CN101397789A

CN101397789A - Extrusion pile-forming method of belled prefabricated pile body

Info

Publication number: CN101397789A
Application number: CNA2007101572493A
Authority: CN
Inventors: 王国奋
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-09-29
Filing date: 2007-09-29
Publication date: 2009-04-01

Abstract

The invention relates to a construction method for building pile foundation engineering, in particular to an extraction pile forming method of an enlarged-base precast pile body, which is the preferred construction method of a multi-stage base large-bearing-capacity pile. The pile forming method of the invention comprises the following process steps: an immersed tube with a metal pile head is sunk to a hard soil layer for designing elevation; the metal pile head is drawn out; the base is enlarged to form a lower base space and all fine earth is thoroughly taken out to ensure that fine earth is cleaned; a lower base is cast; a lower precast pile body and dowels are put into and anchored with the lower base; the immersed tube is pulled upward to a preset height H; the base is enlarged to form an upper base space and all fine earth is thoroughly taken out; steel bars are put into from the opening of the immersed tube and extended into the upper part of a lower recast hollow pile body, and flowing concrete is used for casting the upper base and casting the upper pile body of the reinforced concrete in place; and the immersed tube is pulled out, and concrete slurry is injected into the gap. The construction method has the advantages that: the bearing capacity and the reduction factor of a single pile are enhanced, the utilization rate of the material strength is improved, and the construction method is safe and stable, the construction cost of the pile base is reduced, therefore, the designed expected effect is reached.

Description

The extrusion pile forming method of bottom-enlarging prefabricated pile body

Technical field

The present invention relates to the extrusion pile forming method of a kind of construction of building pile foundation engineering, particularly a kind of bottom-enlarging prefabricated pile body.It is the job practices of the big bearing peg first-selection of multistage base.

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, and its pile body diameter of above factor must be done greatlyyer; and this a plurality of base 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 present invention is directed to problem that prior art exists provide a kind of extrusion pile forming method of bottom-enlarging prefabricated pile body, purpose be make that bearing capacity of single pile is big, strength of materials utilization rate height, reduction coefficient height, safe and reliable, guarantee the pile foundation engineering quality, reduce cost, technology is reasonable.

The extrusion pile forming method of bottom-enlarging prefabricated pile body of the present invention comprises following processing step: a, the immersed tube that has metal pile head is sunk to the hardpan design elevation; B, taking-up metal pile head; C, expand the end with extrusion equipment and form lower base space, and get clean hack, keep the noresidue hack; D, cast lower bottom base; E, put into down precast pile, joint bar and lower bottom base is anchored; F, on pull out immersed tube to the distance H of setting; G, expand the end with extrusion equipment and form upper base space, and get clean hack, keep the noresidue hack; H, put into the concrete cast upper bed-plate that flows, will put into upper bed-plate with the last precast pile of joint bar again and be anchored from the immersed tube mouth; I, extract immersed tube, and between the slit, inject cement paste.

Described extrusion equipment is that hydraulic pressure props up disc shaping machine.

Getting clean hack among described operation c and the g is to get the hack that is dug down only with inhaling indigenous equipment or mixing method.

The concrete steps that described mixing method is got the hack that is dug down only 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.

Distance H among the described operation f is 2-10 a times of base diameter.

It is a kind of in precast hollow pile body and the solid precast pile or both combinations that following in described e and the h operation gone up precast pile.

The extrusion pile forming method of bottom-enlarging prefabricated pile body comprises following processing step: a, the immersed tube that has metal pile head is sunk to the hardpan design elevation; B, taking-up metal pile head; C, expand the end with extrusion equipment and form lower base space, and get clean hack, keep the noresidue hack; D, cast lower bottom base; E, put into down precast pile, joint bar and lower bottom base is anchored; F, on pull out immersed tube to the distance H of setting; G, expand the end with extrusion equipment and form upper base space, and get clean hack, keep the noresidue hack; H, put into the top that reinforcing bar 7 extends into down the precast hollow pile body, with pile body 5 on flow concrete cast upper bed-plate and the cast-in-situ steel concrete from the immersed tube mouth; Operation i extracts immersed tube 2 and inject cement paste in the slit; I, extract immersed tube, and between the slit, inject cement paste.

The present invention is compared with prior art owing to changed traditional piling method; do protection and support with immersed tube; rationally arrange operation to eliminate the defective of existing piling method effectively in addition; and significantly improve the supporting capacity and the reduction coefficient of single pile through evidence; improved the utilization rate of the strength of materials; and safe and reliable, reduce the pile foundation engineering cost, reached the Expected Results of design.

Description of drawings

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

The construction view of the master operation of Fig. 2 embodiment 2.

Among the figure 1, lower base space; 2, immersed tube; 3, following precast pile; 4, go up precast pile; 5, pile body on the cast-in-place notes; 6, joint bar; 7, reinforcing bar; 8, upper base space.

The specific embodiment

Embodiment 1:

Embodiments of the invention 1a-1g in conjunction with the accompanying drawings are described in detail.

The extrusion pile forming method of bottom-enlarging prefabricated pile body of the present invention comprises following processing step: a, the immersed tube 2 that has metal pile head is sunk to hardpan to design elevation; B, taking-up metal pile head; C, expand the end with extrusion equipment and form lower base space 1, hack is got hack only with the suction indigenous equipment; D, pour in the immersed tube 2 or hang in the concrete cast lower bottom base that flows with barreled; E, put into down precast pile 3, joint bar and lower bottom base are anchored; F, on pull out immersed tube 2 to the distance H of setting, its H be base diameter 2-10 doubly, its value size depends on that what of base progression are relevant with the pile body height; G, expand the end with extrusion equipment and form upper base space 8, hack is got hack only with the suction indigenous equipment, and following precast pile 3 is that its hollow hack falls in the hollow preformed pile body and needn't clear up; H, put into the concrete cast upper bed-plate that flows from 2 mouthfuls of immersed tube, the solid precast pile 4 of going up that will have joint bar 6 is again put into upper bed-plate and is anchored; I, extract immersed tube 2, in the slit, inject cement paste.

Above-mentioned extrusion equipment is that hydraulic pressure props up disc shaping machine.

Getting clean hack among above-mentioned operation c and the g is to get the hack that is dug down only with inhaling indigenous equipment or mixing method.Wherein to get the concrete steps of the hack that is dug down only as follows for mixing method: 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.

Embodiment 2:

Its operation a to g is identical with embodiment 1, and operation h puts into the top that reinforcing bar 7 extends into down the precast hollow pile body from the immersed tube mouth, with pile body 5 on flow concrete cast upper bed-plate and the cast-in-situ steel concrete; Operation i extracts immersed tube 2 and inject cement paste in the slit.Pile body 5 on the cast-in-place notes as shown in Figure 2.

It is a kind of in precast hollow pile body and the solid precast pile or both combinations that following described in embodiment one and the embodiment two gone up precast pile.

Claims

1, the extrusion pile forming method of bottom-enlarging prefabricated pile body is characterized in that it comprises following processing step: a, the immersed tube that has metal pile head is sunk to the hardpan design elevation; B, taking-up metal pile head; C, expand the end with extrusion equipment and form lower base space, and get clean hack, keep the noresidue hack; D, cast lower bottom base; E, put into down precast pile, joint bar and lower bottom base is anchored; F, on pull out immersed tube to the distance H of setting; G, expand the end with extrusion equipment and form lower base space, and get clean hack, keep the noresidue hack; H, put into the top that reinforcing bar extends into down the precast hollow pile body, with pile body on flow concrete cast upper bed-plate and the cast-in-situ steel concrete from the immersed tube mouth; I, extract immersed tube, and between the slit, inject cement paste, pile.

2, the extrusion pile forming method of bottom-enlarging prefabricated pile body according to claim 1 is characterized in that described extrusion equipment is that hydraulic pressure props up disc shaping machine.

3, the extrusion pile forming method of bottom-enlarging prefabricated pile body according to claim 1, it is characterized in that getting among described operation c and the g clean hack is to get the hack that is dug down only with inhaling indigenous equipment or mixing method.

4, the extrusion pile forming method of bottom-enlarging prefabricated pile body according to claim 3, it is as follows to it is characterized in that described mixing method is got the concrete steps of the hack that is dug down only: 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.

5, the extrusion pile forming method of bottom-enlarging prefabricated pile body according to claim 1, it is characterized in that distance H among the described operation f be base diameter 2-10 doubly.

6, the extrusion pile forming method of bottom-enlarging prefabricated pile body according to claim 1 is characterized in that it is a kind of in precast hollow pile body and the solid precast pile or both combinations that following in the described e operation gone up precast pile.

7, the extrusion pile forming method of bottom-enlarging prefabricated pile body according to claim 1 is characterized in that it is a kind of in precast hollow pile body and the solid precast pile or both combinations that following in the described h operation gone up precast pile.