Eccentric tamping probe providing lateral compaction

Abstract

The invention relates to an eccentric Tamping probe that belongs to the field of Geotechnical Engineering and provides mechanical improvement along lateral direction of the soil at the desired depth, especially in loose and medium dense granular grain dominated soils with insufficient bearing capacity or excessive settlements in the natural state. The eccentric tamping probe of the invention, which provides mechanical improvement by compacting the soil in a lateral direction when attached to a standard drilling machine or engine, comprises an eccentric crankshaft (2), wing fasteners (8), ramming wings (4), a central distributor (9), a main frame (7), a drilling bit (1), and a protective fabric.

Description

[0001] ECCENTRIC TAMPING PROBE PROVIDING LATERAL COMPACTION

[0002] Field of the Invention

[0003] The invention relates to an eccentric tamping probe that belongs to the field of Geotechnical Engineering and provides mechanical improvement along lateral direction of the soil at the desired depth, especially in loose and medium dense granular grain dominated soils with insufficient bearing capacity or excessive settlements in the natural state .

[0004] Known State of the Art

[0005] Urbanization and population growth are driving a rapid increase in the number of buildings . Construction is often performed on soils with insufficient bearing capacity and excessive settlement behavior due to land limitations . However , this situation poses ris ks like partial or complete building collapse . Therefore , the significance of enhancing unsuitable soil is growing .

[0006] In the process of ground improvement in Geotechnical Engineering, techniques such as j et grouting, stone columns or deep mixing can be used to improve soil properties , while driven or bored piles , which are among the deep foundation types , can also be used . In mechanical stabilization, which is mostly used for the improvement of granular grain dominated soils , it is also known in the art that different methods such as compaction by dropping weights on the ground surface , roller compaction, compaction in vertical direction based on vibratory effect are applied . In the aforementioned conventional methods , only the water and / or air phase in the soil is removed in the vertical direction, increasing the unit weight and relative density, and reducing the permeability and void ratio . However, these methods , which are applied in the vertical direction from the surface , are generally preferred for shallow improvement and require high- capacity equipment and significant costs where they need to be used in deep applications .

[0007] There are documents in the art regarding advancements in equipment used for soil compaction .

[0008] The patent document No . CN217733978U may be referred as an example for the current state of the art . The said document relates to a high-frequency compaction wheel comprising a seating plate . At the bottom of the seat plate there are slots for two wheels , a rotatable wheel shaft between the slots and a press wheel outside the wheel shaft . The high-frequency compaction wheel for the excavator can meet different soil compaction requirements . Compression level and efficiency are high . A vibration motor in the compaction wheel drives a rotating crankshaft , which compacts the soil .

[0009] Patent document No . JP2021042553A may be given as another example of the current state of the art . The said document relates to a soil compaction device . The purpose of the low- cost and portable size device mentioned in the document is to provide a soil compaction device that efficiently improves the soft ground in a short time under the impact effect . This device consists of coils , a solenoid with a plunger and a load plate that is pushed downwards by the plunger movement to apply an impact effect on the soft ground .

[0010] Patent document No . CN101054787A may be given as another example of the current state of the art . The present invention discloses a mini-type smooth-moving vibratory compaction roller comprising a drum and a drive mechanism . An eccentric shaft is fixed to the drum, or the drum is fixedly connected to two transmission shafts of the eccentric block .

[0011] Review of the documents in the art , the compaction process applied for the improvement of the soil is performed from the surface of the ground . Therefore , the compaction of the soil cannot be carried out at the desired depth or requires large machinery for sufficient energy .

[0012] In order to eliminate the above-mentioned disadvantages , an eccentric tamping probe has been developed that provides mechanical ground improvement in the lateral direction at the desired depth .

[0013] Detailed Description of the Invention

[0014] The invention relates to an eccentric tamping probe that belongs to the geotechnical field and provides mechanical improvement at the desired depth and lateral direction of the soil , especially in loose and medium dense granular grain dominated soils with insufficient bearing capacity or excessive settlements in the natural state .

[0015] An obj ect of the invention is the development of an eccentric tamping probe that enables the ground improvement process to be performed at the desired depth .

[0016] Another obj ect of the invention is the development of an eccentric tamping probe that enables the ground improvement process to be applied laterally to the ground, in contrast to conventional methods .

[0017] The invention relates to an eccentric tamping probe for lateral compaction of the soil fixed to a rotary motor or drilling machine for the improvement of the soil , and in its most general form comprises ; - at least single-protrusion or multi-protrusion crankshaft (2) , comprising a first connection end for connection to the motor or drilling machine and a second connection end for connection to a drilling bit (1) , which allows the rotational movement from the rotary motor or drilling machine to be converted into lateral movement,

[0018] - multiple ramming wings (4) , including at least one connection lug (3) fixed to the eccentric crankshaft (2) on its inner surface, which is coordinated with the eccentric crankshaft (2) and moves horizontally with respect to the ground, applying lateral compression force to the soil,

[0019] - a fixed main frame (7) comprising the lower disc (5) and the upper disc (6) joined by rods positioned between the ramming wings (4) and having a space in the center of the lower disc (5) and the upper disc (6) through which the eccentric crankshaft (2) passes,

[0020] - at least one wing fastener (8) positioned at one end to the protrusions on the eccentric crankshaft (2) and at the other end to the connection lug (3) on the ramming wings (4) , which provides a movable connection between the eccentric crankshaft (2) and the ramming wings (4) ,

[0021] - at least one drilling bit (1) at the end of the eccentric tamping probe for drilling into the ground and conveying the loosened soil during drilling in front of the ramming wing ( 4 ) .

[0022] In an embodiment of the invention, the eccentric crankshaft (2) , connection lug (3) members, ramming wings (4) , lower disc (5) , upper disc (6) , main frame (7) and wing fasteners (8) are made of steel.

[0023] In an embodiment of the invention, the eccentric crankshaft (2) is positioned to be symmetrical and equiangular. In an embodiment of the invention, there are at least two ramming wings (4) .

[0024] In an embodiment of the invention, the number of eccentric crankshaft (2) protrusion is equal to the number of ramming wings ( 4 ) .

[0025] In an embodiment of the invention, the number protrusions of the eccentric crankshafts (2) are twice the number of ramming wings ( 4 ) .

[0026] In an embodiment of the invention, the eccentric crankshaft (2) can be mountable.

[0027] In an embodiment of the invention, the outer surface of the eccentric tamping probe of the invention is conical form.

[0028] In an embodiment of the invention, the ramming wing (4) is in the form of a quarter circle which, when in the closed position, forms a conical shape limits to the outer surface of the eccentric tamping probe.

[0029] In an embodiment of the invention, there are four ramming wings (4) and the ramming wings (4) are positioned symmetrically in the lateral direction of 90° with respect to the ground and are at an angle of 10° with the horizontal.

[0030] In an embodiment of the invention, it comprises at least one rail channel (12) on the surface of each ramming wing (4) in contact with the upper disc (6) and a rail (11) engaging with the said rail channel (12) to ensure stable forward-backward movement . In an embodiment of the invention, the lower disc (5) , the upper disc (6) and the main frame (7) rods are secured with screws so that the eccentric crankshaft (2) can be removed.

[0031] In an embodiment of the invention, when the protrusion of the eccentric crankshaft (2) is single, it comprises at least one central distributor (9) with a hole in the center through which the protrusion passes, with a number of connection holes on the edges as the number of ramming wing (4) , respectively transmitting the horizontal movement from the eccentric crankshaft (2) to the ramming wings (4) .

[0032] In an embodiment of the invention, there is a copper washer on the lower and upper parts of the central distributor (9) .

[0033] In an embodiment of the invention, it comprises a protective fabric surrounding the probe from the outside to prevent the soil particles from escaping between the eccentric crankshaft (2) and other connection details. In said embodiment, the protective fabric comprises aramid fabric.

[0034] In an embodiment of the invention, the fabric is passed through the lower disc (5) and secured to the upper disc (6) using a rope.

[0035] In an embodiment of the invention, there is at least one angled plate (10) and / or spiral on the outer surface of the drilling tip.

[0036] The purpose of the methods containing special probes that create vibration by dynamic compaction or vibration effect applied by rolling the weights from certain heights with cylinders, which are generally used for the improvement of granular grain dominated soils in the field of Geotechnical Engineering, is to improve the parameters of soils with insufficient bearing capacity or excessive settlements in the natural state .

[0037] The eccentric tamping probe of the invention is a unique metal component equipment adapted to a standard drilling machine and makes simultaneous drilling and lateral directional improvement on the natural granular grain dominated soil by transferring the rotational movement from the drilling machine or engine to the ramming wings ( 4 ) . The eccentric tamping probe , which is designed and produced in two different systematics including single or multiple crankshafts ( 2 ) and proven to be applicable in large-scale laboratory field experiments , is an alternative to existing methods in terms of its ability to provide rapid, economical and effective improvement .

[0038] The eccentric tamping probe of the invention has been developed under the scope of Ttibitak 1002 proj ect number 122M098 in order to mechanically improve the ground at the desired depth and lateral direction in the borehole in loose and medium dense granular grain dominated soils with sufficient water content . Thanks to the eccentric tamping probe , which can be produced in the number of ramming wings ( 4 ) suitable for single- or multiple-crankshaft ( 2 ) details and can also be applied in soils containing partially fine material , the bearing capacity increases and the settlement levels decrease due to the increase in the relative compaction of the soil .

[0039] In large-scale laboratory studies , poorly graded silica sand ( SP ) was utilized . The cube test cell with a size of 1 . 5 m was filled with an average of 6% water content at 30% , 50% and 70% relative densities at a height of 1 . 2 m and became ready for reference plate loading tests . On completion of the reference tests . A mechanical improvement was achieved in the lateral direction by drilling 50 cm with the help of a tamping probe at 3D, 4D and 5D intervals , with a net diameter ( D) of 20 cm for each relative density value in the cell that was emptied and refilled . In line with the settlement graphs based on the axial stress on the surface obtained as a result of the ground improvement , the axial (vertical ) stress values on the surface corresponding to the 45 mm settling level were examined according to the reference behaviors under the same conditions . Under current conditions , a significant increase in bearing capacity of approximately 60% to 490% has been observed in all cases (Table 1 ) . The most effective data were obtained in 3D interval applications , while a decrease in effectiveness was noted in 4D and 5D interval applications as well as reaching similar outcomes . Relatively low values were reached at 50% relative density . When comparing the stress at a depth of 25 cm, which corresponds to the midpoint of the depth improved with the tamping probe , a reduction of between 2 . 15% and 52 . 90% was achieved based on variables in terms of relative denstiy and interval .

[0040] Table 1 . Rates of bearing capacity increase compared to reference cases after improvement .

[0041] Sand cone experiments were performed to compare the relative compaction difference in the ground both before and after the improvement with the eccentric tamping probe . A significant increase in soil relative compaction values was observed due to the application of ground improvement using the eccentric tamping probe. When lateral tamping was performed on the soil with an average initial relative density of 30%, 50% and 70%, an increase in the relative density values was obtained in the order of 21.07%, 12.43% and 16.21%, respectively.

[0042] The eccentric tamping probe used in large-scale laboratory experiments was affixed to the drilling machine to evaluate its field usability. The eccentric tamping probe has proven to be fast and effective in loosened clay soils, representing sandy and partly fine material grounds.

[0043] The eccentric tamping probe of an embodiment of the invention provides mechanical improvement by compaction in the lateral direction on the ground when attached to a standard drilling machine or engine, and consists of the crankshaft (2) , wing fasteners (8) , ramming wing (4) , central distributor (9) , main frame (7) , drilling bit (1) and protective fabric. Images of the multiple crankshaft (2) design are given in Figure 1 and Figure 2, while designs containing single crankshaft (2) and central distributor (9) are presented in Figure 3, Figure 4 and Figure 5.

[0044] The crankshaft (2) is the main element made of steel that converts the rotational motion given by the engine or drilling machine into lateral motion, thus allowing the wings to compact the soil. When positioned symmetrically and equidistantly from the top on the eccentric tamping probe, any number of ramming wings (4) can be added, with a minimum requirement of at least two. In the crankshaft (2) , one eccentric protrusion in the same direction is required as the number of ramming wings (4) planned for single-point connection for small-size eccentric tamping probes, and twice the number of ramming wings (4) of the same are required for two-point connection for large-size eccentric tamping probes. The bearings or rings on the wing fasteners (8) , which allow rotary movement by mounting on these protrusions on the crankshaft (2) , are moved in coordination with the eccentric crankshaft (2) in the inner part. Wing fasteners (8) affixed to the rings adjust the spacing between the crankshaft (2) and the ramming wings (4) , thereby determining the extent of lateral movement. In the multiple crankshaft (2) design, the oppositely positioned ramming wings (4) are deployed simultaneously. The upper end of the crankshaft (2) has a connection detail suitable for the engine or drilling machine, and the lower end has a connection detail suitable for the drilling bit (1) . The crankshaft (2) is designed to be detachable and reinsertable for maintenance purposes. In the single protrusion crankshaft (2) design, the central distributor (9) is positioned on the protrusion.

[0045] The central distributor (9) used in the design including the single protrusion crankshaft (2) can rotate freely when mounted on the eccentric part of the crankshaft (2) and opens and closes the ramming wings (4) one by one in a clockwise direction. Thus, the crankshaft (2) compacts the soil in all directions when it completes one revolution, without overloading the previous engine and the metal sections. The central distributor (9) has a hole in the center through which the crankshaft (2) can pass, and on the sides, there are as many connection holes as there are ramming wings (4) . During its installation on the crankshaft (2) , copper washers are placed on the lower and upper parts that come into contact with it in order to avoid abrasions and prevent damage to the crankshaft ( 2 ) . The wing fasteners (8) are elements made of steel to provide the movable connection between the eccentric crankshaft (2) and the ramming wings (4) . They are members made of steel metal sheet with a bearing or ring positioned at one end not to restrict rotary movement in accordance with the eccentric protrusions on the eccentric crankshaft (2) and a pin slot at the other end that provides the connection to the connection lug (3) on the ramming wings (4) . Due to the conical shape of the outer surface of the eccentric tamping probe, the length and positioning of the wing fasteners (8) on the inner surface of the ramming wing (4) vary accordingly.

[0046] The quarter-circular steel ramming wings (4) , which form a conical shape zero to the outer surface of the eccentric tamping probe in the closed position, provide dynamic compaction in the horizontal direction by striking the inner surfaces of the borehole drilled in the ground during drilling operation as well. In this way, steel plates compressing the loose soil provide improvement in the ground by increasing the relative density. In this design, 4 identical ramming wings (4) , which are positioned symmetrically in 90° lateral directions, make a 10° angle with the horizontal in order to provide a conical form and have the desired amount of movement. On the inner surface of the ramming wings (4) , there is a connection lug (3) where the connection elements to the eccentric crankshaft (2) will be fixed at appropriate positions. The channels under the ramming wing (4) are rail channels (12) that provide balanced forward-backward movement .

[0047] The main frame (7) made of steel is formed by joining the upper disc (6) and the lower discs (5) centering the eccentric crankshaft (2) with steel bars vertically. The rods are positioned between the ramming wings (4) and constitute the boundaries of the wings. The main frame (7) mounted on the rotator motor or drilling machine is stationary. There are enough holes in the center of the upper disc (6) and the lower disc (5) for the crankshaft (2) to pass through, and the bearing is fixed in these holes in order to ensure smooth rotation if necessary. In addition, the rails (11) fixed to the inner part of the upper disc (6) provide axial centering and limit movement by moving the rail channel (12) on the ramming wings (4) . The upper disc (6) , the lower disc (5) and the rods are secured with screws, allowing for the crankshaft (2) to be removed and installed. To enable the removal and installation of the crankshaft (2) , slots were created in the lower disc (5) , and poles inserted into these slots are secured with screws.

[0048] The conical drilling bit (1) with angled plates (10) or spiral on its outer surface both provides drilling on the ground and conveys the loose ground during drilling in front of the ramming wings (4) . In this way, the soil in front of the ramming wings (4) can be compressed with the dynamic compaction effect in the lateral direction.

[0049] There is a protective fabric between the crank parts that completely wraps the probe from the outside in order to prevent soil particles from escaping. The tent, which is sewn from aramid fabric, a fabric with high cut resistance, is passed through the lower disc (5) on the eccentric tamping probe and fixed to the upper disc (6) by strangulation with the help of a rope. If necessary, the steel ramming wings (4) can be connected to each other with flexible tubes and a single movement can be achieved by passing the fabric over it .

[0050] The operability of the probe, designed and manufactured for a 40-cm crankshaft (2) length has been verified in laboratory and field environments . The ramming wings ( 4 ) , shaped like quarter circles in the four primary directions , facilitate lateral compaction by creating a continuous dynamic effect on the surrounding soil within the borehole . The probe , which is conical in longitudinal section, provides an additional compaction potential in the vertical direction depending on the expansion of the diameter as it moves through the ground .

[0051] One advantage of the eccentric tamping probe of the invention is that the ground is improved by mechanically compacting the ground at the desired depth .

[0052] Another advantage of the eccentric tamping probe of the invention is that soil compaction can be performed in a lateral direction to the ground .

[0053] Another advantage of the eccentric tamping probe is its ease of operation, as it can be connected to a motor or drilling machine .

[0054] Description of the Figures

[0055] Figure 1 : A perspective view of the eccentric tamping probe of multiple crankshaft design

[0056] Figure 2 : An exploded view of the eccentric tamping probe of multiple crankshaft design

[0057] Figure 3 : A perspective view of the eccentric tamping probe of single crankshaft design

[0058] Figure 4 : An exploded view of the eccentric tamping probe of single crankshaft design

[0059] Figure 5 : Images of the eccentric tamping probe ( a ) , inner part (b ) and ramming wing ( c ) of single crankshaft design

[0060] Description of Reference Numerals in the Figures

[0061] 1 . Drilling bit 2. Crankshaft

[0062] 3. Connection lug

[0063] 4. Ramming wing

[0064] 5. Lower disc 6. Upper disc

[0065] 7. Main frame

[0066] 8. Wing fastener

[0067] 9. Central distributor

[0068] 10. Angled plate 11. Rail

[0069] 12. Rail channel

Claims

CLAIMS1. An eccentric tamping probe for lateral compaction of the soil fixed to a rotary motor or drilling machine for the improvement of the soil, comprising: at least single-protrusion or multi-protrusion crankshaft (2) , comprising a first connection end for connection to the motor or drilling machine and a second connection end for connection to a drilling bit (1) , which allows the rotational movement from the rotary motor or drilling machine to be converted into lateral movement, multiple ramming wings (4) , including at least one connection lug (3) fixed to the eccentric crankshaft (2) on its inner surface, which is coordinated with the eccentric crankshaft (2) and moves horizontally with respect to the ground, applying lateral compression force to the soil, a fixed main frame (7) attached to the rotating motor or drilling machine, comprising the lower disc (5) and the upper disc (6) joined by rods positioned between the ramming wings (4) and having a space in the center of the lower disc (5) and the upper disc (6) through which the eccentric crankshaft (2) passes, at least one wing fasteners (8) positioned at one end to the protrusions on the eccentric crankshaft (2) and at the other end to the connection lug (3) on the ramming wings (4) , which provides a movable connection between the eccentric crankshaft (2) and the ramming wings (4) , at least one drilling bit (1) at the end of the eccentric tamping probe for drilling into the ground and conveying the loosened soil during drilling in front of the ramming wing ( 4 ) .

2. An eccentric tamping probe according to claim 1, wherein the eccentric crankshaft (2) , the connection lug (3)elements members, the ramming wings (4) , the lower disc (5) , the upper disc (6) , the main frame (7) and the wing fasteners (8) are made of steel.

3. An eccentric tamping probe according to claim 1, wherein the eccentric crankshaft (2) is positioned to be symmetrical and equiangular.

4. An eccentric tamping probe according to claim 3, wherein there are at least two ramming wings (4) .

5. An eccentric tamping probe according to claim 1, wherein the protrusion of the eccentric crankshaft (2) is equal to or twice the number of ramming wings (4) .

6. An eccentric tamping probe according to claim 1, wherein the eccentric crankshaft (2) can be mountable.

7. An eccentric tamping probe according to claim 1, wherein the outer surface is conical form.

8. An eccentric tamping probe according to claim 1, wherein the ramming wing (4) has the form of a quarter circle which, when in the closed position, forms a conical shape limits to the outer surface of the eccentric tamping probe .

9. An eccentric tamping probe according to claim 1, wherein there are four ramming wings (4) and the ramming wings (4) are positioned symmetrically in the lateral direction of 90° with respect to the ground and are at an angle of 10° with the horizontal.

10. An eccentric tamping probe according to claim 1, comprising at least one rail channel (12) on the surface of eachramming wing (4) in contact with the upper disc (6) and a rail (11) engaging with the said rail channel (12) to ensure stable forward-backward movement.

11. An eccentric tamping probe according to claim 1, wherein the lower disc (5) , the upper disc (6) and the main frame (7) rods are fixed with screws so that the eccentric crankshaft (2) can be removed.

12. An eccentric tamping probe according to claim 1, wherein, when the protrusion of the eccentric crankshaft (2) is singular, it comprises at least one central distributor (9) with a central hole through which the protrusion passes, multiple connection holes on the edges as the number of ramming wings (4) , which sequentially transmits the horizontal motion from the eccentric crankshaft (2) to the ramming wings (4) .

13. An eccentric tamping probe according to claim 12, wherein the central distributor (9) has copper washers on the upper and lower parts.

14. An eccentric tamping probe according to claim 1, comprising a protective fabric that surrounds the probe from the outside to prevent the ground from getting between the crankshaft (2) protrusions and connection details.

15. An eccentric tamping probe according to claim 14, wherein the protective fabric includes aramid fabric.

16. An eccentric tamping probe according to claims 14 and 15, wherein the fabric is passed through the lower disc (5) and fixed to the upper disc (6) with the help of a rope.

7. An eccentric tamping probe according to claim 1, wherein the outer surface of the drilling bit (1) has at least one angled plate (10) and / or a spiral.

Images