A Construction Method of Drilling Outer Expansion Pipe in Goaf

Abstract

The invention belongs to the technical field of geological subgrades, and in particular relates to a construction method for drilling and expanding pipes in goafs. The construction method includes the following steps: step S1, construction stakeout, and site cleaning; step S2, drill the initial hole through the drilling rig, and drill into the first layer goaf with variable diameter; step S3, put the externally expanded pipe into To the goaf of the first layer, the cross section of the externally expanded pipe is a special-shaped pipe, and the externally expanded pipe is put into the first goaf along the axis of the borehole; step S4, utilizing the externally expanded drill bit to expand the externally expanded pipe; step S5, continue drilling to the goaf of the next layer, and repeat the operations in steps S2-step S4 in the goaf of the next layer until drilling to the target goaf position; step S6, docking the grouting pipe with the borehole , to inject slurry into the target goaf. The construction method effectively saves material waste in untreated layers, saves a large amount of grouting materials and steel pipes, and reduces construction costs. This construction method also greatly shortens the construction period.

Description

technical field [0001] The invention belongs to the technical field of geological subgrades, and in particular relates to a construction method for drilling and expanding pipes in goafs. Background technique [0002] With the continuous development of the national economy, there are more and more engineering constructions under adverse geological conditions. When constructing buildings on the goaf, sometimes it is difficult to ensure the safety of the ground buildings only by using various protection measures on the ground, and the goaf must be treated. The roof of the abandoned goaf collapsed, the coal pillars were broken, or the coal pillars were pressed into the softer floor. The resulting overlying rock movement damage and ground subsidence may occur decades or even hundreds of years after mining. The amount of subsidence and the time of subsidence are difficult to predict accurately, which is extremely harmful to the buildings on the ground. In this case, the problem...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a construction method for drilling and expanding pipes in goafs, so as to at least solve the problems that the current construction method not only prolongs the construction period but also increases the construction cost by grouting the untreated layer.

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