地震-燃气爆炸灾害链效应对剪力墙结构的损伤研究

Research on Damage of Shear Wall Structures Subjected to Earthquake-Gas Explosion Hazard Chain Effect

地震可能会导致管道损坏和燃气泄露并引发爆炸,从而在短时间内形成灾害链效应作用于结构上。目前研究大多对地震或爆炸单独作用于结构对其动力响应进行分析,对于这种灾害链效应所导致的损伤规律尚不清楚。提出剪力墙结构考虑地震-燃气爆炸灾害链效应的动力响应分析方法,利用TNT当量法将燃气荷载等效为立方体炸药,在地震作用结束后一段时间内施加爆炸荷载以模拟灾害链效应,通过ANSYS/LS-DYNA软件分析结构的动力响应。以一个12层剪力墙建筑结构为例,选取3条地震波并考虑不同的爆炸位置的影响进行非线性时程分析,研究剪力墙结构的动力响应和损伤规律。结果表明:同地震单独作用相比,地震-燃气爆炸灾害链效应会进一步导致结构的局部出现明显损伤;燃气爆炸荷载作用于结构中间楼层时,结构的总体损伤面积增大,剪力墙严重破坏甚至丧失承载能力;燃气爆炸荷载作用于楼层中心位置时,结构的损伤程度明显大于其作用于同楼层角部位置时的工况。

Earthquakes may break the pipeline and result in gas leakage and explosion,thus forming a disaster chain to the structure in a short time. However,the dynamic structural responses under earthquakes or explosion are always separately investigated,and the damage patterns due to the disaster chain(e. g.,the continuous earthquake-gas explosion) is not clear. A comprehensive dynamic response analysis method is proposed for shear wall structures considering the effect of the earthquakegas explosion disaster chain. The gas explosion load is calculated by simulating the TNT as a cube explosive. The explosion load is applied to the structure after a couple of minutes of the ending of an earthquake to simulate the disaster chain,and the dynamic response of the structure is analyzed by ANSYS/LS-DYNA software. A 12-story shear wall building structure is used as a representative case,in which three earthquake records are selected for nonlinear time history analysis. Different explosion positions are selected to study the dynamic response and damage patterns of the shear wall structure. The numerical results indicate that the effect of the earthquake-gas explosion chain will further aggravate the local damage of the structure compared to the individual seismic excitations. In addition,the shear wall structure will have a larger overall damage area and will experience severe damage or even lose its bearing capacity when the gas explosion is located in the middle story of the structure.Compared to the gas explosion load acting on the corner of the same floor,the damage degree of the structure is more significant for the explosion locating near the center of the floor.