Research On Calculation Method Of Bearing Capacity Of The Spandrel-filled Stone Arch Bridge

The spandrel-filled stone arch bridge designing and building on the basis of Highway bridge and culvert standard drawings (The Stone Arch Bridge JT/GQB 018-73) has existed for 30 to 40 years. Due to various reasons during the actual application of the bridge, these bridges suffer different problems which affects their regular service so that urgent assessment and maintenance and even reinforcement are badly needed. At the same time, regardless of the arch construction to improve the bearing capacity, the original design and calculation of the bridge only consider the carrying capacity of the main arch ring, which is too conservative, so how to determine the bearing capacity is an urgent problem to solve in the practical engineering.In this paper, by using the large finite element software Ansys to calculate and analyze the potential bearing capacity of the spandrel-filled stone arch bridge designed and built according to Highway bridge and culvert standard drawings (The Stone Arch Bridge JT/GQB 018-73), the influence of the bearing capacity of various diseases is appropriately considered, and the bearing capacity of the standard arch bridge is quantized. At last the method of potential bearing capacity factor is put forward used to calculate the actual bearing capacity of the standard arch bridge.At first, according to Highway bridge and culvert standard drawings (The Stone Arch Bridge JT/GQB 018-73) a real bridge model of the spandrel-filled stone arch bridge and the corresponding theoretical model with only the arch ring are established. Comparing action-effect of the two models under the same load conditions, the concept of carrying capacity coefficient is put forward using the relative difference of action-effect between these two models, then the potential bearing capacity of the spandrel-filled stone arch bridge is quantized. In order to fully consider the influence factors of carrying capacity, the nonlinearity of the material and the load transverse distribution are taken into consideration in the model calculation, then the general law of the coefficient of bearing capacity is summed up;Afterwards, the common diseases and their reasons of the spandrel-filled stone arch bridge are summarized and analyzed. According to the degree of the influence on the bearing capacity, the common diseases are divided into major and minor defects, then main diseases’ influence on the behavior of bridge structure is analyzed by using the finite element software;Finally, the shortcomings and limitations of existing specification relating to the detection and assessment to the carrying capacity of the spandrel-filled stone arch bridge are summarized and analyzed. Then the method of potential bearing capacity factor and its applicable scope are put forward. The influence of diseases and the potential bearing capacity of the spandrel-filled stone arch bridge with the increases of the actual operation load are all taken into consideration, so that this method can be used to determine the bearing capacity of the spandrel-filled stone arch bridge designed and built according to Highway bridge and culvert standard drawings (The Stone Arch Bridge JT/GQB 018-73).