顶管隧道穿越地裂缝的结构性状与防治OACHSSCD

To study the influence of ground fissure activity on a pipe jacking tunnel,a three-dimen-sional finite element numerical model was established with the background of an electric power tunnel crossing the f12 ground fissure in Xi'an.The deformation and stress characteristics of the pipe jacking tunnel under ground fissure displacement were analyzed,and the structural countermeasures were dis-cussed.The results show that the tunnel experiences significant abrupt deformation near the fissure,with the inner steel ring occurring obvious stress.When the dislocation is 50 cm,the inner steel ring in some joints of the footwall has reached yield strength,exhibiting a"hinge-like"opening phenome-non.The maximum joint opening angle is at the 6th section in the hanging wall and the 13th section in the footwall.Lining contact pressure and strain show opposite changes in the hanging wall and foot-wall,with a clear void area between the tunnel and surrounding soil near the ground fissure.It is rec-ommended to enhance the longitudinal stiffness of the structure for the pipe jacking tunnel crossing ground fissures,adopt multi-layer waterproofing at joints.The reinforcement measure of secondary lin-ing and Ⅰ-steel can effectively control the joint opening and longitudinal stress of the tunnel.The find-ings provide a scientific guidance for preventing structural damage in pipe jacking tunnels in area with developed ground fissure.