Supporting and retaining structure of existing retaining wall straight penetrated by large-span tunnel and construction method thereof

Abstract

The invention belongs to the technical field of tunnel engineering and particularly relates to a supporting and retaining structure of an existing retaining wall straight penetrated by a large-span tunnel and a construction method thereof. The supporting and retaining structure comprises two rows of anti-skid piles, a ground coupling beam, coupling beams, a top beam, inclined struts, an anchor stay cable structure and a grouting reinforcement body. The two rows of anti-skid piles are mounted on the outer side of the supporting and retaining structure. The front row of anti-skid piles are at a certain distance from the supporting and retaining structure and are connected with one another through the ground coupling beam. The rear row of anti-skid piles are tightly attached to the supporting and retaining structure and connected with one another through the top beam, the coupling beams and the ground coupling beam. The two rows of the anti-skid piles are connected through the ground coupling beam and the inclined struts to form an overall frame structure. The rear row of anti-skid piles are provided with opposite-pull anchor stay cables. Rock and soil masses on the stressed sides of the peripheries of the anti-skid piles are subjected to grouting reinforcement, and the bearing capacities of the rock and soil masses and the supporting and retaining structure are improved. The supporting and retaining structure is applicable to an entrance and an exit of the large-span tunnel and a tunnel entrance heading slop with the requirement of small deformation, the reinforcing effect is guaranteed, and traffic operation is not blocked.

Description

Technical field [0001] The invention belongs to the technical field of tunnel engineering, and particularly relates to a supporting structure and a construction method for a large-span tunnel passing through an existing retaining wall. Background technique [0002] Since the 21st century, with the construction of my country's high-speed railway network, expressway network, high-grade highway network and urban municipal road network, my country's transportation engineering infrastructure construction has been booming. In my country’s inland areas where there are many mountains, houses, roads, etc. are mostly built on the slopes after reinforcing the slope with retaining walls according to local conditions. The construction of higher road networks often adopts the form of tunnel structure crossing the mountain and slope sloping, which involves the entrance and exit of the tunnel. There is a problem with the existing retaining wall structure when the section passes through houses, ro...

AI Technical Summary

Problems solved by technology

Grouting is mainly to reduce deformation by improving the strength characteristics of rock and soil. It is suitable for the development of cracks, loose rock and soil, insufficient filling compaction, and insufficient structural base resistance. For structures that have bulging deformation, cracking and grouting The grout cannot improve the stability of the sliding body but increases the sliding force and other diseases. Not only has no effect but aggravates the diseases, the road surface grouting construction of the municipal road section not only interferes with traffic operations but also affects the surrounding environment

The pulling force of anchor cables (rods) is limited, and it is not suitable for structures that are subject to large forces and require small deformations, especially large deformations at tunnel exits and busy road slope support structures mean structural damage, which seriously threatens safety

Corbels and anti-slide piles are commonly used outside the existing structure. Generally, the construction is convenient, the construction period is short, and it will not interfere with the operation of the road above. However, it affects the appearance and requires land occupation. To ensure the effect, the distance between them is generally Smaller, not suitable for retaining reinforcement of existing structures on the upward slope of the large-span tunnel entrance

[0004] In view of this, it is necessary to invent a retaining structure for the existing retaining wall and its construction method, which can not only adapt to the domestic terrain and geological conditions to reinforce the existing retaining structure, but also ensure the supporting effect of the structure and the normal operation of the adjacent traffic. operation, and can overcome the small spacing defects of the existing reinforcement structure, and is suitable for the reinforcement of the entrance and exit of long-span tunnels and slope retaining structures that require small deformation

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