform similar to static test, have been reinforced necking uproot tensile damage, evenreinforced concrete around the damaged, some specimens appear small concretedestruction cone. Due to structural adhesive bonding degradation result from repeatedloads, compared with the corresponding static specimens yield load and ultimatebearing capacity of the six specimens were lower. What is can be seen from the skeleton line and stiffness degradation curve is that bearing capacity of each specimenwas not significantly reduced after the peak load capacity, they can continue to play adeformation without a significant reduction in capacity, which indicates a goodductility. In addition, indexes like ductility coefficient also can support this conclusion.This structure has good plastic deformation ability and before damage shows obvioussigns, which belongs to the ductile fracture morphology. Adding anchor spacing andedge distance can significantly improve the bearing capacity of the joint. Theimprovement of spacing can reduce tension overlap area between vertebral bodies;improvement of edge distance can make sure that tension vertebral bodies staycomplete so that effective stress area can be increased to improve bearing capacity.Increasing spacing and edge distance can improve ductility factor and equivalentviscosity stiffness coefficient, which is advantageous to the earthquake. When spacingis about10d, overlap region between two adjacent tensile vertebral bodies will notpresents so that anchor group effect can be avoided; when edge distance comes toabout8d tensile vertebral area has been in full, and if the distance exceed more than8d,bearing capacity reduction caused by insufficient edge distance can be avoided. Sortof bearing capacity adjustment of norms at home and abroad are analyzed in this paper.According to the test results and foreign specifications, this paper put forward0.8asthe post the anchor connection seismic bearing capacity reduction coefficient.(4) Comprehensively analysis of the result of bending shear test and low reversedcyclic loading test have been conducted in this paper, and it is clear that how theanchor spacing and edge distance of anchor group affect bending shear performanceand seismic behavior and critical spacing and edge distance of the anchor group havebeen gained. Finally, in this article, the research content is analyzed and summarizedand the future research is prospected.