关键词: 高压水射流切割;清障;盾构掘进;桩-土相互作用;极限平衡分析;参数分析;

Abstract: Considering that the shield tunneling method is easily restricted by unfavorable stratum conditions, we introduced a new obstacle breaking method of cutting pile, namely water jet cutting method, and studied the tunnel face stability of shield tunneling under this method. Based on the limit equilibrium theory and relative parameters, a tunnel face failure model was proposed. The limit support pressure of the tunneling face was obtained and an ahead reinforcement length formula was further given. Then numerical simulation and a case study were conducted to verify the model. Through parametric analysis, the influence of the soil friction angle, buried depth ratio, reinforcement length on the tunneling face stability was analyzed. The results showed that the support pressure was positively correlated with the buried depth ratio, and negatively correlated with the soil friction angle and reinforcement length. Finally, the Spearman correlation coefficient method was used to obtain influential degree of the three parameters on the support pressure in a decaying order of the reinforcement length> friction angle> buried depth ratio, and the correlation between the internal friction angle and the buried depth ratio was poor.

Key words: water jet cutting; obstacle breaking; shield tunneling; pile-soil interaction; limit equilibrium analysis; parametric analysis