黄土公路隧道钢管混凝土支护力学特性数值模拟分析

发布时间：2018-04-24 16:19

本文选题：黄土隧道 + 初期支护　；参考：《长安大学》2014年硕士论文

【摘要】：初期支护作为隧道的主要支护结构，对维持围岩稳定、控制围岩变形具有重要作用。锚喷支护作为常用的初期支护，喷层薄、强度弱，难以改善部分黄土隧道变形大、难收敛的现象，初期支护承载能力的不足，将对隧道施工和运营带来安全隐患。因此，针对黄土隧道初期支护展开研究，具有现实意义。本文针对黄土隧道支护特点，提出了钢管混凝土支护体系，即利用空心钢管、注浆后形成钢管混凝土及模筑混凝土组成的支护体系，作为黄土隧道的初期支护，旨在通过增大初支厚度和刚度提高承载能力，减小施工对黄土介质的扰动，最大程度的保存围岩的天然强度，严格控制围岩的变形。本文应用假定抗力法及数值计算等方法，对钢管混凝土支护体系的成本经济性，支护效果，结构安全性及不同施工工法下的围岩变形和结构受力特性进行了研究分析。对钢管混凝土支护体系和锚喷支护进行比选，从成本经济性和支护效果两方面进行考虑，，得出较为合理的初支形式，并作出评价。应用假定抗力法，对钢管混凝土支护体系的衬砌内力进行了计算，验算结构安全性。应用MIDAS/GTS软件建立三维仿真模型，针对中断面和大断面黄土隧道的常用施工方法（环形开挖留核心土法和CD法），以钢管混凝土支护体系为对象，重点研究了施工过程中围岩变形情况和支护结构自身的受力情况，揭示了围岩与支护结构施工力学行为的空间效应。以上研究结果表明：钢管混凝土支护体系是安全、稳定且经济的初期支护新形式。
[Abstract]:As the main supporting structure of tunnel, initial support plays an important role in maintaining the stability of surrounding rock and controlling the deformation of surrounding rock. As a common initial support, bolting and shotcreting, with thin layer and weak strength, is difficult to improve the phenomenon of large deformation and difficult convergence in some loess tunnels. The insufficient bearing capacity of the initial support will bring safety hidden trouble to the construction and operation of the tunnel. Therefore, it is of practical significance to study the initial support of loess tunnel. According to the characteristics of loess tunnel support, this paper puts forward a concrete filled steel tube (CFST) supporting system, which is composed of concrete filled steel tube (CFST) and formwork concrete, which is used as the initial supporting system of loess tunnel. The purpose of this paper is to increase the bearing capacity by increasing the initial support thickness and stiffness, reduce the disturbance to the loess medium, preserve the natural strength of the surrounding rock to the maximum extent, and strictly control the deformation of the surrounding rock. In this paper, the cost economy, support effect, structural safety, deformation of surrounding rock and structural mechanical characteristics of concrete-filled steel tube support system under different construction methods are studied and analyzed by means of the method of assumed resistance and numerical calculation. By comparing and selecting the support system of concrete-filled steel tube and bolting and shotcreting support, the reasonable initial support form is obtained and evaluated from the aspects of cost economy and support effect. The lining internal force of concrete-filled steel tubular (CFST) support system is calculated by using the method of assumed resistance, and the safety of the structure is checked. The 3D simulation model is established by using MIDAS/GTS software. Aiming at the common construction methods (ring excavation with core soil method and CD method), the concrete filled steel tube (CFST) supporting system is taken as the object. The deformation of surrounding rock and the stress of supporting structure during construction are studied, and the spatial effect of mechanical behavior of surrounding rock and supporting structure is revealed. The results show that CFST support system is a safe, stable and economical new form of initial support.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U455.7;U452.1

【参考文献】