【作者】 岳顺；

【导师】 尹光志；

【作者基本信息】 重庆大学 ， 安全技术及工程， 2009， 博士

【摘要】 作为西部开发省际通道渝湘高速公路武隆至水江段的控制性工程——白云隧道具有地质条件复杂、埋深大、隧道长等特点,施工中将遇到破碎带、褶皱、岩溶、揭煤、瓦斯等不良地质现象。对这种具有复杂地质条件的隧道围岩动力失稳及破坏机理进行深入系统的研究具有重要的理论和工程意义。本文对白云隧道掘进过程的进行了现场调研、室内试验研究、围岩失稳破坏的理论分析、隧道开挖全过程的数值模拟、拱顶下沉的ARMA时间序列建模及预测分析,具体表现在以下几个方面:(1)重点研究区域的现场调研及弹性波测试表明:白云隧道各类岩石的刚度和强度均较高,围岩中灰岩弹性波速在2500~4900m/s之间,泥页岩弹性波速在2100~3700m/s之间,围岩完整性系数在0.56~0.78之间,并以些对围岩类别进行了分级。(2)利用自行研制的准平面应变试验装置,对白云隧道洞身段泥页岩变形局部化破坏方式进行了试验研究,得到了泥页岩局部化剪切带的倾角与加载速度之间的类对数关系和剪切带形式。(3)利用自行研制的三轴蠕变试验系统,对白云隧道洞身段泥页岩进行了卸围压蠕变试验,研究隧道开挖后岩体卸荷过程中的失稳破坏机理。试验结果表明,卸荷水平对岩体稳定性有较大影响,卸荷水平越低围岩变形越大、出现加速变形的时间越短。研究成果对白云隧道的开挖方式及初期支护相对时间的确定有重要的工程实际意义。(4)将隧道围岩上覆岩层简化为弹塑性双参数基础梁力学模型,经数学推导和力学分析得到了拱顶上覆岩层挠曲线、隧道围岩变形弹性基础梁挠曲线和拱顶下沉的理论模型。(5)针对白云隧道的特点,选取隧道深埋、浅埋、断层破碎带等典型断面进行静力和动力有限元模拟分析,得到了在开挖、支护与地震等不同工况下隧道施工过程的应力演化、衬砌、锚杆的受力情况。(6)利用动态时间序列及自回归滑动平均的原理,对白云隧道YK46+180断面的拱顶变形进行了模拟,建立了基于ARMA模型和自回归(AR)模型的拱顶下沉预测模型,结果表明利用时间序列模型对隧道施工过程中的围岩变形进行动态建模分析及预测是可行的,比静态建模有更高的精度。更多还原

【Abstract】 As the dominant engineering of inter-provincial highways from Changsha to Wulong of Chongqing in Western Development, Baiyun Tunnel, characterized by complex geological conditions, deep, long etc., bad geological phenomenon, such as broken belt, fold, karst region, unveiling coal, gas and other harmful gases, will be encountered in the period of construction. Further systematically study the dynamic instability and the mechanism of rock failure in tunnel with complex geological conditions has very important practical significance.In this paper, through researching the physical and mechanical properties in laboratory and insitu tests during the tunnel excavation, analysis of dynamics theory, numerical simulation of the whole process of tunnel excavation, the sinking arch ARMA time series modeling and forecasting analysis, we can obtain some conclusions as follows:(1)a. All types of rock in Baiyun Tunnel having higher stiffness and intensity, elastic wave velocity of limestone is 2,500~4,900m/s and that of mud stone and shale is 2,100~3,700 m/s. The integrity coefficient of rock is 0.56~0.78, proving better integrity.(2)Using self developed quasi-planar strain load equipment , study the deformation localization failure mode of shale in the plane strain state under the condition of the same moisture content, different loading speed and different moisture content, the same loading speed separately, having acquired the logarithm relation and the form of shear band(3)Using self developed triaxial creep test system, experiments of unloading confining pressure creep on shale in the Baiyun Tunnel was conducted to study the mechanism of instability breaking during the unloading process when the tunnel is excavated. The experiment result shows that the unloading level have great effect on the stability of rock, lower unloading level result in larger deformation and shorter time before the deformation speeding up. The research result has an important practical project significance to determine the way of excavation and the relative time of the initial support of the Baiyun Tunnel.(4)Simplifying the overlying strata of tunnel into two-parameter elastic-plastic foundation beam mechanical model, through mathematical derivation and analysis of mechanics we can acquire the specific form of the deflection differential equation of the overlying strata of vault and the elastic foundation beam of the tunnel surrounding rock deformation. Derive the expression Sinking speed of vault and explain the deformation of tunnel surrounding rock theoretically;(5)In view of the characteristic of Baiyun Tunnel , select typical cross-section of the section of deep, shallow and fault fracture zone to make static and dynamic analysis and acquire the evolution of stress, initial lining and the working conditions of bolt during the of the whole process of the tunnel construction under four types project conditions.(6)Making use of basic ideas of dynamic time series and the basic principles based on stationary processes autoregressive moving average (ARMA) model, simulated the vault deformation of the YK46 +180 cross-section, developed prediction model of vault sinking displacement based on the autoregressive moving average (ARMA) model and autoregressive (AR) mode, and the actual calculation shows that the accuracy is higher than the static modeling.更多还原