深部高地应力地层TBM掘进速度和滚刀寿命预测模型研究

Compared with the traditional drilling and blasting method, tunnel boring machine (TBM) method requires enormous financial investment in the pre-construction phase and has high geologic risks in the terms of construction period and cost. Therefore, TBM performance prediction has always been a hot topic in the tunneling industry. The penetration rate and cutter life were systematically studied by establishing a database for TBM tunneling in shallow grounds by the applicant, but the influences of high in-situ stress in deep grounds on the penetration rate and cutter life were not considered in this preliminary study. In the current study, two typical TBM projects in deep grounds under high in-situ stress are investigated, and a database for TBM tunneling in deep grounds under high in-situ stress is established by using the comprehensive approaches including field data collection, field testing and laboratory experiment. Through the correlation analysis and multiple regression analysis, the empirical relationships between the field penetration index and some common rock mass parameters are revealed, and a multiple regression model to predict field penetration index is established, and the rock mass boreability evaluation method and penetration rate prediction model in deep grounds under high in-situ stress are proposed. Moreover, the wear rule of large-diameter disc cutters in deep grounds under high in-situ stress is revealed by statistically analyzing the disc cutter wear types and changes and the accumulated cutter ring wear extent at different positions on the cutterhead, and a new cutter life prediction model is suggested. The results of this study can provide the theoretical support to estimate the construction period and cost of the TBM tunneling projects in deep grounds under high in-situ stress.

与传统钻爆法相比，TBM工法前期设备投资大，且在施工工期和项目成本方面存在高地质风险。因此，TBM掘进性能预测一直是隧道行业内的热门研究话题。申请人前期通过构建浅部地层TBM掘进性能数据库，对掘进速度和滚刀寿命进行了系统研究，但深部高地应力条件对TBM掘进速度和滚刀寿命的影响还未完全探究清楚。本项目拟依托典型深部高地应力地层TBM施工案例，通过现场数据收集、现场试验和室内试验，构建深部高地应力地层TBM掘进性能数据库；结合相关性分析和多元回归分析方法，揭示深部高地应力地层现场贯入度指数与常用岩体参数之间的经验关系，建立现场贯入度指数的多元回归模型，提出岩体可掘性评价方法，开发掘进速度预测模型；统计分析滚刀磨损类型、不同刀位号滚刀换刀次数和刀圈累计磨损量情况，揭示深部高地应力条件下大直径滚刀的磨损规律，开发滚刀寿命预测模型。研究成果可为深部高地应力地层TBM项目的工期和成本估计提供理论支撑。

TBM工法已成为长大隧道施工的首选方法。与传统钻爆法相比，TBM工法前期设备投资大，且在施工工期和项目成本方面存在高地质风险。因此，TBM掘进性能预测一直是隧道行业内的热门研究话题。本项目围绕TBM掘进性能预测中的“掘进速度”和“刀具寿命”预测两大关键问题进行研究，主要开展了如下研究工作：(1)基于收集的LXB输水隧洞和吉林引松输水隧洞相关资料，按照相应数据筛选准则，构建了一个新的包含134组有效数据的TBM掘进性能数据库；(2)选取现场贯入度指数FPI作为岩体可掘性评价指标，探究了数据库中各岩体参数与现场贯入度指数FPI之间的经验关系，选取显著影响FPI的多个岩体参数，利用多元回归方法、SMA-ELM神经网络、SSA-BP神经网络三种方法建立了现场贯入度指数FPI预测模型，基于现场贯入度指数FPI对岩体可掘性进行了分级，并利用该分级方法建立了掘进速度预测模型；(3)基于刀具磨损现场数据揭示了不同类型滚刀磨损规律，分析并总结了两类滚刀寿命评价指标与安装半径之间的经验关系，利用灰色敏感度分析法探究了滚刀刀圈磨损速率与两类刀具磨损影响参数（完整岩石参数和TBM掘进参数）之间的敏感性，选取合理参数，开发了一个新的正面滚刀寿命预测模型。本项目取得的重要结果和关键数据为：(1)基于三种不同方法建立的现场贯入度指数预测模型中，SMA-ELM模型预测精度最高，SSA-BP模型次之，多元回归模型稍差；(2)边缘滚刀平均单个刀位的刀圈累计磨损量约为中心滚刀的7倍、正面滚刀的3倍，边缘滚刀平均单个刀位的刀圈更换数约为中心滚刀和正面滚刀的3~4倍，边缘滚刀刀圈平均利用率约为中心滚刀和正面滚刀的2~2.5倍；(3)考虑完整岩石参数和TBM掘进参数，基于单轴抗压强度UCS、刀盘推力F和刀盘转速w开发的正面滚刀寿命预测模型预测效果最优(R2=0.964)。上述研究成果可为掘进速度预测和岩体可掘性评价、滚刀磨损规律和刀具寿命预测提供方法支撑，进而为TBM项目的工期和成本估计提供理论支撑。