深部隧道稳健试验设计及支护围岩稳健性分析

发布时间：2018-04-26 17:52

本文选题：隧道围岩 + 不确定性　；参考：《湖南大学》2015年硕士论文

【摘要】：随着我国国民经济和国防建设的迅速发展,地下空间的开发与利用成为了一种必然的趋势。地下洞室开挖及支护后的稳定性关系到工程施工及运营期间的安全,是工程领域重要研究内容之一。然而,深部隧道由于其赋存的特殊地质环境,在“三高一扰”的影响下,岩体力学性质表现出高度的离散性和各向异性,设计时必须考虑参数的不确定性,这给隧道围岩的稳定性评价带来了一定难度。针对地下结构不确定性的特点,本文引入了非确定性结构设计的稳健设计方法,包括稳健试验设计和稳健可靠度分析。主要研究内容如下:首先,本文介绍了稳健设计概念,引入田口“三次设计”方法。根据相似原则配制模型试验材料,选择正交表进行配比试验。将试块单轴抗压强度作为质量特性指标,由望大特性的信噪比函数将质量特性指标转化为信噪比,通过信噪比分析材料配比对质量特性的影响。其次,引入Info-gap理论,深入研究支护围岩稳健可靠度分析方法。采用Info-gap模型描述不确定参数实际值在名义值附近的波动,并将结构失效前能够允许的不确定参量的最大波动幅值作为稳健可靠度指标。在Info-gap模型的基础上,进一步研究了稳健优化模型。稳健优化采用Info-gap稳健函数来衡量设计结果对约束条件的稳健性。通过移动约束函数法将不确定性设计变量转化为一系列确定性优化,使结构在满足优化的同时具有一定的稳健性。最后,分析了围岩强度破坏和失稳破坏,通过剪切滑移线场理论和组合拱理论推导了理想弹塑性围岩的极限承载能力,并得到地下结构稳定分析的功能函数,建立了支护围岩稳健分析流程。实例工程展示了稳健可靠性方法的具体操作程序。分析了围岩力学参数和支护性能对支护结构稳健性的影响,探究了内摩擦角和粘聚力对结构稳健性能影响的重要程度。该方法对参数信息要求低,只需要知道参数取值的边界,因而在处理地下结构不确定性问题时,具有一定的优势。
[Abstract]:With the rapid development of national economy and national defense construction, the development and utilization of underground space has become an inevitable trend. The stability of underground caverns after excavation and support is related to the safety of construction and operation, and is one of the important research contents in engineering field. However, due to the special geological environment of deep tunnel, under the influence of "three high and one disturbance", the mechanical properties of rock mass show high dispersion and anisotropy, and the uncertainty of parameters must be taken into account in the design. This brings some difficulty to the stability evaluation of tunnel surrounding rock. In view of the uncertainty of underground structure, this paper introduces the robust design method of non-deterministic structure design, including robust test design and robust reliability analysis. The main contents are as follows: firstly, this paper introduces the concept of robust design and introduces Taguchi's cubic design method. According to the principle of similarity, the model test materials were prepared, and the orthogonal table was selected to carry out the proportioning test. The uniaxial compressive strength of the test block is taken as the quality characteristic index, and the quality characteristic index is converted from the signal-to-noise ratio function of the large characteristic to the signal-to-noise ratio. The influence of the material ratio on the quality characteristic is analyzed by the signal-to-noise ratio (SNR). Secondly, Info-gap theory is introduced to analyze the robust reliability of surrounding rock. The Info-gap model is used to describe the fluctuation of the actual value of uncertain parameters near the nominal value, and the maximum fluctuation amplitude of the uncertain parameter which can be allowed before the failure of the structure is taken as the robust reliability index. Based on the Info-gap model, the robust optimization model is further studied. Robust optimization uses the Info-gap robust function to measure the robustness of the design results to the constraints. The uncertain design variables are transformed into a series of deterministic optimization by moving constraint function method, which makes the structure have a certain robustness while satisfying the optimization. Finally, the strength failure and instability failure of surrounding rock are analyzed, the ultimate bearing capacity of ideal elastoplastic surrounding rock is deduced by the theory of shear slip line field and combined arch theory, and the function function of stability analysis of underground structure is obtained. The steady analysis flow of supporting surrounding rock is established. The concrete operation procedure of the robust reliability method is demonstrated by an example project. The influence of mechanical parameters of surrounding rock and supporting performance on the robustness of supporting structure is analyzed, and the importance of the influence of internal friction angle and cohesive force on structural robustness is explored. This method only needs to know the boundary of parameter value because of its low requirement for parameter information, so it has some advantages in dealing with the uncertainty of underground structure.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U451

【参考文献】