浅埋三舱管廊甲烷爆炸的地面响应规律

地下综合管廊可燃性气体爆炸事故时有发生,给地面人员的生命和财产造成了巨大损失。依托重庆市某地下综合管廊试点工程,基于物质点法,采用点火增长模型模拟浅埋管廊泄漏甲烷气体爆炸冲击管廊本体结构和围岩的过程,研究爆炸作用下地面压强与位移的响应特性。研究发现:泄爆作用下管廊及围岩会出现因接触面反射和折射产生的次生应力波,管廊横向方向次生波振幅随距起爆点水平距离的增大而增大,而管廊纵向方向产生的次生波振幅较小,且随距离增大变化较小;爆炸作用造成整体地面沉降,但在起爆点中心附近地面隆起,这种隆起由管廊本体结构破裂,气体直接冲击岩土体形成的剧烈隆起和管廊整体震动形成的轻微隆起两部分组成。

Ground Response Law of Methane Explosion in Shallow Buried Three-Cabin Pipe Gallery

Explosion venting accidents in underground comprehensive pipe corridors occur from time to time,causing huge losses to ground personnel and property.Based on a pilot project of an underground comprehensive pipe gallery in Chongqing and the material point method,a high-energy combustion model is used to simulate the process of leaking methane gas explosive’s impact on the structure and surrounding rock of the pipe gallery.Through the simulation,the response characteristics of ground pressure and displacement are studied.The results show that:under the effect of explosion,secondary stress waves caused by reflection and refraction of the contact surface will appear in the pipe gallery and surrounding rock.In the transverse direction,the amplitude of the secondary wave increases with the increase of the horizontal distance from the initiation point,while that generated in the longitudinal direction keeps smaller,and the change remains small with the increasing distance.The explosion caused the overall ground subsidence,but the ground bulged near the center of the detonation point.This bulge was composed of a violent bulge formed by the pipe gallery lining broken and gas directly impacting the rock and soil,and a slight bulge formed by the overall vibration of the pipe gallery.