大断面黄土隧道围岩稳定性研究

发布时间：2018-04-26 20:18

本文选题：大断面黄土隧道 + 围岩特性曲线　；参考：《北京交通大学》2014年硕士论文

【摘要】：摘要：针对大断面黄土隧道的围岩的稳定性问题,总结了往年隧道围岩稳定性的研究方法：围岩的失稳原因、破坏模式以及破坏准则。对比采用理论解析、数值模拟以及现场监控等方法对黄土围岩稳定性及在考虑初支加固条件下的稳定性进行研究,通过对比分析,主要研究结果如下所示： (1)综合系统的总结了围岩稳定性的影响因素、破坏模式以及破坏准则,尤其是对在含有地下水条件下的围岩失稳破坏案例进行归纳分析。得出了围岩稳定性与含水量,埋深等因素的关系。 (2)针对黄土的围岩的特性曲线进行分析,通过数据采集拟合黄土吸湿曲线,推导在理论条件下的变形解,且将理论解与数值解进行对比,从而对模型参数进行修正；进而考虑在不同含水量条件下以及不同埋深条件下对围岩特性曲线以及围岩的纵向变形曲线的影响；综合考虑围岩特性曲线以及围岩的纵向变形曲线,提出了代表性的黄土隧道的围岩变形时空效应。 (3)针对大断面黄土隧道的支护情况,根据壳体力学的计算方法,推导出圆形断面隧道中喷射混凝土与钢架构成的初期复合支护结构的力学模型,通过ABAQUS数值计算来验证模型的准确性；对各种因素对初支效果的影响进行了分析；并且建立了钢架的局部效应模型,提出了在等效刚度的情况下钢架在初支作用中的影响范围。 (4)根据现场监控的监测数据,得到了大断面黄土隧道的初支受力以及变形规律,说明了黄土隧道具有明显的流变特性；支护结构在空间上的受力并不是均匀的,通过数值模拟的对比可以看出与实际工程相类似,隧道设计中应予以考虑。
[Abstract]:Abstract: aiming at the stability of surrounding rock of large section loess tunnel, this paper summarizes the research methods of surrounding rock stability in previous years, such as the cause of instability of surrounding rock, failure mode and failure criterion. The stability of loess surrounding rock and the stability under the condition of initial support reinforcement are studied by theoretical analysis, numerical simulation and field monitoring. The main results are as follows: 1) the factors affecting the stability of surrounding rock, failure mode and failure criterion are summarized systematically, especially the case of rock instability under the condition of groundwater is summarized and analyzed. The relationship between surrounding rock stability and water content, burial depth and other factors is obtained. 2) analyzing the characteristic curve of the surrounding rock of loess, fitting the moisture absorption curve of loess by data acquisition, deducing the deformation solution under the theoretical condition, and comparing the theoretical solution with the numerical solution, so as to modify the model parameters; And then consider the influence of different water content and buried depth on the characteristic curve of surrounding rock and the longitudinal deformation curve of surrounding rock, and consider the characteristic curve of surrounding rock and the longitudinal deformation curve of surrounding rock synthetically in consideration of the characteristic curve of surrounding rock and the longitudinal deformation curve of surrounding rock. The spatiotemporal effect of surrounding rock deformation of representative loess tunnel is proposed. According to the supporting condition of large section loess tunnel, according to the calculation method of shell mechanics, the mechanical model of initial composite support structure composed of shotcrete and steel frame in circular section tunnel is deduced. The accuracy of the model is verified by ABAQUS numerical calculation, the influence of various factors on the initial support effect is analyzed, and the local effect model of the steel frame is established, and the influence range of the steel frame in the initial support under the condition of equivalent stiffness is proposed. 4) according to the monitoring data on the spot, the law of initial support and deformation of large section loess tunnel is obtained, which shows that the loess tunnel has obvious rheological characteristics, and the force of supporting structure is not uniform in space. Through the comparison of numerical simulation, it can be seen that the tunnel design should be considered.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U451.2;U456.3

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