装配式地下管廊穿越活动地裂缝的适宜性分析

Suitability Analysis of Assembly Underground Utility Tunnel through Active Ground Fissures

在地裂缝分布广泛的地区,装配式地下综合管廊穿越活动地裂缝的适宜性尚不明确。为了研究装配式地下管廊在地裂缝活动作用下的受力与变形特性,通过建立装配式地下综合管廊穿越地裂缝的三维有限元模型,设置了10 cm、15 cm,20 cm和25 cm 4种不同沉降量工况以及45°、60°、75°和90°4种不同的地裂缝与管廊相交角度,分别进行了数值模拟计算分析。结果表明:随着地裂缝活动量的增加,管廊的变形与纵向应力均呈增大的趋势,且当沉降量接近20 cm时,管廊底板最大纵向拉应力达到混凝土抗拉极限,位置在下盘接触且靠近地裂缝处;地裂缝与管廊交角越小,管廊最大纵向拉应力越小,但扭转效应明显;在地裂缝活动性较弱的场地,装配式管廊穿越地裂缝表现出对不均匀变形更优越的适宜性。研究成果对地裂缝活动作用下装配式管廊的破坏机理的研究以及灾害防治具有重要意义。

In the area where ground fissures are widely distributed,the suitability of the assembly underground utility tunnel to pass through the active ground fissures is not clear.In order to study the stress and deformation characteristics of assembly underground utility tunnels under the action of ground fissures,threedimensional finite element models of assembly underground utility tunnels crossing the ground fissures were established.Four different settlement conditions of 10cm,15cm,20cm,and 25cm and four different intersection angles of 45°,60°,75°,and 90°were set.The numerical simulation and analysis are carried out,respectively.The calculation results show that with the increase of ground fissure activity,the deformation and longitudinal stress of the utility tunnel increase.When the settlement is close to 20cm,the maximum longitudinal tensile stress of the bottom plate of the utility tunnel reaches the tensile limit of concrete,which is located near the ground fissure in the footwall.The smaller the intersection angle between the ground fissure and the utility tunnel,the smaller the maximum longitudinal tensile stress of the utility tunnel,but the torsional effect is obvious.In the site with weak ground fissure activity,the prefabricated underground utility tunnel crossing the ground fissure shows better suitability for uneven deformation.The research results are of great significance to the study of failure mechanism and disaster prevention of assembly utility tunnels under the action of ground fissures.