高磨蚀深长隧道TBM滚刀磨损机制和破岩机理研究

This research program is based on South Qinling tunnel of Hanjiang-to-Weihe River project, and two issues will be investigated. One is on abrasion mechanism of hobbing cutters. First of all, in the view of micro mineral compositions, rock abrasiveness tests are to be carried out. The specimen is made up of seven main rock-forming minerals and a new self-developed transparent rock-like resin material. Quantitative abrasion rules of the seven minerals on hobbing cutters will be ascertained. Then from macro perspectives, contents and abrasiveness of mineral compositions will be adopted as vital index for hobbing cutter abrasion. Subsequently by taking into account of other factors, such as stratum compressive strength, installing parameter of hobbing cutters, physical index and mechanical parameters of rock masses, and so on, prediction model of hobbing cutter abrasion will be established. The other is on rock breaking mechanism of Tunnel Boring Machine (TBM). Rock engineering software FLAC3D is applied to simulate and study rock breaking actions of TBM. The dynamic mechanical model of hobbing cutter to rock masses is established based on moving area load and a self-developed elastic-brittle constitutive model is applied throughout the computational process. Therefore the fracture characters and disturbance laws of rock masses will be studied. Meanwhile, large-scale model experiments on TBM rock breaking will be carried out. The experiment is on rolling rock breaking of three hobbing cutters. Finally, the experiments and numerical calculations will verify each other.

本项目以在建的引汉济渭工程秦岭隧洞岭南TBM施工段为背景，拟开展两方面研究。一是滚刀磨损机制：先从细观岩石矿物成分角度出发，采用自主研制的新型类岩石透明树脂材料为介质制作试样，开展岩石磨蚀性实验，探明自然界七种最重要造岩矿物对TBM滚刀磨蚀的定量规律；再从宏观角度，将矿物成分含量和磨蚀度作为影响滚刀磨损的重要指标，并综合地层抗压强度、滚刀布置参数、岩体物性指标和力学参数等，建立现场滚刀磨损的预测模型。二是TBM破岩机理研究：利用FLAC3D岩土软件模拟研究TBM破岩行为，建立基于移动面荷载的刀-岩动态作用力学模型，计算过程采用自主改进的弹脆性本构模型，研究滚刀作用下不同工况岩体的破裂特征和扰动规律；开展TBM组合滚刀破岩的大型模型试验，进行三滚刀滚压破岩试验，与数值计算相互校验。

随着我国铁路、公路及跨海隧道工程、水利水电等基础规模的不断扩大，TBM因其施工速度快、效率高、隧道成型好等优点，目前已成为世界长大隧道施工最有效、最先进的大型综合性施工设备之一。本项目以在建的引汉济渭工程秦岭隧洞岭南TBM施工段为背景，开展了两方面研究。一是滚刀磨损机制：现场方面，基于监测数据，对依托工程的不同部位滚刀磨蚀影响因素及机理进行了详细分析；理论方面，建立了基于材料磨损机制的磨损值预测模型；室内实验方面，研制出一种新型类岩石透明树脂材料，并创立了基于该材料试件的矿物磨蚀度精准检测技术及实验方法；此外，还开展了滚刀磨损的仿真模型实验，分析了各参数对滚刀磨损的影响。二是TBM破岩机理研究：试验方面，利用滚刀岩机作用综合试验台和TBM掘进模态综合实验台，开展了针对石灰岩和高强度花岗岩的系统性TBM滚刀滚压破岩试验；FLAC3D软件二次开发方面，编制了移动面荷载计算程序，分别建立了无水和有水因素下的岩体破裂耦合分析模型，模拟研究了不同条件下隧道围岩的破裂演化规律和隧道稳定性。本项目研究成果对降低由于滚刀消耗量不确定而引起的工程招投标风险，以及提高我国TBM自主设计与制造能力，具有较好的指导意义和实践价值。