关键词: 顶管施工, 正面附加推力, 注浆压力, 土体损失, 摩阻力, 土体变形

Abstract:

Pipe jacking has been widely applied to water supply and drainage pipelines and small-diameter tunnels; however, the soil deformation induced by pipe jacking may increase the risk of serious construction problems. The main factors causing soil deformation include positive additional thrust of cutter, friction between jacking machine or subsequent pipes and soil, grouting pressure and soil loss. This research focused on and analyzed the soil deformation caused by above factors. The feasibility of deformation formula was proposed by addition of all deformation formula, and was applied to 0# test pipe jacking of Zhuhai connection highway in Hongkong-Zhuhai-Macao bridge project. The results show that the maximum soil deformation induced by soil loss, grouting pressure and frictional resistance between soil and jacking machine is respectively -8.000、2.500 and ±2.020 mm. It also indicates that they are major factors to influence soil deformation. However, the maximum soil deformation induced by positive additional thrust and frictional resistance between soil and subsequent pipes is only ±0.075 and ±0.230 mm respectively, which is non-significant. Except that the deviation is larger at maximum subsidence, the soil deformation calculated value is more close to measured value, compared to Peck formula.

Key words: pipe jacking, positive additional thrust, grouting pressure, soil loss, frictional resistance, soil deformation