公路桥梁板式橡胶支座失效标准研究

Study on Failure Standard of Highway Bridge Rubber Bearing

通过对山西省3条高速公路上的板式橡胶支座进行现场调研,确定了该类型支座存在的主要病害问题是支座局部脱空和支座剪切变形.然后通过单轴拉伸试验、双轴拉伸试验和平面剪切试验得出运营桥梁支座实际的特性参数.通过建立板式橡胶支座的有限元模型,分析得出橡胶支座的极限脱空率和极限剪切角.最后通过软件试算,模拟局部脱空和剪切变形两种病害同时存在的情况下支座的受力,拟合出板式橡胶支座在两种病害同时作用下的失效判别公式和失效曲线,如果局部脱空和剪切变形的组合满足失效判别公式或者在失效曲线范围之外,说明支座失效.研究得出的失效标准可以为板式橡胶支座的更换提供依据,具有较高的工程应用价值.

In a on-site examination on the plate type elastomeric pad bearings on three expressways in Shaanxi Province,the main problems of this type of pad bearings were local cavitation and bearing shear deformation.Then the uniaxial tensile test,biaxial tensile test and plane shear test were carried out to obtain the actual characteristic parameters of bridge bearing.By establishing a finite element model of the plate rubber bearing,the ultimate void ratio and ultimate shear angle of the rubber bearing were obtained.Finally,through the software trial calculation,the simulation the force of the pad bearings was conducted with both the local cavitation and the shear deformation,the failure identification formula and the failure curve of the rubber bearing in the plate under the simultaneous action of the two diseases were fitted.If the combination of partial void and shear deformation satisfied the failure criteria or was outside the failure curve range,the bearing failure was indicated.The failure criterion obtained in this paper could cast extra light on the basis for the replacement of the plate rubber bearing,and were of great engineering application value.