干湿循环作用膨胀土隧道钢管混凝土支护结构力学性能与可靠性分析

发布时间：2018-06-13 23:19

本文选题：膨胀土隧道 + 钢管混凝土支护结构　；参考：《山东大学》2017年硕士论文

【摘要】：随着隧道建设规模和速度的迅猛发展,隧道建设过程中难免要穿过膨胀土这种复杂条件地层。由于传统的支护方式不能满足现实需要,导致该类隧道的安全及稳定问题突出,膨胀土隧道围岩新型支护技术亟待进行深入研究。钢管混凝土拱架由于其良好的力学性能已经在矿山等地下工程中得到了应用,控制变形效果显著。然而针对膨胀土隧道围岩钢管混凝土支护技术的研究仍处于起步阶段,在此背景下,本文主要进行了以下的研究工作,并取得了相关有益结论。本文研究膨胀土隧道的变形破坏,并对钢管混凝土拱架进行了理论分析;然后以广西云桂铁路某隧道为工程背景,进行了膨胀土隧道在干湿循环作用下开挖施工过程的模型试验,分析了开挖过程、降雨及烘干情况下围岩的应力、位移演化规律,为膨胀土隧道的支护设计和施工安全提供了依据。钢管混凝土支护结构受力复杂,影响因素较多,仅通过理论研究和模型试验不能够全面分析其受力特点。基于ABAQUS有限元分析软件,针对不同支护结构截面型式,研究了不同截面形式钢管混凝土支护结构的力学特性,并与传统支护进行对比分析,进而阐述了钢管混凝土支护效应。结果表明,钢管混凝土支护结构承载能力大,支护效果好。其结果可为支护设计提供重要的参考依据。此外,本文采用基于连续介质的可靠性计算方法,将钢管混凝土支护结构中的钢管壁厚和混凝土膨胀角作为随机变量,通过ABAQUS软件分别求得支护最大应力值关于钢管壁厚和混凝土膨胀角的函数,再将两个变量进行组合,从而得到支护最大应力值关于随机变量的显示表达式,进而对钢管混凝土支护结构的承载力的可靠度进行了初步评估,并计算出了相应的支护结构可靠指标。
[Abstract]:With the rapid development of the scale and speed of tunnel construction, it is inevitable to pass through the complex conditions of expansive soil in the process of tunnel construction. Because the traditional support method can not meet the practical needs, the safety and stability of this kind of tunnel is prominent, and the new supporting technology of surrounding rock of expansive soil tunnel needs to be deeply studied. Concrete-filled steel tubular arch frame has been applied in underground engineering such as mines because of its good mechanical properties, and the effect of deformation control is remarkable. However, the research on concrete-filled steel tube (CFST) supporting technology of expansive soil tunnel is still in its infancy. Under this background, the following research work has been carried out in this paper, and some useful conclusions have been obtained. In this paper, the deformation and failure of expansive soil tunnel are studied, and the concrete filled steel tube arch frame is theoretically analyzed, and then a tunnel of Yun-Gui railway in Guangxi is taken as the engineering background. The model test of the excavation process of expansive soil tunnel under the action of dry and wet circulation is carried out, and the evolution law of stress and displacement of surrounding rock under the conditions of excavation, rainfall and drying is analyzed. It provides the basis for the support design and construction safety of expansive soil tunnel. Concrete filled steel tube (CFST) supporting structure can not be fully analyzed by theoretical research and model test. Based on Abaqus finite element analysis software, the mechanical characteristics of concrete-filled steel tube (CFST) supporting structures with different cross-sections are studied, and compared with the traditional support, the effects of CFST support are discussed. The results show that the bearing capacity of concrete filled steel tube (CFST) supporting structure is large and the supporting effect is good. The results can provide important reference for support design. In addition, using the reliability calculation method based on continuous medium, the wall thickness of steel tube and the expansion angle of concrete filled steel tube in the concrete filled steel tube support structure are taken as random variables. By Abaqus software, the function of the maximum support stress value on the wall thickness of steel pipe and the expansion angle of concrete is obtained, and then the two variables are combined to obtain the display expression of the maximum support stress value on the random variable. Furthermore, the reliability of concrete filled steel tube supporting structure is evaluated and the corresponding reliability index of supporting structure is calculated.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U455.7

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