锤击作用下钢筋混凝土框架倒塌性能试验研究

为研究钢筋混凝土平面框架结构在局部构件失效后的静、动力特性,完成了两榀两跨单层平面框架试验,其中一榀框架用于静载试验以获取框架静力特性数据,另一榀框架分别在空载、均布线荷载情况下采用锤击法进行动力试验,获取试验框架的位移、加速度和钢筋应变等动力响应数据.通过对比分析静载与动力试验结果,研究框架梁在锤击过程中的受力特性.试验结果表明:在大当量力锤锤击作用下,动力位移幅值与输入冲量近似呈线性关系,随着锤击力的增加,结构阻尼变化较小,频率下降.布有均布线荷载的框架梁在锤击荷载作用下产生了拱效应,刚度略有提高.尽管力锤最大锤击力超过框架梁最大抗力,但冲击能量不可使其发生倒塌.

Experimental Study of the Collapse Performance of RC Frame under Hammer Load

Two 2-bay, 1-story RC plane frames were tested to study the static and dynamic behavior of RC frame structure after the column's failure. A static experiment was done to obtain the static behavior data of frame structure, and based on another test frame, hammer experiments were used to obtain the frame beam's dynamic response data of displacement, acceleration and steel strain under no load and uniformly distributed load, respectively. The mechanic behavior of the frame beam under hammer load was studied by comparing the static and dynamic test results. The tests results were as follows: there was a linear relationship between the dynamic displacement amplitude and the input impulse under hammer load; with the increase of the hammer load, the damping of the structure changed little while the frequency decreased; the frame beam with uniformly distributed load formed the arch effect under hammer load, so its stiffness increased slightly; the maximum hammer load exceeded the frame beam's maximum resistance force, but the frame beam did not collapse because of the small impact energy.