Reaming method for pile hole of building and reaming bit for screw drilling machine

Abstract

The present invention relates to a reaming method for building pile hole and its special-purpose reaming drilling equipment of spiral drilling machine. It is characterized by that it makes the bowarmcutter progressively outward move to cut peripheral soil layer in the course of that the bowarm cutter is upwards and downwards moved with the lifting device so as to obtain the required pile form. Said special-purpose reaming drilling equipment has an internal pipe, said internal pipe is connected with drilling rod of spiral drilling machine, the periphery of the internal pipe is equipped with helical blade whose exterior has an external sleeve, and has a bowarm cutter which can be progressively outward movel under the action of lifting device. Its operation is simple and its accuracy is high.

Description

Technical field: [0001] The invention belongs to the forming technology for bottom expansion and plate expansion for pile holes in the field of construction, and mainly provides a method for expanding pile holes in construction and a special hole expansion drill for auger drilling machines. Background technique: [0002] In the late 1950s, foreign countries began to use multi-section reaming piles in expansive soils. In the 1960s and 1970s, foreign countries also began to apply them in black cotton soil, loess, loam, clay and sandy soil. Experience shows that compared with straight hole piles, reaming piles have greatly improved bearing capacity, small settlement, and significant technical and economic benefits. In the late 1970s, this technology began to be used in China. In the 1990s, Zhang Junsheng in Beijing invented the hydraulic extruded and expanded support plate forming machine, which was applied in projects in Beijing, Tianjin, Henan and other places, and achieved ...

AI Technical Summary

Problems solved by technology

After many years of practical application and analysis by the inventor, this hydraulic extrusion method has the following disadvantages: 1. The forming machine is heavy and heavy, and the cost is high; Application cost is high

When forming, under many geological conditions, the soil layer is not compacted but is destroyed and then falls, resulting in landslides and irregular forming and inaccurate dimensions; at the same time, a special crane is required to cooperate with it, which increases the cost and difficulty of operation

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