燃气爆炸作用下蒸压加气混凝土砌体墙的加固性能

为研究燃气爆炸作用下蒸压加气混凝土砌体墙的加固性能，基于有限元软件LS-DYNA，建立了砌体墙简化数值模型，分析了GB 50779-2012 石油化工控制室抗爆设计规范中建议的荷载作用下砌体墙高度和厚度的影响，对比了玄武岩纤维(basalt fiber reinforced plastic, BFRP)布与喷涂式聚脲对蒸压加气混凝土单向砌体墙的加固效果，并以防止砌体墙倒塌为设计目标，给出了加固建议。研究表明，本文中建立的简化数值模型能较好地模拟燃气爆炸作用下蒸压加气混凝土砌体墙的变形和破坏模式，计算结果与试验吻合良好；《规范》建议荷载作用下，未加固砌体墙以弯曲破坏为主，随着墙体高度增加，破坏模式由弯曲破坏向剪切破坏转变；BFRP布条加固可以有效提高墙体抗弯刚度和压拱效应，而聚脲涂层加固对抗弯刚度提高有限但墙体拉拱效应明显，二者均能显著提高墙体抗爆性能；加固墙体均发生弯曲破坏，BFRP布条材料的断裂一般发生在墙体位移最大处，而聚脲涂层材料的断裂发生在跨端边界处。

Performance of retrofitted autoclaved aerated concrete masonry walls subjected to gas explosions

Numerical studies were conducted by using the finite element software LS-DYNA to investigate the performances of the retrofitted autoclaved aerated concrete masonry (AAC) walls subjected to gas explosions. A simplified numerical model for the masonry walls was developed and calibrated with the test data. Under the blast loads specified by the design codes, the influences of wall height and thickness on the structural response of the unstrengthened one-way AAC masonry walls were discussed. In addition, the performances of the BFRP strip and spray-on polyurea strengthened one-way AAC masonry walls were compared and the retrofitting suggestions for engineering practice were proposed. It is found that the numerical predications of the mid-span displacements and failure modes are in agreement with the test data. Under the specified blast loads, the unstrengthened masonry walls mainly fail for bending of the structures, and with the increase of wall height, the failure mode changes from flexure failure to shear failure. Using the BFRP strips can improve the stiffness and arching effect of the walls significantly while the spray-on polyurea can enhance the tensile membrane effect of walls effectively. The failure mode of the strengthened masonry walls is a typical flexure failure. The fracture of the BFRP strips generally occurs at the mid-span area of the one-way masonry walls, while the fracture of spray-on polyurea occurs at the boundary of the masonry walls.