燃气爆炸作用下地下综合管廊动力响应模拟

针对地下综合管廊结构的抗爆性能,依托某工程实例,建立综合管廊结构在燃气爆炸荷载作用下的三维有限元模型,确定燃气爆炸荷载曲线及其在地下管廊上的加载方式,分析了地下管廊在燃气爆炸荷载作用下的动力响应,讨论了燃气爆炸荷载峰值、持时等主要参数对地下管廊衬砌动力破坏特征的影响。结果表明,燃气爆炸荷载作用下,管廊衬砌的损伤破坏具有局部性和弱传递性;当超压峰值小于0.2 MPa,管廊损伤程度不大;随燃气爆炸荷载峰值的增大,管廊衬砌的损伤程度逐渐加重,达到0.7 MPa时,即便较短持时,燃气室也将出现明显破坏;随燃气爆炸荷载持时的增大,管廊结构损伤破坏加重;相同冲量时,荷载达到峰值时间越短,管廊衬砌的损坏范围和损伤程度越大。

Numerical Simulation of Blast-resistant Performance ofUtility Tunnel under Gas Explosion

A 3D finite element model for calculating anti-blast performance of a utility tunnel was established according to a practical project. The dynamic response of the utility tunnel under gas explosion loading have been analyzed by determining the gas explosion loading curve and the loading method. The influence of the main parameters such as peak gas explosion loading and its duration on the dynamic failure characteristics of the utility tunnel lining was discussed. The results indicate that the damage of lining is localized and weakly transitive under the action of gas explosion; when the overpressure peak value is less than 0.2 MPa, the degree of damage in the utility tunnel is not large; the damage of the lining is increased with an increasing peak value of gas explosion. With the peak value reaching 0.7 MPa, the gas chamber could also be significantly damaged for a short duration. Moreover, as the duration increases, the damage of the structure is aggravated. For the same impulse, the utility tunnel lining will be more severely damaged when the time for gas blast is shorter.