CN101135151A

CN101135151A - Blasting pile forming method for high-bearing prefabricated and cast-in-situs steel concrete composite pile body

Info

Publication number: CN101135151A
Application number: CNA2007101572934A
Authority: CN
Inventors: 周亚萍; 吴伟林
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-09-29
Filing date: 2007-09-29
Publication date: 2008-03-05

Abstract

The present is prefabricating, in-situ reinforcing concrete casting and blasting process for constructing high bearing capacity combined pile stem. The process includes the following steps: 1. immersing immersed tube with metal pile head into hardpan to design elevation; 2. taking out the metal pile head; 3. forming the lower base space, taking out soil, casting lower concrete base, immersing one prefabricated hollow pile stem with steel dowels in the lower end into the immersed tube, and drawing upwards the immersed tube to one first designed distance; 4. forming the middle base space, drawing upwards the immersed tube to one second designed distance, forming the upper base space and penetrating reinforcing bars through the upper and the middle base spaces; 5. pouring concrete to form the upper base, the lower base and the middle pile stem; 6. setting the prefabricated pile stem with steel dowels into the immersed tube; and 7. withdrawing the immersed tube.

Description

The blasting pile-forming method of the prefabricated and cast-in-situ steel concrete combined pile body of high-bearing capacity

Technical field

The present invention relates to the blasting pile-forming method of the prefabricated of a kind of construction of building pile foundation engineering, particularly a kind of high-bearing capacity and cast-in-situ steel concrete combined pile body.It is the job practices of the multistage base large bearing capacity of highrise building pile foundation engineering first-selection.

Background technology

According to the national regulation whole body be cast-in-place (be the pile body Cast-in-place concrete, base also is a Cast-in-place concrete) its base diameter ratio maximum value of expanded bore pile is limited in 3-3.5, and pipe sinking prefabricated steel concrete club-footed pile, this stake is the prefabricated concrete of pile body, the base Cast-in-place concrete, obviously this ratio 3-3.5 is broken, generally 3.5-5 can be reached,, requirement of engineering can't be satisfied although bearing capacity is bigger, particularly, the opposite end bearing capacity to give a discount 0.9 when bellout diameter during greater than 1.5 meters.For this reason, immersed tube prefabricated multistage under-reamed pile has appearred again.Existing multiple bearing capacity dish stake technology has two common ground, and first all is to expand the end with positive crossover-circulating type method pore-forming; Second all carries out pile without immersed tube expands the end.This two point-to-points load dish (at the bottom of the multistage expansion) stake is quite unfavorable, in other words, bring two problems, 1), national building code requirement, expand the base end load at the end with positive crossover-circulating type method pile and will take advantage of 0.45 coefficient, because have mud existence and pile bottom sediment to clean out, (Zhejiang Province's standard is 0.24 discount) gives a discount too big, though a plurality of bases are arranged, loss end load is very big; 2); without immersed tube; condition of construction can not get protection; positive in addition crossover-circulating type method is operation under water; expand bottom application worker situation and cannot see, the difficult measurement noted down, when also usually taking place to expand the end under water; top soil body a slice situation that falls down also happens occasionally; also have because the multistage stake of prior art all is the whole body Cast-in-place concrete, and that the intensity of Cast-in-place concrete is done is not high, and difficult quality guarantee; and in water, water concrete; the difficult control of quality adds that the pile capacity of a plurality of bases is all bigger, must do greatlyyer based on its pile body diameter of above factor; and the stake of this many bases is afraid of that pile body diameter is big most; development test shows that pile body diameter increases, and its bearing capacity decay is very serious.

Summary of the invention

The problem that the present invention is directed to the prior art existence provides the blasting pile-forming method of the prefabricated of a kind of high-bearing capacity with the cast-in-situ steel concrete combined pile body, and purpose is to improve utilization rate and reduction coefficient, base diameter and the pile body diameter ratio and the single pile bearing capacity of the strength of materials.

Another object of the present invention is providing a kind of accurate positioning, utilizes multistage base of control and pile body concentricity and guarantees that pile foundation quality can reach the piling method of expected design effect.

The blasting pile-forming method of the prefabricated and cast-in-situ steel concrete combined pile body of high-bearing capacity of the present invention, the immersed tube that comprise following processing step: a, has a metal pile head sinks to the hardpan design elevation; B, taking-up metal pile head; C, put into oil emulsion or tnt explosive from the immersed tube mouth, every 0.5m ³Consumption is the 1-5 kilogram, seals the immersed tube mouth behind the ignition charge, treat that explosive charge is finished after, open the article of sealing the immersed tube mouth and form lower base space, get clean hack, pour into a mould lower bottom base with concrete, the precast hollow pile body that the lower end has joint bar is lowered to immersed tube, on pull out immersed tube to setpoint distance H ₁D, put into oil emulsion or tnt explosive from the immersed tube mouth, every 0.5m ³Consumption is the 1-5 kilogram, seals the immersed tube mouth behind the ignition charge, treat that explosive charge is finished after, open the article of sealing the immersed tube mouth and form the center base space, on pull out immersed tube to the distance H of setting ₂, expanding end processing upper base space with extrusion equipment, hack sweeps in the precast hollow pile body, and long reinforcing bar runs through middle base space; E, perfusion concrete be cast-in-place to be gone up, middle base and stage casing pile body; F, in immersed tube, put into the band joint bar precast pile; G, extract immersed tube.

The blasting pile-forming method of the prefabricated and cast-in-situ steel concrete combined pile body of high-bearing capacity, the immersed tube that comprise following processing step: a, has a metal pile head sinks to the hardpan design elevation; B, taking-up metal pile head; C, put into oil emulsion or tnt explosive from the immersed tube mouth, every 0.5m ³Consumption is the 1-5 kilogram, seals the immersed tube mouth behind the ignition charge, treat that explosive charge is finished after, open the article of sealing the immersed tube mouth and form lower base space, get clean hack, pour into a mould lower bottom base with concrete, the precast hollow pile body that the lower end has joint bar is lowered to immersed tube, on pull out immersed tube to setpoint distance H ₁D, put into oil emulsion or tnt explosive from the immersed tube mouth, every 0.5m ³Consumption is the 1-5 kilogram, seals the immersed tube mouth behind the ignition charge, treat that explosive charge is finished after, open the article of sealing the immersed tube mouth and form the center base space, on pull out immersed tube to the distance H of setting ₂, expand end processing upper base space with extrusion equipment, following prefabricated solid pile body, get clean hack after, will long reinforcing bar from top to bottom from immersed tube put down run through the stage casing and pass in base bottom a bit; E, with in the concrete pouring, upper bed-plate and in, epimere cast-in-situ steel concrete pile body; F, taking-up immersed tube, pile.

Among the described operation d is that hydraulic pressure props up disc shaping machine with extrusion equipment.

The concrete steps of getting clean hack among the above-mentioned operation c are as follows: inhale indigenous equipment with air and fetch earth, when only surplus a small amount of loosing during soil in the base, from immersed tube mouth pouring, pouring limit, limit sops up, and is clean up to fetching earth.

Setpoint distance H among described operation c and the d ₁And H ₂Be base diameter 2-10 doubly.

The present invention is compared with prior art owing to adopt immersed tube to do protection and support, be combined into the technical measures of multistage base stake with precast pile and cast-in-situ steel concrete pile body in addition, and evidence has technology reasonable, accurate positioning, make multistage base and pile body concentricity height, the utilization rate, the reduction coefficient that have obviously improved the strength of materials can reach 0.9-1.0; Base diameter and pile body diameter ratio can reach 3.5-5.0, have improved the supporting capacity of single pile greatly, guarantee the pile foundation engineering quality, and the safe coefficient height reaches the Expected Results of design fully.

Description of drawings

Fig. 1 a-Fig. 1 g is the construction view of master operation of the present invention.

Fig. 2 a-Fig. 2 b is the master operation construction view of another embodiment of the present invention.

Among the figure 1, lower base space; 2, immersed tube; 3, following precast pile; H ₁, H ₂Be base diameter 2-10 times; 4, middle base space; 5, reinforcing bar; 6, upper base space; 7, go up precast pile; 8, long reinforcing bar.

The specific embodiment

Embodiments of the invention are described in detail in conjunction with the accompanying drawings, to further specify summary of the invention.

Embodiment 1:

As Fig. 1 a-Fig. 1 g is master operation construction view of the present invention.The blasting pile-forming method of the prefabricated and cast-in-situ steel concrete combined pile body of high-bearing capacity of the present invention, the immersed tube 2 that comprise following processing step: a, has a metal pile head sinks to hardpan to design elevation; B, taking-up metal pile head; C, put into oil emulsion or tnt explosive from the immersed tube mouth, every 0.5m ³Consumption is the 1-5 kilogram, seal the immersed tube mouth behind the ignition charge, after treating that explosive charge is finished, open the article of sealing the immersed tube mouth and form lower base space 1, except that mach, should keep noresidue hack in it with moulding, normally, also hack can be swept in the prefabricated empty pile body 3 with inhaling indigenous equipment or the clean hack of the legal cleaning of dried wet mixing; Particularly being suitable for forming base space with extrinsion pressing when the chiltern soil layer is constructed is advisable, pour into a mould lower bottom base with concrete, the following precast hollow pile body 3 or the solid precast pile that the lower end are had joint bar are lowered in the immersed tube 2, and joint bar and lower bottom base are anchored, go up and outside pile body, inject cement paste in the slit, pull out immersed tube 2 to setpoint distance H ₁, its span is base diameter 2-10 times; D, put into oil emulsion or tnt explosive from the immersed tube mouth, every 0.5m ³Consumption is the 1-5 kilogram, seals the immersed tube mouth behind the ignition charge, treat that explosive charge is finished after, open the article of sealing the immersed tube mouth and form center base space 4, on pull out immersed tube to the distance H of setting ₂, as shown in Figure 3, its span be base diameter 2-10 doubly, expand end processing upper base space 6 with extrusion equipment, if when precast pile 3 is hollow down, needn't fetch earth, hack swept get final product in the precast hollow pile body; Otherwise use solid precast pile, need to get clean hack, reinforcing bar 5 is put into immersed tube 2, centre and upper base space 4,6 are fused with borrow equipment; E, perfusion concrete be cast-in-place to be gone up, middle base and stage casing pile body; Last precast hollow or solid pile body 7 that f, lower end have joint bar are lowered in the immersed tube, make joint bar and upper bed-plate anchoring; G, extract immersed tube, as shown in Figure 7.Among the operation d is that hydraulic pressure props up disc shaping machine with extrusion equipment.

Embodiment 2:

Shown in Fig. 2 a and Fig. 2 b, its operation a to c is identical with embodiment 1, and operation d processes upper base space 6, following prefabricated solid pile body 3, after hack got clean hack with the suction indigenous equipment, will long reinforcing bar 8 from top to bottom from immersed tube 2 put down run through the stage casing and pass in base bottom a bit; E, with in the concrete pouring, upper bed-plate and in, epimere cast-in-situ steel concrete pile body; F, taking-up immersed tube 2, pile.Shown in Fig. 8-9.

The concrete steps of getting clean hack among embodiment 1 and the embodiment 2 described operation c are as follows: inhale indigenous equipment with air and fetch earth, when only surplus a small amount of loosing during soil in the base, from immersed tube mouth pouring, pouring limit, limit sops up, and is clean up to fetching earth.

Claims

1. the blasting pile-forming method of the prefabricated and cast-in-situ steel concrete combined pile body of high-bearing capacity is characterized in that it comprises following processing step: a, the immersed tube that has a metal pile head sinks to the hardpan design elevation; B, taking-up metal pile head; C, put into oil emulsion or tnt explosive from the immersed tube mouth, every 0.5m ³Consumption is the 1-5 kilogram, seals the immersed tube mouth behind the ignition charge, treat that explosive charge is finished after, open the article of sealing the immersed tube mouth and form lower base space, get clean hack, pour into a mould lower bottom base with concrete, the precast hollow pile body that the lower end has joint bar is lowered to immersed tube, on pull out immersed tube to setpoint distance H ₁D, put into oil emulsion or tnt explosive from the immersed tube mouth, every 0.5m ³Consumption is the 1-5 kilogram, seals the immersed tube mouth behind the ignition charge, treat that explosive charge is finished after, open the article of sealing the immersed tube mouth and form the center base space, on pull out immersed tube to the distance H of setting ₂, expanding end processing upper base space with extrusion equipment, hack sweeps in the precast hollow pile body, and long reinforcing bar runs through middle base space; E, perfusion concrete be cast-in-place to be gone up, middle base and stage casing pile body; F, in immersed tube, put into the band joint bar precast pile; G, extract immersed tube.

2. the blasting pile-forming method of the prefabricated and cast-in-situ steel concrete combined pile body of high-bearing capacity according to claim 1 is characterized in that among described operation c and the d being that hydraulic pressure props up disc shaping machine with extrusion equipment.

3. the blasting pile-forming method of the prefabricated and cast-in-situ steel concrete combined pile body of high-bearing capacity according to claim 1, the concrete steps that it is characterized in that getting among the above-mentioned operation c clean hack are as follows: inhale indigenous equipment with air and fetch earth, when only surplus a small amount of loosing during soil in the base, from immersed tube mouth pouring, pouring limit, limit sops up, and is clean up to fetching earth.

4. the blasting pile-forming method of the prefabricated and cast-in-situ steel concrete combined pile body of high-bearing capacity according to claim 1 is characterized in that the setpoint distance H among described operation c and the d ₁And H ₂Be base diameter 2-10 doubly.