Test and Analysis of Jacking Force and Friction Resistance of Large-Diameter Concrete Pipe-Jacking with Super-long Distance at Seabed

Based on the in-situ measured data of the first pipe-jacking of Xiamen Xiang’an subsea comprehensive pipe gallery project,the correlation between the jacking force F_p,the average resistance friction f_k and the jacking distance L were studied,so as to refine the value of the average resistance friction f_k in the second pipe-jacking. The results show that:f_khas a large absolute value and fluctuates frequently when L = 0 ～ 20 m; f_k≈3.0 k Pa when L>30 m; when L>380 m,and f_k<2.0 k Pa,f_koscillates up and down at 2.0 k Pa and never exceeds 3.0 k Pa. When the construction stops,f_k increases significantly in the range of 2 ～ 5 m of recovery jacking and then it quickly falls back to normal level. The research results provide the basis for the average friction value of the second pipe-jacking and the layout of the relay wall.