WO2015029054A1

WO2015029054A1 - Slotted holes meshed plug steel pile

Info

Publication number: WO2015029054A1
Application number: PCT/IN2014/000171
Authority: WO
Inventors: Naresh Kumar; Ashutosh TRIVEDI
Original assignee: Naresh Kumar; Trivedi Ashutosh
Priority date: 2013-08-27
Filing date: 2014-03-18
Publication date: 2015-03-05

Abstract

Described herein is a "Slotted Holes Meshed Plug Steel Pile" that can be used in a variety of soil conditions as well as apparatus and associated methods. Slotted holes helps in increase of effective stresses in soil-steel pile surface interaction by draining out extra buildup of pore water pressure in the immediate and longer run of time. As the potential flow of water will not be outwards but inwards to inside of steel pile through slotted holes of steel pile. It relieves of chances of buildup of excess pore water pressure for liquefaction of soils in the radially stressed zones of interaction of soil-steel pile.

Description

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DESCRIPTION

COMPLETE SPECIFICATIONS

Technical Field

[0001]

The present invention relates to special feature of a steel pile to be used in foundations of building structures. It shall be known as "Slotted Holes Meshed Plug Steel Pile".

Background Art

[0002]

As shown in Fig. l, that is a conventional pile to be driven into the ground inside a local slot on ground having a shallow depth and its top portion is covered with reinforced cement concrete. It is to be connected to the reinforced cement concrete horizontal grade beams or to be connected to the base of reinforced cement concrete column (vertical or inclined) of a building structure. Also, threaded steel bolts having good anchorage capability can also be put in reinforced concrete covering top portion of "Slotted Holes Meshed Plug Steel Pile".

[0003]

A very strong driving force is needed to drive this type of a conventional Steel pile. If driving force (via gravity hammer) is applied to the top of a steel pile for driving it into the ground then strong vibrations will be felt up to a significant distance in horizontal and radial directions. The pile driving method is applicable when in the neighborhood; no existing buildings are there. If static force is applied for pressing a steel pile (i.e. by press in technique) then as expected the vibrations will not be produced as was being felt in the case of pile driving. Additionally, side resistance shall develop along the pile. It will take a little more time for the development and then dissipation of pore water pressure in case of partially and fully saturated soils. It will also depend on whether the soil is cohesive, partially cohesive or non-cohesive soil. Disclosure of the invention

Problem to be solved by the invention [0004]

An aim of the present invention is to provide a "Slotted Holes Meshed Plug Steel Pile" to replace a conventional steel pile at preferred locations. Meanwhile, the present inventors proposed a "Slotted Holes Meshed Plug Steel Pile" as a pile to allow the flow of water inside the pile through the slotted holes via meshed sieve of a meshed -filter plug of the steel pile.

[0005]

When the steel pile is driven either by gravity hammer or motor driven hammer or by press-in-technique by hydraulic jacking force, then in its vicinity high buildup of pore water pressure is build up in the soil surrounding the lateral surface of a steel pile. As water travels from high gradient to low gradient, so, slotted holes in steel pile lateral surface are created in interface of soil-steel pile in the steel pile so that water due to extra buildup of pore water pressure is immediately drained of through the holes. It will increase the effective stress through the soil-steel pile structural interaction as the effective stress is equal to total stress minus pore water pressure. As the draining out of water takes place through the slotted holes of steel pile via meshed-filter plug sieve, till the pore water pressure becomes normal, the effective stress will be increased because of transfer of stress from water to soil particles. And effective strength of a soil mass is directly proportional to shear strength of a soil mass. This increase of shear strength leads to increase of side resistance. Not only the side-resistance of soil-steel pile is increased, the chances of increase in liquefaction are reduced to a large extent. Rather, potential of liquefaction of soil is reduced to a very large extent.

[0006]

The water can be pumped out at regular time intervals by having a mechanism of any prevalent system in the market. Also, the slotted holes fitted with mesh-plugs on the steel pile lateral surface will increase the side resistance of a slotted holed steel pile, thereby, increasing the load carrying capacity of a slotted holed pile and that, too, in a relatively short span of time. Means for Solving Problem [0007]

In Fig. 1., a "Slotted Holes Meshed Plug Steel Pile" is shown. The holes are provided at regularly or zig-zag spaced intervals all over the lateral surface of the steel pile. A mechanical machine in the form of driller, easily available in the market, is used to make either slots or complete holes in the steel pile lateral surface penetrating through the thickness of the pile wall. Then a water pipe of 2.54 cm is put inside the pile through the slotted hole, provided near the top portion of the pile, till it reaches the conical pile tip. Then an iron plate is bolted to the flange which is welded to the top portion of the pile. Then the above invented pile will be put at the desired position. On its head, a driving hammer is guided to fall on its top to let the slotted holes steel pile go inside the ground. Certainly, vibrations will be there. If in the neighborhood existing buildings are there, then piles could be driven inside the ground by press- in -technique by hydraulic jack force.

[0008]

Industrial Applicability of Invention:

1. This invention leads to fast as well as more development of side- resistance in comparison to use of conventional steel pile. Not only that it improves liquefaction potential of surrounding soil of newly invented pile but it improves consolidation properties of surrounding soil mass.

2. It will also help in dewatering of water table as per requirements of construction of foundations for building structures.

3. It will also help in getting required quantity of water for construction purpose.

4. It will also help in getting required quantity of water for drinking and commercial purpose. [0009]

EXAMPLE

1. In one example, the steel pile is 25 cm in internal diameter and 25.6 cm external diameter and the length of steel pile is 1.5 m. The spacing between the slotted holes is 9 cm from center to center in one row. The diameter of the slotted holes is 10 cm. There are

- eight holes in one row. The numbers of rows are eight in number. The spacing between the rows is 20 cm.

2. The conical steel pile tip is 25 cm in diameter. This conical steel pile tip is welded at lower end of the slotted steel pile. The vertical angle of conical steel pile tip is 60 degrees. The vertical height of the conical steel pile tip is 21.87 cm. The slant height of conical pile is 25.2 cm.

- 3. The mesh-filter is having a sieve-size of 0.150 mm (150 micron).

The sieve- size was arrived at after sieve-size analysis of surrounding soil mass of a steel pile. In my case, the highest particle sieve size of surrounding soil mass is 4.75 mm and lowest particle sieve size of surrounding soil mass is 0.075 mm. As the cumulative % retained was around 93 percent, corresponding to the sieve -size selected of 150 micron.

4. The mesh-plug having filter on outer end was put inside the steel pile from the outer lateral surface of steel pile.

5. Then a vertical steel pipe of 1.27 cm is poured from the top end of the steel pile and just below 5 cm from top end of steel pile, a steel elbow was fixed and then, another steel pipe of 1.27 cm was attached and passed through top hole near the top end, outer periphery of full covered plate of thickness 10mm and 35 cm diameter via nuts and bolts four in number placed at orthogonal positions and then through holes of flange which is welded at outer periphery of steel pile near its top end. The flange plate is a hollow one having thickness of, outer diameter 35 mm and internal diameter 28mm. It is having four holes of 10mm

positioned at 90 degrees to each other.

6. Then, a square pit of size 740 cm (length) by 740 cm (breadth) by - 214.3 cm depth was made. The above dimensions are internal dimensions. The thickness of the wall was one brick thick. The cement mortar used was 1 : 1 (1 part cement and 1 part sand). The pit was 80 cm deep inside the ground and 134.3 cm above the ground.

7. In the pit, a dry sand was mixed with water to achieve desirable water content, was poured in the pit. A known relative density was calculated by recognized experimental method.

8. Then, a conventional steel pile was driven into the sand by drop hammer. A number of blows were calculated for every 10 cm penetration of a conventional steel pile, The steel pile pile was driven inside the sand till its top end remains out by around 10 to 25cm.

9. Then, the top end is reinforced by reinforced cement concrete

having sufficient designed thickness through grade beams.

[0010]

Illustrations of Drawings

1. Fig.1 illustrates drawing of slotted holes mes]i- plugged steel pile with pile cap.

In this drawing, slotted holes are put up at desired designed spacing on the lateral surface of the steel pile. Then a mesh- plug is put up inside the steel pile via slotted hole through the outer surface of the steel pile. A technology for putting mesh-plug inside the steel pile is by hammering a plug on its top or by rotating it in threaded slotted hole by any

mechanical method available in the industrial market. Similarly, all the slotted holes are plugged by mesh-plugs all over its lateral surface. A steel pipe 1.27 cm to 2.54 cm is put inside the steel pile through the top slotted hole. Then a steel cover plate is connected to the top open end of a steel pile through a flange welded to outside of a top end of steel pile but. below the steel cover plate via nuts and bolts. Then a steel pile is hammer- driven from its top end. The bottom end of the mesh-plugged steel pile is placed inside a shallow pit- hole in ground which is, then,either, hammer-driven from its top end or pressed inside into the designated hollow pit by press-in-technique method. The steel pipe is connected through a water motor having sufficient horse power with all the electrical connections having either mechanical sensor or wireless- communicated electrical sensor. Then, steel reinforcement is put up around the top end of the steel pile as per codal provisions of pile foundations and codes of detailing of reinforcement prevalent in that country. Then, a designed rich mix of workable cement concrete, in and around reinforcement, having sufficient cover is poured and propelled through a workable means and compacted through a mechanical or electrical vibrator.

In the above drawing the filter thickness is shown by the label number 14 and the clear picture is shown in Fig 3.

Label numbers have been explained in the drawings in Fig 3, Fig 4 and Fig 5.

2. Fig.2 illustrates drawing of conventional steel pile with pile cap.

Then a steel plate is connected to the top open end of a steel pile through a flange welded to outside of a top end of steel pile via huts and bolt. Then, steel reinforcement is put up around the top end of the steel pile as per codal provisions of pile foundations and codes of detailing of reinforcement prevalent in that country. Then, a designed rich mix of workable cement concrete, in and around reinforcement, having sufficient cover is poured and propelled through a workable means and compacted through a mechanical or electrical vibrator.

3. Fig.3 illustrates drawing of slotted holes of steel pile without pile cap. Label 1 shows a steel pile. Label 2 shows a steel pile thickness. Label 3 shows a slotted hole and Label 4 shows a conical pile tip welded at cross-section, just 20 mm after the end of bottom-most row of mesh- plugged slotted holes of steel pile. Label 12 shows a steel pipe of 1.27 cm or 2.54 cm diameter for pumping out water by an electric motor. Label 14 shows mesh-filter of mesh-plug that is put up inside the steel pile. Label 18 shows mesh-plug. Label 15 shows cross- section of a steel pile.

4. Fig.4 illustrates drawing of slotted holes meshed-plug steel pile without pile cap. Label 1. Label 2, Label 4 and Label 15 have been explained in Fig. 3, Whereas Label 5 shows length of a steel pile. Label 6 shows internal diameter of a steel pile. Label 7 shows external diameter of a steel pile.

5. Fig.5 illustrates drawing of slotted holes meshed-plug steel pile without pile cap. Label 1. Label 2, Label 4 and Label 15 have been explained in Fig. 3, Whereas Label 5 shows length of a steel pile. Label 6 shows internal diameter of a steel pile. Label 7 shows external diameter of a steel pile. ■

6. Fig.6 shows a drawing detailing isometric view of conventional steel pile without pile cap. But labels have been explained already in previous drawings.

-7. . Similarly, Fig.7 shows a drawing that illustrates isometric view of "Mesh-filtered Push-in Hollow Plug" that had been put inside the steel pile. But labels have already been explained already in previous drawings. Label 18 shows mesh-filter of a mesh-plug. Label 19 shows open x-section of a mesh- filtered Push-in hollow plug. Label 20 shows lateral surface of a mesh-filtered Push-in Hollow Plug.

8. Similarly, Fig. 8 shows a drawing that illustrates isometric view of "Mesh-Filtered Threaded Hollow Plug" that had been put inside the steel pile. But labels have already been explained already in previous drawings. Label 18 and Label 19 have already been explained in Fig. 7. Label 21 shows threaded surface of "Mesh-Filtered Threaded Hollow Plug".

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BRIEFING OF SYMBOLS

1. Steel Pile

2. Steel Pile Thickness

3. Slotted Hole

4. Conical Pile Tip

5. Length of Pile

6. Internal Diameter of Steel Pile

7. External Diameter of Steel Pile

8. Reinforced Cement Concrete as per design

9. Reinforcement or Steel Bar as per design

10. Pile Cap of Foundation

11. Electric Motor

12. Steel Pipe for Pumping Out Water

13. Anchoring Rods

14. Mesh-filter of Mesh-Plug

15. Cross-section of A Steel Pile

16. Sieve-size of Filter of Mesh-Plug

17. Mesh-Plug diameter Just Less Than Internal

Diameter of Slotted Holes of Steel Pile

18. Mesh-Plug

19. Hollow Pipe

20. Plain Surface of Mesh-Plug

21. Threaded Surface of Mesh- Plug

22. Electrical or wireless-sensor for switch-on and switch-off of electrical motor

Claims

1. We claim in the above invention that we provided slotted holes of equivalent thickness in the lateral surface of a hollow/ tubular steel pile except the conical pile tip.

2. A steel pipe of 1.27 cm to 2.54 cm or any corresponding sizes less than 10% of inner diameter of the pile is put from its top and extracted out from its top hole. This steel pipe goes down inside the steel pile till it reaches the bottom of the conical tip.

3. A slotted hole, according to claim 1 above, wherein the diameter of the Hole either remains uniform throughout or could be of different sizes.

4. Spacing could be uniform between the holes or slots, along the circumference or could vary in zig-zag manner.

5. Some slotted holes may or may not penetrate through the thickness of the steel pile.

6. The slotted holes which may not fully penetrate through the thickness of the steel pile may be called holed slots or slots alone.

7. Some slotted holes may or may not have a filter plug or a meshed sieve plug to provide drainage.

8. The slotted holes cross-section may be of circular, triangular, square, and rectangular or of any polygonal shape. The shape may take form of a plus sign, multiplication sign, minus sign or a star sign.

9. The holes surface along the thickness of steel pile may or may not be tapered one from outer to inner or vice-versa.

10. The inside surface of the steel pile may or may not have meshed sieve filter plug having varied sieve sizes.

1 1. The inside surface of the hole may have uniform diameter or a tapered one. The inside surface of the hole could be machined, threaded or can be made rough by any other means.

12. The diameter of the steel pile may remain constant throughout the steel pile or could vary from top to bottom in a tapered or stepped . manner.

13. The material of the steel pile could be of any anti-corrosive composition or anodic attachments.

14. The outside surface of the slotted hole meshed steel pile may or may not be be painted with any material to modify the side -resistance.

15. The diameter of the conical tip at a welded joint may be other than the diameter of the steel pile or remains the same.

16. The conical tip may not or may have slotted holes of any dimension size or shape.

17. The water level indicator with an electronic or mechanical sensor may or may not be provided.

18. The slotted holes may have mesh-filtered hollow plug which may be a push-in or externally threaded by rotation or internally threaded by rotation.

19. A mesh-filtered hollow plug may have filter on its circular end or on its lateral cylindrical surface or all over its surface.

20. A mesh-filtered hollow plug may have cylindrical surface or conical surface having a tapered one.