关键词: 顶管顶进, 硬岩, 管底积渣, 射流振荡原理, 试验研究

Abstract: During hard rock pipe jacking, muck accumulation at the pipe bottom frequently increases jacking resistance and can even cause pipe blockage, severely compromising construction efficiency and safety. To identify the key factors influencing muck removal efficiency and to establish the relevant technical principles, a methodology combining theoretical analysis, model experiments, and engineering validation is employed. A novel muck removal technique based on the principle of jet oscillation is proposed. The effects of jet pressure, overburden mass, and jet type on muck removal efficiency are systematically examined. The effectiveness of the proposed method is validated using data from a superhard rock pipe jacking project. The findings are as follows: (1) Muck removal efficiency increases with jet diameter, improving by 41%－75% as the diameter increases from 0.5 to 0.7 mm. (2) Jet pressure, overburden mass, and jet type collectively influence muck removal. Specifically, muck removal exhibits a linear positive correlation with jet pressure and a negative correlation with overburden mass. Rotary jets are more sensitive to pressure variation, while straight jets are more affected by overburden mass. (3) Under high overburden mass conditions, rotary jets outperform straight jets by 75.4%－104.6%, with 40 MPa rotary jet pressure identified as the optimal parameter. (4) Compared with conventional methods, the jet oscillation-based muck removal technique improves muck-removal efficiency by 99.5% and reduces total jacking resistance by 17.18% after muck clearance.

Key words: pipe jacking, hard rock, muck accumulation, jet oscillation principle, experimental study