双舱矩形管廊正交地裂缝的数值模拟与分析

Numerical Simulation and Analysis of Orthogonal Ground Fissures in Double Cabin Rectangular Utility Tunnel

在活动地裂缝场地开展综合管廊建设具有较大的风险,很多学者建议在规划综合管廊时,应该尽可能与地裂缝正交。为了研究双仓矩形管廊正交地裂缝时的破坏机理,运用数值模拟的方法分析了双仓矩形管廊的破坏特征,并与类似工况下的地铁隧道进行了对比和验证。结果表明:(1)双仓矩形管廊最大纵向拉应力和压应力主要集中在底板和盖板,纵向应力与离截面几何中心线的距离成正比;(2)最大竖向剪应力主要集中在中隔板和侧壁中心线处,越靠近截面几何中心线竖向剪应力越大;(3)管廊和地铁隧道正交地裂缝时的破坏特征只与连接方式有关(现浇还是拼接),与截面形式无关,建议管廊在穿越地裂缝时的防治措施可参考已有地铁隧道的防治措施。

There is a great risk in the construction of comprehensive utility tunnel in the active ground fissure site.Many scholars suggest that the comprehensive utility tunnel should be orthogonal to the ground fissure as much as possible.In order to study the failure mechanism of double cabin rectangular utility tunnel under orthogonal ground fissures,the failure characteristics of double cabin rectangular utility tunnel are analyzed by numerical simulation method,and compared with subway tunnel under similar conditions.The results show that:(1)the maximum longitudinal tensile stress and compressive stress are mainly concentrated in the bottom plate and the cover plate,and the longitudinal stress is proportional to the distance from the geometric center line of the utility tunnel section;(2)the maximum vertical shear stress mainly concentrates on the center line of the middle diaphragm and side wall,and the closer to the geometric center line of the section,the greater the vertical shear stress;(3)the damage characteristics of the utility tunnel and subway tunnel are only related to the connection mode(cast-in-place or splicing),and have nothing to do with the cross-section form.It is suggested that the prevention and control measures of utility tunnel crossing ground fissures can refer to the existing prevention and control measures of subway tunnel.