卵石地层土压平衡盾构撕裂刀布置模式对比研究

Comparative Analysis of Arrangement Modes of Tearing Cutters for Earth Pressure Balance Shield Tunneling in Cobble Stratum

为研究卵石地层土压平衡盾构撕裂刀布置模式对刀具磨损的影响,结合北京地铁19号线平—积区间、牛—金区间基本相同地层条件下撕裂刀不同布置模式的盾构掘进工程案例,采用数学回归分析方法对比“大高差宽间距”和“小高差窄间距”2种撕裂刀布置模式下的刀具磨损系数。研究结果表明:1)在地质情况、掘进参数、渣土改良等条件基本一致的情况下,采取“小高差窄间距”撕裂刀布置模式的刀盘上刀具磨损量更大,其高撕裂刀、低撕裂刀、刮刀的磨损系数分别为“大高差宽间距”模式的1.5、3.2、2倍;2)“大高差宽间距”撕裂刀布置模式下,高、低撕裂刀起到了良好的分层犁松作用,有效降低了撕裂刀的磨损;3)“大高差”撕裂刀布置模式比“小高差”布置模式下的刮刀磨损系数减小了42.7%,“宽间距”布置模式比“窄间距”布置模式下的刮刀磨损系数减小了36.1%。

To investigate the influence of tearing cutter arrangement modes on the wear of tearing cutters during earth pressure balance shield tunneling in cobble strata,a case study is conducted on shield tunneling projects of the Ping′anli-Jishuitan and Niujie-Jinrongjie sections of Beijing metro line 19.Using mathematical regression analysis,the wear coefficients of tearing cutters under two arrangement modes:large height difference and distance and small height difference and distance,are investigated and compared.The findings are as follows.(1)Under identical geological conditions,excavation parameters,and soil improvement techniques,the wear is significantly higher with the small height difference and spacing arrangement mode compared to the large height difference and spacing arrangement mode.Furthermore,the wear coefficients for high tearing cutters,low tearing cutters,and scrape cutters are 1.5,3.2,and 2 times greater,respectively,under the small height difference and spacing arrangement mode.(2)The high and low tearing cutters,when placed with a large height difference and spacing,effectively contribute to layering and loosening,thus reducing tearing cutter wear.(3)Scrape wear coefficients under the large height difference and spacing arrangement modes are 42.7%and 36.1%lower compared to the small height difference and spacing arrangement modes,respectively.