The Study For The Shear Test Method Of The Elastomeric Bearings For Bridge And Stiffness Of Testing System

The elastomeric bearings are important parts of bridge. Bridge bearings are designed to accommodate the changes in the length of the bridge girder resulting from the temperature variations, shrinkage, and creep, while simultaneously supporting the dead and live loads. Research of the shear test method of the elastomeric bearings and stiffness of testing system were performed in this article.The shear modulus of the elastomer is the most important mechanical property related to the behavior of elastomeric bearings used principally at supports in bridges. At home and abroad, most current test methods, called the compression-shear test, for determining the shear elastic modulus usually is limited to compressive loads because of the inherent difficulty and cost of applying compression and shear simultaneously. A new shear test method, called inclined compression test, relies on static principles to produce simultaneous compression and shear on a bearing merely through application of compression load. The shear force causes the center platen to move horizontally a distance △, which is measured. The shear elastic modulus can then be calculated.After correlative designing and modifying existing equipments, two pairs of elastomeric bearings were tested by the inclined compression test method. Additional tests were performed to determine if the difference in test results was related to compressive stress. By means of two test methods, the curves of G~ σ were obtained respectively. The result of analysis was concluded that the inclined compression test could be used as a replacement or an alternative to the compression-shear test standardized by nation. It is a cost-effective and easy test method for determining the...