The wear of the cutter in the high abrasive dense sandy stratum seriously restricts the construction efficiency.This paper aims to accurately predict the wear and the digging distance of the scraper of the large diameter slurry shield TBM.It statistically analyses the dense composite sandy stratum by counting the area ratio and the volume ratio of each stratum in the typically tunnel cross section and district.The sandy stratum distance ranges from the DK0+0 to DK1 +780 of Sutong GIL Utility Tunnel Engineering.The weighted average abrasion coefficient K′and its variation for each cross section and district in the composite sandy stratum can be obtained by combining the area ratio of each stratum,the volume fraction of each stratum and the abrasion coefficient K of each stratum. The calculated weighted average abrasion coefficient K′and the corresponding tool wear model are used to predict the tool wear and the digging distance of the large diameter slurry shield TBMin the dense composite sandy stratum. The results of tool wear and life prediction are compared with those in the actual construction process of large diameter slurry shield in Nanjing Yangtze River Tunnel under similar engineering geological conditions.The results show that the weighted average abrasion coefficient K′gradually increases with the increase of the mining mileage. The maximum value is at the milestone of 1778m and the maximum value is K′max =18.36 ×10-3 mm·km-1 .The maximum wear of the cutter locates at the installation diameter D=12.07m.If the upper limit wear value is set as δ=5mm,the cutter needs to be replaced twice,with the corresponding digging distance of L1 =1063m and L2 =453m.The comparison with the actual wear of the slurry shield TBM in Nanjing Yangtze River Tunnel shows that the prediction results are reliable.The results of the study provides theoretical basis for the wear prediction and cutter replacement of the slurry shield TBM in the Sutong GIL Utility Tunnel Engineering and similar cross-river tunnels.%高磨蚀性致密砂层中盾构刀具磨损严重制约施工效率.为准确预测大直径泥水盾构刮刀的磨损量与削掘距离寿命,本文采用隧道断面面积统计分析法和分段体积统计分析法对苏通GIL综合管廊工程DK0+0~DK1+780段隧道所穿越的密实复合砂层进行统计分析.结合典型断面各地层面积权重,分段各地层体积权重及单一地层磨耗系数K得到了隧道穿越密实复合砂层各典型截面和分段上加权平均磨耗系数K′及其变化规律.根据加权平均磨耗系数K′及相应刀具磨损模型,对大直径泥水盾构在密实复合砂层中刀具磨损量及削掘距离寿命进行预测.并将预测结果与类似工程地质条件下南京长江隧道大直径泥水盾构实际施工过程中刀具磨损量及削掘距离寿命进行比较.研究结果表明:加权平均磨耗系数K′随掘进里程增加整体呈逐渐增大趋势,在1778m处取得最大值K′max=18.36×10-3 mm·km-1;刀具最严重磨损发生在安装直径D=12.07m处.取限定磨损量 δ=5mm,对应的削掘距离寿命分别为L1=1063m和L2=453m,因此需要进行两次刀具更换.与南京长江隧道泥水盾构刀具实际磨损情况的对比表明预测结果具有较高的可靠性.该研究成果为苏通GIL综合管廊工程及类似地层条件下越江隧道盾构刀具磨损预测及更换提供了一定的理论依据.
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