复杂岩石地层盾构掘进速率预测模型研究

为提高盾构掘进效能,指导盾构掘进施工,对泥岩砂岩交互地层条件下越江隧道盾构掘进速率预测模型进行了研究。在施工现场进行盾构掘进试验,通过盾构数据采集存储系统,获取盾构掘进的基本参数,并进行点荷载强度试验以获得岩石强度数据。运用多元回归分析的方法,分析了盾构掘进速率与岩石点荷载强度及刀盘推力的关系,分别构建了泥岩和砂岩地层盾构掘进速率的预测模型,并对其进行了应用。研究和应用表明,在泥岩和砂岩两种地层条件下,盾构掘进速率均随岩石强度的增大而降低,随刀盘推力的提高而增大,掘进速率与刀盘推力、点荷载强度均呈幂函数关系。

Shield Tunneling Rate Prediction Model for Complex Rock Stratum

In order to improve shield tunneling performance and provide guides for shield construction,prediction models of shield tunneling rate in alternation of mud rock and sand rock strata of Chongqing Yangtze River tunnel were discussed.Based on the field shield excavation tests,shield tunneling data were acquired by data acquisition and storage system of shield machine.Meanwhile rock point load index(PLI) tests were carried out to produce rock strength parameters.Subsequently,the relationships of shield tunneling rate with PLI and thrust force of cutter wheel were studied.Upon the above data and analysis,tunneling rate prediction models of mud rock and sand rock strata were developed by means of multiple regression analysis method results indacate that(1) in the two strata,the higher the rock strength,the lower the tunneling rate,and the higher the thrust force of cutter wheel,the higher the tunneling rate;(2) the relationships of tunneling rate with thrust force and point load index are all subjected to exponential function.The models can be used conveniently with simple form,few parameters,and high precision.Simultaneously the models can also be used to perform back analysis of rock PLI only with simple transformation.