【作者】 王其胜；

【导师】 李夕兵；

【作者基本信息】 中南大学 ， 岩土工程， 2008， 博士

【摘要】 矿山在进入深部开采后,软岩巷道围岩出现显著变形,围岩破碎严重,对巷道围岩稳定性的控制变得极其困难。鉴于此,本文以深部软岩巷道支护中存在的问题作为研究对象,通过现场调查及监测,分析了深部软岩巷道破坏原因与破坏类型,探讨了深部软岩巷道底鼓的原因和机理;揭示了深部软岩巷道变形具有较强时效性的特点;基于实测数据,采用多种方法对巷道位移监测过程和模型产生的厘米级系统误差进行了消除,提高了现场量测结果的精度。基于突变理论分析了巷道围岩的变形和其工程力学属性具有突变性的特点,提出了矿山在进入深部后存在一临界深度,并运用突变理论对巷道围岩进行了稳定性分析,得出了围岩变形的稳定性判据;首次采用集对分析方法对不确定性的围岩体系进行了围岩质量评价,建立了围岩质量评价的集对分析模型。基于混沌理论揭示了深部软岩巷道围岩变形过程的非线性动力学特征,提出了用混沌吸引子维数D和最大Lyapunov指数来判定巷道围岩系统的混沌程度。根据实测的巷道位移时间序列数据,重构了巷道位移的混沌时间序列状态空间,并给出了最大Lyapunov指数、嵌入空间维数和混沌吸引子维数D的计算方法,建立了围岩变形的混沌预测模型,得出了巷道围岩变形的相对稳定期。运用数值模拟方法分析了深部软岩巷道开挖后围岩应力和位移分布规律,揭示了深部软岩巷道围岩变形的发展趋势;利用岩体塑性软化模型建立了深部软岩巷道围岩支护体系的非线性力学模型,给出了巷道围岩弹性区、塑性区、破碎区范围和应力的解析解。基于半空间问题的位移解,给出了全长粘结锚杆杆体所受的剪应力和轴力的计算方法,探讨了粘结锚杆杆体与浆体以及浆体与围岩的粘结机理。探讨了动载下深埋巷道支护中用钢纤维混凝土代替素混凝土实施初支护的可行性,并分别对钢纤维混凝土进行了静态、动态以及动静组合加载下的力学性能对比试验,得出了适合深部软岩巷道支护的最佳钢纤维体积率。根据深部软岩巷道围岩变形破坏的规律,分别提出了浅埋和深埋巷道的合理支护形式;在数值模拟计算和理论分析的基础上,对支护参数进行了优化设计;提出了深部软岩巷道预防与控制底鼓的具体措施;工业试验结果表明,所提出的支护方案对围岩变形的控制效果较好,而且对于深埋巷道,用钢纤维混凝土和树脂锚杆代替砂浆锚杆挂网支护,不仅可以达到有效支护目的,而且还可以减少作业工序,大大提高了工作效率。更多还原

【Abstract】 After mining in depth, the surrounding rock’s deformation of soft rock tunnel become prominent, the surrounding rock is cracked seriously and the control to the stability of the surrounding rock is also difficulty particularly. In view of this, the support problems of deep soft rock tunnel had been as the research object in this paper. By the field survey and measure, destruction causes and styles of deep soft rock tunnel were analyzed and the cause and mechanism of floor heave was discussed. The strong age characteristic of the surrounding rock’s deformation of deep soft rock tunnel was concluded. Based on measured data, methods were used to eliminate the centimeter-level system errors from the model and observation process. So, the measure precision was improved largely.Based on calastrophe theory, the mutation features of the surrounding rock’s deformation and mechanics properties in engineering were analyzed. The concept of the critical depth was put forward after mining into depth. The stable criterion was obtained through the stability analysis the surrounding rock by this theory. Set pair analysis method was firstly adopted to evaluate on the surrounding rock quality about uncertain surrounding rock system and the set pair analysis model was also established.Based on chaos theory, the characters of non-linear dynamic of the surrounding rock’s deformation process were discussed. The chaotic attractor dimension D and the largest Lyapunov index (E_max) were put forward to determine whether the deformation process of roadway is chaotic and the degree of chaos. On basis of the measured data of the tunnel displacement time series, the state space of the chaotic time series of tunnel displacement was reconstructed. The calculation method of chaotic attractor dimension D , the largest Lyapunov index (E_max) and the imbedding dimension was offered. The chaotic time series model to predict the surrounding rock’s deformation of deep soft rock tunnel was established. The relative stability period of the surrounding rock’s deformation was obtained. By numerical modeling method, the distribution laws of stress and displacement of deep soft rock after excavation were analyzed. The developing tendency of the surrounding rock’s deformation was concluded. Based on plastic soften rockmass model, the nonlinear mechanical model of tunnel surrounding rock-support system was established. The analytical solution of the stress and plastic zone, elastic zone and crushing zone of tunnel surrounding rock. Based on the results of Mindlin, the calculation method of shearing stress and axial force of full-grouted bolt were obtained. The bonding mechanism of between full-grouted bolt and slurry, between slurry and surrounding rock were discussed.The feasibility using steel fiber concrete as a substitute for plain concrete in deep tunnel support under dynamic load was studied. Compared test of steel fiber concrete under static, dynamic and static-and-dynamical combination load were carried out. The optimal influence of fiber volume ratio fitting to support deep soft rock tunnel was obtained.On basis of laws of the surrounding rock’s deformation and destruction, the reasonable support styles fitting to shallow tunnels and deep ones were put forward respectively. After numerical modeling and theoretical analysis, support parameters were optimized. The concrete measures to control and prevent floor heave were put forward. The industrial test results indicated that the applied support scheme was better, not only steel fiber concrete could control he surrounding rock’s deformation, but also it could reduce working procedure and advance work efficiency greatly.更多还原