Pier Height Impact Study Of The Damping Effect Of The Lrb

The principle of bridge vibration reduction design, operation mechanism, mechanical characteristics and parameters calculation of LRB (Lead-Rubber-Bearing) are introduced in this paper. The continuous beam bridge calculation model with the same height of piers and the consolidation of the piers and basement is built. The two-level fortification criterions and two stage design method and elastic response spectrum theory are adopted, and the program of NBA (Nonlinear-aseismic Analysis for Beam Bridge) is used for computation. Through the analysis of the influence parameters which affect the decreasing rate, the lead areas of LRB and heights of the piers are determined as the two main factors, and the height range of the piers in which LRB can realize 30 percent decreasing rates is given. The distinguishing method, whether the goal of satisfied decreasing rates can be realized by use of LRB as to the continuous beam bridge and the dimensionless constant(demarcation constant Kz) are put forward in the first time. Finally, the section strength of the pier is checked and the influence of the ductility of the piers to the decreasing rates of LRB is analyzed. The result shows that the decreasing aim that piers remain elastic working condition under large earthquake cant not be achieved by use of LRB, but the influence of a certain extent of ductility to the decreasing effect of LRB is insignificant. So the reliability of demarcation constant Kz is demonstrated.