济南复合地层土压平衡盾构掘进效能实测分析#br#

依托济南轨道交通一号线复合地层土压平衡盾构掘进施工，提出一种在盾构机额定配置条件下的分项功耗和施工参数离散性指标双结合的掘进效能评价方法，并据此分析得到刀盘切削、盾构推进和螺机出土效能的变化特征。结果表明：①土压平衡盾构穿越济南复合地层时，盾构掘进总功耗在400~1250kW变化，其中，刀盘切削和盾构推进是盾构掘进功耗的主要组成部分，占总功耗的66%~84%；②刀盘切削的扭矩和转速具有明显的聚集特征，而盾构推进速度和推力分布形态的聚集特征弱于刀盘参数；③螺机出土的转速和扭矩在不同地层中的差异性不大，螺机参数的聚集特征不明显；④由于盾构掘进的分项功耗与其离散性指标不存在必然的联系，盾构施工中可能存在掘进功耗小但施工控制困难的情况，应在盾构选型及施工过程中予以充分考虑。

Measurement and analysis on EPB shield machine tunneling efficiency in#br# Jinan composite stratum

Based on the earth pressure balanced (EPB) shield tunneling practice of Jinan metro line 1, an evaluation method of tunneling efficiency was proposed by combining the respective power dissipation index and construction parameter dispersion index under the rated configurations of shield machine. Furthermore, by applying the evaluation method, the following varying characteristics of tunneling efficiency, including cutting of cutterhead, advancing of shield and soil conveying of screw machine, were obtained. The results show that the total tunneling power of shield machine changes from 400kW in loess-silty composite stratum to 1250kW in silty-cobble composite stratum. The cutting of cutterhead and advancing of shield machine account for 66%-84% of the total energy consumption of shield tunneling. The cutting torque and rotating speed of cutterhead have obvious accumulation characteristics, but the advancing speed and thrust force distribution of shield machine have less accumulation characteristics than cutterhead parameters. However, the rotating speed and torque of screw machine have unobvious distinction in different stratums. Furthermore, there is no necessary correlation between respective power dissipation and parameter dispersion index. In some exceptional cases, it could be difficult to control a shield machine although the energy consumption during tunneling is less, which shall be carefully considered in the selection of shield types and construction process.