Tunnel opening surrounding rock anti-collapsing device and construction method

Abstract

The invention discloses a tunnel opening surrounding rock anti-collapsing device and a construction method. The tunnel opening surrounding rock anti-collapsing device comprises an advance grouting anchor rod which is the first to be hit into a surrounding rock and multiple layers of supporting units which are installed later and comprise the first protective layer, the water-proof layer, the reinforced duct, the second protective layer, the reinforced supporting frame layer, the secondary lining layer and the arch foot reinforcing layer. The reinforced duct adopts the mode of double steel sleeves, the inner steel sleeve is concentrically arranged in the outer steel sleeve, and the tail portion of the inner steel sleeve is provided with steel rod nails; the reinforced supporting frame layer is composed by sequentially connecting four steel pipes which comprise the two inverted-L-shaped steel pipes and the two oblique supporting steel pipes; and after laying of the first protective layer, the water-proof layer, the reinforced duct, the second protective layer and the reinforced supporting frame layer is completed, inverted arches are arranged at the bottom of a tunnel, the secondary lining layer is laid onto the whole tunnel later on, and then concrete is sprayed onto arch feet to form the arch foot reinforcing layer. The tunnel opening surrounding rock anti-collapsing device has the characteristics of being multiple in supporting, safe, stable, simple in structure and convenient to install, has the functions of drainage and monitoring at any moment and can effectively avoid the surrounding rock from collapsing.

Description

technical field [0001] The application relates to a surrounding rock collapse preventing device and a construction method, in particular to a tunnel entrance surrounding rock collapse preventing device and a construction method. Background technique [0002] The structure of the surrounding rock at the tunnel entrance is generally loose and weak. According to the concept of surrounding rock classification, it is usually grade IV or grade V, which belongs to poor surrounding rock and requires strong support to resist the settlement of surrounding rock; on the other hand , the tunnel entrance is often washed by rainwater, which further reduces the strength of the surrounding rock; in the existing technology, the surrounding rock of the tunnel entrance is often strengthened by advanced conduits, bolts, primary support and secondary lining, but it will still Surrounding rock settlement, water leakage, cracks, and even collapses are caused by insufficient support strength. Cont...

AI Technical Summary

Problems solved by technology

[0002] The structure of the surrounding rock at the tunnel entrance is generally loose and weak. According to the concept of surrounding rock classification, it is usually grade IV or grade V, which belongs to poor surrounding rock and requires strong support to resist the settlement of surrounding rock; on the other hand , the tunnel entrance is often washed by rainwater, which further reduces the strength of the surrounding rock; in the existing technology, the surrounding rock of the tunnel entrance is often strengthened by advanced conduits, bolts, primary support and secondary lining, but it will still Subsidence, water leakage, cracks, and even collapse of surrounding rocks occur due to insufficient support strength

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