GB2062073A - Pre-stressed concrete spiral pile - Google Patents
Pre-stressed concrete spiral pile Download PDFInfo
- Publication number
- GB2062073A GB2062073A GB8001909A GB8001909A GB2062073A GB 2062073 A GB2062073 A GB 2062073A GB 8001909 A GB8001909 A GB 8001909A GB 8001909 A GB8001909 A GB 8001909A GB 2062073 A GB2062073 A GB 2062073A
- Authority
- GB
- United Kingdom
- Prior art keywords
- pile
- concrete
- spiral
- cement
- concrete pile
- 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.)
- Granted
Links
- 239000011513 prestressed concrete Substances 0.000 title claims description 12
- 239000004567 concrete Substances 0.000 claims abstract description 41
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 30
- 239000010959 steel Substances 0.000 claims abstract description 30
- 238000000034 method Methods 0.000 claims abstract description 12
- 239000002689 soil Substances 0.000 claims abstract description 12
- 238000007599 discharging Methods 0.000 claims abstract description 6
- 238000010276 construction Methods 0.000 claims description 18
- 239000000835 fiber Substances 0.000 claims description 17
- 239000004568 cement Substances 0.000 claims description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 4
- 239000003638 chemical reducing agent Substances 0.000 claims description 3
- 238000000465 moulding Methods 0.000 claims description 3
- 230000003014 reinforcing effect Effects 0.000 abstract description 7
- 238000010008 shearing Methods 0.000 description 10
- 239000011210 fiber-reinforced concrete Substances 0.000 description 5
- 230000035515 penetration Effects 0.000 description 5
- 230000006378 damage Effects 0.000 description 4
- 230000006835 compression Effects 0.000 description 3
- 238000007906 compression Methods 0.000 description 3
- 238000012669 compression test Methods 0.000 description 2
- 239000011372 high-strength concrete Substances 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- WURBVZBTWMNKQT-UHFFFAOYSA-N 1-(4-chlorophenoxy)-3,3-dimethyl-1-(1,2,4-triazol-1-yl)butan-2-one Chemical compound C1=NC=NN1C(C(=O)C(C)(C)C)OC1=CC=C(Cl)C=C1 WURBVZBTWMNKQT-UHFFFAOYSA-N 0.000 description 1
- 229920000535 Tan II Polymers 0.000 description 1
- 230000002929 anti-fatigue Effects 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
- E02D5/22—Piles
- E02D5/56—Screw piles
Landscapes
- Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
- Paleontology (AREA)
- Civil Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Piles And Underground Anchors (AREA)
- Placing Or Removing Of Piles Or Sheet Piles, Or Accessories Thereof (AREA)
Abstract
A method of driving a pile into the ground in which the pile has a preformed concrete spiral rib or flange, comprises rotating the pile, with application of torque so as to drive it into the ground without disturbing or discharging the soil. The pile (Fig. 2) has reinforcing bars 5, 5a, 5b and a spiral rib 4. The concrete is also strengthened by the addition of steel fibres and is molded centrifugally. <IMAGE>
Description
SPECIFICATION
Pre-stressed concrete spiral piles
This invention relates to pre-stressed concrete spiral piles and to a method of driving pre-stressed concrete spiral piles.
In general, areas for carrying out civil engineering works and the construction of buildilngs in cities.
are often situated adjacent to residential areas. Various noises and vibrations produced by these constructional operations, though temporary, often affect the living environment of inhabitants in these areas and neighbouring houses and buildings in cities where construction takes place suffer damage.
This has now become a major social problem. Accordingly, construction works in urban areas, or the peripheral areas thereof, are often prolonged because of restrictions on construction time and the costs of the construction tend to be increased due to changes in construction methods. This results in difficulties during the progress of the construction and increases the costs thereof. Specifically, because of regulations relating to noises and vibrations, it is difficult in practice to use noise producing tools such as diesel hammers and vibro-hammers in the pile driving necessary for the construction of foundations of structures and buildings in urban areas.Thus, as a result of the social need to reduce noise and vibrations produced by conventional pile driving methods, a so-called noise-free and vibration-free constructional method has been developed instead of the conventional pile driving methods.
With the increase of urban construction works many different constructional methods of the noise-free and vibration-free type have been proposed. However, each conventional noise-free and vibration-free constructional method comprises various additional steps and the cost thereof is substantially greater than conventional noisy pile driving methods. The apparatus used in these construction methods is supported by the ground in which the piles are driven so that there is an increasing possibility of inadequate supporting strength due to destruction and relaxation of the ground.
It is an object of the present invention to provide a noise-free and vibration-free construction method which is economical and whereby the construction of ground work may be more easily completed.
It is another object of the present invention to provide a new noise-free and vibration-free construction method of driving a pre-stressed concrete spiral pile wherein basic pile driving work may be completed by means of a single step of driving a concrete pile into the ground without discharging soil.
According to one feature of the present invention, a pile driving construction method comprises the steps of providing a pre-stressed concrete pile with a spiral flange and driving said concrete pile into the soil by rotating it with application of torque and without discharging the soil, so that said concrete pile may provide support as a friction pile or a supporting pile.
According to another feature of the present invention there is a pre-stressed concrete pile wherein a spiral flange portion is provided along the surface of the pile partially or entirely along its length, and the concrete includes steel fibres to increase the strength of the concrete pile.
In the accompanying drawings:
Figure 1 is a front elevation portion of a PC spiral pile embodying the present invention;
Figure 2 is a front elevation of a portion of a PC spiral pile similar to Figure 1 but partly in crosssection; and
Figure 3 is a cross-section of a flange portion of the pile.
Figures 1 and 2 show a PC spiral concrete pile embodying this invention wherein steel bars 5, reinforcing bars 5a and spiral reinforcing bars 5b. In manufacturing the pile these bars are assembled and they are put into a frame (not shown) for forming the concrete by a centrifugal force. A high strength concrete 4 mixed with steel fibres 3 is injected into the frame and a concrete pile 'a' having a spiral flange 1 is finally formed by centrifugal force molding. The pile per se will provide support as a friction pile or a supporting pile, by applying torque to the pile to impart rotation and penetration into the soil without discharging the soil.It would not be possible using a concrete pile with conventional strength concrete to provide a flange having sufficient penetrating capability because cracks and breaks are produced in the conventional concrete by the uneven penetration or collision with boulders in the soil.
To deal with this problem, the inventor has developed a steel fibre concrete which is more highly reinforced than conventional concrete. For instance, a sample of steel fibre reinforced concrete with a diameter of 0.3 to 0.5 mm and a length of about 25 to 30 mm with steel fibres 3 uniformly mixed into it, has the following merits which has never been witnessed in the conventional concrete.
[a] It has a high stiffness and has a high resisting characteristic;
[b] It has a high tensile strength and a high blending characteristic;
[c] It is less subjected to cracks and breaks in end portions and corners;
[d] It has a high anti-fatigue characteristic; and
[e] It has good heat resisting characteristics, and high resistance to freezing and melting.
By use of such a steel fibre reinforced concrete, the flange portion 1 which is not liable to cracks and breaks and which has a sufficient strength, can be formed.
A specimen of this concrete, which is used in the PC spiral pile 'a' of the invention was submitted to a compression test and the twenty-eight day standard strength was a28 = 750 kg/cm2 or more.
The concrete may be manufactured using the following mixture:-
Amount of Steel Maximum Size of Water/Cement Fine Aggregate Fibre Coarse Aggregate (w/c) (s/A) (vol. %) (mm) (%) (%) 1.0 15 45.0 50.0 Unit Amount (kg/m3) Water Cement Fine Aggregate Coarse Aggregate Steel Fibre 194 460 780 881 78 LL Admixture (Sigma 1000) Water-Reducing Agent (Mighty) 10% 1.0% (to weight of cement) (to weight of cement) The 28-days compression strength of the steel fibre reinforced concrete with this mixture was 028 = 767 kg/cm2. It was almost equal to the compression strength '28 = 753 kg/cm2 of a concrete in which the steel fibre is not mixed in it.However, the tensile strength without steel fibre was sot = 59 kg/cm2 against 83 kg/cm2 with steel fibre, thus increasing the tensile strength about 1.4 times by mixing in the steel fibre.
Moreover, for the purpose of comparing the durability to cracks and breaks due to shock or impact between the steel fibre reinforced concrete according to the present invention and the conventional concrete with no steel fibre mixed therein, the applicant tested and checked the frequency of producing the cracks and the number of destructions by simply supporting the bending test specimen at a span of 45 cm for 28 days and then by repeatedly dropping a steel ball of 7.5 kg in weight on to the middle of the span from a height of 30 cm. As a result, cracks were produced in the concrete with no steel fibre contained in it after dropping the ball only three times and almost at the same time it was destroyed.On the other hand, in the concrete with steel fibre contained in it according to the present invention, cracks were not produced until the ball had been dropped forty one times and it was not destroyed until the ball had been dropped 164 times.
It was found that the flange 1 which has an appropriate size for sufficient penetration of the spiral piles has a sufficient durability against cracks and breaks when colliding with boulders in the ground or when uneven penetration thereof takes place. In the PC spiral pile 'a' according to the present invention, a very high strength of the steel fibre reinforced concrete with the twenty-eight day standard strength of a28 = 750 kg/cm2 or more was used for the standard compression test specimen. Moreover, as the PC spiral pile 'a' is molded by use of a centrifugal force the strength of the pile has been increased by about 20% through adhesion and the dehydrating process. In this concrete with high strength, the tensile strength naturally increases, thus producing a tensile strength of 1/5 to the compression strength.
Furthermore, the tensile strength has been increased 1.5 times by the reinforcing of the steel fibre.
When exerting a torque on the pile a shearing force is produced in the cross-section of the pile and the largest shearing stress is produced in the periphery of the pile.
By assuming that the shearing stress is T, the principal stresses a, and a2 become: a1 = - a2 ='r The direction of the principal stress a, in relation to the pile axis becomes; tan 2 4 = Go, (6 = 450 and the tensile stress of a, = T is produced in the direction of 45 to the pile axis and in turn the compressive stress of a2 = -'r is produced perpendicular to the tensile stress.
When the stress , reaches the tensile strength at of the concrete cracks are produced in the direction perpendicular to the tensile stress. That is, the shearing stress, at the time of producing cracks is as follows; = at Namely, the shearing stress which produces cracks becomes T = at.
Next, when introducing a pre-stress of the compressive force a0 into the pile, the condition of the stress on the peripheral surface of the pile becomes the combination of the compressive stress a, in the direction of the pile axis and the shearing stress 'which occurs at the same time. In this case, the principal stress a2 and a2 become;
The direction of the principal-stress a1, to the pile axis becomes;
22 tan25 +7r
aO The tensile stress a, is produced in the direction of 0 to the pile axis, while the compressive stress a2 is produced in the direction perpendicular thereto.
When the principal stress a1 reaches the tensile strength at of the concrete, cracks will be produced. Thereby the shearing stress Tcr which produces cracks becomes
and the direction of cracks to the pile axis becomes;
In the concrete with the standard strength a28 = 750 kg/cm over 28 days of duration which is used for the PC pile 'a' according to the present invention, the compressive strength has been increased 20% and a0 becomes about 900 kg/cm2 by the centrifugal force molding.
The tensile strength thereto is about 1/1 5 of the compressive strength; at = 60 kg/cm2. The tensile strength of at = 78 kg/cm2 which is stronger 1.3 times than the conventional ones is obtainable by reinforcing by use of the steel fibre. In this case, the shearing stress at the time of producing cracks becomes Tcr = at = 78 kg/cm2 on the condition that the prestress is not introduced. However, when the prestress of 100 kg/cm2 is introduced, the shearing stress becomes Tcr = 11 8 kg/cm 2 by use of a0 = 100 kg/cm2 and the direction of cracks becomes 0 ' = 250 to the pile axis. Moreover, when introducing the prestress of 200 kg/cm2 the shearing stress becomes T Cr = 147 kg/cm2 and the direction of cracks becomes s' = 180.That is, when the prestress of 100 kg/cm2 is introduced in the pile, the torque which produces cracks becomes 1.5 times stronger than that of non-introduction of the prestress into it and is about 1.9 times stronger for the prestress of 200 kg/cm2.
Furthermore, the direction of cracks is j! = 450 to the pile axis when the prestress is not introduced, while the direction declines in the pile direction by the introduction of the prestress and the angle of cracks becomes small. Accordingly, the higher the stress produced by the prestress, the more the torque which produces cracks increases, thus the angle of cracks can be made small in relation to the pile axis.Thereby, it should be noted that in a PC spiral pile which is driven into the soil by the rotation with torque, the high strength concrete with the high prestress has become more advantageous than the conventional ones.
When the spiral reinforcing bar 5b is arranged nearly perpendicular to the direction of cracks, the torque which more produces the cracks can be increased. The following table shows a result of a twisting test for the conventional PC pile with a diameter of 300 mm and a thickness of 60 mm and the
PC spiral pile 'a' with a length of 1.2 m.
Crack producing Concrete of Prestress twisting moment two kinds (kg/cm2) (ton-m) Remarks High strength 47.0 3.19 Average of concrete four piles 100.0 4.08 Average of two piles 150.0 423 Average of two piles Concrete with 100.0 4.82 Average of steel fibre three piles 150.0 5.58 1 Average of three piles l
If a concrete pile has nearly same twisting moment as the one which is obtainable by the steel fibre reinforcing concrete penetration of the concrete pile by the twisting to the ground necessary for establishing the pile foundation will become sufficient by taking the safety rate into consideration.
The PC spiral pile according to the invention can be penetrated in the soil by the rotating with the application of torque without discharging soil, so that destruction and looseness of ground can be avoided in contrast with other noise-free, non-vibration construction methods. Rather, a large supporting force is obtainable as the ground will be tightly consolidated and, as the flange is provided on the pile itself, the friction between the concrete and the foundation can be greatly increased.
Furthermore, it is also possible to retain strength in soft ground by driving the PC spiral pile 'a' into soft ground without producing noise and vibration.
The PC spiral concrete pile according to the present invention is more economical than the conventional PC pile according to the hammer driven construction method and a larger supporting force is obtainable, thus guaranteeing a greater safety in construction as well as yielding other advantageous industrial effects.
A PC spiral concrete pile according to the present invention is preferably manufactured under the following conditions:
steel fibre amount: 0.6 to 1.2 vol.%
maximum size of coarse aggregate: 13 to 20 mm
water/cement ratio: 30 to 45%
fine aggregate ratio, s/A: 45 to 55%
cement unit amount: 460 to 500 kg/cm3
admixture ratio to weight of cement: 7 to 12%
water-reducing agent ratio to weight of cement: 1.0 to 1.4%
Claims (7)
1. A pile driving construction method comprising the steps of providing a prestressed concrete pile with a spiral flange and driving said concrete pile into the soil by rotating it with application of torque and without discharging the soil so that said concrete pile may provide support as a friction pile or a supporting pile.
2. A method according to claim 1 wherein the pile is formed of prestressed concrete with steel fibres embedded in the concrete.
3. A method according to claim 2 wherein the pile is formed by centrifugal molding.
4. A prestressed concrete pile wherein a spiral flange portion is provided along the surface of the pile partially or entirely along its length, and the concrete includes steel fibres to increase the strength of the concrete pile.
5. A PC spiral concrete pile according to claim 4 which comprises:
steel fibre amount 0.6 to 1.2 vol.%
maximum size of coarse aggregate: 13 to 20 mm
water/cement ratio: 30 to 45%
fine aggregate ratio, s/A: 45 to 55%
cement unit amount: 460 to 500 kg/m3
admixture ratio to weight of cement: 7 to 12%
water-reducing agent ratio to weight of cement: 1.0 to 1.4%.
6. A high strength steel fibre reinforced prestressed concrete pile with a spiral flange substantially as hereinbefore particularly described and illustrated in the accompanying drawing.
7. A method of driving a prestressed concrete pile substantially as hereinbefore particularly described.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP54140585A JPS5854211B2 (en) | 1979-10-31 | 1979-10-31 | Torsion penetrating type PC spiral pile |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2062073A true GB2062073A (en) | 1981-05-20 |
| GB2062073B GB2062073B (en) | 1983-03-16 |
Family
ID=15272105
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8001909A Expired GB2062073B (en) | 1979-10-31 | 1980-01-21 | Pre-stressed concrete spiral pile |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS5854211B2 (en) |
| DE (2) | DE8029098U1 (en) |
| FR (1) | FR2468696A1 (en) |
| GB (1) | GB2062073B (en) |
| IT (1) | IT1127376B (en) |
| NL (1) | NL8002777A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0127221A1 (en) * | 1983-05-03 | 1984-12-05 | Pieter Faber | Concrete foundation pile and device for driving the same into the ground |
| GB2220689A (en) * | 1988-07-15 | 1990-01-17 | Helix Reinforcements | Soil reinforcement |
| WO1999024676A1 (en) * | 1997-11-07 | 1999-05-20 | Peter Cornelis Peters | Method of manufacturing a reinforced oblong concrete product for longitudinal load-bearing purposes, and a driven pile |
| GB2362672A (en) * | 2000-05-22 | 2001-11-28 | Laing Rail Ltd | Conical foundation pile having a screw thread for urging the pile into the ground |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58185627U (en) * | 1982-06-07 | 1983-12-09 | 丹羽 友道 | Screw-in PC concrete pile |
| DE3521627A1 (en) * | 1985-06-15 | 1986-12-18 | Strabag Bau-AG, 5000 Köln | Method of producing an inclined composite grouted pile |
| DE3617025A1 (en) * | 1986-05-21 | 1987-11-26 | Delmag Maschinenfabrik | PRE-PREPARED CONCRETE PILE AND METHOD AND DEVICE FOR ITS PLACING INTO THE GROUND |
| DE3827703A1 (en) * | 1988-08-16 | 1990-02-22 | Bilfinger Berger Bau | Supporting elements for forming foundation bodies |
| DE4020757C2 (en) * | 1990-06-29 | 1996-08-01 | Pfleiderer Verkehrstechnik | Reinforced concrete foundation pile and process for its manufacture |
| DE19743415A1 (en) * | 1997-10-01 | 1999-06-10 | Josef Dipl Ing Behrens | Self boring concrete pile |
| FR2915498B1 (en) | 2007-04-25 | 2011-09-30 | Jean Marie Renovation | DEVICE AND METHOD FOR ESTABLISHING A FOUNDATION HELICOIDAL MICROPY |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE255282C (en) * | ||||
| GB252975A (en) * | 1925-10-23 | 1926-06-10 | Alexander George Rotinoff | Improvements relating to reinforced concrete |
| DE1634356A1 (en) * | 1966-09-23 | 1970-06-18 | Feidner Dipl Ing Erich | Pile foundations for buildings as well as methods and tools for their production |
| US3986885A (en) * | 1971-07-06 | 1976-10-19 | Battelle Development Corporation | Flexural strength in fiber-containing concrete |
| SE7712323L (en) * | 1976-11-02 | 1978-05-03 | Gillen Jr William Francis | THREADED CONCRETE POLE |
-
1979
- 1979-10-31 JP JP54140585A patent/JPS5854211B2/en not_active Expired
-
1980
- 1980-01-21 GB GB8001909A patent/GB2062073B/en not_active Expired
- 1980-02-29 IT IT48051/80A patent/IT1127376B/en active
- 1980-05-05 FR FR8009960A patent/FR2468696A1/en not_active Withdrawn
- 1980-05-13 NL NL8002777A patent/NL8002777A/en not_active Application Discontinuation
- 1980-10-31 DE DE19808029098U patent/DE8029098U1/en not_active Expired
- 1980-10-31 DE DE19803041125 patent/DE3041125A1/en not_active Withdrawn
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0127221A1 (en) * | 1983-05-03 | 1984-12-05 | Pieter Faber | Concrete foundation pile and device for driving the same into the ground |
| US4708530A (en) * | 1983-05-03 | 1987-11-24 | Pieter Faber | Concrete foundation pile and device for driving the same into the ground |
| GB2220689A (en) * | 1988-07-15 | 1990-01-17 | Helix Reinforcements | Soil reinforcement |
| WO1999024676A1 (en) * | 1997-11-07 | 1999-05-20 | Peter Cornelis Peters | Method of manufacturing a reinforced oblong concrete product for longitudinal load-bearing purposes, and a driven pile |
| US6652791B1 (en) | 1997-11-07 | 2003-11-25 | Peter Cornelis Peters | Method of manufacturing a reinforced oblong concrete driving pile for longitudinal load-bearing purposes |
| GB2362672A (en) * | 2000-05-22 | 2001-11-28 | Laing Rail Ltd | Conical foundation pile having a screw thread for urging the pile into the ground |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5854211B2 (en) | 1983-12-03 |
| JPS5719417A (en) | 1982-02-01 |
| FR2468696A1 (en) | 1981-05-08 |
| DE8029098U1 (en) | 1981-11-26 |
| IT8048051A0 (en) | 1980-02-29 |
| GB2062073B (en) | 1983-03-16 |
| DE3041125A1 (en) | 1981-05-14 |
| NL8002777A (en) | 1981-06-01 |
| IT1127376B (en) | 1986-05-21 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |