矿山深部工程FLAC3D初始地应力场生成的速度-应力边界法

摘要

Initial stress field is the foundation for the computation and the analysis of engineering stability.More stability simulation of rock underground engineering proved that the widely used methods (i.e.,velocity boundary method and rapid stress boundary method) can generate the initial stress field moderately agreed with the practice in FLAC3Dprogram;However, for deep engineering,the ground stress generated by the velocity boundary method is not consistent with the actual,and when u-sing the rapid stress method,the boundary condition may be applied difficultly and the generated ground stress at the shallow level disagrees with the actual.Thus,by combining the advantages of the above two methods,the velocity-stress boundary meth-od to generate the initial stress field of deep engineering is proposed in FLAC3D.Then,the loading range of the velocity bounda-ry condition and the stress boundary condition of the model is discussed to determine.Finally,the reasonableness of the veloci-ty-stress boundary method is proven by the analysis of an example.The results show that:the numerical model for deep engi-neering can be built by the velocity-stress boundary method and its loading range of velocity boundary and stress boundary con-dition may be determined through computing many times;the initial stress field generated by the velocity-stress boundary meth-od consist with the measured data;The problems existing in the above two methods are solved.The results can serve as refer-ence and guidance for the numerical simulation and analysis of deep mine engineering.%初始地应力场是工程稳定性数值模拟分析的基础.已有较多的岩石地下工程稳定性模拟证明,在FLAC3D模拟时常用的速度边界法和快速应力边界法可以生成与实际较为一致的初始地应力场;但对于矿山深部工程,利用这2种边界条件加载方法,则模拟结果分别存在"地应力与实际不符"、"边界条件施加困难和浅部区域地应力与实际不符"的问题.针对这些问题,综合前述2种边界条件加载方法的优点,提出了矿山深部工程FLAC3D初始地应力场生成的"速度-应力边界法",探讨了模型速度边界条件与应力边界条件加载范围的确定方式,通过算例分析验证了"速度-应力边界法"生成初始地应力场的合理性.研究表明:采用"速度-应力边界法"构建的矿山深部工程数值计算模型,可以通过多次试计算的方式确定速度边界条件与应力边界条件的加载范围;生成的初始地应力场与矿山深部工程地应力实测数据基本一致;解决了前述2种边界条件加载方法存在的问题.研究成果可为矿山深部工程的数值模拟分析提供参考.