为满足城市核心区浅覆土大断面矩形顶管隧道施工过程中对地表沉降和邻近既有结构变形控制要求，以淞沪路—三门路下立交工程项目为背景，采用MJS对近距离穿越既有箱涵结构进行加固保护、设计应用新型压力自补偿自锁式管节止退系统、科学合理地设置顶管推进施工参数、研发新型减摩触变泥浆及压注工艺体系，实现大断面小间距矩形顶管隧道施工对周边环境的微扰动。结果表明： MJS加固技术对被顶管穿越的既有结构有着良好的保护效果；新型的管节止退装置将管节的平均累计后退变形量控制在20 mm以内，推进过程中主要参数控制在设定范围内；新型减摩触变泥浆能有效填充建筑间隙、降低摩擦作用。基于现场实测变形数据分析可知，地表累计沉降控制在-19.74~6.92 mm，下穿合流污水箱涵结构周边土体沉降控制在-3.67~3.01 mm，结构本体垂直位移控制在-4.54~4.26 mm。

A case study is conducted on the Songhu roadSanmen road underpass project to control the surface settlement and deformation of adjacent structures while constructing a largesection rectangular pipe jacking tunnel with shallow overburden in the urban core area. Moreover, the metro jet system(MJS) method is used to reinforce the adjacent existing box culvert structure, a new pressure selfcompensating and locking pipe joint antireaction system is designed and developed, the pipe jacking construction parameters are scientifically and rationally set, and a novel frictionreducing thixotropic slurry and injection technology are developed, realizing microdisturbance on the surrounding environment caused by the construction of a largesection rectangular pipe jacking tunnel with small spacing. The results are as follows: (1) The MJS reinforcement technology protects the existing structure crossed by the pipe jacking. (2) The antireaction of the pipe joint controls the average cumulative retreat deformation of the pipe joint within 20 mm. (3) The primary parameters during the propulsion process are regulated within a predetermined range. (4) The frictionreducing thixotropic slurry effectively fills the building gap and reduces friction. According to the fieldmeasured deformation data, the cumulative surface settlement is controlled between 〖WT5BZ〗-〖WT５《TNR》〗19.74 and 6.92 mm, the settlement of the surrounding soil around the box culvert structure above the pipe jacking is controlled between 〖WT5BZ〗-〖WT５《TNR》〗3.67 and 3.01 mm, andthe vertical displacement of the structure is controlled between 〖WT5BZ〗-〖WT５《TNR》〗4.54 and 4.26 mm, indicating a good construction effect.