Reinforcing structure for sandwiched rocks of small-distance overlapped tunnel and construction method thereof

Abstract

The invention provides a reinforcing structure for sandwiched rocks of a small-distance overlapped tunnel and a construction method thereof. The reinforcing structure comprises a top arch pipe shed arranged at the top of a lower-layer tunnel, an inverted arch pipe shed arranged at the bottom of an upper-layer tunnel and counter-bracing rods connected between the upper-layer tunnel and the lower-layer tunnel in a bracing manner. The counter-bracing rods are arranged at overlapped positions between the upper-layer tunnel and the lower-layer tunnel at spaced intervals. Two ends of each counter-bracing rod are connected into the upper-layer tunnel and the lower-layer tunnel. A main body of each rod is arranged in a sandwiched rock between the upper-layer tunnel and the lower-layer tunnel in apenetrating manner. During construction, pipe sheds are firstly built and tunnels are dug out. The lower-layer tunnel is firstly dug out. The counter-bracing rods are dug out in the sequence from proximal to distal at the sandwiched rocks. After the lower-layer tunnel is finished, the upper-layer tunnel starts digging from distal, near sandwiched rocks, to proximal. The counter-bracing rods are fixed. The structure plays a role in clamping and reinforcing the sandwiched rocks of the small-distance overlapped tunnel, thereby effectively carrying upper loads. Additionally, the construction method is simple and convenient to operate.

Description

technical field [0001] The invention relates to the field of tunnel construction, in particular to a small clear distance overlapping tunnel interlayer rock reinforcement structure and a construction method thereof. Background technique [0002] With the rapid development of my country's infrastructure construction, the engineering space continues to expand, and the number of tunnel projects is gradually increasing, with a trend of small clearance, multiple chambers, and large cross-sections, which brings new challenges to tunnel design and construction. In the construction of overlapping tunnels with a small clear distance, due to repeated disturbances in the construction of the upper and lower tunnels, the interlayer rock between the tunnels is often the weakest and bears the most complicated force, which is the key link affecting the overall stability of the overlapping tunnels. Therefore, certain measures are often taken during the construction process technical means to...

AI Technical Summary

Problems solved by technology

At present, the most common reinforcement method for interlayered rock in overlapping tunnels is advanced pre-grouting, but advanced pre-grouting is suitable for weak and broken rock formations, and for relatively dense strata, grouting is relatively difficult and the reinforcement effect is very limited. Therefore, it is necessary to propose A Reinforcement Structure and Construction Method Applicable to Interlayered Rock in Overlapping Tunnels with Small Clear Distance

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