TBM在穿越断层、破碎带、岩溶发育区等不良地质时有时出现突涌水、塌方、卡机等灾害事故,导致TBM掘进效率低下、工期延误甚至是TBM机械损坏和人员伤亡。出现上述问题的一个主要原因就是TBM工作环境极为复杂,难以提前获取前方不良地质与主要岩体参数。因此,提出了一套以地球物理超前地质预报和基于“岩-机关系”预测岩体主要参数的解决方法。在该方法中,采用三维地震超前预报技术远距离识别和预报断层、破碎带、大型溶洞等不良地质;采用三维激发极化获取掌子面前方含、导水地质构造;采用机器学习的手段挖掘TBM机械电液参数与主要岩体力学参数的关系,并初步实现了TBM前方岩体单轴抗压强度的预测。以上述三种方法为核心,提出了TBM前方不良地质与主要岩体参数的综合获取方法及其流程,在实际工程中得到了验证。实际案例表明,综合获取方法可为TBM安全、高效掘进提供前方不良地质和单轴抗压强度信息,并为TBM掘进方案决策提供依据。
TBM construction tunnel was easily hampered by hazard and accidents like water inrush, collapse and TBM jam, in the occurrence of faults, fractured zone and karstic area, which could cause the losing of TBM excavation efficiency and delay the tunnel construction. It was because of the complex environment in TBM construction tunnel that the adverse geology and rock properties was hard to be acquired. To solve the problem, a solving methodology was put forth based on geological prospecting and rock property estimation. The methodology was consisted of ahead geological prospecting by using geophysical methods and rock properties estimation based on the relationship between the rock properties and TBM machine data. In this methodology, the 3D seismic prospecting method was used to identify and locate the faults, fractured zone or karst cave ahead of the tunnel face. The 3D IP method was used to prospect the water bearing geological structure ahead of tunnel face. In addition, the rock properties were estimated by means of machine learning. The uniaxial compression strength of the surrounding rocks was estimated using data mining. Based on three methods mentioned above, an integrated acquisition method and its procedure of adverse geology and rock properties were proposed. With the test and verification in the field case of a project, the proposed methodology was proved to be feasible and could provide reasonable reference for TBM excavation.