复杂地层EPB/TBM双模式盾构掘进性能分析

Analysis of Tunneling Performance of Earth Pressure Balance/Tunnel Boring Machine Double-Mode Shield in Complex Strata

为探究EPB/TBM双模式盾构在土层、土岩结合地层、长距离硬岩等复杂地层中掘进性能的优势及不同模式下各种地层中掘进参数变化、刀具消耗的规律,从怀福区间左线掘进各项施工参数分析入手,收集自盾构始发至模式转换到出洞完整施工周期的施工参数,对比双模式盾构在相同模式下不同地层、不同模式下相同地层的参数变化、掘进工效的变化情况,分析每个影响施工效率的参数因素。得到:1)在EPB施工模式下,土压力和刀盘转速对掘进参数影响明显,在软土地层中,要保证地面变形在设计范围内,应尽可能降低土压力;在岩石地层中,应尽量减少积渣高度,提高刀盘转速,以提高推进速度,从而得到更高的施工效率。2)在TBM施工模式下,掘进参数主要受岩体节理发育程度影响,应及时根据岩体的节理发育调整转速、贯入度等参数,以此提高TBM模式下的施工效率。通过分析在硬岩掘进过程中对应不同地质情况、不同模式下刀具消耗的位置及消耗的原因,得到在全断面硬岩掘进条件下降低刀具正常损耗的主要因素在于降低土舱内存渣量对滚刀的二次磨损的施工建议。

To investigate the advantages of earth pressure balance(EPB)/tunnel boring machine(TBM)dual-mode shield tunneling in complex strata such as soil,soil-rock combination strata,and long-distance hard rock,and the regularity of tunneling parameters and cutter consumption in various strata under dual modes,a case study is conducted on left-line excavation in the Huaide-Fuyong section of the Shenzhen metro.Then,the construction parameters from shield launching to mode conversion and construction completion period of tunnel excavation are collected,the parameter variations and tunneling efficiency of shield tunneling in different strata under the same mode and those in same strata under different mode are comparatively examined,and the parameter factor affecting construction efficiency is analyzed.It is concluded that:(1)Under EPB mode,the influence of soil pressure and cutter rotation speed on excavation parameters is significant.In soft soil layer,to guarantee the ground deformation within the design range,the soil pressure should be lowered as far as possible;in rock formation,the height of muck accumulation should be minimized,and the cutter rotation speed should be increased so as to improve the construction efficiency.(2)Under TBM mode,the excavation parameters are mainly affected by the degree of joint development of rock mass.The main parameters such as rotation speed and penetration degree should be adjusted in time to improve the construction efficiency.The cutting tool consumption locations and causes are analyzed when tunneling in hard rock formation with different geologies and modes,and the suggestion of reducing secondary abrasion of disc cutter induced by residue in the soil chamber is proposed to reduce the cutting tool consumption in full-face hard rock formation.