多层砌体1/4比例模型墙体顶部裂缝试验研究

Model Experimental Research on Cracking Development at the Top Section of a 1/4 Scale Multi-story Building

为了研究多层砌体结构房屋顶端裂缝问题,根据简单相似性原理构建了一1∶4比例、每层均布有构造柱和圈梁的H型六层混凝土小型空心砌块砌体结构墙体模型.通过对墙体模型进行竖向加载的拟静力试验,模拟了纵横墙荷载差,深入研究了在竖向荷载差作用下砌体房屋顶端裂缝的产生行为和发展规律.研究结果表明:随着承重墙上竖向荷载的增加,承重墙与非承重墙之间的荷载差所引起墙体的竖向变形差增大,同时承重墙中部变形相对承重墙和非承重墙交界处变形较大.当荷载增加到一定值时,由于承重墙对非承重墙产生的拉应力进一步加大,承重墙上靠近非承重墙一端顶部出现裂缝.随着荷载的继续增加,承重墙上裂缝宽度增大并扩展,并有新的裂缝出现.由于构造柱-圈梁体系的约束作用,有效地控制了承重墙与非承重墙之间的竖向变形差的增大.

In order to study the cracks of multi-story masonry buildings,according to the simple similarity principle of model test,a 1：4 scale six-story H-type small-sized hollow concrete block masonry model was constructed,which arranged a constructional column-beam system in each story.By carrying out the test under vertical load and imitating the load difference between the bearing wall and non-bearing walls,the deformation and cracking behaviors in multi-story masonry buildings were investigated.The test indicated that the compression deformation increased with the increase of the vertical load.The vertical load resulted in different deformation between the bearing wall and non-bearing walls,which led to cracking on the bearing wall near non-bearing walls.Besides,the vertical deformation at the central section of the bearing wall exceeded those at the intersection between the bearing wall and non-bearing wall.Due to the increase of the tensile stress of the bearing wall,cracks occurred at the top section of non-bearing walls near the bearing wall＇s ends.With the increase of vertical load,the previous cracks enlarged and developed along with new cracks.The constructional column-beam system restricted the differential vertical deformation effectively.