AU2018102180A6

AU2018102180A6 - Anti-clogging strengthened permeable pile and construction method

Info

Publication number: AU2018102180A6
Application number: AU2018102180A
Authority: AU
Inventors: Xinzhuang CUI; Qing JIN; Jin Li; Jun Li; Jieru WANG; Yilin Wang; Jiong Zhang; Xiaoning Zhang
Original assignee: Shandong University; Shandong Jiaotong University
Current assignee: Shandong University; Shandong Jiaotong University
Priority date: 2018-05-18
Filing date: 2018-12-18
Publication date: 2020-10-22
Anticipated expiration: 2026-12-18
Also published as: ZA202006047B; CN108442365A; WO2019218666A1; AU2018102180A4; CN108442365B; AU2018424102A1

Abstract

The present invention discloses an anti-clogging strengthened permeable pile and a construction method. A permeable geotextile is strengthened and two-way geogrids are added to form a geotextile tube, which can not only increase the forming capability of a pile body, but also increase the strength of the permeable pile. Then, the geotextile tube is wrapped with a permeable concrete pile to form a bagged permeable concrete pile, which can ensure good permeability, reduce the entry of soil particles and avoid clogging of the permeable concrete pile. In addition, the geogrids themselves have large tensile strength, and enclose the pile body tightly, so that the pile body has high strength and modulus and its resistance to deformation and damage is improved.

Description

ANTI-CLOGGING STRENGTHENED PERMEABLE PILE AND CONSTRUCTION METHOD

Field of the Invention

The present invention relates to the field of civil engineering, in particular to an

anti-clogging strengthened permeable pile and a construction method.

Background of the Invention

With the wide application of permeable materials in civil engineering, people

gradually put forward the design concept of permeable piles. The novel pile bodies

have high strength, can form a pile body function, and can improve the bearing

capacity of the foundation. The permeable concrete piles have large porosity and

strong permeability, and can form good vertical drainage channels, accelerate the

foundation consolidation rate in embankment construction and pre-compression

periods, and reduce post-construction settlement. However, the permeable piles may

encounter the clogging problem during construction, resulting in degradation of the

permeability; and during the consolidation of the foundation, movable particles in

piping soil will enter the pores of pile materials under the effect of large enough

seepage force, causing clogging.

Summary of the Invention

In order to solve the technical problems in the prior art, the present invention discloses

a construction method of an anti-clogging strengthened permeable pile, in which a

permeable geotextile is strengthened and two-way geogrids are added to form a

geotextile tube, which can not only increase the forming capability of a pile body, but

also increase the strength of the permeable pile. Then, the geotextile tube is wrapped

with a permeable concrete pile to form a bagged permeable concrete pile, which can

ensure good permeability, reduce the entry of soil particles and avoid clogging of the

permeable concrete pile. In addition, the geogrids themselves have large tensile

strength, and enclose the pile body tightly, so that the pile body has high strength and

Description

modulus and its resistance to deformation and damage is improved.

The specific implementation scheme adopted by the present invention is as follows:

An anti-clogging strengthened permeable pile includes a concrete pile, an outer ring

of the concrete pile is provided with a geotextile tube, the geotextile tube is composed

of geogrids and a permeable geotextile, and a lower part of the geotextile tube at the

bottom of a pile body is connected to a top of a pile tip of the concrete pile.

Further, a side face of the geotextile tube at the bottom of the pile body is provided

with a connecting ring, a hook is arranged above the pile tip of the concrete pile, and

the hook is hooked on the connecting ring.

Further, the connecting rings include a plurality of connecting rings, and the plurality

of connecting rings are distributed annularly along the side face of the lower part of

the geotextile tube.

Further, the hooks include a plurality of hooks, and the plurality of hooks are

distributed annularly along an upper cross section of the pile tip.

Further, a top of the pile tip is provided with a groove, and the groove has a height of

cm to 8 cm and a diameter that is 1 cm to 2 cm larger than the diameter of a casing

pipe.

Further, the geotextile tube is 0.5 m to 1 m higher than the concrete pile, and the

excess length is bound and fixed at the top of the pile.

Further, the geotextile tubes include plurality of geotextile tubes, the plurality of

geotextile tubes are distributed up and down along the axis of the concrete pile, and

the adjacent geotextile tubes are lapped by a certain length and bonded together.

The construction method of the permeable pile is as follows:

step 1, transporting a pile driver to the site, determining an erection height and a

length of a sinking pipe according to the design length and the depth of sinking pipe

soil, followed by the assembly thereof;

step 2, placing the pile tip according to the design, the pile tip being prefabricated by

concrete or steel;

step 3, fabricating a geotextile tube according to the pile diameter and the pile length;

wherein the geotextile tube is divided into two parts: permeable geotextile and

Description

two-way geogrids; wherein the two-way geogrids are bent into a tube shape and then

covered by the permeable geotextile, the permeable geotextile and the two-way

geogrids form a whole and then cover the casing pipe, and the diameter and the length

of the geotextile tube can be determined according to the pile diameter and the pile

length;

step 4, wrapping the geotextile tube at the outside of the casing pipe, then connecting

the casing pipe with the pile tip, inlaying iron rings to the geotextile tube, and

connecting the iron rings to the hooks at the top face of the pile tip, so that the

geotextile tube is hard to fall off during the process of vibration sinking;

step 5, forming a hole using a vibration sinking machine; sleeving the geotextile tube

outside the pipe, lifting the geotextile tube by a hoist, sinking the geotextile tube with

the pipe during the process of hole formation, and pouring the permeable pile after the

pipe reaches the design elevation; pulling the pipe to the natural ground while pouring

permeable concrete, and then sinking the pile to the bottom; vibrating for a certain

time after the casing pipe is full of the permeable concrete, then starting to pulling the

pipe, and pulling the pipe while vibrating, stopping the pulling every certain distance

and vibrating for a certain time, and so on, till the pile pipe is completely pulled out

and the pile body is formed; and

step 6, tying and closing the geotextile tube higher than the pile body with wires to

avoid contamination of the pile body by debris, and clearing the surrounding of the

pile hole.

Further, the geogrids have a grid size of 80 mm x 80 mm, widths of horizontal ribs

and longitudinal ribs of 4 mm to 5 mm, and a thickness of 2 mm to 3 mm; and in

order to ensure the tight contact between the geotextile tube and the pile wall and pipe

wall, the diameter of the geotextile tube is preferably 5 cm to 8 cm larger than that of

the casing pipe, the length of the geotextile tube is preferably 0.5 m to 1 m longer than

the designed pile length, and the excess length is bound and fixed at the top of the

pile.

Because the pile body is relatively long and the structure of the geotextile tube is

relatively short, a plurality of geotextile tubes are arranged up and down on a pile

Description

body, and the lap width of the adjacent geotextile tubes is more than or equal to 200

mm, with tight joints and sufficient bonding.

Further, before starting and sinking the pipe, the sinking depth of the pile tip of the

pile must be determined according to the ground elevation of the pile position and the

design elevation of the pile end. During the sinking process of the pile pipe and after

the pile pipe sinking to the design depth, the verticality of the pile pipe should be

checked in time, and the deviation of the verticality is not more than 1%.

Beneficial effects of the present invention are as follows:

The permeable geotextile has the function of allowing water to pass to block the loss

of sand particles, and is combined with the permeable pile to solve the clogging

problem well. During construction of the permeable pile, problems such as irregular

formation of the pile body are prone to occur, so the pile body of the permeable pile

can be strengthened by the geogrids. The permeable geotextile is strengthened and the

two-way geogrids are added to form the geotextile tube, which can not only increase

the forming capability of the pile body, but also increase the strength of the permeable

pile. Then, the geotextile tube is wrapped with a permeable concrete pile to form a

bagged permeable concrete pile, which can ensure good permeability, reduce the entry

of soil particles and avoid clogging of the permeable concrete pile. In addition, the

geogrids themselves have large tensile strength, and enclose the pile body tightly, so

that the pile body has high strength and modulus and its resistance to deformation and

damage is improved.

Brief Description of the Drawings

The accompanying drawings constituting a part of the present application are intended

to provide a further understanding of the present application, and the illustrative

embodiments of the present application and the descriptions thereof are intended to

interpret the present application and do not constitute improper limitations to the

present application.

FIG. 1 is a front view of a pile tip;

FIG. 2 is a top view of the pile tip;

Description

FIG. 3 is a plan view of a geotextile bag;

FIG. 4 is a construction process diagram;

In the figures: 1 pile tip, 2 hook, 3 groove, 4 geogrid, 5 permeable geotextile, 6

connecting ring, 7 geotextile tube, 8 casing pipe.

Detailed Description of the Embodiments

It should be noted that the following detailed descriptions are exemplary and are

intended to provide further descriptions of the present application. All technical and

scientific terms used herein have the same meaning as commonly understood by those

of ordinary skill in the technical filed to which the present application belongs, unless

otherwise indicated.

It should be noted that terms used herein are intended to describe specific

embodiments only rather than to limit the exemplary embodiments according to the

present application. As used herein, unless otherwise clearly stated in the context,

singular forms are also intended to include plural forms. In addition, it should also be

understood that when the terms "include" and/or "comprise" are used in the

description, it indicates the presence of features, steps, operations, devices, ingredients,

and/or combinations thereof.

For the convenience of description, the terms "upper", "lower", "left" and "right" in

the present invention only indicate the upper, lower, left and right directions of the

drawings, do not limit the structure, are only for the convenience of description and

the simplification of description, do not indicate or imply that the devices or elements

must have specific directions or be constructed and operated in specific directions,

and therefore cannot be understood as limitations to the present invention.

Explanation of terms: Two-way geogrids are grids formed in a warp direction and a

weft direction.

As introduced in the background art, permeable piles in the prior art encounter the

clogging problem during construction, resulting in degradation of the permeability;

and during the consolidation of the foundation, movable particles in piping soil will

enter the pores of pile materials under the effect of large enough seepage force,

Description

causing clogging. In order to solve the above technical problems, the present

application proposes a construction method of an anti-clogging strengthened

permeable pile, in which a permeable geotextile is strengthened and two-way geogrids

are added to form a geotextile tube, which can not only increase the forming

capability of a pile body, but also increase the strength of the permeable pile. Then,

the geotextile tube is wrapped with a permeable concrete pile to form a bagged

permeable concrete pile, which can ensure good permeability, reduce the entry of soil

particles and avoid clogging of the permeable concrete pile. In addition, the geogrids

themselves have large tensile strength, and enclose the pile body tightly, so that the

pile body has high strength and modulus and its resistance to deformation and damage

is improved.

The specific technical solution is as follows:

of the concrete pile is provided with a geotextile tube 7, the geotextile tube 7 is

composed of geogrids and a permeable geotextile, a side face of a lower part of the

geotextile tube 7 is provided with a connecting ring 6, a pile tip of the concrete pile is

provided with a hook 2, and the hook 2 is hooked on the connecting ring 6.

The connecting rings 6 include a plurality of connecting rings, and the plurality of

connecting rings are distributed annularly along the side face of the lower part of the

geotextile tube, that is, a circle of connecting rings is provided; the hooks 2 include a

plurality of hooks 2, and the plurality of hooks 2 are distributed annularly along an

upper cross section of the pile tip, that is, a circle of hooks is provided; and the

number of hooks is equal to the number of connecting rings.

Further, preferably, a top of the pile tip 1 is provided with a groove 3, and the groove

has a height of 5 cm to 8 cm and a diameter that is 1 cm to 2 cm larger than the

diameter of a casing pipe;

Further, preferably, the geotextile tube is 0.5 m to 1 m higher than the concrete pile,

and the excess length is bound and fixed at the top of the pile.

Further, the permeable geotextile 5 is a novelty type of construction material, and the

raw materials are synthetic fibers of high molecular polymers such as polyester,

Description

polypropylene, acrylic, and nylon. The geotextile has excellent filtering, isolation,

reinforcement and protection functions, high tensile strength, good permeability, high

temperature resistance, freezing resistance, aging resistance and corrosion resistance.

Geogrids 4 are a mesh-like reinforced earth material composed of longitudinal ribs

and transverse ribs, and are two-dimensional grids or three-dimensional screen grids

having a certain height, which are thermally plasticized or molded from high

molecular polymers such as polypropylene and polyvinyl chloride. The geogrids are

attached to the inside of the permeable geotextile tube, which not only improves the

tensile strength of the entire geotextile tube, but also considers the permeable function

of the permeable geotextile. The strength of the entire pile body is improved, and at

the same time, the clogging of the permeable pile by soil particles is reduced.

The specific construction method is as follows:

1. A pile driver is transported to the site, an erection height and a length of a sinking

pipe are determined according to the design length and the depth of sinking pipe soil,

followed by the assembly thereof. The pile tip is placed according to the design, and

the pile tip is prefabricated by concrete (or steel). The shape of the pile tip is shown in

the figure. There is a groove in the middle of the pile tip, so that the pile tip can be

firmly combined with the casing pipe to avoid falling off during the sinking process

and affecting the quality of the pile body. The groove has a height of 5 cm to 8 cm and

a diameter that is 1 cm to 2 cm larger than the diameter of the casing pipe, so that the

casing pipe can be easily pulled out, and the pile tip remains at the bottom of the hole

after the pipe is pulled out. A circle of hooks is prefabricated at the edge of the top

face of the pile tip to connect with the geotextile tube.

2. The geotextile tube is fabricated according to the designed pile diameter and the

pile length, and the specific process is as follows:

The geotextile tube is divided into two parts: permeable geotextile and two-way

geogrids. Wherein the two-way geogrids are bent into a tube shape and then covered

by the permeable geotextile, the permeable geotextile and the two-way geogrids form

a whole and then cover the casing pipe, and the diameter and the length of the

geotextile tube can be determined according to the pile diameter and the pile length;

Description

Further preferably, the geogrids have a grid size of 80 mm x 80 mm, widths of

horizontal ribs and longitudinal ribs of 4 mm to 5 mm, and a thickness of 2 mm to 3

mm. In order to ensure the tight contact between the geotextile tube and the pile wall

and pipe wall, the diameter of the geotextile tube is preferably 5 cm to 8 cm larger

than that of the casing pipe, the length of the geotextile tube is preferably 0.5 m to 1 m

longer than the designed pile length, and the excess length is bound and fixed at the

top of the pile. The lap width of the geotextile tubes is 200 mm, with tight joints and

sufficient bonding. The geotextile tube is first wrapped at the outside of the casing

pipe, and then the casing pipe is connected to the pile tip. The bottom of the geotextile

tube is inlaid with iron rings (connecting rings), and the iron rings (connecting rings)

are then connected to the hooks at the top face of the pile tip, so that the geotextile

tube is hard to fall off during the process of vibration sinking.

3. A hole is formed using a vibration sinking machine. Before starting and sinking the

pipe, the sinking depth of the pile tip of the pile must be determined according to the

ground elevation of the pile position and the design elevation of the pile end. During

the sinking process of the pile pipe and after the pile pipe sinking to the design depth,

the verticality of the pile pipe should be checked in time, and the deviation of the

verticality is not more than 1%. The geotextile tube is sleeved outside the pipe and

lifted by a hoist. The geotextile tube sinks with the pipe during the process of hole

formation. After the sinking pipe reaches the design elevation, the permeable pile is

poured.

4. The geotextile tube sinks with the pipe during the process of hole formation. When

the pipe is sunken to a feed port approximately 0.5 m above the ground, a window is

opened, a grouting pipe is inserted into the casing pipe, permeable concrete is poured

while the pipe is pulled out to the natural ground, and then the pile is sunken to the

bottom. After the casing pipe is full of the permeable concrete, the permeable concrete

is first vibrated for 5 s to 10 s, then the pipe is pulled while vibrating, the pulling stops

every 0.5 m to 1.0 m for vibrating 5 s to 10 s, and so on, till the pile pipe is

completely pulled out and the pile body is formed. The geotextile tube higher than the

pile is tied and closed with wires to avoid contamination of the pile by debris, and the

Description

surrounding of the pile hole is cleared.

Described above are merely preferred embodiments of the present application, and the

present application is not limited thereto. Various modifications and variations may be

made to the present application for those skilled in the art. Any modifications,

equivalent substitutions, improvements and the like made within the spirit and

principle of the present application shall fall within the scope of the present

application.

Claims

Claims

1. An anti-clogging strengthened permeable pile, comprising a concrete pile, an outer

ring of the concrete pile is provided with a geotextile tube, the geotextile tube is

composed of geogrids and a permeable geotextile, and a lower part of the geotextile

tube at the bottom of a pile body is connected to a top of a pile tip of the concrete pile.

2. The anti-clogging strengthened permeable pile according to claim 1, wherein a side

face of the geotextile tube at the bottom of the pile body is provided with a connecting

ring, a hook is arranged above the pile tip of the concrete pile, and the hook is hooked

on the connecting ring.

3. The anti-clogging strengthened permeable pile according to claim 1, wherein the

connecting rings include a plurality of connecting rings, and the plurality of

connecting rings are distributed annularly along the side face of the lower part of the

geotextile tube.

4. The anti-clogging strengthened permeable pile according to claim 1, wherein the

hooks include a plurality of hooks, and the plurality of hooks are distributed annularly

along an upper cross section of the pile tip.

5. The anti-clogging strengthened permeable pile according to claim 1, wherein a top

of the pile tip is provided with a groove, and the groove has a height of 5 cm to 8 cm

and a diameter that is 1 cm to 2 cm larger than the diameter of a casing pipe.

6. The anti-clogging strengthened permeable pile according to claim 1, wherein the

geotextile tube is 0.5 m to 1 m higher than the concrete pile, and the excess length is

bound and fixed at the top of the pile.

7. The anti-clogging strengthened permeable pile according to claim 1, wherein the

geotextile tubes include a plurality of geotextile tubes, the plurality of geotextile tubes

are distributed up and down along the axis of the concrete pile, and the adjacent

geotextile tubes are lapped by a certain length and bonded together.

8. A construction method of the anti-clogging strengthened permeable pile according

to claim 1, comprising:

step 1, transporting a pile driver to the site, determining an erection height and a

length of a sinking pipe according to the design length and the depth of sinking pipe

soil, followed by the assembly thereof;

Claims

step 2, placing the pile tip according to the design, the pile tip being prefabricated by

concrete or steel;

step 3, fabricating a geotextile tube according to the pile diameter and the pile length;

wherein the geotextile tube is divided into two parts: permeable geotextile and

two-way geogrids; wherein the two-way geogrids are bent into a tube shape and then

covered by the permeable geotextile, the permeable geotextile and the two-way

geogrids form a whole and then cover the casing pipe, and the diameter and the length

of the geotextile tube can be determined according to the pile diameter and the pile

length;

step 4, wrapping the geotextile tube at the outside of the casing pipe, then connecting

the casing pipe with the pile tip, inlaying iron rings to the geotextile tube, and

connecting the iron rings to the hooks at the top face of the pile tip, so that the

geotextile tube is hard to fall off during the process of vibration sinking;

step 5, forming a hole using a vibration sinking machine; sleeving the geotextile tube

outside the pipe, lifting the geotextile tube by a hoist, sinking the geotextile tube with

the pipe during the process of hole formation, and pouring the permeable pile after the

pipe reaches the design elevation; pulling the pipe to the natural ground while pouring

permeable concrete, and then sinking the pile to the bottom; vibrating for a certain

time after the casing pipe is full of the permeable concrete, then starting to pulling the

pipe, and pulling the pipe while vibrating, stopping the pulling every certain distance

and vibrating for a certain time, and so on, till the pile pipe is completely pulled out

and the pile body is formed; and

step 6, tying and closing the geotextile tube higher than the pile body with wires to

avoid contamination of the pile body by debris, and clearing the surrounding of the

pile hole.

9. The construction method of the anti-clogging strengthened permeable pile

according to claim 8, wherein the geogrids have a grid size of 80 mm x 80 mm,

widths of horizontal ribs and longitudinal ribs of 4 mm to 5 mm, and a thickness of 2

mm to 3 mm; and the diameter of the geotextile tube is preferably 5 cm to 8 cm larger

than that of the casing pipe, the length of the geotextile tube is preferably 0.5 m to 1 m

Claims

longer than the designed pile length, and the excess length is bound and fixed at the

top of the pile;

the overlap width between the adjacent geotextile tubes is more than or equal to 200

mm.

10. The construction method of the anti-clogging strengthened permeable pile

according to claim 8, wherein before starting and sinking the pipe, the sinking depth

of the pile tip of the pile must be determined according to the ground elevation of the

pile position and the design elevation of the pile end; during the sinking process of the

pile pipe and after the pile pipe sinking to the design depth, the verticality of the pile

pipe should be checked in time, and the deviation of the verticality is not more than

100.