Normalization Studies on Tunneling Parameters of Large Diameter Earth Pressure Balanced Shield in Composite Strata

摘要

Studies on the correspondences among shield tunneling parameters and their relationships with geological/hydrogeological parameters have significances to maintain good shield tunneling posture, to meet the requirements of construction schedule, safety, and quality, and to control ground subsidence effectively. In this paper, taking diameter 8.8 m shield tunnel of Zhuhai City to Zhuhai Airport intercity rail transit project as the background and according to real-time tunneling parameter recordings and engineering geology/hydrogeology prospecting reports, the correlations among shield tunneling parameters, and between shield tunneling parameter and geology/hydrogeology parameter were analyzed by normalizing each parameter in the process of shield tunneling, and by weighting processing on the contributions of geology/hydrogeology parameters of different strata, such as ground bearing capacity and permeability coefficient, to shield tunneling. The change trends of the tunneling parameters after "normalization" and weighted processing were illustrated and the corresponding rules between every two parameters were summarized. At the same time, the correlations between tunneling parameters and geological/hydrogeological parameters were analyzed. The results show that there is a good positive correlation between the total thrust force and the torque of the cutter head; there is a good negative correlation between the cutter depth and the cutter torque and the total thrust; and it is feasible to identify stratum based on the parameters of soil, including basic bearing capacity and soil permeability coefficient, and parameters of shield tunneling.