Rapid hole-forming construction method of large-diameter deep hole pile foundation under karst geology

Abstract

The invention discloses a rapid hole-forming construction method for a large-diameter deep hole pile foundation under karst geology. 'Rotary drill and reverse circulation impact drill' combined relaydrilling is performed, a rotary drill rapidly performs drilling construction of a covering layer, and a reverse circulation impact drill is used for relay construction when a karst geological layer isdrilled. The combined construction process gives full play to the advantages of the two kinds of drills under the situations of different geological conditions and hole depths, the advantages are complemented with each other, and the construction efficiency and economic benefits of the large-diameter deep hole pile foundation under the karst geology are improved. Drilling of single drilling equipment is converted into combined drilling of the two different kinds of drilling equipment, the construction progress of the pile foundation is greatly accelerated under the condition of ensuring the hole-forming quality of the pile foundation, meanwhile, environmental friendliness is better achieved, civilized construction is facilitated, input of personnel and mechanical equipment is reduced, andthe good economic benefits are generated.

Description

technical field [0001] The invention relates to a construction method for bridge engineering pile foundation structures, in particular to a rapid hole-forming construction method for large-diameter deep-hole pile foundations under karst geology. Background technique [0002] With the rapid development of my country's economy and society, the scale of infrastructure construction is also increasing. As an important foundation structure of bridge engineering, the construction of pile foundations is particularly important. The traditional hole-forming construction of large-diameter deep-hole pile foundations in karst geology uses positive circulation percussion drilling technology, but due to positive circulation percussion drilling through mud Circular slag discharge, low slag discharge efficiency, coupled with the hole forming method of using a single steel wire rope to lift the drill bit for up and down impact movement, it is difficult and inefficient to drill in the clay-sil...

AI Technical Summary

Problems solved by technology

As an important foundation structure of bridge engineering, the construction of pile foundations is particularly important. The traditional hole-forming construction of large-diameter deep-hole pile foundations in karst geology uses positive circulation percussion drilling technology, but due to positive circulation percussion drilling through mud Circular slag discharge, low slag discharge efficiency, coupled with the hole forming method of using a single steel wire rope to lift the drill bit for up and down impact movement, it is difficult and inefficient to drill in the clay-silt-dominated overburden

When drilling in karst geological layers, accidents such as inclined holes, dropped drills, and stuck drills are likely to occur in karst caves, which seriously affect the progress of the project, and the effective drilling depth of the positive circulation percussion drill should not be greater than 70m, which has certain limitations.

Images