超长距离顶管施工技术研究及应用

Application of a Construction Method in an Ultra Long Distance Pipe Jacking

以汤逊湖污水处理厂尾水排江工程中穿湖顶管为例,分析了长距离大直径顶管顶进过程中的受力机理,并研究了对于复杂地层中引起管节上浮与下沉的影响因素。通过顶管所处地层的力学性质、施工控制等因素分析了机头上浮的原因。综合现场条件,采取补勘查明地质、软土区域预加固处理、管内压载处理、启用中继间、管节底部及顶部开孔、加强顶管连接、控制顶进速度并及时纠偏等措施控制管节位移,使现场管节波峰回落,管节处于稳定状态。为后续在复杂不均匀地层区域顶管施工防止机头上浮或机头下载以及控制顶管施工中管道的变形提供理论依据与技术支撑。

This paper presents a case history of the pipe jacking for the wastewater discharge project of Tangxun Lake Sewage Treatment Plant.The force mechanism during the long-distance and large-diameter pipe jacking process is analyzed,and the influencing factors of the pipe joint floating and the sinking in the complex strata are studied.The reason for the floating of the machine head was analyzed through factors such as the mechanical properties of the strata where the pipe jacking is located and construction control.Based on the comprehensive on-site conditions,measures such as the supplementary exploration and the identification of geology,pre reinforcement treatment of soft soil areas,ballast treatment inside the pipe,activation of the relay rooms,the opening of holes at the bottom and top of the pipe joint,strengthening of pipe jacking connection,control of the jacking speed,and the timely correction of the deviation are taken to control the displacement of the pipe joint,so that the peak of the pipe joint on site falls back and the pipe joint is maintained in a stable state.To provide the theoretical basis and the technical support for the prevention of the head from floating or downloading during the subsequent pipe jacking construction in complex and uneven geological areas,as well as controlling the deformation of pipelines during pipe jacking construction.