泥水平衡顶管下穿高速桥梁施工关键技术研究

RESEARCH ON KEY TECHNOLOGY OF CONSTRUCTION OF MUD-WATER BALANCED PIPE JACKING DOWN HIGH-SPEED BRIDGE

顶管施工是城市地下空间开发建设中常用的施工过程,其是一种不需要地表开挖或较少地表开挖的管道敷设施工技术。近年来,我国在顶管技术的理论和施工技术领域取得了长足发展,但由于我国地域辽阔,不同的地区和城市地质条件、水文条件差距相对较大,地下空间环境相对复杂。顶管推进过程将使周围土壤发生挤压、剪切、卸载,不可避免地产生地层扰动变形,从而迫使邻近结构发生扰动。因此,研究复杂环境条件下大截段顶管工程施工过程中存在的关键技术具有重要的现实意义。研究以怀柔新城南部地区污水干线工程污水管道工程为背景,研究了当前国内外顶管施工方法的关键技术,结合工程地质条件和施工技术要求等,提出了下穿高速桥梁顶管施工中后背结构设计、姿态控制与纠偏方法和触变泥浆减阻措施等关键控制技术,并利用力学分析和监控量测方法进行验证,为项目的顺利施工提供了可靠依据。

Pipe jacking construction is a commonly used construction process in the development and construction of urban underground spaces.It is a pipeline laying construction technique that does not require surface excavation or less surface excavation.In recent decades,China has made significant progress in the theoretical and construction fields of pipe jacking technology.However,due to the vast territory and relatively large geological and hydrological conditions in different regions and cities,the underground space environment is relatively complex.The process of pipe jacking will cause compression,shear,and unloading of the surrounding soil,inevitably resulting in geological disturbance and deformation,thereby forcing adjacent structures to undergo disturbance.Therefore,studying the key technologies that exist in the construction process of large-section pipe jacking engineering under complex environmental conditions is of great practical significance.The study takes the sewage pipeline engineering of the sewage trunk line project in the southern part of Huairou new city as the background,and studies the key technologies of current domestic and foreign pipe jacking construction methods.Combining engineering geological conditions and construction technology requirements,key control technologies such as the design of the back structure,attitude control and correction methods,and thixotropic mud drag reduction measures in the construction of underpass high-speed bridges are proposed.Mechanical analysis and monitoring measurement methods are used for verification,provided reliable reference basis for the smooth construction of the project.