地下洞室施工力学特性及合理断面研究

发布时间：2018-01-14 01:08

本文关键词：地下洞室施工力学特性及合理断面研究　出处：《重庆交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：在地下洞室施工时，，不同的施工方法和不同的施工顺序都会导致围岩产生不同的位移和应力结果。而洞室断面的形式决定了洞室施工的难易程度和施工过程中围岩及支护结构的稳定程度；洞室断面跨度越大，洞室施工难度越大、围岩支护结构的稳定性越复杂。大跨度断面洞室的支护衬砌参数、断面型式及施工方案是洞室建设研究的重点和难点。以昆明轨道交通3号线太平村站~虹桥村站区间隧道工程洞室断面形式为依托，结合岩石力学、弹塑性力学方面的理论知识，用弹塑性力学理论、D-P屈服准则，考虑岩土的非线性因素等，建立有限元ansys模型，分别对不同围岩级别时，不同高跨比形式的断面形式，进行模拟分析，得出以下结论； ①对（单心圆、三心圆及五心圆）衬砌轮廓断面进行分析比选，得出合理的衬砌轮廓断面形式； ②对模拟衬砌结构的竖向位移收敛、初期衬砌受力、围岩应力分布及初期衬砌的偏心距等因素进行了详细的分析与比较，得出不同围岩级别时，洞室断面的合理高跨比； ③对两车道隧道标准断面形式进行计算分析，求解出衬砌结构的抗力区范围； ④对上下台阶法施工过程进行了数值模拟，通过对上、下台阶开挖后洞室结构的竖向位移、水平位移收敛值、初期衬砌受力、围岩应力分布等因素进行了对比分析，得出台阶法施工时，洞室结构施工过程中的竖向位移、水平位移收敛值、初期衬砌的受力、围岩应力分布的变化情况，并结合现场监测数据进行了比较和分析，实际开挖过程和模拟开挖相比较，隧道围岩的变形在开挖后的相同部位变化趋势基本一致，证明有限元方法可以有效模拟隧道施工。
[Abstract]:During the construction of the underground cavern. Different construction methods and different construction sequence will lead to different displacement and stress results of surrounding rock, and the form of tunnel section determines the difficulty of construction and the stability of surrounding rock and supporting structure during construction. Degree; The larger the section span, the more difficult the construction, the more complex the stability of surrounding rock supporting structure. The support lining parameters of large-span cross-section cavern. Section type and construction scheme are the key and difficult points in the study of tunnel construction. Based on the cross-section form of tunnel between Taiping Village Station ~ Hongqiao Village Station of Kunming Rail Transit Line 3, combined with rock mechanics. Based on the theory of elastoplastic mechanics and the D-P yield criterion, the finite element ansys model is established for different surrounding rock classes, taking into account the nonlinear factors of rock and soil. The section forms of different height / span ratio are simulated and analyzed, and the following conclusions are drawn. The main contents are as follows: (1) analyze and select the contour section of lining (single center circle, three center circle and five center circle), and get the reasonable profile section form of lining; 2. The factors of vertical displacement convergence, initial lining force, stress distribution of surrounding rock and eccentricity of initial lining are analyzed and compared in detail, and different surrounding rock levels are obtained. Reasonable height / span ratio of tunnel section; (3) the standard section of two-lane tunnel is calculated and analyzed, and the range of resistance zone of lining structure is solved. The vertical displacement, horizontal displacement convergence value and initial lining force of the cavern structure after the excavation of the upper and lower steps are simulated by numerical simulation of the construction process of the upper and lower step method. The stress distribution of surrounding rock and other factors are compared and analyzed, and the vertical displacement, horizontal displacement convergence value, initial lining force and stress distribution of surrounding rock are obtained during the construction of cavern structure by step method. Combined with the field monitoring data to compare and analyze the actual excavation process and simulation of excavation the tunnel surrounding rock deformation in the same position after excavation the trend of change is basically the same. It is proved that the finite element method can simulate the tunnel construction effectively.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U455;U456.3

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