Seismic Performance Test And Numerical Analysis Of Prefabricated Segmental Piers Repaired By CFRP

Prefabricated segmental piers are widely used in modern bridge construction because of their advantages such as fast construction speed,good construction quality and little impact on the surrounding environment of the site.At the same time,there are many seismic zones in our country,and the damage of piers in the earthquake will seriously threaten the safe use of bridges.It is of great significance to repair the damaged piers in the earthquake by using fast and effective methods to rush through the rescue channel,reduce economic losses and save reconstruction funds.The seismic performance of the repaired bridge pier directly affects the safety,stability and reliability of the bridge in the future.In view of a series of problems of the seismic performance of the repaired concrete piers,this paper combines the structural characteristics and seismic response characteristics of the prefabricated segmental piers,uses the method of carbon fiber to repair the concrete structure,and at the same time,with the fast curing steel glue to repair the damage of the proportion model of the prefabricated segmental piers,and the seismic performance of the repaired model test pieces Experimental study was carried out.At the same time,using the general finite element simulation software ABAQUS,the influence of CFRP repair parameters on the seismic performance of the repaired pier structure is studied,and the following research work is carried out in detail:(1)After the cyclic loading test on the original pier model,the damaged concrete position of the damaged model was filled with steel glue and wrapped with CFRP.After the repair of the model,the cyclic loading test with the same loading system is carried out,and the damage characteristics,hysteretic curve,energy dissipation and other performances of the two kinds of bridge pier models are compared and analyzed;(2)Referring to the test model,the three-dimensional solid finite element model of the original pier model is established by using the finite element software ABAQUS,the geometry of the damaged concrete part is simplified,the three-dimensional solid model of the damaged concrete part filled with steel glue is established,and the loading process of the side wrapped with carbon fiber cloth is simulated,and the finite element calculation results and the test results are compared and analyzed;(3)In this paper,ABAQUS software is used to carry out parametric analysis of the bridge pier model repaired by CFRP,including the study of whether there is a CFRP package,the thickness of the CFRP package,the height of the CFRP package and whether the fiber crosses the joint of the section,and the seismic performance under different repair parameters is compared,and the effect of different repair parameters on the seismic performance of the bridge pier model is analyzed.The main conclusions are as follows:(1)Using carbon fiber wrapped method to repair the damaged precast segmental assembled pier can effectively restore the bearing capacity of the damaged pier,at the same time,the level of energy dissipation has been improved to a certain extent,and the bearing capacity of the pier under the condition of large displacement of the pier top has been significantly improved compared with the original test piece;the concrete segment repaired by CFRP has no obvious damage,carbon fiber has no obvious fracture,repair The seismic performance of piers has been restored and improved,and the overall safety reserve is large;(2)The results of the experiment and the finite element calculation,such as the hysteretic curve,the skeleton curve and the material stress-strain curve of the bridge pier model,are basically consistent,which proves that the simplification of the defect position filled with steel glue and the three-dimensional solid finite element model of the bridge pier repaired with CFRP are reasonable,which can better reflect the response of the whole structure and material.It also shows that the membrane element is reasonable in Advantages of carbon fiber cloth simulation;(3)The thickness of CFRP package has an obvious effect on the bearing capacity of the repair model,while the height of CFRP package has a more obvious effect on the energy dissipation level of the repair model.However,there is an upper limit for the wrapping thickness.When the wrapping thickness of carbon fiber cloth is too large,the energy consumption capacity of the bridge pier will decrease.In this paper,the two-layer carbon fiber cloth wrapped bridge pier model is 8.7% higher than that of the non wrapped bridge pier model in terms of bearing capacity,and its energy consumption capacity is also improved to some extent.When the wrapping thickness of carbon fiber cloth is fixed,the larger the wrapping range,the higher the energy consumption capacity The energy consumption level of repaired bridge pier is 22.7% higher than that of 25% of the wrapped section when the wrapped section reaches 75% of the section height.When the wrapped CFRP across the joint between segments,the relative slip between segments basically disappears,and the shear failure of concrete almost turns into flexural failure.At the same time,under the circumferential constraint of CFRP,the energy consumption level and bearing capacity of repaired piers have been significantly improved.