综合管廊燃气爆炸冲击波压力及动态响应研究

采用流固耦合算法,建立6种体积甲烷 空气混合燃气在综合管廊内发生爆炸的有限元模型,计算空气冲击波峰值压力、混凝土管廊的应力和位移时程曲线。并对各空气单元的压力峰值进行统计分析,提出相同燃气体积距燃气边缘不同距离的空气冲击波超压峰值曲线的数学解析式。对6种工况下管廊内距燃气边缘不同距离的空气冲击波超压峰值进行拟合,提出不同燃气体积、距燃气边缘不同距离的空气冲击波超压峰值曲面的数学解析式,并应用该曲面公式进行综合管廊燃爆响应分析计算并与原流固耦合模型的计算结果进行对比。结果表明利用冲击波超压峰值曲面解析式和在管廊内直接加载相结合的方法,在计算管廊节点最大位移、混凝土有效应力峰值和钢筋轴向及Mises应力峰值方面与流固耦合算\法结果差异较小,可以满足工程实践的要求。

Research on Shock Wave Pressure and Dynamic Response of Gas Explosion in Utility Tunnel

Based on the fluid-solid coupling algorithm,the finite element models of bix different volumes of methane-air mixed gas explosion in a concrete utility tunnel were established,and the peak pressure of air shock wave,the stress and displacement time history curves of the utility tunnel were calculated.The peak pressure of each air unit was statistically analyzed,and the mathematical analytic formula of the peak overpressure curve of the air shock wave with the same gas volume at different distances from the gas edge was proposed.The air shock wave ovepressure peaks at different distances from the gas edge in the utility tunnel under those six work-ing conditions was analyzed,and the mathematical formula of air shock wave overpressure peak surface with dif-ferent gas volumes and different distances from the gas edge was proposed.This surface formula was used to cal-culate the combustion and explosion responses of the utility tunnel,and the calculated results were compared to those from the original fluid-solid coupling model.The results show that for the maximum displacement of the utility tunnel node,the peak effective stress of the concrete,and the axial and Mises stress of the steel bar,there is lttle difference between the fluid-solid coupling algorithm method and the direct loading method based on the air shock wave overpressure peak surface formula.This method can meet the requirements of engineering practice.