【作者】 巫德斌；

【导师】 徐卫亚；

【作者基本信息】 河海大学 ， 岩土工程， 2005， 博士

【摘要】 岩体力学参数的合理确定是岩石边坡工程中一项基础的工作。由于岩体具有不均匀性、不连续性和随时间变化的特性，目前在层状岩体边坡工程的岩体力学参数选取方面仍然存在一些问题。本文针对当前岩体力学参数研究的难点进行了研究，并将研究成果应用到实际边坡工程中。 本文研究工作主要内容如下： 1．提出了修正的RMR法——GSMR法，并用于边坡岩体力学参数的估算。该方法较全面地考虑了完整岩石强度、结构面产状、结构面间距、结构面粗糙度、地下水条件、岩石质量指标、边坡高度、研究区域地震基本烈度、开挖方法和人工边坡形态等影响岩体力学性质的因素，并提出了连续性权值修正的方程(二次函数关系或半对数关系)，对完整岩石强度、岩石质量指标、结构面间距权值进行了连续修正，减少了主观判断带来的误差。在边坡岩体力学参数预测方面，将GSMR值代替RMR值，更能反映边坡岩体实际力学性质，并将其用于边坡稳定分析，是一种边坡工程上可行的方法。 2．用微结构张量表示广义Hoek-Brown强度准则参数，使之可以考虑边坡岩体各向异性特性；把边坡开挖弱化因子和锚固增强因子引入广义Hoek-Brown强度准则，并提出了两个因子的计算公式，研究了爆破开挖和锚固对边坡岩体力学参数的影响程度，计算了爆破开挖和锚固后的岩体力学参数。算例分析表明：变形模量、抗拉强度、粘结力和加载方向与结构面夹角正弦的平方呈线性相关，具有不同程度的各向异性，粘结力的各向异性特别地明显：内摩擦角在未扰动、开挖和描固条件下的各向异性不明显，均保持不变。开挖对不同边坡岩体的力学参数的影响程度不同，一般地对坚硬岩体的影响大于软弱岩体；开挖弱化因子与变形模量、粘结力和内摩擦角呈线性相关，与抗拉强度呈指数相关。锚固对变形模量、抗拉强度、粘结力提高幅度大，对内摩擦角提高幅度不大；锚固增强因子与变形模量、粘结力和内摩擦角呈线性相关，与坚硬岩体的抗拉强度呈线性相关，与软弱岩体的抗拉强度呈指数相关。 3．考虑圆形截面岩石简支梁中央受集中力作用，用应变片测定简支梁某些点的应变值，推导了量测应变值与流变参数蠕变柔量之间的关系表达式；根据粘弹性本构模型理论，推导了系统模型蠕变柔量的一般形式；当岩石简支梁出现弹-粘塑性变形时，推导了量测应变与梁挠度之间的关系表达式；使用最小二乘法建立目标函数，对模型流变参数进行估计；用龙滩水电站泥板岩岩样流变试验所测得的应变值，反演了泥板岩的流变参数，进行了泥板岩粘弹性模型辨识，得出了符合泥板岩的流变本构模型。中文摘要 4.假定层状岩体为层状复合材料，采用复合介质的等效介质理论研究了层状岩体的等效弹性模量，并提出与边坡类型对应的等效介质模型，与层状岩体边坡 (包括切层边坡和反倾向边坡)对应的力学模型为并联模型，与顺层边坡对应的力学模型为串联模型。研究表明:Voigt一Reuss模型上下限范围大、精度不高，Hashin一Shtrikman模型上下限范围小、精度高，Eshelby模型、自洽模型、微分模型和Mori~1’a naka模型预测结果基本保持一致。 5.利用本文的研究成果，给出了向家坝水电站左岸层状岩体边坡未扰动区和开挖扰动区的岩体力学参数建议值，并在此基础上对该边坡变形进行三维数值模拟分析，进行了工程实例分析验证。关键词:层状岩体边坡、力学参数、GSMR法、Hoek一Brown强度准则、蠕变柔 量、等效弹性模量、向家坝水电站更多还原

【Abstract】 The reasonable confirmation of rock mass mechanical parameter is a fundamental job in rock slope mechanics and engineering. Because rock mass possesses heterogeneity, discontinuity and rheology property, there exists some problems on the choice of rock mass mechanical parameter of layer rock mass slope engineering. In this paper, the currently difficult problems on rock mass mechanical parameter are carried out, which study results are applied to the slope engineering practice.The main study work in the dissertation are focused on following several aspects:1. Based on the advantages of RMR on the slope rock mass quality evaluation, GSMR(General Slope Mass Rating) method is proposed, which is applied to the evaluation of slope rock mass mechanical parameters. Intact rock strength, orientation, interval and roughness of structural plane, groundwater condition, rock quality index, slope height, basic earthquake intensity in study zone, excavation method, shape of artificial slope, the factors of affecting the rock mass mechanical properties, are all taken into account by the GSMR system. The continuous modification quadratic function or semi-logarithmic function for intact rock strength, rock quality index or structural plane spacing are put forward, and then the error caused by the subjective judgement is decreased. So the RMR value can be replaced by the GSMR value when slope rock mass mechanical parameter is forecasted, which can reflect the slope rock mass mechanical properties, what’s more, the slope stability analysis can be used the GSMR value. It shows that the GSMR method is a feasible method on the slope engineering.2. Aiming at the deficiencies of using Hoek-Brown strength criterion estimate the rock mass mechanical parameter in the practical application, the microstructure tensor is adopted to describe the parameters of the Hoek-Brown strength criterion, which can consider the anisotropism of slope rock mass. The slope excavation softening factor and anchorage strengthen factor is introduced to Hoek-Brown strength criterion, and the commutated equation of the above two factors is put forward, which investigates the effect extent of blast excavation and anchorage on the slope rock mass mechanical parameters, and at the same time rock mass mechanical parameters behind blast excavation and anchorage are computed. Case research indicates that deformation modulus, tensile strength, and cohesion take linear relation with the sine squared ofthe angle between the loading direction and structural plane, which possess the anisotropism with different extents. The anisotropism of cohesion is clear specially, however the anisotropism of internal friction angle isn’t very distinct and basically a constant under the undisturbed, excavated and bolted conditions. The effect extent of excavation on mechanical parameters of different slope rock mass is varying. In a general way, the influence on the hardness rock mass is greater than that on the softness one. The excavation softening factor and deformation modulus, cohesion, internal friction angle have a linear relation, but it takes index relation with the tensile strength. The deformation modulus, tensile strength, cohesion are increased greatly by the bolt strengthen factor, nevertheless the internal friction angle is increased weakly by the bolt strengthen factor. The relation between the bolt strengthen factor and deformation modulus, cohesion, internal friction angle, tensile strength of the hardness rock is linear, and the tensile strength of the softness rock possesses index relation.3. Considering a concentrated force in the middle of the rock simple beam with round section, the strain value of some points on the rock simple beam is investigated by using the strain gauge, and the relation between the strain value and the creep compliance (rheological parameter) is deducted. Then the general format of creep compliance of the system model is derived on basis of visco-elastic constitutive model theory, and the relation between the strain value and beam deflection is de更多还原