A cone-mill integrated drill bit for ground stress testing

Abstract

The invention discloses a coning-grinding integrated drill for a ground stress test. The coning-grinding integrated drill comprises a water return port (1), a coning plane (4) is arranged on the outer side of the water return port (1), the outer edge of the coning plane (4) is connected with a conical surface (2), the other end of the conical surface (2) is connected with a flat grinding surface (3) which is parallel to the coning plane (4), and a drainage channel (5) communicates with the water return port (1) through the flat grinding surface (3), the conical surface (2) and the coning plane (4). By means of the coning-grinding integrated drill, drilling of a small test hole is accelerated, working efficiency and working quality are greatly improved, and time and labor are saved; and compared with the prior art, only one drill is used for completing the steps of flat grinding and horn mouth coning.

Description

Technical field [0001] The invention belongs to the field of geotechnical engineering survey, and particularly relates to a cone-grinding integrated drill bit in rock mass stress testing by a stress relief method. Background technique [0002] With the increasing scale of construction projects in my country, more and more underground chambers are used in water conservancy and hydropower, mining, military, railway and other projects, and the buried depth is also increasing. However, these deep underground projects are facing high ground stress. Induced structural safety, rock burst, large deformation and other issues. In-situ stress is the main factor that causes deformation and destruction of underground engineering. It is a prerequisite for stability analysis of surrounding rock, selection of underground engineering axis direction, section shape, support design or engineering excavation design. Therefore, measuring the magnitude and direction of the in-situ stress and studying t...

AI Technical Summary

Problems solved by technology

The traditional method has the following two problems: (1) The operation is cumbersome, especially for deep drilling in a narrow adit, installation and grinding of the drill bit → installation and feeding of the drill pipe → grinding → Disassemble the drill pipe → replace the tapered drill bit → install and feed the drill pipe → taper the bell mouth → dismantle the drill pipe, the above 8 processes are required only to drill the guide bell mouth, and it takes 2 to 3 hours to drill a small test hole, which is very Time-consuming and labor-intensive; (2) When grinding and tapering the bell mouth, it is difficult to judge the drilling footage of the drilling rig, and it is often "over-drilled" or "under-drilled". When the bottom of the hole is not ground or the bell mouth is not tapered, it needs to be reworked, which will be more time-consuming and laborious

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