Both Bridge Technique Condition Evaluation Based On Load Test And The Numerical Simulation Research

Stone arch bridge is awidely used bridge form in China,it has a long history,according to incomplete statistics,a total number of stone arch bridge is more than four million.The stone arch bridge has many advantages such aswide material sources,low cost,and elegant appearance.Due to the limitations of economic conditions and design level,also the influence of natural environment,overload,operation and management,and design specifications change.At present a lot of stone arch bridge existing in disease and damage,can not meet the requirements of the safety and stability.In order to solve this problem,it is urgent to test and evaluate the damaged bridges,whichhas a strong practical significance to assess the bearing capacity,and provides a basis for the maintenance,repair and reinforcement of the bridge structures.Of course,it will give some references on the later design and detection of the bridge structures.In the beginning of this paper,it discusses the research background of the stone bridge,gave a brief introduction of bridge types,made some surveys on common damages,carried on some related analysis,elaborated testing methods and theory and presented the bridge testing methods.Take a stone bridge in Chizhou as a sample,in this paper it presents inspectors did site investigations and related mechanics of materials performance test systematacially by adapting modern testing technology.According to the testing results and methods of assessing arch bridge appearance,it made the technique evaluation for the bridge.According to the field survey and design technical data,the large structure calculation software MIDAS/Civil was adopted to modeling calculation of stone arch bridge in this paper.The loading conditions of static load test,the loading and unloading stage under different working conditionsm,the main control section and the arrangement of measuring points in control section was determined by the characteristics of stone arch bridge structure and internal force calculation.On the basis of the analysis results of modeling calculation,the static load test of stone arch bridge was carried out,and the edge normal stress of cross sections in different conditions obtained by static load tests and the measured data of vertical deflection was analyzed comparatively with the theoretical value in the calculation of modeling.Combined with the verification coefficient,the actual bearing capacity of the bridge was reflected clearly by the curve diagram.Through the analysis of data,the whole rigidity of the stone arch bridge is better,and the bridge structure was in the elastic working state.Besides,the bridge dynamic test was conducted(Including:pulse test,test driving and braking test),and the related technical parameters was achieved.The natural frequency and damping ratio of the bridge was obtained by the calculation of the theory,and it was shown that the actual stiffness of arch bridge is larger than the theoretical value.Therefore,the bridge has superior dynamic performance.