Safe and fast construction method of down-traversing river shallow depth bored tunnel

Abstract

The invention discloses a safe and fast construction method of a down-traversing river shallow depth bored tunnel. The method includes the steps that on the two sides of the tunnel, the upstream and the downstream of a river are each provided with a clay cofferdam so that the river can be intercepted, and a dry river bed is formed in a tunnel construction area; the two constructed clay cofferdams are communicated through a flow guiding pipe, and therefore upstream river water and downstream river water can flow; the two sides of the tunnel are each provided with at least one row of Larsen steel plate piles, and the tunnel is excavated after the Larsen steel plate piles extend to a river bank in the axial direction of the tunnel. The clay cofferdams, the flow guiding pipe and the Larsen steel plate piles are matched coordinately and comprehensively utilized, and tunnel construction safety is guaranteed by the clay cofferdams, the flow guiding pipe and the Larsen steel plate piles jointly. The method is good in construction safety and high in construction efficiency, treatment measures are flexible, pertinent adjustment can be performed according to different geological conditions, and manufacturing cost of projects is saved as much as possible on the premise that safety is guaranteed.

Description

technical field [0001] The invention discloses a safe and rapid construction method for a shallow-buried underground excavation tunnel passing through a river, and belongs to the technical field of tunnel construction. Background technique [0002] With the development of tunnel engineering, more and more tunnels need to pass through rivers. In shallow buried tunnels, the place where the river passes below is generally the key control point of the project. Large-scale water seepage may even cause instability and collapse of the working face. How to ensure construction safety and improve construction efficiency needs to be solved urgently. [0003] In the construction of shallow buried tunnels that cross rivers, there are usually two construction methods. The first method is to excavate the tunnel only by strengthening the support in the tunnel without changing the current status of the river; the second method is to use cut-off or The river is diverted, and then tunnels ar...

AI Technical Summary

Problems solved by technology

This construction method has the following defects: 1. The construction risk is relatively high. In the event of water gushing or collapse, the river water will flow backward into the tunnel, which will not only affect the downstream section of the river, but is more likely to submerge the entire tunnel, which will bring new problems to the tunnel construction. Catastrophic impact; 2. Choose conservative construction methods, reduce the cycle footage, slow down the construction progress, and increase the time cost; 3. The space in the cave is narrow, and the construction operation of the reinforced support system is inconvenient, which affects the construction organization and reduces the construction efficiency. And the construction quality is difficult to guarantee

However, this method also has the following defects: 1. River diversion may involve demolition, pipeline movement, etc., which requires the coordination and cooperation of multiple departments such as the government, and the processing costs are high, making it difficult to implement; Flood control and drainage or flushing ability will adversely affect the lives of nearby residents, and cannot prevent the impact of upstream river water seeping along the riverbed in the horizontal direction on the tunnel construction site; 3. River bottom treatment, before the river bottom treatment still needs to be done Temporary cofferdams are poorly observable after river bottom treatment, and problems cannot be discovered and remedied in time. Once the river bottom treatment measures fail, it will seriously affect the tunnel construction; 4. Stratum precipitation, stratum precipitation can easily cause stratum subsidence Threat to the safety of adjacent buildings, and the requirements for daily maintenance and management are high, consuming a lot of material resources and manpower

[0006] In the prior art, in the construction of shallow-buried underground tunnels that pass through rivers, usually more attention is paid to taking treatment measures in the cave to strengthen the support in the cave. Consider comprehensive treatment measures outside the cave

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