Large-section soft ground tunnel full-section construction structure and construction method

Abstract

The invention discloses a large-section soft ground tunnel full-section construction structure and a construction method. The structure comprises a tunnel excavation and anchorage system formed by multiple tunnel excavation and anchorage mechanisms for excavating and anchoring rock masses in front of a working face, wherein each tunnel excavation and anchorage mechanism comprises an anchor rod, ananchorage mechanism and a rotary excavation cutter. The method comprises the steps of (1) constructing a rear-end segment; (2) constructing a next tunnel segment; and (3) repeating the step (2) for one time or multiple times until the tunnel construction process is accomplished. The large-section soft ground tunnel full-section construction structure provided by the invention is reasonable in design, simple and convenient to construct and good in use effect; the construction quality is easy to control; and when the rock masses in front of the working face are effectively dynamically anchoredby the tunnel excavation and anchorage system formed by adopting the multiple tunnel excavation and anchorage mechanisms, a large-section soft ground tunnel can be mechanically full-section excavatedat the same time, so that the tunnel surrounding rock and tunnel structure is ensured to be stable, the construction risk is reduced, the construction progress can be effectively accelerated, and thetunnel construction quality is easy to control.

Description

technical field [0001] The invention belongs to the technical field of tunnel construction, and in particular relates to a full-section construction structure and a construction method of a large-section soft ground tunnel. Background technique [0002] In recent years, among underground projects such as railway tunnels, highway tunnels, and urban subways that are being built and planned, there are more and more tunnel projects that pass through weak strata. It occupies a very high proportion, and there are many tunnel projects passing through the loess layer, and the tunnel section is getting larger and larger. The probability of plastic deformation of soft rock (that is, weak surrounding rock) is very high, which often causes the clearance of the tunnel to become smaller, affecting normal tunnel construction and use. Due to the loose geological structure and extremely poor stability of the weak surrounding rock itself, it is determined that it will inevitably be deformed ...

AI Technical Summary

Problems solved by technology

This type of method has the following three common defects: the first, the excavation section has many divisions (also known as many blocks), and the process is complicated; the second, each part of the excavation section is small, and the degree of mechanization is low; The ring protection period is long and the deformation is large

However, the manufacturing cost of large-section shield machines is relatively high, and the equipment is not very versatile, resulting in high engineering costs. In addition, large-section shield segment tunnels sometimes need to add secondary linings in consideration of the seismic performance of the structure. At this time, it is very uneconomical to adopt the shield tunneling method for construction.

Images