TBM净掘进速度预测模型发展现状及参数分析

TBM净掘进速度预测模型能为隧道施工方法选择、施工进度安排和成本估算提供科学依据。本文对国内外32个典型模型开展参数定性和定量分析。根据各模型建模原理可将参数输入过程划分为按逻辑和组合关系输入、作为修正参数输入、直接输入参数三种类型。评价TBM掘进速度的岩体参数以单轴抗压强度、岩石质量指标、隧道与结构面夹角和岩石脆性指数居多,机械参数主要是单刀推力和刀盘转速。通过调整岩体工程特性关键参数影响区间以及引入机械参数,可将钻爆法岩体分类(RMR、RSR、Q_(system))应用到TBM净掘进速度预测。模型参数选取需要权衡简易性和准确性,参数太少虽然简易但影响预测精度,参数过多会导致实际操作繁琐而不利于工程广泛应用。参数选取合理、组合恰当以及权重分配符合实际是净预测模型准确可靠的关键,随着对掘进过程和破岩机理的深入理解,开展与岩-机作用相关的新评价参数研究将是未来发展趋势。

Development status and parameter analysis of TBM net tunneling speed prediction model

TBM tunneling speed prediction model can provide scientific basis for the selection of tunnel construction method，the construction schedule arrangement and the cost estimation，for which the qualitative and quantitative analysis on 32 typical models at home and abroad is made herein. In accordance with the modeling principles of all the models，the parameter inputting processes can be divided into three types，i. e. inputting according to logic and combined relationship，inputting as revising parameter and directly inputting parameter. The rock mass parameters for evaluating the TBM tunneling speed are mostly the indexes of the uniaxial compressive strength，the rock quality designation，the angle between tunnel axis and structural plane and the rock brittleness，while the mechanical parameters are mainly the thrust per cutter and the cutter head rotation speed. The rock mass classification ( ＲMＲ，ＲSＲ，Qsystem ) for drilling-blasting method can be applied to the prediction of the TBM net tunneling speed through adjusting the influencing intervals of the key parameters of the rock mass engineering characteristics. Simplicity and correctness are necessary to be considered for selecting the model parameters，for which less parameters are simple but affect the prediction accuracy，while more parameters can lead to complicated actual operation and be unfavorable for the widespread application to the engineering project. Ｒeasonable selection of parameters，proper combination and practical weight distribution are the key points to make the prediction model accurate and reliable. Following with the in-depth understanding of tunneling process and rock breaking mechanism，carrying out the study on new evaluation parameters related to the rock-machine interaction is to be an important development trend in the days to come.