Construction method of super long pipe shed in soft surrounding rock section of tunnel portal

Abstract

The invention discloses a construction method of a super long pipe shed in a soft surrounding rock section of a tunnel portal. The accuracy of the construction of the pipe shed is ensured through utilizing a guiding technology, the drilling process records the geography and provides a reference for tunnel excavation, and effective advance support provides technical support for tunnel excavation. Before tunnel excavation and entering the portal, a front slope on the edge of the portal is excavated in place, a pipe shed guiding wall is applied, a guiding pipe is pre-embedded, meanwhile, a drill pipe is machined, a high-speed air compressor is arranged, after a drilling machine is in place, a positioning device is mounted in a drill pipe head for positioning, deviation is rectified in time in the drilling process according to the drilling bias of a rod body, meanwhile, the power is adjusted according to the drilling length and soil layer geological conditions, the depth and the location of the drilling machine are ensured, and after drilling is completed, the drilling machine and the drill pipe are separated and grouting is conducted; and construction of the next pipe shed is started, and a stable arch ring outside excavation is formed. According to the construction method of the super long pipe shed in the soft surrounding rock section of the tunnel portal, the phenomena of hole shifting and hole collision do not exist, the hole-forming efficiency is high, and the construction method is suitable for environments such as complex geological conditions, a loose sand layer and a clay layer.

Description

technical field [0001] The invention relates to a construction method for super-long pipe shed advanced support for the long and weak section of the tunnel entrance in the mountainous section of the rainy area, and specifically relates to the weak surrounding rock of the mountain tunnel, uneven softness and hardness, and surrounding rock with water (levels V and VI) It is a construction method for super-long pipe shed advanced support at tunnel entrances with particularly complex geological conditions such as rocks and rocks. Background technique [0002] In the opening construction of high-speed railway tunnel projects in my country, pipe sheds are very common as the advance support for entering the tunnel, and the construction methods are also very mature. The two common methods are the method of jacking through the leading hole and the method of drilling with the pipe. There are two main working principles of the pipe shed: a beam structure, which forms a simply supported...

AI Technical Summary

Problems solved by technology

Although the conventional construction technology is equipped with a guide pipe for the hole, due to the uneven geology, the phenomenon of partial hole often occurs during the introduction hole or drilling process of the pipe shed, and the inspection means are limited during the construction process, so it is impossible to grasp the drilling of the pipe shed. The trajectory of the process cannot effectively achieve the final purpose of grouting and consolidation around the excavation of the tunnel. It is often found that the tail of the pipe shed falls into the excavation contour line after excavation. Therefore, the pipe shed of the conventional construction method is generally Control within 30-40m, the construction progress is relatively slow, and the construction accuracy is also low

Images