装配式梁桥整体托换装置及瞬态冲击效应研究

Research on the integral underpinning device and transient shock impact of fabricated beam bridge

针对桥下改造空间受限的装配式梁桥给出了一种刚柔支撑的整体托换装置,重点就装置中移动横梁与混凝土梁体移动瞬间的冲击效应进行了研究,建立了能反映两梁体间相互关系和摩擦系数的结构动力学方程,从理论上明确了上部滑道动静摩擦系数比值0.5是移动横梁能否追上下部待拆梁体的临界点,数值模拟验证了理论模型的正确性,同时给出了混凝土梁体吊点处的动应力变化规律,发现其最大值与两梁体相对位置有关,移动横梁与下部梁体水平距离最小时混凝土梁体吊点处应力达到最大值.

Aiming at limited transformation space under the fabricated beam bridge to design a rigid and flexible support integral underpinning device and focus on the research on instant transient shock impact of moving crossbeam and concrete main beam which belonging to device. The structural dynamic equation is established which can reflect the interaction and friction coefficient between two beams. Theoretically it is made clear that the upper slideway static and dynamic friction coefficient ratio of 0.5 is the critical point of moving crossbeam that can keep up with the beam to be demolished.The validity of the theoretical model is verified by numerical simulation. At the same time, the dynamic stress change rule of concrete beam is presented. It is found that the maximum stress value is related to the relative position of the two beams.When the distance between the moving crossbeam and the lower beam horizontal is minimum, the concrete beam hanging point stress reached the maximum.