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Dynamic Response Characteristics and Reasonable Design Parameters for Railway Tunnel Floor Structures under Heavy Loading
(1 School of Civil Engineering, Central South University, Changsha 410075; 2 Henan Provincial Communication Planning Surveying d Design Institute, Zhengzhou 450052)
Abstract A numerical model coupling a heavy-haul railway tunnel structure and its surrounding rock is estab? lished using the excitation function and based on the theory of dynamic finite element. The influence of different rise-span ratios and the thicknesses of the filling layer and invert on the characteristics of the dynamic response in a heavy-haul railway tunnel structure are analyzed. The results show that dynamic response of the whole floor structure of a heavy-haul railway tunnel is larger than that of normal railway tunnel and it is unfavorable for the stability of tunnel structure. The maximum response values of different mechanical indexes for a tunnel floor structure under heavy load and corresponding positions are obtained. Reasonable design parameters for the floor structure of a double-track railway tunnel under a heavy load are discussed; for the floor structure of a heavy-haul double-track railway tunnel, a reasonable rise-span ratio and thickness of the filling layer and invert are 1/10~1/11, 1.2~1.3 m and 40~50 cm, respectively. These parameters could effectively improve the dynamic response and stress state of these structures.
Abstract：
A numerical model coupling a heavy-haul railway tunnel structure and its surrounding rock is estab? lished using the excitation function and based on the theory of dynamic finite element. The influence of different rise-span ratios and the thicknesses of the filling layer and invert on the characteristics of the dynamic response in a heavy-haul railway tunnel structure are analyzed. The results show that dynamic response of the whole floor structure of a heavy-haul railway tunnel is larger than that of normal railway tunnel and it is unfavorable for the stability of tunnel structure. The maximum response values of different mechanical indexes for a tunnel floor structure under heavy load and corresponding positions are obtained. Reasonable design parameters for the floor structure of a double-track railway tunnel under a heavy load are discussed; for the floor structure of a heavy-haul double-track railway tunnel, a reasonable rise-span ratio and thickness of the filling layer and invert are 1/10~1/11, 1.2~1.3 m and 40~50 cm, respectively. These parameters could effectively improve the dynamic response and stress state of these structures.
.Dynamic Response Characteristics and Reasonable Design Parameters for Railway Tunnel Floor Structures under Heavy Loading[J] MODERN TUNNELLING TECHNOLOGY, 2017,V54(5): 86-92
2017, Vol. 54 