CN2558696Y

CN2558696Y - Temporary prestressed concrete pipe pile

Info

Publication number: CN2558696Y
Application number: CN 01257735
Authority: CN
Inventors: 朱传浦
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-11-01
Filing date: 2001-11-01
Publication date: 2003-07-02
Anticipated expiration: 2011-11-01

Abstract

The utility model discloses a post-tensioned concrete pipe pile which can save steel bar and is especially suitable for basis of buildings built on soft soil foundation. The utility model comprises a pipe pile body (1), a prestressed reinforcement (2), a pile point (4) and a pile top cover board (3). The prestressed reinforcement is made into prestressed anchor through the pile top cover board and the pile point and the pile body should be pre-stressed before pile driving; after the pile is driven into the ground, the prestressed reinforcement and pile top cover board can be pulled out. The prestressed reinforcement and pile top cover board can be reused for a plurality of times, thereby guaranteeing the quality of the pile, but also saving steel material.

Description

Concrete pipe pile provided with temporary prestressing force

＜one〉technical field: the utility model relates to a kind of prestressed concrete pipe pile that is applied in the building construction Foundation Design.

＜two〉background technology: a lot of tube-sinking cast-in-situ piles that adopt at present general building construction basis, it is low that this stake has cost, and stake is long can be with advantages such as ground variations.But the pile concrete of this stake is that employing is cast-in-place, in work progress, because concrete ot-yet-hardened, pile body concrete quality is subject to the external factors influence, tube drawing during as piling construction, play adjacent stake, the pile driver surrounding soil that all can make stake such as walk about on ground produces distortion, thereby causes the pile concrete distortion.Therefore, quality accidents such as broken pile, bottleneck stake appear in this stake easily, particularly in containing the ground of soft layer.Adopt prestressed concrete pipe pile can overcome above-mentioned shortcoming, because prestressed concrete pile is prefabricated, pile quality guarantees.But the prestressed concrete pile steel using amount is big, the cost height.

＜three〉summary of the invention: the purpose of this utility model provides a kind of post-tensioned prestressed concrete pile tube.After stake is squeezed into soil and reached projected depth, prestressed reinforcement is taken out from stake, prestressed reinforcement and ancillary service thereof are reusable, have both saved steel, reduce cost, the assurance of getting back of the quality of stake.

In the piling process, stake very big longitudinal tension stress can occur under pile monkey hits, and tensile stress often surpasses pile concrete tensile strength, causes pile body breaking.Therefore, in order to offset and to reduce this tensile stress, must apply longitudinal prestressing to pile body; When piling finishes, drive piles to cause that tensile stress disappears, and just there is no need to continue to keep the prestressing force of pile body.Therefore, prestressed reinforcement can take out, to save steel.

The utility model belongs to a kind of post-tensioned prestressed concrete pile tube, and it is made up of pile tube body, prestressed reinforcement, stake point, pile cap decking four parts.

Pile tube is as the nonprestressed reinforcement concrete pipe, the merogenesis manufacturing, and every joint length is generally 7-8 rice, also will produce some stubs for collocation.Pile body must make hollow, and prestressed reinforcement can pass from the cavity of stake.The pile tube body can be used the centrifugal process manufacturing, and strength grade of concrete requires more than C45, and pile body also can be prefabricated in the building site, and strength grade of concrete requires more than C40.In order to satisfy transportation and lifting requirements, pile body will be joined a small amount of longitudinal reinforcement.Pile body lateral deformation when driving piles in order to resist, pile body will be joined circumferential reinforcement, closeer near stake end place circumferential reinforcement spacing, dredges in pile body interlude circumferential reinforcement spacing.Pile crown is subjected to the pile monkey hitting power big especially, and therefore, the steel-sheet cuff will be overlapped in pile body two.

Prestressed reinforcement adopts hard drawn wire reinforcement or spiral reinforcement, and bar diameter is decided on the prestressing force design load.Major diameter reinforcing bar of the general employing of prestressed reinforcement can adopt many reinforcing bars when prestressing force is big.The purpose that adopts the major diameter reinforcing bar is because when reclaiming prestressed reinforcement, reverse prestressed reinforcement, and itself and the sharp screw of stake are broken away from, and therefore, presstressed reinforcing steel must have certain anti-twisting property.As long as satisfy this anti-twisting property requirement, also can adopt the other types presstressed reinforcing steel, make presstressed reinforcing steel side by side and also be fine as adopting high-strength steel tow overcoat metal tube to do presstressed reinforcing steel or many non-major diameter reinforcing bars.

The stake point generally with reinforced concrete prefabricated (its arrangement of reinforcement is identical with general reinforced concrete pile point), also can be processed welding with steel plate; Here, a stake point is again a prestressed anchor, therefore, the stake ogival want pre-buried lead screw＜or discount so that be connected with prestressed reinforcement.

Pile cap decking is a circular steel plate, and its diameter is a bit larger tham pile body, and the cover plate central hole is so that prestressed reinforcement passes.

Owing to lifting and transportation reason, every joint stake can not be done oversizely, is generally 7-8 rice.Therefore, want pile extension during piling construction.Pile extension can adopt two kinds of methods, and a kind of is welding, promptly buries a small amount of steel plate underground at top, pile body two ends, during pile extension two joint pile crown alignment is welded; Another kind method is material pile extensions such as employing sulphide mastic, is about to two joint stake longitudinal reinforcements to welding, and materials such as sulphide mastic are filled in the gap between.

Before the piling 2-3 joint stake is connected on ground, make prestressed reinforcement pass pile body, the stake point is loaded onto in a stake bottom, and prestressed reinforcement lower end and a stake point give and bury screw and is connected, and pile cap decking is placed at the stake top, leans on nut to be connected with pile cap decking on the prestressed reinforcement.When applying prestressing force, jack is the bearing prestressed reinforcement of tensioning with the pile cap decking, and pile tube body, prestressed reinforcement, stake point and pile cap decking are linked as a whole.Because of prestressed reinforcement stretches out about 200 millimeters on the stake top, must add short steel bushing of cover on the stake top.Then stake is hung on pile driver and drive piles.

Below the utility model is made comparisons with stake of immersed tube notes and prestressed concrete pipe pile.

The utility model stake diameter is 380 millimeters (Fig. 1-3), 90 tons of single pile design bearing capacities (900,000 Ns); Every meter pile length concrete 0.08 side, 6 kilograms of steel; About 130 yuan of the unit length cost (wherein the prefabricated pipe pile body is every meter about 70 yuan, every meter about 60 yuan of expenses such as transportation, piling) of stake.

Adopt tube-sinking cast-in-situ pile, 480 millimeters of stake diameters, 60 tons of single pile design bearing capacities (600,000 Ns); Concrete 0.19 side is used in every meter stake, every meter long cost 80-90 unit of stake.

On the surface, price of the present utility model is than tube-sinking cast-in-situ pile height, but further analysis just finds that both price differences are few; At first, bearing capacity of single pile of the present utility model is 1.5 times of tube-sinking cast-in-situ pile, and promptly one equals one and half; Secondly, the utility model pile cap volume reduces, and what use as tube-sinking cast-in-situ pile is three pile caps, can change two pile caps into the utility model, the corresponding cushion cap cost that reduced; Therefore two kinds of pile foundation total costs roughly maintain an equal level, and still, adopt the utility model can avoid occurring quality accidents such as broken pile, bottleneck stake, particularly in soft foundation.

Compare with prestressed concrete pipe pile, the utility model has the advantages that the saving steel.Because: the longitudinal rib of (1) prestressed concrete pipe pile is to use high tensile reinforcement, and longitudinal rib of the present utility model is only joined a small amount of plain bars; (2) the stake end of prestressed concrete pipe pile connect steel plate except that as pile extension with the member, still the ground tackle of prestressed reinforcement of tensioning bears very hightension, the connection steel plate processes with 19 millimeters steel plate monoblocks, steel using amount is big; It is the member that connects stake usefulness purely that stake end of the present utility model connects steel plate, and the consumption of steel plate significantly reduces.(3) after soil is squeezed in stake, have a bit of unnecessary stake to want amputation, its length is from 1 meter to several meters.For prestressed concrete pipe pile, the stake prestressing force that blocks disappears, and broken pile is passed into disuse; But the utility model can block stake with two joints to be connected, and is about to the vertical muscle welding of two joint broken piles, coheres with high-strength binding material between two broken piles, becomes a stub and reuses.

＜four〉description of drawings

Fig. 1 is a pile tube body longitudinal plan;

Fig. 2 is a pile tube body drawing in side sectional elevation;

Fig. 3 is the concrete pipe pile provided with temporary prestressing force constructional drawing;

Fig. 4 is jack tension figure when pile body is applied prestressing force.

＜five〉specific embodiment: the utility model is described in further details below in conjunction with accompanying drawing and specific embodiments.

As depicted in figs. 1 and 2, pile tube body diameter is 380 millimeters, and pipe thickness is 80 millimeters; Concrete strength of pile grade C50, pile body adopts prefabricated by centrifugal process.Along 8 diameters of tube wall configuration is 10 millimeters longitudinal reinforcement [1], joins diameter and be 4 millimeters circumferential reinforcement [2], and in the 1 meter scope in nearly pile body two ends, the circumferential reinforcement spacing is 40 millimeters, and the circumferential reinforcement spacing of all the other pile body interludes is 80 millimeters.Steel sheet cylinder cuff [3] is respectively overlapped at the pile body two ends, and steel plate thickness is 1.6 millimeters, and cuff is high 150 millimeters, and external diameter equates with the pile body external diameter.The connection steel plate [4] that pile extension is used is buried at top, pile body two ends underground, connects 10 millimeters of steel plate thickness, and it links by dowel and pile concrete.

Fig. 3 is the concrete pipe pile provided with temporary prestressing force constructional drawing, and prestressed reinforcement [2] is that a diameter is 32 millimeters hard drawn wire reinforcements, and prestress value is 35 tons (350,000 Ns); The pre-buried lead screw of reinforced concrete pile point [4] [6], stake point are positioned at the bottom of stake, pile cap decking＜3〉be positioned at the top of stake, will box out in the pile cap decking center, so that prestressed reinforcement passes.When applying prestressing force, prestressed reinforcement＜2〉pass pile tube body＜1 〉, its lower end and stake sharp screw＜6〉is connected, the upper end leans on nut [5] to be connected with pile cap decking [3].Fig. 4 is a jack tension prestressed reinforcement schematic diagram when applying prestressing force, and the stretching head of jack [7] is connected with prestressed reinforcement [2], does bearing with pile cap decking [3], prestressed reinforcement of tensioning [2]; The stretch-draw value is read by oil pressure gauge, reach the prestressing force design load after, tighten nut [5], unload jack [7], hang the stake and put pile cover, can drive piles.

Every joint pile length 7-8 rice, one joint stake falls short of during construction, necessary pile extension during piling, pile extension adopts welding here.For first, second, third joint stake, butt joint welds on ground with each earlier before the piling, and applies prestressing force, hangs on pile frame piling, and 3 joint stake maximum lengths are 20 meters.As falling short of with 3 joint stakes, then must on pile driving frame, connect the 4th joint stake, the prestressing force of soon having squeezed into the stake of soil discharges, take out pile cap decking, the 4th joint stake of slinging connects prestressed reinforcement, with three, four joint pile joints welding, unload jack after applying prestressing force again, continue piling.After having beaten a pile, this prestressing force is discharged, take out prestressed reinforcement＜2 and pile cap decking＜3, prestressed reinforcement and pile cap decking can be repeatedly used.

Claims

(1) a kind of prestressed concrete pipe pile of forming by concrete pipe pile body, longitudinal prestressing reinforcing bar and prestressed anchor, the prestressed reinforcement two ends are anchored on the prestressed anchor; It is characterized in that: concrete pipe pile body＜1〉be hollow, prestressed reinforcement＜2〉pass the hollow parts of pile tube body, pile cap decking＜3 and stake point＜4 or a stake end steel plate do prestressed anchor; Stake point＜4〉be positioned at the bottom of stake, is connected pile cap decking＜3 with the prestressed reinforcement lower end〉be positioned at the top of stake, by nut＜5〉with prestressed reinforcement on be connected; After having beaten a pile, take out prestressed reinforcement＜2〉and pile cap decking＜3.
(2) prestressed concrete pipe pile according to claim 1 is characterized in that adopting the major diameter reinforcing bar to do prestressed reinforcement, or employing other steel identical with major diameter reinforcing bar torsional rigidity are done presstressed reinforcing steel.
(3) prestressed concrete pipe pile according to claim 1 is characterized in that answering in advance reinforcing bar＜2〉be to rely on screw or discount and stake point＜4 or an end steel plate be connected.