浅埋小间距矩形顶管掘进姿态控制技术探讨

为解决采用结构分割转换工法（CC工法）建造的某地下停车场小间距隧道群矩形顶管施工中顶管机出现栽头及掘进姿态控制困难的问题，结合项目施工过程的姿态监控数据，对产生栽头及姿态偏差的原因进行理论分析，提出相应的控制技术，并采取现场试验的方法进行效果验证。结果表明： 1）顶管机栽头现象的原因主要有顶管机体重心偏差、漏浆、姿态预留不够、后靠不稳； 2）通过设备和管节定位处理、洞门密封处理、增加始发姿态预留量、后靠稳定性控制等措施可有效防止顶管机栽头； 3）始发阶段采取洞门预留、破除等控制措施，掘进阶段控制掘进速度并辅以“E”型导向槽进行轴线控制等措施，可有效控制顶管机顶进姿态； 4）通过采取调整铰接油缸行程差、主推油缸行程差及姿态偏差方向的土压等姿态纠偏技术措施，取得了良好的施工效果。

Boring Attitude Control Technology for Shallow covered and  Small spacing Rectangular Pipe Jacking

During the construction of small spacing rectangular pipe jacking in an underground parking lot constructed by cut and convert (CC)method, problems such as the pipe jacking machine declination and difficulty in controlling the jacking attitude often occur. Therefore, the causes for jacking declination and attitude deviation are theoretically analyzed based on attitude monitoring data, and corresponding control measures and field test are carried out. The results show that: (1) The causes for declination include machine body weight deviation, slurry leakage, insufficient attitude reservation and unstable backrest. (2) The declination can be effectively prevented by adopting measures such as equipment and pipe segment positioning, door sealing treatment, initial attitude reservation increasing and backrest stability control. (3) The door reservation and cutting during launching phase and boring speed control and E shaped guide groove for axis control during jacking phase can effectively control the jacking attitude. (4) By adjusting the stroke difference of the articulated cylinder and the main push cylinder and the earth pressure along the direction of the attitude deviation, good effect has been achieved.