Construction method of small-clear-distance parallel tunnel group at inlet section of stone surrounding rock

Abstract

The invention discloses a construction method of a small-clear-distance parallel tunnel group at an inlet section of stone surrounding rock. The construction method comprises the specific construction steps that 1, preparation before tunnel excavation is conducted, specifically, excavation of an open cut tunnel section foundation pit and a pitching slope, pitching slope reinforcement, anti-slide anchor pile construction and advanced long pipe shed construction are included; 2, excavation of tunnels on the two sides is conducted, specifically, a step method is adopted for construction; and 4, excavation of an extra-large section tunnel is conducted, specifically, a three-step seven-part method is adopted for construction. According to the construction method, the pitching slope is reinforced through frame beams and anchor rods, anti-slide piles are arranged between the tunnels, the stability of the pitching slope and tunnel openings is improved, after excavation and support of the small-span tunnels on the two sides of a small-clear-distance influence section are stable, the three-step seven-part method is adopted for excavating the large-span tunnels, disturbance of excavation of the extra-large section tunnel on middle clamping rock and the influence of excavation of the extra-large section tunnel on the tunnel structures on the two sides are reduced advantageously, the construction efficiency is improved, the construction period is shortened, the cost is reduced, and reinforcement and safe construction of the large-span tunnel at an inlet and the small-clear-distance tunnels close to the two sides under the complex condition of a steep slope are achieved.

Description

technical field [0001] The invention relates to the field of tunnel construction, in particular to a construction method for a group of parallel tunnels with a small clear distance at the entrance section of rocky surrounding rock for an extra-large cross-section tunnel and small clear distance parallel sections of tunnels on both sides. Background technique [0002] In the process of tunnel construction, it is unavoidable that there will be tunnel construction with a small clearance distance. In particular, in the tunnel construction process around the city, the surrounding environment is complex, and the construction of a tunnel with a small clearance distance at the entrance section will bring certain impacts to the surrounding railway lines, buildings or structures, etc. influences. The construction process of the ultra-large cross-section tunnel with a small clear distance near the two sides has problems such as structural stability, rock pillar stability between the tu...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a simple and efficient construction process and a small clear distance parallel tunnel group construction method for the entrance section of the stone surrounding rock, so as to solve the problems of the stability of the tunnel body and excessive deformation of the surrounding rock during the construction of the entrance section of the tunnel.

Images