Prefabricated Bridge Pier Connected By Grouting Sleeve Anti-push Performance Analysis

Fully prefabricated bridge assembly technology can not only accelerates the construction speed,but also reduces the workload of on-site construction.It is an important development direction of municipal bridges.The prefabrication technology of bridge superstructure is relatively mature,while the research of bridge substructure prefabrication technology starts late.Because the joints of the prefabricated bridge piers reduce the overall performance of the pier,the seismic performance of the prefabricated piers in the high intensity zone is difficult to determine.The domestic and foreign scholars have initially studied that the prefabricated assembled components connected by the grouting sleeve are reliable in connection and good in seismic performance.However,most of the research on the connection of prefabricated piers to the grouting sleeve focuses on the placement of the cap and the bottom sleeve of the overall prefabricated pier,and there are few studies on the anti-push performance of segment prefabricated piers connected by the grouting sleeves and the joint use of grouting sleeve connection between the pier body and the cap and cover beams.Based on the above-mentioned,this paper mainly conducts the following researches by means of numerical simulation:(1)Combining the connection performance of grouting sleeve and the research method of prefabricated piers,the numerical simulation research method for the pushover analysis of prefabricated bridge piers connected by grouting sleeve connection is proposed.Combined with the existing tests,the ANSYS finite element software is used to establish the precast bridge pier model of grouting sleeve and conduct the quasi-static analysis.The results show that the experimental results are close to the numerical simulation results,which verifies the correctness of the modeling method.(2)Using the above method to simulate the grouting sleeve connection of an actual engineering ramp bridge pier,respectively establish four finite element models,the grouting sleeve segment prefabricated bridge pier(G1),the integral prefabricated piers(G2)with grouting sleeves arranged on both pier body-bearing platform and pier body-cap beams,the integral prefabricated piers(G3)with grouting sleeve installed only at the joint between the bearing platform and pier body,and the cast-in-place pier(RC).Then compare the difference in thrust resistance between the four models.The results show that the overall thrust bearing capacity of prefabricated piers is similar tothat of cast-in-place piers;there is no influence on the anti-push performance of the bridge pier whether the cap beam-pier is connected with grout sleeve;The bridge pier connected by grouting sleeve has good anti-push performance,which can meet the actual engineering needs.(3)Using G1 test piece as the standard test piece to establish 20 kinds of prefabricated bridge finite element model with different parameters,study the influence of parameters such as diameter of connecting reinforcement,number of segments,length of grouting sleeve,ratio of stirrup and axial pressure ratio on the anti-push performance of precast pier with grouted sleeve connection.The results show that too small diameter of connecting steel bar and too low sleeve length are easy to lead to premature failure of the specimen and decrease of comprehensive anti-push performance;When the diameter of the connecting steel bar and the sleeve length reach a certain degree,increasing the diameter of the steel bar and the sleeve length does not significantly improve the anti-push performance of the bridge pie;the change of the number of segments has no obvious influence on the thrust resistance of the pie;The residual displacement of the pier is not changed by the parameters.