JP5406628B2 - Cast-in-place pile installation method - Google Patents

Cast-in-place pile installation method Download PDF

Info

Publication number
JP5406628B2
JP5406628B2 JP2009189469A JP2009189469A JP5406628B2 JP 5406628 B2 JP5406628 B2 JP 5406628B2 JP 2009189469 A JP2009189469 A JP 2009189469A JP 2009189469 A JP2009189469 A JP 2009189469A JP 5406628 B2 JP5406628 B2 JP 5406628B2
Authority
JP
Japan
Prior art keywords
pile
cast
place
place pile
ground
Prior art date
Legal status (The legal status 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 status listed.)
Active
Application number
JP2009189469A
Other languages
Japanese (ja)
Other versions
JP2011038379A (en
Inventor
栄作 河合
Original Assignee
株式会社竹中工務店
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 株式会社竹中工務店 filed Critical 株式会社竹中工務店
Priority to JP2009189469A priority Critical patent/JP5406628B2/en
Publication of JP2011038379A publication Critical patent/JP2011038379A/en
Application granted granted Critical
Publication of JP5406628B2 publication Critical patent/JP5406628B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Description

  The present invention relates to a cast-in-place pile installation method in which a rebar cage assembled in a cylindrical shape is dropped into a hole excavated by a drilling device, and concrete is poured later to form an integrated pile.

Conventionally, a cast-in-place pile formed by this type of cast-in-place pile method can expect not only the support force at the tip of the pile but also the peripheral frictional force as the support force. There was an expanded pile or the like (see FIG. 6 (a)) for the purpose of increasing the number of piles. On the other hand, there existed what formed the node 20 in the outer peripheral surface of the pile P for the purpose of the increase in a peripheral surface frictional force (refer FIG.6 (b)).
In order to form the former cast-in-place pile, as shown in FIG. 6 (a), when the pile hole 3 is formed by the excavator, the enlarged diameter portion 1 excavated to have a larger diameter than the other portion is used. (Hereinafter simply referred to as the first conventional method).
In order to form the latter cast-in-place pile, as shown in FIG. 6 (b), a grout pipe 21 and a grout nozzle are provided so that the grout material G can be injected into the reinforcing bar 4 at a predetermined depth in advance on the outer peripheral side of the pile. 22, the reinforcing bar 4 is dropped into the pile hole 3 and filled with the concrete 5, and then the grout material G is injected from the grout nozzle 22 to form a node 20 by the grout material G on the outer peripheral surface of the pile P. (For example, refer to Patent Document 1) (hereinafter, simply referred to as the conventional second method).

JP 2007-255107 A (FIG. 4)

There are various types of soil such as sandy soil, cohesive soil, and gravel, as well as soil with a small internal friction angle that makes it difficult to maintain the stability of the hole wall during excavation.
In particular, in the above-mentioned enlarged diameter portion, the excavation hole wall is inclined downward, so that collapse tends to occur.
According to the above-described conventional first method, it is difficult to stabilize the ground at the soil layer portion with the small internal friction angle or the expanded diameter portion. Therefore, it is necessary to excavate for a long time so as to suppress the load on the target ground, and there is a problem that the excavation efficiency tends to be low.
In particular, when excavating the enlarged diameter part, it is necessary to reduce the inclination of the borehole wall in order to prevent collapse, and the diameter of the enlarged diameter part cannot be increased unnecessarily. There is a problem that it cannot be secured and it is difficult to increase the bearing capacity of the pile.
On the other hand, according to the second conventional method, as in the case of the first conventional method, it is difficult to stabilize the ground in a portion where the soil having a small internal friction angle forms a layer, and the excavation efficiency tends to be low. There is a point.
In addition, it is necessary to previously embed buried objects such as grout pipes and grout nozzles in the reinforcing steel basket, and these buried objects tend to cause a cross-sectional defect of the concrete and cause a decrease in strength. Furthermore, if the grout material is injected into the ground around the pile before the concrete of the pile body develops sufficient strength, it adversely affects the concrete and tends to cause a decrease in strength.

  Accordingly, an object of the present invention is to provide a cast-in-place pile installation method capable of solving the above-described problems, efficiently forming a pile having a predetermined strength, and ensuring a sufficient support force.

In the first characteristic configuration of the present invention, for each planned location where a plurality of cast-in-place piles are installed at intervals, the ground is improved in advance around the planned location, and then, each planned location is In installing the cast-in-place pile, the cast-in- place pile includes a diameter-expanded portion in a part of the longitudinal direction, and the ground improvement is a part of the total length of the cast-in-place pile, It is in place to carry out at the depth corresponding to the part .

According to the first characteristic configuration of the present invention, since the cast-in-place pile is installed after the ground improvement is performed around the place where the cast-in-place pile is planned to be installed, (Including a small soil layer) has been improved in advance to a state in which it does not easily collapse due to ground improvement.
Therefore, when excavating a pile hole, it can implement without taking time more than necessary, and a pile installation operation can be implemented efficiently.
Moreover, since the cross-sectional defect | deletion of concrete does not arise in a cast-in-place pile, predetermined pile strength can be ensured.
Furthermore, since the unity between the improved soil and the pile whose ground has been improved is obtained, the supporting force of the pile can be improved.
As a result, it is possible to efficiently form a pile having a predetermined strength and to secure a sufficient supporting force.

In addition, since the ground corresponding to the enlarged diameter portion is improved, the ground is improved so that it does not collapse easily, and even when excavation with a large inclination of the borehole wall is performed, the ground can be excavated without collapse.
Therefore, it is possible to increase the supporting force of the pile by enlarging the diameter of the enlarged diameter portion and sufficiently securing the flat area of the enlarged diameter portion.
In addition, about an enlarged diameter part, not only what is called a "bottom pile" provided in the lower end part of a cast-in-place pile but an enlarged diameter part may be provided in an up-and-down intermediate part.

Front view showing the installation status of cast-in-place piles Explanatory drawing showing the construction status of ground improvement Front view showing the installation status of cast-in-place piles Front view showing a cast-in-place pile according to another embodiment Front view showing a cast-in-place pile according to another embodiment Front view showing a conventional cast-in-place pile

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the parts indicated by the same reference numerals as those in the conventional example indicate the same or corresponding parts.

  FIG. 1 shows a cast-in-place pile P installed by the cast-in-place pile installation method of the present invention.

A plurality of cast-in-place piles P are installed at a lateral interval, and the load of building B formed above cast-in-place pile P is supported by these cast-in-place piles P.
The cast-in-place pile P is a reinforced concrete pile formed in a columnar shape, and is provided with an enlarged diameter portion 1 at a lower end portion and an upper and lower intermediate portion.
Of the two enlarged diameter portions 1, the enlarged diameter portion 1B at the lower end contributes to an increase in the tip support force due to the enlargement of the tip end area of the pile.
On the other hand, the enlarged diameter part 1A of the upper and lower intermediate part contributes to the increase in the peripheral surface supporting force including the peripheral surface frictional force of the pile.

In addition, a ground improvement region K is formed in advance on the ground around the enlarged diameter portion 1A of the upper and lower intermediate portions by ground improvement.
With this ground improvement zone K, it is possible to maintain the hole wall when the enlarged diameter portion 1A is formed (when drilling the pile hole), and after the formation of the pile, the bearing capacity is improved by improving the integrity with the pile P. Increase can be achieved.

  In the present embodiment, the ground improvement work is performed by excavating around the planned location 2 where the cast-in-place pile P is to be installed, from the ground, for example, by a boring machine or an auger machine in a cylindrical shape as shown in FIG. By supplying a cement-based material within the range and kneading, an improved body having higher water-stopping strength and strength than the conventional ground is formed. And the cylindrical ground improvement area K can be formed around the said planned location 2 by forming adjacent things in a close state.

Next, the installation method of the said cast-in-place pile P is demonstrated.
[1] For each planned location 2, the above ground improvement work is performed in advance around the planned locations 2 to form a ground improvement zone K (see FIG. 2). In addition, although the ground improvement depth may be implemented over the full length of the cast-in-place pile P, in the said embodiment, only the depth corresponding to the enlarged diameter part 1 of the pile P is ground improvement.
[2] The cast-in-place pile P is installed at each planned location 2.
Specifically, the pile hole 3 is formed from the ground to a predetermined depth by an excavator not shown in the drawing. At that time, at the depth of the diameter-expanded portion 1, a diameter-expansion hole is formed using the diameter-expansion mechanism of the excavator (see FIG. 3A). The reinforcing bar 4 is dropped into the pile hole 3 and the concrete 5 is filled and integrated (see FIG. 3B and FIG. 1).

According to the cast-in-place pile installation method according to this embodiment, since the ground is improved in advance around the planned place 2 of the cast-in-place pile P, when excavating the pile hole 3, hole wall stability is achieved, The diameter-expanded portion 1 can be excavated with a street surplus shape. Moreover, excavation can be performed without taking more time than necessary, and pile installation work can be carried out efficiently.
Furthermore, since the integrity of the improved soil in the ground improvement area K and the pile P obtained by improving the ground is obtained, the supporting force of the pile can be improved.
Accordingly, it is possible to efficiently form a pile having a predetermined strength and to secure a sufficient supporting force.
Moreover, since the ground improvement is performed from the ground, the target ground situation of the cast-in-place pile P can be recognized in advance by the excavation situation (for example, hardness, water permeability, etc.) accompanying the ground improvement. Therefore, it is possible to readjust the formation plan of the cast-in-place pile P based on the prior information.

[Another embodiment]
Other embodiments will be described below.

<1> As described in the previous embodiment, the cast-in-place pile P is not limited to those provided at the two upper and lower portions as the enlarged-diameter portion 1, and for example, the enlarged-diameter portion 1 is provided only at the upper and lower intermediate portions. As shown in FIGS. 4A and 5, the enlarged diameter portion 1 may be provided only at the lower end portion. Further, the enlarged diameter portions 1 may be provided at a plurality of locations in the upper and lower intermediate portions.
Including these, they are collectively referred to as the enlarged diameter portion 1.
<2> The ground improvement area K is not limited to that described in the previous embodiment, for example, the columnar local improvement body is not limited to being arranged in a single radial direction of the pile P, It may be arranged over a plurality of double or more rows. In addition, the construction method for ground improvement can be selected as appropriate.
Regarding the ground improvement depth, it is not limited to the range corresponding to the enlarged-diameter portion 1, but is performed over the entire construction length of the pile P, or only in the upper and lower intermediate portions other than the enlarged-diameter portion 1. It may be a thing (refer FIG. 5).
Further, the shape of the ground improvement region K is not limited to the cylindrical shape, and for example, as shown in FIG. 4B, it has a frustoconical shape, or upside down as shown in FIG. The outer shape of the truncated cone shape may be sufficient.

  In addition, as mentioned above, although the code | symbol was written in order to make contrast with drawing convenient, this invention is not limited to the structure of an accompanying drawing by this entry. In addition, it goes without saying that the present invention can be carried out in various modes without departing from the gist of the present invention.

1 Expanded part 2 Planned part P Cast-in-place pile

Claims (1)

  1. A plurality of place pile for each planned portion to be installed at intervals, around their planned portion, in advance, to implement ground improvement, then, per To install the place pile to the each planned portion, wherein The cast-in-place pile includes an enlarged diameter portion at a part in the longitudinal direction thereof, and the ground improvement is performed at a depth corresponding to the enlarged diameter portion at a part of the entire length of the cast-in-place pile. Pile installation method.
JP2009189469A 2009-08-18 2009-08-18 Cast-in-place pile installation method Active JP5406628B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2009189469A JP5406628B2 (en) 2009-08-18 2009-08-18 Cast-in-place pile installation method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2009189469A JP5406628B2 (en) 2009-08-18 2009-08-18 Cast-in-place pile installation method

Publications (2)

Publication Number Publication Date
JP2011038379A JP2011038379A (en) 2011-02-24
JP5406628B2 true JP5406628B2 (en) 2014-02-05

Family

ID=43766405

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2009189469A Active JP5406628B2 (en) 2009-08-18 2009-08-18 Cast-in-place pile installation method

Country Status (1)

Country Link
JP (1) JP5406628B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106245629A (en) * 2016-09-13 2016-12-21 大连理工大学 A kind of anti-skid uplift pile in mountain area and method for designing thereof

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5972690B2 (en) * 2012-07-09 2016-08-17 大成建設株式会社 Foundation construction method and foundation
JP6255184B2 (en) * 2013-07-31 2017-12-27 株式会社大林組 Cast-in-place pile wall protector and its construction method

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6119771B2 (en) * 1981-09-16 1986-05-19 Toshio Enoki
JPH04265312A (en) * 1991-02-18 1992-09-21 Takenaka Komuten Co Ltd Method of multistage bottom-expanding place pile driving construction
JP3895363B1 (en) * 2006-03-17 2007-03-22 日特建設株式会社 New foundation structure
JP5136270B2 (en) * 2007-08-03 2013-02-06 Jfeスチール株式会社 Synthetic friction pile construction method

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106245629A (en) * 2016-09-13 2016-12-21 大连理工大学 A kind of anti-skid uplift pile in mountain area and method for designing thereof
CN106245629B (en) * 2016-09-13 2018-10-16 大连理工大学 A kind of anti-skid uplift pile in mountain area and its design method

Also Published As

Publication number Publication date
JP2011038379A (en) 2011-02-24

Similar Documents

Publication Publication Date Title
KR101071122B1 (en) Internal excavation method through pile and foundation pile structure
KR100917044B1 (en) Concrete retaining wall construction method with dual wall jointed by anchor
KR100913569B1 (en) Phc pile for retaining wall
JP4722783B2 (en) Foundation reinforcement method for existing buildings
KR100964796B1 (en) Method for constructing the steel pipe-concrete composite pile structurized of burying and unifying into the bedrock, and a pile construction
KR20170005991A (en) soil retaining wall using PHC pile and its construction method
KR101665515B1 (en) Direct-boring pipe roof tunnel construction method and structure non-cutting natural ground
CN104947690B (en) Grooving construction method for embedding underground continuous wall into rock
KR100886445B1 (en) Soil tank type land-side protection wall
KR100869815B1 (en) Apparatus to upgrade end bearing capacity of pile and pile construction method
JP2010236323A (en) Foundation pile structure for on-site formation, and construction method of foundation pile
JP2013136922A (en) Earth retaining wall supporting method, earth retaining wall supporting structure, and underground skeleton constructing method
JP2005180079A (en) Aseismatic reinforcement structure of construction
KR20050020451A (en) Shield tunneling construction method and tunnel structure
KR100618597B1 (en) Cast in place concrete pile using vibro magnetic shovel hammer, and the construction method of this
US7600948B2 (en) Micropile retaining wall
KR101664368B1 (en) A cast-in place pile arrangement method for head of concrete pile exposed to outside using geo tube
KR100910576B1 (en) Embed anchor and construction method of composite basement wall using the same
CN102162250B (en) Protective construction method of excavating large area deep foundation pit in running sand confined water soil layer
CN105714833A (en) Construction method of steel plate pile open caisson support
CN102660955A (en) Quick construction method for foundation pit slope support
KR20110041391A (en) Pile structure
CN102758442A (en) Earth excavation method and open-cut tunnel construction method
JP4599384B2 (en) Embankment structure and construction method thereof
KR20110077334A (en) Retaining wall structure and construction method of the retaining wall structure

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20120627

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20130515

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20130523

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20130708

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20131003

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20131101

R150 Certificate of patent or registration of utility model

Ref document number: 5406628

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150