CFRP网格修复后多层砌体结构墙体的抗震性能

Seismic Performance of Multi-storey Masonry Wall Repaired by Carbon Fiber Reinforced Polymer Grids

为了研究碳纤维增强复合材料(CFRP)网格加固砌体结构的破坏机理及加固效果,通过拟静力试验将一片3层砌体开洞墙体加载至破坏,在破坏集中区域单面粘贴CFRP网格进行加固之后再次进行拟静力试验,以最小加固量为指标对加固前后墙体的抗震性能进行了对比分析,并提出了相应的加固建议.研究结果表明:采用CFRP网格修复可以有效地阻止和延缓墙体受剪斜裂缝的出现及开展,从而提升了墙体的抗震性能,若以抗剪承载力完全恢复为指标,建议最小修复面积为22%;修复后墙体的破坏模式与修复位置相关,本试验以CFRP网格剥离及窗间墙破坏为主,破坏由低至高逐层发生,同层墙肢范围内,由未修复区向修复区发展;考虑窗间墙破坏易引起结构整体破坏和倒塌,因此应优先修复剪力较大层的窗间墙区域,并提供必要的加强措施.

To study the failure mechanism and repair effect of plain masonry structure repaired by carbon fiber reinforced polymer(CFRP) grids, firstly,a three-storey masonry wall with openings was destroyed under the pseudo-static action, then, the areas where the cracks intensively occurred in destroyed masonry wall were repaired by CFRP grids, at last, the pseudo-static action was retested. The seismic performances of the masonry wall prior to and after repair were compared according to the lower limit of repair requirements, and the repairing suggestions were proposed. The results show that CFRP grids can effectively retard or prevent the occurrence of masonry shear diagonal cracks, and then the seismic resistance of masonry walls is developed. The lower limit of repair area is 22% when the shear bearing capacity fully restored is the indicator. The failure modes of the walls after repaired are related to the repair positions, the CFRP grids debonding and piers failure are the majority failure modes of the test. The failures initiate layer by layer from low to high, and develop from the unrepaired to the repaired zones on the same floor. The piers failure is most likely to cause the structure failure or even collapse, therefore, CFRP grids need to be preferentially applied to the piers where the shear stress is relative large, the additional strengthening measures are also essential.