体外预应力加固砌体结构振动台试验研究

Shaking table tests of masonry structures strengthened using external prestressing technique

基于地震作用下砌体结构墙体通常由于受剪能力不足而发生破坏的特点,提出了体外预应力对砌体结构进行抗震加固的方法,即在墙体两侧埋设并张拉预应力筋,使墙体在交角处和主要受力段受到预压力,以提高墙体的抗剪强度,改善砌体结构的抗震性能。为了验证该方法的有效性,制作了2个1∶4整体模型,其中1个模型采用体外预应力法加固,进行了模拟地震振动台模型对比试验。试验结果表明:采用体外预应力法对砌体结构墙体施加竖向整体预应力,可以提高墙体的抗剪、抗弯强度,改善墙体的延性和耗能能力,增强结构的整体性,提高结构整体刚度,且很少增加结构自重,是一种较为理想的抗震加固方法。

Based on the failure characteristics of masonry structures under earthquakes,a strengthening strategy using external prestressing techniques was presented.The external prestressing technique proposed in this research was that the junctions and the main support regions of the walls were pre-pressured by stretching the tendons located on both sides of the walls.It is believed that the shear strength and the seismic performance of the masonry wall structures can be improved by applying this external prestressing technique.The effectiveness of this technique was investigated experimentally through shaking table tests of two 1∶4 scaled whole models,including an experimental model and a control one.The results show that this technique can not only increase the shear strength and the bending strength of the walls,but also improve the ductility and the energy dissipation capacity of the walls.Furthermore,the integrity and the overall stiffness of the structure are also enhanced without substantial increase of the structure weight.