A Construction Method for Bottom Protection of Tunnel Inverted Arches

Abstract

The invention discloses a construction method for preventing bottom heave of a tunnel bottom inverted arch. The construction method adopts a double-layer telescopic arch inverted arch structure. A stress release groove is excavated at the tunnel bottom to release partial stress at the tunnel bottom; double-layer arch structure is adopted, the first layer is a telescopic arch which can release somestress; a 10 cm foam board interlayer is sandwiched between the double-layer arch frame to form a movable stress release interlayer; and a tunnel bottom release structure is adopted, when the stressis released, an irregular vertical stress is formed, an irregular stress structure is formed at the bottom of the inverted arch initial support, vertical stress concentration is prevented, and the arching, bulging and cracking of the inverted arch are avoided.

Description

technical field [0001] The invention relates to the technical field of tunnel bottom inverted arch construction, in particular to a tunnel bottom inverted arch anti-bottom construction method. Background technique [0002] A high-speed railway tunnel is designed as a single-hole double-track, with a total length of 9100m, and one inclined shaft is set up, intersecting the left line of the line at DK566+350. Construction will be organized according to 4 working faces in 3 work areas of entrance, exit and inclined shaft. The site belongs to the mountainous area in the middle of Taihang structural erosion, with large undulations and complex terrain, and a relative height difference of about 360m. [0003] The construction revealed that the geological conditions are complex and changeable, with adverse geological structures such as high-stress rockbursts, rock fracture zones, weak surrounding rocks, and underground water gushing. The tunnel geology is mainly argillaceous limes...

AI Technical Summary

Problems solved by technology

[0009] However, the existing solutions have the following disadvantages: grouting at the bottom of the tunnel is time-consuming, laborious, and expensive, and the grouting reinforcement ring is easily squeezed and broken by the surrounding rock stress, and the reinforcement effect is poor; Arch filling is a rigid, arc-shaped structure with uniform stress and no room for movement. If the ground stress is too large, the vertical stress will concentrate upwards along the fracture surface to a certain extent, which will cause structural damage and cause damage such as fracture, uplift, and cracks in the inverted arch.

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