Variable cross-section tunnel structure and parameter determination method for alleviating tunnel aerodynamic effect

Abstract

The invention relates to the technical field of tunnel engineering, and discloses a variable section tunnel structure for alleviating the aerodynamic effect of a tunnel and a parameter determination method. The aerodynamic effect of the tunnel is alleviated and the construction cost is reduced. The variable section tunnel structure comprises expansion sections with entrance and exit section as a first area and a middle section with the inner section of the tunnel as a second area, the expansion sections at two ends are distributed symmetrically, and the second area is less than the first area.The expansion sections and the middle section are both of arc-shaped structures with coaxial center of a circle.

Description

technical field [0001] The invention relates to the technical field of tunnel engineering, in particular to a variable-section tunnel structure and a parameter determination method for alleviating the aerodynamic effect of the tunnel. Background technique [0002] The change of air pressure caused by a train passing through a tunnel at high speed and its impact on train operation safety, personnel comfort and environment is an important content of train aerodynamics research and a key problem that must be solved to achieve high-speed train operation. In order to alleviate the aerodynamic effect caused by the high-speed train passing through the tunnel, a lot of research has been carried out from both the train and the tunnel at home and abroad. The train includes designing a streamlined shape and improving the airtightness of the car body, etc.; the tunnel includes adding buffer structures, ventilation shafts, etc. . Most of the design of the ventilation shaft is for ventil...

AI Technical Summary

Problems solved by technology

Most of the design of the ventilation shaft is for ventilation, rescue or the measures that are forced to be taken under the constraints of terrain conditions. The fundamental design is not entirely to alleviate the aerodynamic effect of the tunnel, so the effect of its design parameters on alleviating the aerodynamic effect is limited; The buffer structure can alleviate the intensity and gradient of the compression wave formed by the train entering from the very beginning, which is the most commonly used method at present. However, the buffer structure is limited by conditions such as the topography of the tunnel entrance, and the parameters such as the length of the buffer structure must be controlled within Therefore, the effect of mitigating the aerodynamic effect of the tunnel, especially the pressure change in the tunnel is limited

[0003] The tunnels currently built are all equal-section tunnels. In order to alleviate the aerodynamic effect of the tunnel, either a large-section tunnel is built, but the construction cost is greatly increased; or buffer structures or other auxiliary facilities are used, but due to terrain conditions and other constraints, the mitigation effect is limited.

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