Rock stratum super-large tunnel spanning high-side slope tunnel portal supporting structure and construction method thereof

Abstract

The invention discloses a rock stratum super-large tunnel spanning high-side slope tunnel portal supporting structure and a construction method thereof. The supporting structure comprises upward slopeground beams, annular upward slope anchor cables, vertical high-strength prestressed steel cables and in-tunnel system anchor rods or anchor cables, wherein the upward slope ground beams are externalstress structures of a tunnel portal supporting system; the annular upward slope anchor cables are arranged on a side slope of a tunnel portal, and unstable blocks formed by rock fractures and fracture zones at the top of a tunnel portal section structure are fixed on peripheral stable blocks through the annular upward slope anchor cables, or the unstable blocks are connected in series to form the stable blocks; the vertical high-strength prestressed steel cables are arranged in lowering holes of the upward slope ground beams and are arrange in crossed with the annular upward slope anchor cables; and the in-tunnel system anchor rods or anchor cables are arranged above a top middle tunnel and top side tunnels. According to the rock stratum super-large tunnel spanning high side slope tunnelportal supporting structure and the construction method thereof, rapid and safe tunnel entering construction of a hard rock stratum high-side slope ultra-large-span underground structure is achieved,a tunnel portal side slope self-stabilization reinforcing body is formed, and the risk that rock mass on the upper portion of a tunnel forms a slip surface, the unstable blocks or rock mass wedges onthe top of the cavern range collapse due to excavation is avoided.

Description

technical field [0001] The invention relates to the field of underground engineering, in particular to a support structure and a construction method for a super-large-span tunnel high-side slope opening in a rock formation. Background technique [0002] China is a country with many mountains. According to statistics, the area of ​​mountains, hills and plateaus accounts for 69% of the total land area of ​​the country. Most of the strata in these areas are rock strata. Rock formations are also widely distributed in the plains of the country. The silt and fine sandstone layers are mainly distributed in the Yangtze River Delta Plain and the northern Jiangsu region; the fine sandstone layers are mainly distributed in the Lixia River and Taihu Lake areas; , mainly distributed in the plain area of ​​the Yangtze River Delta, the Yellow River flooding area and the coastal areas. [0003] With the development of the national economy, more and more attention has been paid to the devel...

AI Technical Summary

Problems solved by technology

[0004] Super-long-span underground projects in rock strata face problems such as large spans and thin covering soil at the entrance section. In addition, the superposition of weak structural zones such as joints and fissures can easily cause caverns to collapse during construction. How to realize the opening of super-long-span underground engineering in rock strata Little research has been done on safe and rapid construction

Images