Powder chemical injection apparatus for liquefaction-induced ground improvement applications

Abstract

Disclosed herein is a multi-injection apparatus for simultaneous drilling and powder chemical injection for the improvement of partially or completely water-saturated fine sandy soils with liquefaction potential under dynamic effects.

Description

[0001] This application is a National Phase entry of International Application No. PCT / TR2023 / 051645 under § 371 and claims the benefit of Turkish Patent Application No. 2022 / 021512, filed Dec. 30, 2022, which is hereby incorporated by reference in its entirety.FIELD

[0002] The present disclosure relates to a multiple injection apparatus for powder chemical injection for the improvement of partially or completely water-saturated fine sandy soils with liquefaction potential under dynamic effects.BACKGROUND

[0003] As a result of ground improvement applications, it is aimed to provide stability and safety conditions of the structures on the ground by increasing the natural soil parameters. The aim of the existing methods used in the field of geotechnical engineering, including compaction, grouting, chemical improvement or soil reinforcement, is to increase the soil bearing capacity and to reduce the settlement levels. Another important problem encountered especially in fine sandy or silty soils exposed to dynamic effects is liquefaction. In the liquefaction process, serious settlement behaviors occur in soils with temporary loss of bearing capacity according to an excessive increase in pore water pressure. Due to the fact that methods such as jet grouting, which are frequently preferred against liquefaction, are expensive, labor intensive and require a long time, there is a need for effective methods to solve the liquefaction problem.

[0004] In the present state of the art, there are documents on the injection of solutions formed by water-chemical mixture with pressurized systems and in which different techniques for preventing liquefaction are presented in the field of soil improvement by chemical injection. In the documents available in the art, soil and injection material are mixed using cutting blades in soil improvement methods carried out with deep mixing. The mentioned documents generally focus on the drilling phase. Developments regarding the injection stage and the systems / equipment used in this stage to solve the liquefaction problem are very limited.

[0005] An example of the state of the art is the patent document no. US20060013658A1. The mentioned document describes the injection of resin with swelling capacity into vertical or angled boreholes with pressure effect in order to reduce the liquefaction potential of soils under building foundations. During the application, it is stated that depending on the chemical reaction of the resin, a swelling pressure of 40 / 50 tons / m2 is generated and cover pressure may be required to prevent the foundation effect.

[0006] Another example of the state of the art is the patent document no. U.S. Pat. No. 5,868,525A. In this document, a four-stage improvement and strengthening method is proposed for the seismic liquefaction problem seen in loose sandy or sandy soils. In the first stage, a specially formulated mortar-added chemical is impregnated into the soil with a special machine. In the second stage, an injection pipe with a penetration probe positioned far from the center is driven into the soil by creating a compression effect like in piles. In the third stage, cement-containing absorbent material is injected into the soil. In the final stage, the cement penetrates between the soil grains and solidifies.

[0007] Another technical problem with systems in the art is that the materials for oil adsorption are not suitable for reuse. This causes the filtering process to become ineffective after a certain period. Therefore, there is often a need to use new materials.

[0008] Another example of the state of the art is the patent document no. JP5092103B1. In this document, it is stated that liquefaction is prevented by reducing saturation and solidification as a result of injecting silica solution mixed with fine air bubbles into the soil. The equipment details describe the production of air bubbles and the transmission of the liquid mixture obtained by mixing it with the silica solution through pressurized injection pipes to the ground. Another document that can be given as an example of the state of the art is the patent document no. JP2010236181A. In the aforementioned document, a system designed for chemical solution injection is proposed to increase the bearing capacity of weak soils with settlement potential under solid ground by providing consolidation. Following the application, a fast-setting chemical fluid is injected from the surface into the volume remaining in hemispherical form after the application, consolidation is achieved and improvement is realized.

[0009] The systems or methods subject to the documents mentioned above are insufficient to provide a direct solution to the liquefaction problem. Therefore, there is still a need for an apparatus that enables easy, fast and effective powder chemical injection into soils to eliminate the liquefaction problem.SUMMARY

[0010] The present disclosure relates to multiple injection apparatus developed within the scope of Tübitak 1001 project no. 219M397 for powder chemical injection for the improvement of partially or completely water-saturated fine sandy soils with liquefaction potential under dynamic effects.

[0011] An object of the disclosure is the development of alternative apparatuses that provide a direct solution to the problem of liquefaction in soil improvement applications.

[0012] An object of the disclosure is to increase the resistance of the soil against liquefaction especially before earthquakes and to reduce the settlement levels.

[0013] An object of the disclosure is the development of an apparatus that enables multiple drilling at the same time. This provides time, cost and labor advantages.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG. 1 shows an external view of the dual injection apparatus, according to at least one embodiment of the invention.

[0015] FIG. 2 shows an interior view of the dual injection apparatus, according to at least one embodiment of the invention.

[0016] FIG. 3 shows an external view of the triple injection apparatus, according to at least one embodiment of the invention.

[0017] FIG. 4 shows an interior view of the triple injection apparatus, according to at least one embodiment of the invention.

[0018] FIG. 5 shows a view of the chain gear mechanism in the dual injection apparatus, according to at least one embodiment of the invention.

[0019] FIG. 6 shows a view of the gear mechanism in the triple injection apparatus, according to at least one embodiment of the invention.

[0020] FIG. 7 shows a view of the discharge pipes in the multiple injection apparatus, according to at least one embodiment of the invention.

[0021] FIG. 8 shows another view of the discharge pipes in the multiple injection apparatus of at least one embodiment of the invention.

[0022] FIG. 9 shows a top view of the chain system in the dual injection apparatus, according to at least one embodiment of the invention.

[0023] FIG. 10 shows sectional views of the chain system in the dual injection apparatus, according to at least one embodiment of the invention.

[0024] FIG. 11 shows a top view of the gear system in the triple injection apparatus, according to at least one embodiment of the invention.

[0025] FIG. 12 shows sectional views of the gear system in the triple injection apparatus, according to at least one embodiment of the invention.DETAILED DESCRIPTION

[0026] In more detail, the present disclosure relates to multiple injection / placement apparatus for placing sodium polyacrylate or similar chemicals in dry form into the soil in order to prevent liquefaction potential in partially or completely water-saturated sandy soils, to reduce soil bearing capacity losses and settlement levels during and after liquefaction and includes chain and gear configurations.

[0027] The disclosure relates to a multi-injection apparatus for the injection of powdered chemicals for the improvement of partially or completely water-saturated fine sandy soils with liquefaction potential under dynamic effects, in the most general terms it comprises:

[0028] at least one auger injection pipe (2) in the form of a hollow pipe and outer auger, comprising at least two threads (2.1) at the bottom for drilling without the need for a conventional auger,

[0029] at least one main shaft (3.1), the top of which is connected to the rotating equipment or drilling rig,

[0030] at least one central inner pipe (3.2) connected to each auger injection pipe (2) for transmitting the rotary motion from the rotating equipment or drilling rig to the auger injection pipes (2) via the main shaft (3.1),

[0031] a gear mechanism (3) comprising multiple double sprockets (3.5) or gears (3.8) mounted on the main shaft (3.1) and central inner pipes (3.2), which, in contact with each other, transmit rotary motion to the auger injection pipes (2),

[0032] a shaft box (1) with multiple openings for the main shaft (3.1) and the central inner pipes (3.2) to pass through and enclosing the gear mechanism (3), ensuring the distance between the auger injection pipes (2) and the operation of the system by holding all parts together,

[0033] multiple cone bearings (3.4) mounted in bearing shells (3.3) that restrict the movement of the main shaft (3.1) and central inner pipes (3.2) in the vertical axis by fixing them in the shaft box (1), prevent deflection of the auger injection pipes (2) and provide rotational movement only, and

[0034] a powder chemical discharge unit comprising at least one discharge rod (4.3) or discharge pipe (5.4) for discharging the dry powder chemical to be injected into the well, which is inserted into the auger injection pipes (2) through the central inner pipes (3.2).

[0035] In one embodiment of the invention, the main shaft (3.1) is located in the center of the shaft box (1). In this embodiment of the invention, the central inner pipes (3.2) are mounted in the shaft box (1) such that they are arranged around the circumference of the main shaft (3.1). Thus, the rotational motion from the rotating equipment or drilling rig is transmitted through the main shaft (3.1) to the other gears (3.5, 3.8) and finally to the auger injection pipes (2).

[0036] In one embodiment of the invention, there are two auger injection pipes (2) for simultaneous dual drilling and injection. In this embodiment of the invention, the gear mechanism (3) comprises multiple double sprockets (3.5) mounted on the main shaft (3.1) and the central inner pipes (3.2) and at least one pair of solid chains (3.7) which are tensioned to surround the double sprockets (3.5) from the outside. In the embodiment of the invention, a tensioning sprocket (3.6) is provided for adjusting the chain (3.7) to a sufficient tension. The shaft box (1) is preferably provided with two tensioning sprockets (3.6), which are fixed inside the shaft box (1) by means of gear pins (3.10). Thanks to this configuration of the invention, a chain system capable of simultaneous double drilling and injection has been developed. In one embodiment of the invention, in the case of two auger injection pipes (2), in other words, in the case of double drilling with the help of chain (3.7), the shaft box (1) is rectangular shape. Views of the embodiment of the invention enabling simultaneous double drilling are shown in FIG. 1, FIG. 2, FIG. 5, FIG. 9, and FIG. 10.

[0037] In one embodiment of the invention, there are three auger injection pipes (2) for simultaneous triple drilling and injection. In this embodiment of the invention, there are specially manufactured gears (3.8) surrounding the main shaft (3.1) and the central inner pipes (3.2). Thanks to this configuration of the at least one embodiment of the invention, a system with a reduced number of drill and injection gears has been developed by simultaneously removing the triple or auger injection pipes (2). By increasing the number of gears (3.8) in the system, more auger injection pipes (2) can be adapted to the system.

[0038] The apparatus according to one embodiment of the invention comprises three auger injection pipes (2), which are modular auger injection pipes (2), allowing single, double or triple drilling at the same time. In other words, the auger injection pipes (2) are mountable, enabling simultaneous single, double or triple drilling and injection.

[0039] In one embodiment of the invention, in the case of three auger injection pipes (2), in other words, in the case of triple drilling with the help of gears (3.8), the shaft box (1) has the shape of an equilateral triangle.

[0040] Views of the configuration of the at least one embodiment of the invention enabling simultaneous triple drilling are shown in FIG. 3, FIG. 4, FIG. 6, FIG. 11, and FIG. 12.

[0041] In one embodiment of the invention, the shaft box (1) comprises two parts, which comprise two identical parts, a lower part and an upper part.

[0042] In one embodiment of the invention, the shaft box (1) is provided with a mounting cover (1.1) on the side parts of the shaft box (1), which is removable and attachable with bolts for assembly, maintenance and repair operations. In one embodiment of the invention, the mounting cover (1.1) is rectangular shape.

[0043] In one embodiment of the invention, the shaft box (1) comprises a plug hole (1.2) for filling and draining the transmission oil and at least two fixing plates (1.3) for fixing to the rack and pinion gear on the rig tower.

[0044] In one embodiment of the invention, each central inner pipe (3.2) comprises cone bearings (3.4) mounted in a bearing shell (3.3) fixed to the upper and lower parts thereof.

[0045] In one embodiment of the invention, the central inner pipes (3.2) are provided with a wedge (3.9) for fixing the central inner pipes (3.2) to the main shaft (3.1), to the double sprockets (3.5) or to the gears (3.8) and for rotating them together.

[0046] In one embodiment of the invention, there is provided a guide plate (6) comprising a plurality of apertures according to the center position and number of auger injection pipes (2), a guide plate (6) fixed to a sufficient number of guide rod (6.1) passing through the shaft box (1) to minimize deviations in the vertical axis by placing it on the liquefiable soil surface.

[0047] In one embodiment of the invention, the auger injection pipe (2) comprises at its lower end a plastic stopper or adhesive tape for preventing contact with water to eliminate swelling during the transfer of the powdered chemical to the water-saturated soil, and for discharging the powder by opening after reaching the desired depth.

[0048] In one embodiment of the invention, the discharge unit comprises, for use in partially water-saturated soils, cutting blades (4.5) fixed in a staggered manner on a thin rod (4.4) at the bottom and a solid discharge rod (4.3) of a diameter to pass into the auger injection pipe (2) at the top and a rod shell (4.2) holding the discharge rods (4.3) in the prescribed positions. In one embodiment of the invention, the apparatus comprises a mounting frame (4.1) for fixing to the rig tower of the drilling rig.

[0049] In one embodiment of the invention, the discharge unit comprises at least one hollow discharge pipe (5.4) of a diameter that can pass into the auger injection pipe (2) for use in partially or completely water-saturated soil, a pipe shell (5.2) and pin (5.3) for holding the discharge pipes (5.4) in the prescribed positions, and a connector (5.5) made of steel rope or chain for holding the discharge pipes (5.4) together and pulling them up. In one embodiment of the invention, the apparatus comprises a mounting frame (5.1) for fixing to the rig tower of the drilling rig.

[0050] In one embodiment of the invention, the chemical powder comprises sodium polyacrylate, which converts to a gel form when it absorbs water. In one embodiment, the chemical comprises sodium polyacrylate and cement. In one embodiment, the sodium polyacrylate and cement can also be mixed into sand.

[0051] In more detail, one embodiment of the invention relates to dual and triple injection apparatus for the injection of powdered chemicals for the improvement of partially or completely water-saturated fine sandy soils with liquefaction potential under dynamic effects.

[0052] In more detail, the double and triple injection apparatus subject to one embodiment of the invention comprises one or more auger injection pipes (2) in the form of a hollow pipe and outer auger, one or more auger injection pipes (2) with at least two mutually arranged threads (2.1) at the bottom for drilling without the need for an external auger, a main shaft (3.1) that the top of which is connected to the rotating equipment or drilling rig, at least one central inner pipe (3.2) connected to each auger injection pipe (2) by cone bearings (3.4) for transmitting rotary motion from the rotating equipment or drilling rig to the auger injection pipes (2) via the main shaft (3.1), a gear mechanism (3) that comprises multiple gears, mounted on the central inner pipe (3.2) and the main shaft (3.1), which, in contact with each other to transmit rotary motion to the auger injection pipes (2), having a number of openings for the main shaft (3.1) and the central inner pipes (3.2) to pass through, a shaft box (1), which ensures the distance between the auger injection pipes (2) surrounding the gear mechanism (3) and the operation of the system by holding all the parts together, comprises multiple cone bearings (3.4) mounted in bearing shell (3.3) that restrict the movement of the main shaft (3.1) and the central inner pipes (3.2) in the vertical axis by fixing them to the shaft box (1), providing rotational movement and preventing the axis deviation of the auger injection pipes (2) which are mounted in multiple cone bearing shells (3.3).

[0053] The inventive apparatus is not limited to single, double or triple injection, but also includes configurations for more than three simultaneous injections.

[0054] The multi-injection apparatus subject to one embodiment of the invention provides two alternative discharges.

[0055] The powder chemical discharge unit-1 (4) of the apparatus according to one embodiment of the invention comprises cutting blades (4.5) fixed in a staggered manner on a thin rod (4.4) at its lower part, for use in partially water-saturated soils. In the embodiment of the invention, the solid discharge rod (4.3) has a diameter suitable for the upper part of the auger injection pipe (2) to pass into it. A mounting frame (4.1) for fixing to the rig tower of the drilling rig and rod shell (4.2) for holding the rods are present. When the drilling reaches the depth foreseen for ground improvement, the auger injection pipes (2) are filled with powder chemical and the shaft box (1) is completely pulled up after the powder chemical discharge unit-1 (4) is fixed to the rig tower. In this way, the chemical is injected into the soil with the help of the cutting blades (4.5) and then the discharge rod (4.3), even if there is partial swelling after the chemical comes into contact with water after the plastic stopper at the end is removed.

[0056] The powder chemical discharge unit-2 (5) in the apparatus of one embodiment of the invention comprises a hollow discharge pipe (5.4) of a diameter which can pass into the auger injection pipe (2) for use in partially or completely water-saturated soil. There is a mounting frame (5.1) and pipe shell (5.2) to hold the pipes for fixing to the rig tower. When the depth for ground improvement is reached by drilling, the discharge pipes (5.4) are inserted into the auger injection pipes (2) and the powder chemical discharge unit-2 (5) is fixed to the rig tower. After the discharge pipes (5.4) are filled with the powder chemical, the pins (5.3) are pulled and as a result of the free fall, the discharge pipes (5.4) remove the plastic plug and come out of the auger injection pipes (2). Immediately thereafter, the connector (5.5) made of a steel rope or chain holding the discharge pipes (5.4) together is quickly pulled and the chemical is injected into the soil.

[0057] The various portions and functions of the multiple injection apparatus subject to one embodiment of the invention are described in detail below.

[0058] Shaft box: the shaft box (1) enables the system to operate by holding all parts together. In one embodiment of the invention, the shaft box (1) has been developed according to an optimum range of 4 times the diameter of the borehole from center to center as a result of experimental studies. The shaft box (1) is in the form of a rectangle with dimensions of 650 mm×300 mm×100 mm in the double system as shown in FIG. 1, and in the form of an equilateral triangle with an exact side length of 600 mm in the triple system as shown in FIG. 3, in order to ensure the distance between the auger injection pipes (2) and to provide the disassembly and assembly of the parts. In both configurations of the shaft box (1), a removable rectangular mounting cover (1.1) with dimensions of 400 mm×140 mm is fixed to the side parts of the shaft box (1) with bolts for assembly, maintenance and repair operations. On the shaft covers comprising upper and lower two equal parts, there are bearing shells (3.3) with an outer diameter of 170 mm and an exact inner diameter of 100 mm at the center and at the positions where the auger injection pipes (2) are located. Each bearing shell (3.3), which is fitted into the holes drilled on the shaft box (1) containing the upper and lower parts by leaving a 19 mm rabbet, is fixed with 6 pieces of M12 bolts from the points where the corresponding thread is drilled. As can be seen from FIG. 5 and FIG. 6, from top to bottom, there are bearing shell (3.3), cone bearing (3.4), double sprocket (3.5) or special made gear (3.8) and again cone bearing (3.4) and bearing shell (3.3. The central inner pipe (3.2) is fixed to the sprocket by means of a wedge (3.9) so that they rotate together. Cone bearings (3.4) prevent axial movement and provide only rotational movement. The main shaft (3.1) is fixed instead of the central inner pipe (3.2) to the gears in the middle, which transfer the rotational motion coming from the drilling rig to the gear mechanism (3), and the bearing shell (3.3) at the bottom is blind (FIG. 9, FIG. 10, FIG. 11, and FIG. 12). In case of maintenance and repair, the connection is made using M10 bolts to ensure easy removal and installation of the equal shaft covers. Liquid gasket is applied between the shaft covers, bearing shells (3.3) and mounting covers (1.1) to ensure sealing. There are holes of suitable diameters at the points where the guide rods (6.1) will engage. There is a plug hole (1.2) and indicator on the shaft box (1) for filling and draining the transmission oil. On the back side of the shaft box (1), there are fixing plates (1.3) for fixing to the rack and pinion gear on the rig tower.

[0059] Main shaft: The main shaft (3.1) is a rigid steel cylinder with a hexagonal head in the center of the apparatus. As the upper part of the main shaft (3.1) has a diameter suitable for the rotating equipment or drilling rig, a double sprocket (3.5) (FIG. 1 and FIG. 2) in double design suitable for chain gaps (FIG. 1 and FIG. 2) or a special production gear (3.8) in triple design (FIG. 3 and FIG. 4) is mounted on the lower part. In this way, direct connection with other gears is provided. The rotation speed of the main shaft (3.1) determines the operating speed of the system. The main shaft (3.1) is passed through the center hole in the upper part of the shaft box (1) and fixed to the gears (3.5, 3.8) with wedges (3.9) and driven into the inner rings of the cone bearings (3.4). The center bottom cover of the shaft box (1) has a blind bearing shell (3.3).

[0060] Injection pipes: Auger injection pipes (2) are manufactured from hollow pipe profiles with sufficient wall thickness. The outer part of the auger injection pipes (2) is in the form of an auger and thanks to the threads (2.1) at the bottom, it provides drilling without the need for an external auger in the ground improvement process, while at the same time it transfers powdered sodium polyacrylate to the desired depth in the borehole due to its hollow inner part. At the lower end of the auger injection pipes (2), there is a plastic stopper or adhesive tape to prevent contact with water in order to eliminate the swelling during the transfer of the powder chemical to the water-saturated soil and to ensure that the powder is discharged by opening after reaching the desired depth.

[0061] Bearings: The bearings are manufactured by filling metal balls between the inner and outer steel rings. As it is known in the technique, the bearings are frequently preferred in machinery and equipment that contain moving details. In the injection apparatus developed by at least one embodiment of the invention, cone bearings (3.4) are used to fix the main shaft (3.1) and auger injection pipes (2) to the shaft box (1), restricting their movement in the vertical axis, but allowing them to rotate. The cone bearings (3.4), which are placed in the slots in the upper and lower covers of the shaft box (1), are used two for each component, one at the top and bottom of the double sprocket (3.5) and the specially manufactured gears (3.8). The main shaft (3.1) and its center are driven directly into the inner pipes (3.2). The use of double cone bearings (3.4) prevents deflection of the auger injection pipes (2).

[0062] Discharge units: the discharge units (4, 5) are of 2 different types for use in partially saturated or fully submerged sandy soils. In the first alternative powder chemical discharge unit-1 (4), the discharge pipes are composed of a rigid steel discharge rod (4.3) with a closed end, the upper part of which can pass into the auger injection pipes (2), and a thin rod (4.4) with cutting blades (4.5) at the bottom. In FIG. 7, the discharge rods (4.3) are fixed to the rod shell (4.2) on the steel mounting frame (4.1), which is connected to the rig tower with bolts, with pins through the holes in the upper head, to allow the powder chemical to be pushed through the auger injection pipe (2) and removed from the lower end. In the second alternative powder chemical discharge unit-2 (5), the use of a hollow discharge pipe (5.4) is preferred if the ground is submerged in water. in FIG. 8, a pipe with a diameter smaller than the inner diameter of the auger injection pipe (2) is filled with a powder chemical and when the desired depth is reached, the pin (5.3) under the pipe shell (5.2) in the mounting frame (5.1) is removed, the plastic plug pushing allowance is reduced to empty and the impermeable plugs at the end of the auger injection pipe (2) are removed. The top row of pins (5.3) prevents the pipes from falling into the ground. The connector (5.5) made of steel rope or chain, which allows the pipes to move together, is attached to the drilling rig winch and pulled up quickly. In this way, even if there is a partial increase in the volume of the powder chemical poured from the narrow pipe to the wide pipe after contact with water, the chemical discharges quickly into the borehole thanks to the expanding pipe area. If the pipe shells (5.2) are positioned on the mounting frame (5.1) to coincide with the drill points, the same system can be used for any number of injections.

[0063] Guide plate: Guide plates (6) are made of sheet steel with a sufficient number of holes of larger diameter according to the center positions of the auger injection pipes (2). They are placed on the liquefiable soil surface to minimize the out of plane problems in the vertical axis. It is not required in loose soils where auger injection pipes (2) can move easily. However, it is necessary in dense soils that require high torque and rotation. Worm bolts or shafts at appropriate positions are passed through the holes on the shaft box (1) to ensure a stable movement.

[0064] The powder sodium polyacrylate recommended for soil improvement against liquefaction during the use of the multiple injection apparatus subject to at least one embodiment of the invention contains at least 25.00% by weight of pozzolanic cement. The powder mixture can also be used by adding into the sand.

[0065] During the production of the multiple injection apparatus subject to at least one embodiment of the invention, firstly, the parts that require special production in accordance with the technical details were supplied. Although a 3:1 ratio between the size of the main shaft (3.1) gear and the auger injection pipe (2) gears (3.8) was foreseen at the first stage in the triple system, it was decided to use four gears (3.8) of equal size considering the rotation speed of the drilling machine (28-30 rpm). In the triple system, 4 specially manufactured helical gears (3.8) with an outer diameter of 240 mm, an inner diameter of 75 mm and a thickness of 50 mm with a gear angle of 15 degrees and a pitch of 15.70 by module 5 were used. In the gears, which are machined using CK 45 manufacturing steel and induction strengthened, a keyway was drilled in the inner diameter. The unloaded section between 50 mm and 95 mm from the center axis was emptied by 15 mm to save weight. In the dual system, 3 double sprockets (3.5) with outer diameter, neck diameter and inner diameter of 117 mm, 90.5 mm and 65 mm respectively, and 1.50 m double row chain (3.7) with a link detail suitable for the sprockets were provided to perform the rotational movement. In order to adjust the chain (3.7) with sufficient tension in the dual system, 2 tensioning sprockets (3.6) with ball bearings of suitable diameter were used. In the upper and lower parts of each sprocket (3.5 or 3.8), 14 cone bearings (3.4) with a capacity of 100 kN, resistant to axial stresses, were fixed to the bearing shells (3.3) fixed to the shaft box (1).

[0066] Two different shaft boxes (1) were manufactured in the form of a rectangular box with dimensions of 650 mm×300 mm×100 mm and an equilateral triangle with an exact side length of 600 mm for use in double and triple systems, respectively. On the sides of both shaft boxes (1), a removable rectangular mounting cover (1.1) with dimensions of 400 mm×140 mm was fixed with bolts for installation, maintenance and repair operations. For the auger injection pipes (2), hollow pipes with an inner diameter of 50.00 mm and an outer diameter of 60.00 mm with an exact auger length of 120.00 cm were used. A 52.00 mm long pipe with a threaded inner surface was welded at the upper end and 45° angled and bi-directional threads (2.1) were welded at the lower end. The central inner pipes (3.2) with an outer diameter of 65.00 mm, an inner diameter of 50.00 mm and a length of 275.00 mm, which transmit the rotational motion to the auger injection pipes (2), have a male thread at the bottom to be fixed to the female part in the upper part of the auger injection pipe (2). In this way, the auger injection pipes (2) can be easily disassembled and assembled to the shaft box (1). In both systems, the main shafts (3.1), which transmit the rotational motion coming from the drilling rig to the gears (3.5 or 3.8), are 165.00 mm in length and 65.00 mm in diameter. The upper end of the main shafts (3.1) is manufactured in hexagonal form in accordance with the standard drill rig rod. Both the central inner pipes (3.2) and the main shafts (3.1) are fixed to the gears (3.5 or 3.8) by means of wedges (3.9) so that only rotational motion is transmitted. Bearing rings were pressed into the bearing shells (3.3) with a piston in standard form. In order to prevent water ingress during drilling, conical plugs suitable for the lower end of the auger injection pipes (2) were produced with a 3D printer. In order to ensure complete sealing, the plugs were coated with paraffin and a liquid gasket was also used in case of excessive water in the soil.

[0067] The given steps should be followed to assemble the injection apparatus and make it ready for application:

[0068] Positioning the special helical gears (3.8) or double sprockets (3.5) in the shaft box (1),

[0069] Passing the central internal pipes (3.2),

[0070] Inserting the cone bearings (3.4) through the gaps in the top and bottom plates,

[0071] Fixing the bearing shells (3.3) with bolts,

[0072] In dual use, a chain (3.7) is wrapped around the sprockets to make a monolithic connection,

[0073] Applying grease between the chain (3.7) and double sprockets (3.5) in dual use,

[0074] Applying liquid gasket for sealing and fixing the shaft box (1) covers with bolts, Adding transmission fluid up to the indicator level in triple use,

[0075] The shaft box (1) is fixed to the rig tower by means of fixing plates (1.3) and the connection between the main shaft (3.1) and the rotary head of the rig is established with the help of a fitting rod,

[0076] Tightening the auger injection pipes (2) with sealing plugs at the ends to their counterparts in the central inner pipes (3.2) and

[0077] Selecting the powder chemical discharge system (4,5) suitable for the water content in the soil and fixing it to the mounting frame (4.1, 5.1).

[0078] In the application process, the shaft box (1) is fixed to a standard drilling rig or external rotator equipment, and the up-down movement is provided directly by these machines. By means of the main shaft (3.1), rotary motion is given to the gear (3.8) and chain (3.7) gear pins (3.10) at the appropriate speed and drilling is provided with auger injection pipes (2). Upon reaching the planned depth, the plastic plug at the end of the auger injection pipes (2) is removed by the powder chemical discharge unit and the powder chemical is discharged into the borehole. Guide plates (6) can be used to prevent the out of plane problems from the axis in dense soil.

[0079] In scaled laboratory studies of at least one embodiment of the invention, the optimum distance between the powder chemical columns is determined as 5 times the column diameter, while liquefaction is prevented with an excessive pore water pressure reduction of approximately 40%. In the real-scale field application of at least one embodiment of the invention, liquefaction is prevented as a result of damping in pore water pressure values reaching 150%.

[0080] The columns produced by the mixture of sodium polyacrylate, sand and trace amounts of cement injected into the ground in powder form with the multiple injection apparatus subject to at least one embodiment of the invention absorb water and show a significant volume increase and form a gel by changing the structure of the water phase in the soil. The powdered chemical mixture can absorb water up to 125 times its volume and reach a viscosity of 10 Pa. s and a swelling pressure of 6.30 kg / cm2 in gel form. In this way, the excessive increase in pore water pressure that causes liquefaction is balanced and the settlement levels that occur after liquefaction are reduced. The injection apparatus, which has been completed and proven to be applicable in laboratory and large-scale field experiments, also provides time, labor and cost advantages in terms of multiple drilling possibilities at the same time.REFERENCE NUMBERS IN FIGURES1. Shaft box

[0082] 1.1. Mounting cover

[0083] 1.2. Plug hole

[0084] 1.3. Fixing plates

[0085] 2. Auger injection pipe

[0086] 2.1. Thread

[0087] 2.2. Grooved connection pipe

[0088] 3. Gear mechanism

[0089] 3.1. Main shaft

[0090] 3.2. Central inner pipe

[0091] 3.3. Bearing shell

[0092] 3.4. Cone bearing

[0093] 3.5. Double sprocket

[0094] 3.6. Tensioning sprocket

[0095] 3.7. Chain

[0096] 3.8. Gear

[0097] 3.9. Wedge

[0098] 3.10. Gear pin

[0099] 4. Powder chemical discharge unit-1

[0100] 4.1. Mounting frame

[0101] 4.2. Rod shell

[0102] 4.3. Discharge rod

[0103] 4.4. Thin rod

[0104] 4.5. Cutting blades

[0105] 5. Powder chemical discharge unit-2

[0106] 5.1. Mounting frame

[0107] 5.2. Pipe shell

[0108] 5.3. Pin

[0109] 5.4. Discharge pipe

[0110] 5.5. Connector

[0111] 6. Guide plate

[0112] 6.1. Guide rods

Claims

1. A multiple placement apparatus developed for powder chemical injection to improve partially or completely water-saturated soils with liquefaction potential under dynamic effects, the apparatus comprising:at least one auger injection pipe in the form of a hollow pipe and outer auger, comprising at least two threads at the bottom for drilling without the need for a conventional auger,at least one main shaft, the top of which is connected to a rotating equipment or drilling rig,at least one central inner pipe connected to the at least one auger injection pipe for transmitting a rotary motion from the rotating equipment or drilling rig to the at least one auger injection pipe via the at least one main shaft,a gear mechanism comprising multiple double sprockets or gears mounted on the at least one main shaft and the at least one central inner pipe, in contact with each other for transmitting the rotary motion to the at least one auger injection pipe,a shaft box with multiple openings for the at least one main shaft and the at least one central inner pipe to pass through and configured for enclosing the gear mechanism, ensuring a distance between the at least one auger injection pipe and for holding all parts together for the operation of the system,multiple cone bearings mounted in bearing shells, configured for fixing the at least one main shaft and the at least one central inner pipe to the shaft box for restricting movement in a vertical axis, preventing deflection of the at least one auger injection pipe and providing rotational movement only, anda powder chemical discharge unit comprising at least one discharge rod or discharge pipe configured to be inserted into the at least one auger injection pipe through the at least one central inner pipe, for allowing dry powder chemical to be injected to be discharged into a borehole.

2. The apparatus according to claim 1, wherein the at least one auger injection pipe comprises two auger injection pipes for simultaneous dual drilling and injection.

3. The apparatus according to claim 1, wherein the multiple double sprockets are mounted on the at least one main shaft and the at least one central inner pipe, which are in contact with each other for transmitting rotational movement to the at least one auger injection pipe, and at least one solid chain tensioned by at least two tensioning sprockets so as to surround the multiple double sprockets externally.

4. The apparatus according to claim 1, wherein the shaft box is rectangular.

5. The apparatus according to claim 1, wherein the at least one auger injection pipe comprises three auger injection pipes for simultaneous triple drilling and injection.

6. The apparatus according to claim 1, wherein the shaft box has an equilateral triangular shape.

7. The apparatus according to claim 1, wherein the at least one auger injection pipe is mounted for simultaneous single, double or triple drilling and injection.

8. The apparatus according to claim 1, wherein the at least one central inner pipe comprises at least one wedge configured for fixing the at least one central inner pipe to the multiple double sprockets or gears and allowing them to rotate together.

9. The apparatus according to claim 1, further comprising at least one guide plate that comprises multiple openings according to center positions and numbers of the at least one auger injection pipe, and is placed on the liquefiable soil surface to minimize out of plane problems in the vertical axis.

10. The apparatus according to claim 1, further comprising at least one removable mounting cover for mounting, maintenance, and repair operations on side parts of the shaft box, and at least one plug hole for adding transmission oil.

11. The apparatus according to claim 1, further comprising at least two fixing plates for fixing the shaft box to a rack and pinion gear on a rig tower of the drilling rig.

12. The apparatus according to claim 1, wherein the at least one auger injection pipe comprises at least one stopper or adhesive tape at the lower end thereof, configured to prevent contact with water in order to eliminate the swelling during transfer of the dry powder chemical to a water-saturated soil and to enable the dry powder chemical to be discharged by opening after reaching the desired depth.

13. The apparatus according to claim 1, wherein the discharge unit comprises a solid discharge rod having an upper diameter configured to pass into the at least one auger injection pipe and comprising cutting blades fixed in a staggered manner on a thin rod at bottom, and a rod shell configured for holding the discharge rod in the prescribed position.

14. The apparatus according to claim 1, wherein the discharge unit comprises at least one hollow discharge pipe having a diameter configured to pass into the at least one auger injection pipe, a pipe shell and pin configured for holding the at least one discharge pipe in the prescribed positions, and a connector made of steel rope or chain configured for holding the at least one discharge pipe together and allowing them to be pulled up.

15. The apparatus according to claim 13, further comprising a mounting frame configured for fixing to a rig tower of the drilling rig.

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