Study On Bearing Capacity Of Stone Arch Bridge Based On Cohesion Zone Model

Stone arch bridges widely distributed in China's highway network are not only beautiful in shape,but also reflect the local cultural characteristics.They are an important part of the local natural and cultural heritage and overall landscape.Many existing stone arch bridges have been damaged to varying degrees due to long-term loading and aging of materials.The problem of inadequate bearing capacity of structures in use urgently needs to be evaluated accurately.Stone arch bridges are mainly built of stone blocks and bonded together by mortar.This kind of bridge not only has complex three-dimensional characteristics in structure,but also has obvious discontinuous characteristics in medium.The mechanical properties of stone interface,even the shape and distribution of stone,will have a greater impact on its actual bearing capacity.In recent years,many scholars have proposed to replace the checking formula of design criterion with fine numerical model to solve the problem that the existing bearing capacity evaluation system can not reflect the three-dimensional complex characteristics of stone arch bridges.However,how to accurately and conveniently describe the discontinuous characteristics of medium and the complex mechanical behavior of discontinuous deformation of stone arch bridges in the analysis model is still the type of bridge bearing.Difficulties to be solved urgently in load assessment.In order to accurately evaluate the bearing capacity of existing stone arch bridges,the mechanical properties of stone masonry members are tested to determine the constitutive relationship of the structure.Then the interface cohesive element(Cohesive element)based on cohesive force model and the self-defined constitutive relationship of stone masonry based on the test results are used to simulate the lime joint section,thus realizing the discontinuous medium problem of stone arch bridges.Finally,by combining the cohesion model withABAQUS,the numerical analysis model of stone arch ring is established.The mechanical properties of the cracked section and the numerical simulation of discontinuous deformation of the structure are realized.The ultimate bearing capacity and failure mode of the arch ring structure under corresponding loads are obtained.The numerical simulation results of ABAQUS and the experimental results of the actual model are also carried out.The comparative analysis proves the scientific feasibility of the numerical analysis method in this paper.The numerical analysis method in this paper can simulate the whole process of discontinuous deformation and failure of stone arch bridge structure,and can be used to evaluate the bearing capacity of stone arch bridge.