Rheological numerical simulation for thermo-hydro-mechanical coupling analysis for rock mass

Under the environment of seepage field, stress field and temperature field interaction and influence, the three fields will not only produce coupling effect, but also have deformation with time due to the rheological behavior of rock mass. In the paper, based on the fundamental theories of rock mass coupling theory and rheological mechanics, the rheological model for fully coupled thermo-hydro-mechanical analysis for rock mass was set up, and the corresponding constitutive relationship, the conservation equation of mass and the conservation equation of energy were given, and the finite element formulas were derived for coupling analysis of rock mass. During establishing governing equations, rock mass was assumed approximately as macro-equivalent continuum medium. The obtained rheological numerical model for fully coupled thermo-hydro-mechanical analysis can be used for analyzing and predicting the long-term stability of underground caverns and slope engineering under the condition of thermo-hydro-mechanical coupling with rheological deformation.     

Numerical simulation for rheological characteristics of alternating distribution of soft and hard rock layers

The difficulty of selecting appropriate rheological model and parameters for the alternating distribution of soft and hard rock layers was often encountered due to the unhomogeneity, discontinuity and anisotropy of rock mass. The Burgers and generalized Kelvin models were applied to the soft and hard rock respectively and the rheological parameters were obtained based on the method of optimum separation. By using the simulated code FLAC^3D, the stability of surrounding rocks of a certain underground plant was analyzed. The effect of surface load and weakening the parameters intensity of argillaceous and bioclastic interlayers between soft and hard rock on rheological behavior of layer composite rock mass was investigated. The results indicate that the rheological characteristics of soft and hard rock layer in composite rock mass can be described well with above two rheological models.     

数值流形方法中的几点改进

简述了岩石力学中的数值流形方法及其分析过程，并就流形方法的具体实施作了几点改进，给出了相应的公式和算例。     

石窟顶板流变断裂过程的数值模拟与反演分析

龙游石窟5号洞顶板在多处有破坏痕迹和离层变形，经现场调研和实测，在洞室出口处顶板离层变形达75～78mm，侧面岩层出现悬臂梁式的破断现象。为了探讨龙游石窟5号洞顶板破坏过程，了解洞室的长期稳定性，基于最大拉应力追踪法和岩石断裂过程的反演数值模型，利用现场实测破坏形态及变形数据，对5号洞进行了流变断裂过程的数值模拟与反演分析。在反演分析过程中，运用正交试验方法，设计了27种数值模拟方案，通过正交试验设计的直观分析，获得了洞室顶板岩层与薄夹层的流变参数和其他敏感参数的最佳组合方案。利用所获得的参数最佳组合方案，对洞室进行了长期稳定性分析和流变断裂过程的数值模拟，数值模拟结果表明，在洞室出口处顶板离层变形达54．24mm，断裂部位与现场破断部位基本相同。此外，流变模拟分析中出现在洞室深部的顶板离层也十分明显，这一现象与现场观察到的表观变形形态比较相近。     

含夹层盐岩蠕变特性试验及其本构关系

为了解某拟建盐穴储库围岩含夹层盐岩的蠕变特性，对该库址含泥岩夹层盐岩、纯泥岩和纯盐岩3种岩芯试样进行了不同围压下三轴压缩蠕变试验，分析了其蠕变变形规律。实验结果表明：含夹层盐岩初始蠕变阶段的持续时间大于泥岩试件而与盐岩试件基本相同，即第1蠕变阶段的持续时间主要由层状盐岩试件中盐岩体部分决定；第2蠕变阶段的稳定蠕变速率则随着泥质夹层含量的不同呈现较大的差异，在相同应力条件下，含泥质夹层盐岩试件的蠕变速率小于盐岩而大于泥岩。根据3种岩样第2蠕变阶段的蠕变特性，基于含泥质夹层盐岩试件中泥质夹层的体积分数，推导了含夹层盐岩蠕变力学参数与纯盐岩及纯泥岩蠕变参数的关系。     

均匀设计响应面法在管道斜井穿越工程中的应用

斜井穿越法解决了我国长输油气管道穿越大型冲沟和台地的困难。为了探讨斜井穿越后井身及坡体的力学行为的变化规律,并建立有效实用的预测模型,对多因素、多水平参数条件下斜井工程进行了数值模拟试验,建立了相应的响应面回归预测模型。应用结果表明,在数值试验条件范围内,由二次响应面回归模型所预测的斜井工程区土体的变形及屈服区结果具有较高的精度,可为管道斜井穿越工程设计提供参考。     

含杂质盐岩力学特性对比试验研究

从某地拟建地下盐穴储库库区取芯，对含不同杂质盐岩（纯盐岩、钙芒硝质盐岩、硬石膏质盐岩及泥质混合盐岩）进行了力学试验，并对所获得的力学特性进行了对比分析。结果表明：① 在单轴和三轴压缩试验过程中，不同杂质成分对抑制盐岩的变形能力、提高盐岩抗压强度的作用有所不同；② 含不同杂质盐岩的弹性模量、单轴抗压及抗拉强度有较大变化区间，钙芒硝质盐岩的弹性模量和抗拉强度较大；③ 通过三轴压缩试验获得含不同杂质盐岩内摩擦角的量值明显低于纯盐岩，而黏聚力均大于纯盐岩。除纯盐岩外，硬石膏质盐岩的内摩擦角和黏聚力相对较小。     

矿井锚喷支护数值分析

本文对某矿井的井筒、煤巷的锚喷支护进行了有限元数值分析，给出了剪应力和合位移等值线图，开挖后塑性区图和最终塑性区图，以及考虑构造应力情况下的变化。经验证支护参数合理，目前这些典型井巷围岩是稳定的，支护工作状态良好，为后期工程提供了一些有价值的信息。     

五强溪水电站船闸边坡的粘弹性位移反分析及变形预测

位移反分析的提出,可望为边坡工程设计工程师提供一个确定有关地层力学参数和某些地应力分量的新方法。本文针对五强溪水电站左岸边坡岩层的特点,选择了HK模型,并从该边坡的实测位移出发,反演该边坡工程设计所需要的岩体力学参数。文中较详细地阐述了有关原理和可行的方法     

急斜煤层巷道稳定性数值模拟

 针对海北煤矿急斜煤层的复杂条件, 利用有限元模拟试验方法, 对煤层巷道煤柱的留设和回收范围进行了计算模拟试验, 探讨了煤层巷道的稳定性, 所得结果可供工程参考。