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 Mesh Filtered Steel Pile".
Background Art
[0002]
As shown in Fig.l, the first embodiment(Label 1) is a conventional pile.The second embodiment(Label 14) is a mesh-filter, which had been up inside the third embodiment being a "slotted holes mesh-filtered steel pile"which is made after slotted holes are drilled in steel thickness (Label 2) of steel pile(Label 1). The third embodiment is, finally, 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 Mesh Filtered 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 Mesh Filtered Steel Pile" to replace a conventional steel pile at preferred locations. Meanwhile, the present inventors proposed a "Slotted Holes Mesh Filtered Steel Pile" as a pile to allow the flow of water inside the pile through the slotted holes via meshed sieve clung to inside surface 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 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 clung meshed 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.
[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 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 Mesh-Filtered Steel Pile" is shown. Th e 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.
[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 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, so the sieve -size selected was 150 micron.
4. The mesh-filter was put inside the steel pile from the top end of the 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 covered by a flange plate of 35 cm diameter via nuts and bolts four in number placed through holes of flange and flange plate 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.
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 cm. At the end, two dial gauges were fixed to measure settlement of steel pile after application of each incremental load applied axially.
9. Then, a load-settlement graph is drawn.
10. Similarly, a repetition is performed with a slotted holes mesh-
filtered steel pile. A graph is again made between load and
settlement.
11 .Finally, the two graphs are compared.
12.The comparison of graph clearly shows that slotted holes mesh-filtered steel pile has more side resistance than a conventional steel pile.
13. Whereas, side -resistance is a minor part of load carrying capacity of a steel pile in compression (Push-in) but almost full in load carrying capacity of a steel pile in tension (Pull-out).
14. From, a comparison of graph of load- settlement it is clearly shown that slotted holes mesh-filtered steel pile has more side-resistance than a conventional steel pile in compression (Push-in) as well as in tension (Pull-out).
15. Then, a comparison is made by torsional side-resistance between conventional steel pile and slotted holes mesh-filtered steel pile.
16. It is again found that that slotted holes mesh-filtered steel pile has
more side-resistance than a conventional steel pile.
17.Even, the torsional strain energy stored by slotted holes mesh-filtered steel pile was found to have much more than a conventional steel pile.
[0011]
Illustrations of Drawings
Fig.l illustrates drawing of slotted holes mesh filtered 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 filter is put up inside the steel pile through the steel pile. A technology for putting mesh filter inside the steel pile is by any mechanical method available in the industry. A steel pipe 1.27 cm to 2.54 cm is put inside the steel pile through the top slotted hole. 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 nuts and bolts. Then a steel pile is driven through a shallow hole from where a steel pile is going to be driven. The steel pipe is connected through a water motor having sufficient horse power. 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 rich mix of workable cement concrete, in and around reinforcement, is poured and compacted through a vibrator having sufficient cover.
In the above drawing the filter is shown by the label number 14 and the clear picture is shown in Fig 6.
Label numbers have been explained in the drawings in Fig 3, Fig 4 and Fig 5.
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 nuts and bolts. The steel pipe is connected through a water motor having sufficient horse power. 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 rich mix of workable cement concrete, in and around reinforcement, is poured and compacted through a vibrator having sufficient cover.
Fig.3 illustrates drawing of slotted holes mesh filtered steel pile without pile cap. Label 1 shows steel pile. Label 2 shows steel pile thickness. Label 3 shows a slotted hole and Label 4 shows a conical pile tip welded at coss-section of end of slotted holes 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 that is put up inside the steel pile. Label 15 shows cross- section of a steel pile.
Fig.4 illustrates drawing of conventional 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
Fig. 5.illustrates drawing of Mesh Filter of steel wires having sieve-size lesser than least of all the soil particles surrounding the soil mass.
Fig.6 shows a drawing detailing isometric view of mesh-filter in a steel pile (with pile cap foundation) that had been put inside the steel pipe. But labels have been explained already in previous drawings.
Similarly, Fig. 7 shows a drawing that illustrates isometric view of mesh-filter in a steel pile (without pile cap foundation) that had been put inside the steel pipe. But labels have already been explained already in previous drawings.
[0012]
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
9. Reinforcent or Steel Bar
10. Pile Cap of Foundation
11. Electric Motor
12. Steel Pipe for Pumping Out Water
13. Anchoring Rods
14. Mesh-filter
15. Cross-section of a Steel Pile
16. Sieve-size of Filter
17. Mesh-Filter Diameter Just Less Than Internal Diameter of Slotted Holes Steel Pile

[0010]
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. The 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. The 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 inside surface of the steel pile may not or may have meshed sieve having varied sieve sizes.
10. 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.
11. 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.
12. The material of the steel pile could be of any anti-corrosive composition or anodic attachments.
13. The outside surface of the slotted hole meshed steel pile may or may not be painted with any material to modify the side -resistance.
14. The diameter of the conical tip at a welded joint may be other than the diameter of the steel pile or remains the same.
15. The conical tip may not or may have slotted holes of any dimension size or shape.
16. The water level indicator with an electronic or mechanical sensor may not or may be provided.
17. The mesh filter is having a sieve size lesser than the least of all the particle sizes of a surrounding soil mass.