Anti-deformation and shock-absorbing protection structure at top of tunnel

Abstract

The invention provides an anti-deformation and shock-absorbing protection structure at top of a tunnel, and belongs to the technical field of tunnel structure safety. The anti-deformation and shock-absorbing protection structure comprises an outer support arch reinforcement plate, a middle and outer support arch reinforcement plate, a middle and inner support arch reinforcement plate, an inner support arch reinforcement plate, a coordinated connection fixing rod, a locking reinforcement screw member, a tight hoop structure, a built-in seismic buffer setting layer, a built-in mixed support reinforcement medium layer, a side bearing support pile structure, a connection support fixing plate, an inner support fixing bottom plate and an outer support connection top plate, wherein the outer support fixing connection top plate is arranged at the outermost layer of the anti-deformation and shock-absorbing protection structure at the top of the tunnel, and the outer support arch reinforcement plate is arranged in the outer support fixing connection top plate; and according to the invention, the anti-deformation and shock-absorbing protection structure has the following beneficial effects: the convergent deformation of the existing tunnel structure can be limited, the installation is quick and the disassembly is convenient, the main structure of the tunnel is effectively avoided from being damaged in a strong earthquake, and the self-bearing capacity of soil at the top of the tunnel structure is improved significantly.

Description

technical field [0001] The invention belongs to the technical field of tunnel structure safety, in particular to an anti-deformation and shock-absorbing protective structure at the top of a tunnel. Background technique [0002] In the construction of mountain tunnels, the new Austrian method is generally used as the theoretical basis, that is, based on the maintenance and utilization of the self-supporting capacity of the surrounding rock, anchor rods and shotcrete are used as the main support means to support in time and control the surrounding rock. The deformation and relaxation of the surrounding rock make the surrounding rock an integral part of the support system. However, during the construction process, it was found that due to the complex and changeable geological conditions of the surrounding rock, the self-supporting capacity of the surrounding rock is weak in the area where the rock mass is broken. At present, the composite lining structure is generally used in ...

AI Technical Summary

Problems solved by technology

However, due to the limitation of the cavern interior space and the construction trolley and the influence of the construction process, the primary lining cannot be closed in time to form a ring, and the construction of the secondary lining often lags behind the primary lining, and the construction interval generally reaches more than 70m

Before the initial lining is closed into a ring, the end of the steel arch frame is generally reinforced with lock-foot bolts, but the surrounding rock in the fracture zone is relatively broken, and the reinforcement effect of the lock-foot bolts is limited, and grouting takes a while. Play the role of anchoring, so the primary lining collapse accidents often occur in the project, which seriously affects the construction progress and project safety

At present, in order to limit the convergent deformation of the tunnel, a transverse support beam with two ends hinged on the inner wall of the tunnel is generally used. This beam can only limit the extrusion deformation on both sides of the tunnel, and cannot provide upward support for the steel arch. For example, when an earthquake occurs, the vibration will cause the main structure of the mountain tunnel to produce an earthquake response, which may cause the main structure to be damaged in a strong earthquake. Therefore, controlling losses to the greatest extent, increasing the safety factor and reducing the vibration response of the structure are the current issues for a series of projects such as mountain tunnel building structures. Problems to be solved. These unfavorable factors pose a great challenge to the construction safety of the tunnel opening. Due to the increasing span of highway tunnels, from the previous two-lane tunnel to the current four-lane tunnel, the tunnel section tends to be flatter. The deformation of the surrounding rock is difficult to control, and the design and construction technology is relatively complicated

The shaped steel arch frame of the tunnel’s primary lining plays a pivotal role in tunnel construction. It bears the surrounding rock pressure before the primary lining is formed, and bears the subsequent surrounding rock pressure together with the steel concrete formed by the primary lining concrete. The flattening of the steel arch frame during the construction process is more and more complicated, and the phenomenon of alternating tension and pressure poses a greater challenge to the construction safety of mountain tunnel building structures and other series of projects.

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