CN102031775B

CN102031775B - Construction technology of drilled pile in hard oblique rocks by medium hole blasting

Info

Publication number: CN102031775B
Application number: CN201010199094.1A
Authority: CN
Inventors: 江拔其; 胡伟; 郑先奇; 徐华轩
Original assignee: China Railway 16th Bureau Group Co Ltd
Current assignee: China Railway 16th Bureau Group Co Ltd
Priority date: 2010-06-12
Filing date: 2010-06-12
Publication date: 2015-04-29
Anticipated expiration: 2030-06-12
Also published as: CN102031775A

Abstract

The invention relates to a construction technology of a drilled pile in hard oblique rocks by medium hole blasting. In the construction technology, the technologies of drilling a hole, charging, injecting water, backfilling and constructing the drilled pile are utilized, and the invention is characterized in that the construction technology of the drilled pile in the hard oblique rocks by medium hole blasting is as follows: using a geological drill to drill a blast hole at the center of the pile; charging explosive in the blast hole; injecting water, backfilling, and blasting; and constructing the drilled pile. The construction technology can be used in the construction of the drilled pile in the hard oblique rocks, the construction speed is fast, the operation is simple, and the cost is low.

Description

Hard tiltedly rock mesopore blasting boreholes pile construction method

Technical field

The invention belongs to field of civil engineering, particularly relate to a kind of novel hard tiltedly rock mesopore blasting boreholes pile construction method, adopt geological prospecting rig in the center of stake, boring (Φ=110mm) is as big gun hole, put into the blasting charge and carry out explosion, country rock around broken big gun hole, is easy to drilled pile construction.

Background technology

Karst is formed by the chemical corrosion of water for a long time by solublerocks such as limestone.There is solution cavity, lapies, fluid bowl in karst strata, especially solution cavity top (end) plate is indenting, and height differs greatly.Limestone is for a long time by the chemolysis of water, and rock stratum there is soft or hard inequality or half rock half is native, half rock half is molten and slope rock.Karst grows by force the Technology Difficulties that the rock drilled pile inclined hole correction of slope, stratum is karst pile foundation boring.And the drilled pile conventional construction method in the past taked, the not only time-consuming material that takes, and construction speed is very slow, the hard tiltedly rock mesopore blasting boreholes pile construction technology of invention, facts have proved, and this invention speed of application is fast, and expense is low, is easy to operation.

Summary of the invention

Adopt geological prospecting rig in the center of stake, Φ=110mm is as big gun hole in boring, and blast hole depth 50 ~ 80cm fewer than design hole depth, affects bearing capacity of pile tip to guarantee stake end rock stratum not to be subject to the destruction of explosion.Carry out drilling construction owing to growing by force bad ground area at karst, solution cavity causes being difficult to pore-forming often.Geological prospecting rig, when boring runs into solution cavity, according to having non-filler and solution cavity filler situation in solution cavity, can take corresponding technical measures: when running into non-filler in solution cavity, can adopt steel sleeve follow-up guard aperture drilling and forming hole; When run in solution cavity have filler time, according to solution cavity filler situation, can utilize geological prospecting rig grouting methol, at certain limit consolidation solution cavity filler drilling and forming hole.After boring reaches requirement hole depth, the silt particle in residue and mud in cleaning hole, utilize rig to carry out hole clearly, silt boring up to prevent silt particle backflow.

The explosion of drilled pile deep hole water pressure blasting, its cartridge bag belongs to internal action cartridge bag.The design principles controlling cartridge bag amount how many is, within its cartridge bag amount causes the crack of big gun hole rock crusher or generation to be controlled in a footpath scope.At present, the computational methods that the author takes, as deep hole water pressure blasting explosion, namely need broken volume to be multiplied by the total charge that unit administration amount is exactly big gun hole.Such as 333# pier 1# stake, stake footpath 1m, the dark 17m in rock stratum (the dark 34m of stake), then fragmentation volume V=(1/2) ²π × 17=13.35m ³, unit π dose q is through trying quick-friedly finally to be defined as 1.6kg/m3, and big gun hole total charge Q=q × V=21.36kg, reality has filled 21.6kg.

The present invention's tool compared with surface longhole hydraulic pressure demolition, outdoor conventional deep hole blasting, chamber blasting and Tunnel Blasting has the following advantages: simple to operate, each root has the stake of rock stratum only to design a big gun hole, stake and the big gun hole of stake are without contacting, detonate separately, the design in each big gun hole does not involve the parameters such as borehole spacing, array pitch, bench height.

Accompanying drawing explanation

Fig. 1 electric initiating charge constitution schematic diagram;

Fig. 2 fuse arming test experiment initiation charge constitution schematic diagram.

Detailed description of the invention

The explosion of drilled pile deep hole water pressure blasting is divided into the processes such as boring, powder charge water filling, back-filling blinding and percussive drilling by construction succession.

1, geology is adopted to be drilled in pile center's axial location by stake deep drilling big gun hole.Owing to having soil layer, solution cavity may be also had in boring procedure, for preventing promoting collapse hole outside geological drill bit to big gun hole, steel sleeve must be put into outside geological drill bit.Extract outside big gun hole for preventing steel sleeve and occur collapse hole again, plastic bushing must be reinstalled in steel sleeve.After plastic bushing is inserted in, just steel sleeve can be extracted outside big gun hole, and plastic bushing is still motionless in situ.

2, the reinforcing bar that is tied with multiple cartridge bag is put into big gun hole along plastic bushing, then toward water filling in plastic bushing, when water rises to from big gun aperture about 3m, use stemming back-filling blinding.For preventing stemming to be mixed in water, between water and stemming, there is spacer, in fact twisting into group with grass just passable as spacer.

3, after explosion, the impact drilling can be used immediately.

Claims

1. hard tiltedly rock mesopore blasting boreholes pile construction method, comprises boring, powder charge water filling, back-filling blinding and percussive drilling, uses geological prospecting drill hole of drilling machine, carry out deep hole water pressure blasting explosion, reduces boring rock stratum hardness, accelerates drill footage, inclined hole is revised in correction;

Described bore process adopts:

Geology is drilled in pile center's axial location by stake deep drilling big gun hole, puts into steel sleeve, in steel sleeve, load plastic bushing outside geological drill bit, after plastic bushing is inserted in, just steel sleeve can be extracted outside big gun hole, and plastic bushing is still motionless in situ;

Described powder charge water filling and back-filling blinding technique adopt:

The reinforcing bar one being tied with multiple cartridge bag puts into big gun hole along plastic bushing, then toward water filling in plastic bushing, when water rises to from big gun aperture about 3m, uses stemming back-filling blinding, has spacer between water and stemming, twists into group as spacer with grass.