CN102877464A - Self-draining pile and application thereof in soft soil area - Google Patents

Self-draining pile and application thereof in soft soil area Download PDF

Info

Publication number
CN102877464A
CN102877464A CN2012102833970A CN201210283397A CN102877464A CN 102877464 A CN102877464 A CN 102877464A CN 2012102833970 A CN2012102833970 A CN 2012102833970A CN 201210283397 A CN201210283397 A CN 201210283397A CN 102877464 A CN102877464 A CN 102877464A
Authority
CN
China
Prior art keywords
pile
soil
construction
stake
sand
Prior art date
Application number
CN2012102833970A
Other languages
Chinese (zh)
Inventor
吴发红
周乾
戴龙洋
夏军
Original Assignee
盐城工学院
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 盐城工学院 filed Critical 盐城工学院
Priority to CN2012102833970A priority Critical patent/CN102877464A/en
Publication of CN102877464A publication Critical patent/CN102877464A/en

Links

Abstract

The invention discloses a self-draining pile. Vertical 'V'-shaped grooves are formed in the outer side of the periphery of a reinforced concrete precast square pile; and during pile sinking construction, dry sand is filled in the 'V'-shaped grooves by a specially-made hopper. Construction links are greatly reduced; the quantity of construction equipment is low; construction speed is accelerated; construction cost is reduced; pile sinking force is reduced; and because yellow sand is filled in the 'V'-shaped grooves on the side of the pile through the hopper in a pile sinking process, namely, pile sinking and yellow sand filling are carried out simultaneously, so that sliding friction between the side of the original pile and soil is changed into yellow sand rolling friction between the side of the pile and side soil of the pile, and pile sinking force is reduced necessarily.

Description

A kind of from drainage pile and in the application of soft clay area
Technical field
The present invention relates to technical field of buildings, in particular a kind of from drainage pile and in the application of soft clay area.
Background technology
Employed Squeezing Soil Pile comprises Prefabricated Reinforced Concrete Square Pile, pile for prestressed pipe, the steel concrete tube-sinking cast-in-situ pile in the engineering at present.
In the Squeezing Soil Pile pile driving process, the soil body at place, former stake position is extruded, this soil compaction effect, and for not too closely knit sand soil area, all soil of stake in pile sinking, is made the soil body produce compacted effect by compacted, and this is favourable to improving bearing capacity of pile foundation.But in the process of the pile sinking of the Squeezing Soil Pile of the soft clay area such as large in water content, that compressibilty is high, bad hydraulic permeability is coastal, the compacted effect of soil is also not obvious, on the contrary along with the stake position soil body to lateral compression, the soil Pore Pressure rises, formed the very slow excess pore water pressure that disappears, this excess pore water pressure makes soil compaction aggravation, its result be easy to cause prefabricated generation " floating stake " phenomenon that has sunk to, or makes the castinplace pile of having constructed produce broken pile.And may exert an influence to surrounding environment, make the inclination of adjacent building deposits yields, crack, even collapse, underground utilities be produced destroy.For avoiding the generation of above-mentioned phenomenon, when using Squeezing Soil Pile in this class area, usually take following measures:
(1) at design aspect
Adopt the high long stake of bearing capacity, can enlarge pilespacing like this, reduce the stake number, also will strengthen as far as possible simultaneously the distance between pile foundation zone and the adjacent structure.
(2) aspect construction
1, adopts the method for prebored hole
This kind way is that the stake bit position soil body is drained with the method for boring, to reduce soil compaction effect.Its way generally is: the diameter of boring is about 70% of stake footpath, and drilling depth be long by 1/3~1/2.
2, adopt sanding, sand pocket well, broken stone pile, sand-gravel pile or plastic draining board
This kind way mainly is to reduce rapidly excess pore water pressure, gets rid of pore water.
3, the soil compaction groove is set
Before contiguous protective structure and underground utilities from the pile sinking district, locate to arrange the degree of depth greater than the soil compaction groove of Nearby Structure basis or underground utilities buried depth about 3m.Simultaneously, when the groove body is larger, can in groove, pour water or slurry coat method, cave in preventing.The method also is to utilize soil box, reduces or avoids soil compaction on the impact of adjacent structure.
4, control Piling speed
The main purpose of this kind way is to reduce excess pore water pressure and the soil compaction effect that causes.
5, adopt antiseepage to squeeze wall
Namely set in advance the safeguard procedures such as diaphragm wall, Reinforcement with Cement-mixed Piles wall, rotary jet strengthening wall, impervious sheet pile and campshed formula sand pile, lime pile, broken stone pile along the Soft Soil Layer buried depth in pile sinking district vicinity; its objective is and reduce the excess pore water pressure influence basin; and reinforcement is effectively protected adjacent structure to the effect of contraction of pile sinking neighbouring area ground.
6, anti-extrusion hole is set
In the pile sinking district and in close building one side, along the Soft Soil Layer buried depth, before piling construction, by quincunx the deep hole that single diameter is 30cm is set, and in the hole, pour into mud off, discharge the dissipation of the caused effective stress of piling construction and excess pore water pressure to be conducive to foundation soil, and reduce excess pore water pressure in the foundation soil body and influence basin and the degree of foundation soil body distortion.
All provable from theory and engineering practice, the above-mentioned traditional method of soil compaction effect that reduces can alleviate Squeezing Soil Pile soil compaction effect in pile driving process really.These methods are for guaranteeing the pile sinking quality, and alleviating pile sinking is effective on the impact of surrounding environment.But state in the use in the process of method, when achieving success, also there are the following problems.
If 1 adopts long stake when design, to reach the increase pilespacing, reduce pilespacing, finally reach the purpose that reduces soil compaction effect, probably produce the consequence that Pile Foundations Design is unreasonable, increase construction investment (cost) but do like this.
If 2 adopt prebored hole or the soil compaction groove are set or employing sanding, sand pocket well, broken stone pile, sand-gravel pile or plastic draining board, or adopt antiseepage to squeeze wall and the method such as anti-extrusion hole is set, the capital increases construction investment, construction link increases, duration is spun out, and these all are incompatible with the target of engineering construction.Control Piling speed even gloss is used, and do not take the method for other measures, also greatly increased the duration of a project.
More to the soil compaction effect research of Squeezing Soil Pile both at home and abroad.As: the Analysis of Bearing Capacity of Pile Foundation (Peng Ji etc. that consider soil compaction effect, 2002), considered the variation of the stress of the pile peripheral earth that effect of driving pile causes and void ratio and on the impact of soil body non-linear nature, revised existing load transfer functions, worked out calculation procedure, and a data of pile test has been carried out computational analysis; The soil compaction effect analysis that pile sinking causes in the cohesive soil and research (Wang Dalong, 2002), the land movement problem discussion that causes with regard to soil compaction during pile driving affect several key factors of soil compaction effect, pass through case history, with the comparison of soil body vertical displacement measured result and the calculated results, verified the reasonability of the method calculating land movement that proposes with this paper; Use some Research on Problems (Huang Zhishang, 2003) of PHC stake, analyzed the pile sinking that the impact owing to soil compaction causes and be difficult to reach the design elevation problem.These researchs mainly are the research that the soil compaction mechanism of Squeezing Soil Pile is carried out, and seek the method that reduces soil compaction effect outside pile body.Not yet find by the self-draining method of pile body, reduce the case study of soil compaction effect.
Summary of the invention
Above-mentioned many deficiencies for the reinforced concrete prefabricated square pile existence that belongs to Squeezing Soil Pile, adopt from drainage pile, i.e. this kind stake is outside possessing the due function of normal pile foundation herein, and stake itself has the pore water pressure of quickening and discharges, get rid of pore water, reduce the effects such as soil compaction effect.
A kind of from drainage pile, the outside adds vertical " V " shape groove around reinforced concrete prefabricated square pile, during piling construction, dry sand is fills up in " V " shape groove with special funnel.
Described from the application of drainage pile in soft clay area.
In the preformed pile pile driving process, in original plan sand pile, sand pocket well, broken stone pile, sand-gravel pile or plastic draining board place are set, at first heavy from drainage pile, what these were heavy well just is equivalent to original set sand pile, sand pocket well, broken stone pile, sand-gravel pile or plastic draining board from drainage pile in the effect aspect the draining.Simultaneously, first heavy stake all can be the decompression drainage channel of rear pile sinking.The prefabricated pile foundation that like this, just will originally need multiple working procedure, multiple construction machinery, consumes material construction becomes a kind of machine, a kind of construction machinery, consumes the construction of the prefabricated pile foundation of material less more.
In addition, should also have two other effect by " V " shape groove, yellow ground in the first " V " the shape groove is loose structure, therefore, and in pile driving process, under the effect of stake lateral earth pressure, certainly will will become closely knit, but the difference of sand loose volume and closely knit volume holding portion stake position soil again that is to say, because stake side yellow ground is compressed, also can reduce the part soil compaction effect.So, being used for from reducing soil compaction effect, its total effect is not less than the effect of Fig. 1.It two is to be embodied in to increase the bearing capacity of pile foundation aspect.Since a stake side be friction factor much larger than the yellow ground of weak soil, and stake week is larger than former square pile with the contact surface of soil all around, so aspect bearing capacity, this kind product is larger than former stake.These are aspects of the advantage that possesses from drainage pile.That is to say, reaching outside the stake type commonly used effect from drainage pile also have the unexistent function of stake type commonly used.In addition, this product is compared with existing product, also has the following advantages.
1, construction link is greatly reduced
In order to reach the purpose that reduces soil compaction, not to hole in addition in the former method, in the hole, fill with sand, anti-extrusion hole, soil compaction groove are set exactly, or impermeable wall is set.And this product is in normal pile driving process, can reach all purposes.Therefore, can greatly reduce by the construction link that make.
2, construction equipment is few
Owing to will carry out the construction of aforementioned all Alternatives, its construction machinery at least also will increase boring and fill with sand equipment except the machinery that satisfies normal pile sinking requirement, or soil excavation equipment etc.
3, speed of application is accelerated
Owing to reduced construction link and corresponding working procedure, working procedure is greatly accelerated.
4, reduce construction cost (or investment)
Because the minimizing of construction link and construction equipment has also reduced the consumption of unnecessary material simultaneously, so engineering cost (or investment) is greatly reduced.
5, reduced pile sinking power
Because in the process of pile sinking, by funnel and " V " shape groove that is arranged on a side, yellow ground is filled in " V " shape groove, that is to say, limit pile sinking, limit filling yellow ground, like this, just the sliding friction between former stake side and the soil body is become the rolling friction that yellow ground is arranged between stake side and stake side soil, this will reduce pile sinking power (hammering energy or pile driving pressure).
Description of drawings
Fig. 1 sand drain schematic diagram; 1-1 is lateral view, and 1-2 is top view;
Fig. 2 is from drainage pile drainage principle figure; 2-1 is lateral view, and 2-2 is top view;
Fig. 3 is from drainage pile arrangement of reinforcement schematic diagram;
Fig. 4 is from drainage pile template schematic diagram;
Fig. 5 fills with the sand hopper structural representation;
Fig. 6 fills with the sand artwork from drainage pile;
Piling foundation plan under Fig. 7 master's cushion cap, the piling precedence diagram;
Fig. 8 stake design section figure;
Fig. 9 stake arrangement of reinforcement;
10 arrangements of reinforcement; 11 fill with sand hopper;
The specific embodiment
Below in conjunction with specific embodiment, the present invention is described in detail.
1, the aforementioned conventional method reduces the principle of soil compaction effect
Fig. 1 is the schematic diagram that former job practices is got rid of pore water pressure, and the pore water in the soil enters sand (stone) pile body under the effect of excess pore pressure, because the path of pore water shortens dramatically, so pore water pressure discharges very fast, thereby has reduced soil compaction effect.
2, from drainage pile operating principle and advantage
For the situation of the precast reinforced concrete piles in the Squeezing Soil Pile and design from drainage pile.In order to alleviate when the soft clay area ground carries out the preformed pile pile sinking, produce soil compaction effect owing to excess pore water pressure increases, discharge by former steel concrete precast square pile being designed to from drainage pile, making self to have the pore water pressure of quickening, get rid of pore water, reduce the effects such as soil compaction effect.Under the condition that does not increase construction machinery and difficulty of construction, can reach corresponding purpose equally.
Fig. 2 is the profile schematic diagram from drainage pile.Namely on the basis of normal reinforced concrete prefabricated square pile, the outside adds vertical " V " shape groove around it, during piling construction, dry sand is fills up in " V " shape groove with special funnel.Because yellow ground has been full of " V " shape groove, its drainage principle is same as in figure 1, and namely pore water is by being located at a side and being full of " V " shape groove of yellow ground when the pile sinking, and " V " shape groove is just the same with the effect of sand pile among Fig. 1 all around, shorten its drainage path, accelerate the eliminating of pore water.
From drainage pile method for designing and step with the ordinary reinforced concrete preformed pile.Because Pile Foundations Design requires the main tendon protective layer of reinforced concrete prefabricated square pile to be not less than 30mm, when carrying out this kind stake design, its topping can be designed to 35~40mm, this commonly uses when reinforced concrete prefabricated square pile design.Like this, its arrangement of reinforcement still can be pressed the complete squared design of section.For guaranteeing that in pile driving process pile body is not broken, static pressure pile-sinking technique is adopted in suggestion as far as possible when design.Joint also can be slurry anchor formula joint for can be welding point, if the stake section is less, should use as far as possible slurry anchor formula form.
The production technology of precast reinforced concrete piles comprises makes and two stages of pile sinking.
1, system stake
(1) reinforcing bar
According to the requirement of design, stake is square sectional, and arrangement of reinforcement adopts uniform reinforcement, and sectional dimension and number of steel bars all satisfy design, as shown in Figure 3.All the other manufacture crafts are with common precast square pile.
(2) template
Die shape is with the ordinary reinforced concrete precast square pile, but need add " V " shape channel mould in the template inboard, see Fig. 4, and " V " shape groove height is 25mm, and wide is 100mm.Making available " V " the shape channel mould direct pressing of end face " V " shape groove.
(3) concreting
Concreting is with the ordinary reinforced concrete preformed pile.
2, pile sinking
(1) plant equipment
1) makes (pressure) stake machine
Identical with construction ordinary reinforced concrete preformed pile.
2) funnel
Funnel is made of 2.5~3mm steel plate, sees Fig. 5, the end opening Width design wide 50mm of stake, and height is 500mm, the wide 1000mm of Length Ratio end opening suitable for reading.
(2) process for sinking
Put a stake position → pile-forming machine perching → placements and fill with sand hopper → hang stake → pitching pile → in funnel, put dry sand → beat (pressure) stake → pile extension (saving as designing more than) → drive piles ...
Fine sand during yellow ground is used.But because yellow ground is in beating (pressure) stake process, flow in a side " V " the shape groove by gravity own, so, in order to guarantee sand enough flowabilities are arranged, must use the dry sand through drying or drying during construction.
During construction, stake and funnel cooperate sees Fig. 6, and stake is passed from the funnel end opening, injects dried husky.
Engineering is used example
Certain six story frame structure industrial premises, long 61.76m, wide 19.6m, height overall 22.5m.This project is positioned at the coastal area, northern Suzhou, and this area is typical coastal soft clay area, and soil property is saturated silt clay, and layout design is reinforced concrete prefabricated square pile, counts 361.The stake number is more, and lower several 8 of main cushion caps are seen Fig. 7, and plum blossom-shaped is arranged, two of centres, 6 of 4 weeks.The stake section is 400 * 400mm, the long 18m of every pile, up and down two each 9m of joint.If do not consider measure in design and the construction, probably cause the piling quality problem, and may exert an influence to surrounding environment.So this engineering attempts adopting from drainage pile.
Design section from drainage pile is seen Fig. 8, and every limit arranges 2 notches, each slot opening 100mm, and dark 25mm, two notch spacing 160mm, notch is to stake limit 70mm; Join the HRB335 reinforcing bar of 8 diameters 16, see Fig. 9.Use the sulphide mastic joint.
System stake template wooden form, " V " shape groove is adopted template and is adopted the 5mm welded steel plate, welds a reinforcement along the every 250mm of " V " shape slot length direction.Be fixed on the wooden form with wood screw.The wide 100mm of " V " shape groove end opening, height is 25mm.
Funnel adopts the 2.5mm welded steel plate.
Pile foundation construction adopts the 2500kN static pile press.Piling divided for two phases carried out, and the first phase is pressed first the central pile of each cushion cap, such as main cushion cap 1, No. 2 stakes, so after the central pile of cushion cap has been pressed, press other stakes of cushion cap, when pressing other, must guarantee that the central pile of this cushion cap finishes full 3d again.
Back-up sand in " V " shape groove middle fine sand of the local concreting of commonly using, fineness modulus is 3.5.
The maximum pile driving pressure of layout design single pile is 1650kN, the maximum pile driving pressure of this engineering construction equal about 1600.Design drawing ultimate bearing capacity of single pile 1800kN, last test pile ultimate bearing capacity of single pile average out to 1890kN.
Engineering finishes stake is carried out an acceptance inspection, and the plane of stake, vertical error all in the scope that standard allows, not as contiguous housing construction, the phenomenon of error occurs surpassing.
Should be understood that, for those of ordinary skills, can be improved according to the above description or conversion, and all these improvement and conversion all should belong to the protection domain of claims of the present invention.

Claims (2)

1. one kind from drainage pile, it is characterized in that, the outside adds vertical " V " shape groove around reinforced concrete prefabricated square pile, during piling construction, dry sand is fills up in " V " shape groove with special funnel.
2. according to claim 1 from the application of drainage pile in soft clay area.
CN2012102833970A 2012-08-04 2012-08-04 Self-draining pile and application thereof in soft soil area CN102877464A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN2012102833970A CN102877464A (en) 2012-08-04 2012-08-04 Self-draining pile and application thereof in soft soil area

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN2012102833970A CN102877464A (en) 2012-08-04 2012-08-04 Self-draining pile and application thereof in soft soil area

Publications (1)

Publication Number Publication Date
CN102877464A true CN102877464A (en) 2013-01-16

Family

ID=47478965

Family Applications (1)

Application Number Title Priority Date Filing Date
CN2012102833970A CN102877464A (en) 2012-08-04 2012-08-04 Self-draining pile and application thereof in soft soil area

Country Status (1)

Country Link
CN (1) CN102877464A (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006138095A (en) * 2004-11-11 2006-06-01 Haseko Corp Cast-in-place steel pipe reinforced concrete pile
CN2873886Y (en) * 2005-10-25 2007-02-28 河海大学 Anti-liquefying discharging water rigid pile
CN201778324U (en) * 2010-09-14 2011-03-30 盐城市同力新型建材有限公司 Prestressed concrete square pile with grooves

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006138095A (en) * 2004-11-11 2006-06-01 Haseko Corp Cast-in-place steel pipe reinforced concrete pile
CN2873886Y (en) * 2005-10-25 2007-02-28 河海大学 Anti-liquefying discharging water rigid pile
CN201778324U (en) * 2010-09-14 2011-03-30 盐城市同力新型建材有限公司 Prestressed concrete square pile with grooves

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
周乾等: "弱挤土效应桩的设计与试验", 《四川建筑科学研究》 *

Similar Documents

Publication Publication Date Title
CN1837511B (en) Double-rowed cofferdam and method for manufacturing the same
CN101725258B (en) Integral jacking method of heritage buildings
CN102465524B (en) Double radial mesh-cage sand-gravel pile and construction technology thereof
CN101974894B (en) Combined dam
CN101343852B (en) Method for filling highroad roadbed by waste steel slags
CN201089893Y (en) Foundation pit circle shield prefabricated driven pile
CN100572686C (en) The construction technology of hole support system in the hole
CN107313431B (en) Close on not contour foundation pit method for synchronously constructing
CN101440622B (en) CFG pile, pipe pile embankment reinforcement system and construction method thereof
CN103952986B (en) A kind of off-load formula rigid culvert structure
CN103967031B (en) A kind of caisson of consolidated subsoil and stake combination foundation and construction method thereof
CN101250868A (en) Precipitation prepressing association motivation induration deep densification method
CN201250408Y (en) Recovery type steel structure foundation pit exterior-protected device
CN107905212B (en) A kind of construction method of water filling element earth pile composite foundation in situ
CN104963346A (en) Support construction method for deep foundation pit in complex geological condition
CN203213136U (en) Caisson and pile combined foundation of consolidated subsoil
CN102425082A (en) Subgrade strengthening structure for highly karstified station turnout zone on high-speed railway
CN102660936A (en) Method for realizing seepage prevention of bridge wall by means of polyvinyl chloride film
CN102864788A (en) Method for underpinning reinforced bridge pile foundation by bear-type static pressure cluster pile
CN103526770A (en) High-impermeable anti-floating pile raft structure and construction method
CN104895089B (en) Basement floor and the construction method of the cooperative permanent support system of support pile
CN103510528B (en) For the blind drainage structure of underground structure anti-floating
CN103526721B (en) A kind of permeable pile foundation groynes
CN102888834B (en) A kind of construction method of major diameter broken stone pile
CN103410156B (en) Support space enclosing structure and application process thereof before a kind of recyclable vertical type steel pipe

Legal Events

Date Code Title Description
PB01 Publication
C06 Publication
SE01 Entry into force of request for substantive examination
C10 Entry into substantive examination
RJ01 Rejection of invention patent application after publication

Application publication date: 20130116

C12 Rejection of a patent application after its publication