浅埋矩形顶管群密贴施工的顶推力分析研究

为明确矩形顶管群密贴施工中顶管顶推力的发展规律与影响因素，以圆形顶管顶推力计算理论为基础，依托实际的试验工程背景，分7个工况分别进行顶推力的统计分析。通过多工况理论估算与实测数据对比，验证管顶推力的实测值与理论值在规律上的一致性，同时得出该理论值较实测值偏小的结论。针对试验工程中出现的减摩失效、顶管背土、姿态异常等问题展开研究，通过对比分析不同工况实测顶推力发展规律，最终得出: 就本工程而言，减摩泥浆的减摩效果明显，顶推力减小约38.2％； 顶管背土与顶管姿态对顶推力具有较大的负面影响，其中,顶管背土导致每节顶推力增加约16.7％，顶管姿态异常引起顶推力额外增加17.8节的理论推力。

Analysis of Thrust Force of Adjacent Construction of Shallow buried Rectangular Pipe Jacking Tunnel Group

Based on the jacking force theory used in circular pipes, the development law and influencing factors of thrust force of rectangular pipe jacking tunnel group are analyzed through 7 working conditions in actual experimental engineering. The uniformity of the monitored pipe jacking force and theoretical values is verified by comparison between theoretical estimation and monitored data, and it is concluded that the theoretical values are smaller than monitored data. And then the problems of friction reduction, the phenomenon of pipe carrying soil, and attitude deviation are studied. Finally, by comparatively analyzing the development law of thrust force in different working conditions, it is concluded that: (1) The friction reduction effect of lubricating mud is obvious, i.e. the thrust force is reduced by about 38.2%. (2) The phenomenon of pipe carrying soil and attitude deviation greatly affect the thrust force, wherein the thrust force of each segment induced by the phenomenon of pipe carrying soil is increased by about 16.7%, and that induced by attitude deviation is increased by 17.8 of pipe force. 