Bridge Rubber Bearing Performance At Low-temperature In Cold Region

At present plate rubber bearings are widely used in small bridge models in our country. Plate rubber bearings are not only key components of load transferring between upper and lower structure, but also play the role of ensuring the bridge rotation and displacement. Therefore, plate rubber bearings are quite critical in bridge structure. Bridge bearings located in northern China have long been in low temperature environment, which has a greater impact on the performance of rubber bearings. However, in recent years, the bearing research are mainly focused on the physical and mechanical properties of rubber materials in our country with more focus on the shock absorption measures and effects at the present stage. Low temperature performance of the rubber bearing has not been in-depth studied. In this thesis, mechanical properties of the plate rubber bearings are studied systematically at low temperature by trial and statistical analysis.Firstly, the research situation of plate rubber bearing is introduced in this paper and a new research direction is stated, in which the influence of low temperature condition to mechanical performance index of the rubber bearing is studied. Combined with the temperature change characteristics of Daxinganling mountain region, the mechanical performance index and change rule of cooling temperature variations of two hardy type rubber bearing is discussed based on experiment.Factors leading to this change rule are discussed, such as, with the decrease of temperature, the degree of hardening effect of rubber bearing on compressive elast ic modulus, shear modulus of elasticity, allowable angle and allowable shear angle; the effect of consistency change of Grease oil and molecular activity of contact surface on friction coefficient and the effect of failure pattern on peel strength and ultimate compressive strength.Secondly, combined with test data and analysis results, the selection of the bearing in Daxinganling mountain region is discussed, in which valuable suggestions is put forward.Finally, calculation theory and method of horizontal force distribution of continuous deck simple supported beam bridge is introduced. Calculation analysis of horizontal force is conducted combining with the shear modulus of elasticity in the bearing test at low temperature to study the influence law of temperature distribution to bridge horizontal force.