基于数字岩芯技术的高温压浸润岩石摩擦机理研究

Application of digital rock technology to saturated rock friction mechanism under high pressure and temperature

基于量子力学格子玻尔兹曼理论和多尺度计算机断层成像(CT)技术,在并行中央处理器-图形处理器(CPU-GPU)平台下,为低密度砂岩、花岗岩、大理岩、榴辉岩及橄榄岩等典型岩石试样建立三维数字岩芯模型;进而,应用夹杂超奇异积分-D3Q27格子玻尔兹曼法对多时空尺度(时间尺度:10～100μs;空间尺度:10μm～10cm)、高温压(温度范围:0～600℃;压力范围:0～1GPa)饱和浸润典型岩石试样摩擦过程进行虚拟实验研究,得到摩擦面微裂纹亚临界扩展、摩擦面摩擦应力变化和摩擦面摩擦系数大小随滑动速度、滑动时间、温度和压力大小及加载方式变化规律;最后,通过分析虚拟实验中高温压饱和浸润典型岩石从静止到发生滑动摩擦过程,讨论了离子态水对摩擦系数影响和摩擦面微观摩擦机理.研究结果为地球内部物质软流圈-岩石圈-地壳间运移机理问题、水库对断层活动构造带影响机理问题分析在理论上提供了支持和帮助.

Based on the digital rock technology that combines lattice Boltzmann theory （LBM-numerical method） and multi--scale computed tomography （CT-experimental method） method, the three dimensional digital rock models for typical rocks （sand, granite, marble, eclogite and olivine） are established. Then, the micro-scale saturated pore- network dislocations-defects propagation, the concentrated stress distribution and the saturated rock friction coefficient （SRFC） of rock and rock masses under various conditions （temperature up to ~600 ~C, pressure up to ~1 GPa） at multi-temporal （10~100 μs） and spatial （10 /μm^10 cm） scales are calculated, and the SRFC as function of slip velocity, slip time, temperature, and pressure is obtained. The method of combining experimentally measured physical 3D model with computer simulation （virtual experiments） to analyze high temperature and pressure rock friction mechanism provides a novel new approach to understanding the rocks-minerals convection inthe earth interior and reservoir-induced earthquake problem.