Loess compaction pile construction device and method

Abstract

The invention discloses a loess compaction pile construction device and method, and relates to the technical field of foundation treatment.The loess compaction pile construction device comprises a stirring bin arranged on a vehicle cabin, a filler conveying device arranged in the vehicle cabin and communicated with the stirring bin so as to convey filler into a compaction pile hole, and a water tank arranged on one side of the stirring bin and communicated with the stirring bin; the lifting device is arranged at the end, far away from the stirring bin, of the vehicle cabin, the lifting device is detachably connected with a pipe sinking device used for reaming and compaction or a tamping device used for tamping filler, and the foundation humidifying device is arranged on the side, close to the lifting device, of the vehicle cabin. The humidifying device, the pipe sinking device used for reaming and compaction, the tamping device used for tamping filler and the stirring bin are integrated, so that the problems that multiple machines are needed to be matched for operation in the prior art, construction is tedious, machine team cost is high, humidifying time is long, and moisture diffusion is uneven are solved, and application and development of a humidifying foundation treatment technology are promoted.

Description

Technical Field

[0001] The present invention relates to the technical field of foundation treatment, and particularly relates to a construction device and method for rammed lime-soil piles in loess. Background Art

[0002] Highway engineering construction is gradually advancing towards the arid and semi-arid regions in the west. Due to the law that the distribution of collapsible loess in China gradually weakens from west to east and from north to south, the collapsible loess with strong collapsibility is mainly distributed in the northwest region of China. The thickness of its collapsible loess layer is mostly greater than 10 meters, and its collapsibility develops extremely rapidly after soaking and has strong self-weight collapsibility. How to eliminate the collapsibility of the soil layer and improve the bearing capacity of the foundation has always been the core issue in the engineering construction of this region. Traditional foundation treatment methods include: dynamic compaction method, impact rolling method, lime-soil compaction pile method, etc. According to relevant domestic and foreign research, the above traditional methods often have poor treatment effects on the loess in the arid regions of the northwest, the reinforcement influence depth is limited, and the collapsibility is difficult to completely eliminate. Subsequently, many foundation treatment methods combined with humidification emerged in the northwest region, such as: humidified lime-soil compaction pile, humidified dynamic compaction method, pre-soaking method by drilling, etc. However, the current research on the supporting construction machinery devices for humidification and foundation treatment technology is very limited. Usually, multiple machines such as drill rigs, vibro-drilled pipe pile hammers, dynamic compactors, and filler rammers need to cooperate for construction. Many problems such as cumbersome construction, high hourly rate, long humidification time, and uneven water diffusion seriously restrict the application and development of the humidified foundation treatment technology.

[0003] In addition, due to the poor physical and mechanical properties of loess, it is easy to crack and settle. Therefore, it is often necessary to improve and solidify it during the foundation treatment process. Traditional soil improvement methods include: cement-solidified loess, lime-solidified loess, etc. However, the widespread application of cement and lime is also accompanied by limitations in terms of high energy consumption and high carbon emissions, which pose challenges to the current advocated concept of green and sustainable development.

[0004] Therefore, it is necessary to develop and design a construction device and method for rammed lime-soil piles in loess, integrate a humidification device, a vibro-drilled pipe device for reaming and compaction, a ramming device for ramming fillers, and a mixing bin into one, solve many problems such as the need for multiple machines to cooperate for construction in the past, cumbersome construction, high hourly rate, long humidification time, and uneven water diffusion, and promote the application and development of the humidified foundation treatment technology, which is an urgent technical problem to be solved by those skilled in the art at present. Summary of the Invention

[0005] To solve the above problems, the present invention provides a construction device and method for loess compaction piles, integrating a humidification device, a pipe sinking device for hole expansion and compaction, a ramming device for ramming fillers, and a mixing bin, solving many problems such as the need for cooperation of multiple machines in the past, cumbersome construction, high hourly rate, long humidification time, and uneven moisture diffusion, and promoting the application and development of the humidified foundation treatment technology.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A construction device for loess compaction piles includes a mixing bin arranged on a vehicle cabin, a filler conveying device arranged inside the vehicle cabin and communicated with the mixing bin to convey fillers into the compaction pile holes, a water tank arranged on one side of the mixing bin and communicated with the mixing bin, and a lifting device arranged at one end far from the mixing bin. The lifting device is detachably connected with a pipe sinking device for hole expansion and compaction or a ramming device for ramming fillers, and also includes a foundation humidification device arranged on the vehicle cabin near one side of the lifting device.

[0008] Preferably, the foundation humidification device includes an air compressor arranged on the vehicle cabin, a high-pressure drilling steam humidification device communicated with the air compressor, and a steam generator and an air compressor arranged on the vehicle cabin. The water tank is communicated with the air compressor through the steam generator.

[0009] Preferably, the high-pressure drilling steam humidification device includes a large slide rail arranged on the vehicle cabin, a vertical frame slidably connected with the large slide rail, a small slide rail arranged on the vertical frame, a directional hoop slidably connected with the small slide rail, a drill pipe surrounded by the directional hoop to keep vertical through the directional hoop, and a steam transmission pipe with one end communicated with the end of the drill pipe and the other end communicated with the air compressor.

[0010] Preferably, two or more through holes are evenly distributed in the circumferential direction of the drill pipe.

[0011] Preferably, the lifting device includes hydraulic lifting devices arranged on both sides of the end of the vehicle cabin, a cross beam arranged on the top of the hydraulic lifting devices for connecting the hydraulic lifting devices, a support frame fixedly arranged on the cross beam, and a motor arranged above the support frame. A transfer interface for detachably connecting the pipe sinking device or the ramming device is arranged below the support frame.

[0012] Preferably, the pipe sinking device includes a hollow cylinder, a conical structure arranged at the end of the hollow cylinder, and a lock arranged at one end of the hollow cylinder far from the conical structure and connected with the transfer interface. The transfer interface is rotatably connected with the motor.

[0013] Preferably, the tamping device includes an adapter connected to the adapter interface, a hoist lifting frame disposed below the adapter, and a rammer connected to the hoist lifting frame by a cable. The hoist lifting frame raises and lowers the rammer through the motor.

[0014] Preferably, the mixing bin includes a polymer mixing bin disposed on one side of the top of the mixing bin, a first filler mixing bin disposed below the polymer mixing bin, and a second filler mixing bin disposed on one side of the polymer mixing bin and the first filler mixing bin. A polymer discharge port is provided at the bottom of the polymer mixing bin, and a filler discharge port is provided at the bottom of the mixing bin.

[0015] Preferably, the filler conveying device includes a conveyor belt disposed inside the vehicle compartment directly below the mixing bin, and a discharge hopper disposed at one end of the vehicle compartment away from the mixing bin. The discharge hopper is communicated with the conveyor belt.

[0016] The present invention also discloses a construction method for loess compaction piles, and the construction steps are as follows:

[0017] Marking the positions: Reconnoiter the site and, according to the results, design the layout form, pile spacing, pile length, and filler type of the compaction pile holes, and mark the positions;

[0018] Mechanical preparation: Check the working conditions of the mechanical equipment;

[0019] Hole expansion and compaction: Complete the hole expansion and compaction operation through the pipe sinking device;

[0020] Mixing the filler: Pour the filler in the mixing device into the compaction pile holes;

[0021] Tamping the filler: Tamp the filler in the pile holes through the tamping device;

[0022] Inspection and acceptance: Accept the pile body.

[0023] The present invention has achieved the following technical effects compared with the prior art:

[0024] By integrating the humidifying device, the pipe sinking device for hole expansion and compaction, the tamping device for tamping the filler, and the mixing bin into one, it solves many problems such as the need for multiple machines to cooperate in the past, cumbersome construction, high shift costs, long humidifying time, and uneven moisture diffusion, and promotes the application and development of the humidified foundation treatment technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] To more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0026] Appendix Figure 1 Figure 5 is a schematic front view structure diagram of the rammed earth compaction pile construction device disclosed in the present invention;

[0027] Appendix Figure 2 Figure 9 is a schematic top view structure diagram of the rammed earth compaction pile construction device disclosed in the present invention;

[0028] Appendix Figure 3 Figure 14 is a schematic side view structure diagram of the rammed earth compaction pile construction device disclosed in the present invention;

[0029] Appendix Figure 4 Figure 19 is a schematic perspective view structure diagram of the rammed earth compaction pile construction device disclosed in the present invention;

[0030] Appendix Figure 5 Figure 25 is a schematic overall structure diagram of the high-pressure drilling steam humidifying equipment of the rammed earth compaction pile construction device disclosed in the present invention;

[0031] Appendix Figure 6 Figure 30 is a schematic top view structure diagram of the high-pressure drilling steam humidifying equipment of the rammed earth compaction pile construction device disclosed in the present invention;

[0032] Appendix Figure 7 Figure 35 is a schematic structure diagram of the adapter of the rammed earth compaction pile construction device disclosed in the present invention;

[0033] Appendix Figure 8 Figure 40 is a schematic structure diagram of the pipe sinking device of the rammed earth compaction pile construction device disclosed in the present invention;

[0034] Appendix Figure 9 Figure 45 is a schematic overall structure diagram of the mixing bin of the rammed earth compaction pile construction device disclosed in the present invention;

[0035] Appendix Figure 10 Figure 50 is a schematic front view structure diagram of the mixing bin of the rammed earth compaction pile construction device disclosed in the present invention;

[0036] Appendix Figure 11 Figure 55 is a schematic structure diagram of the tamping device of the rammed earth compaction pile construction device disclosed in the present invention;

[0037] Among them, 1 - central control room, 2 - air compressor, 3 - steam generator, 4 - water tank, 5 - large slide rail, 6 - high-pressure drilling steam humidification equipment, 61 - steam transmission pipe, 62 - vertical frame, 63 - small slide rail, 64 - drill pipe, 65 - directional hoop, 7 - hydraulic lifting device, 8 - cross beam, 9 - motor, 10 - support frame, 11 - adapter, 111 - locking device, 12 - mixing bin, 121 - polymer mixing bin, 122 - polymer discharge port, 123 - filler mixing bin, 124 - filler discharge port, 13 - car body, 14 - conveyor belt, 15 - discharge hopper, 16 - support leg, 17 - crawler wheel, 18 - pipe sinking device, 181 - lock, 19 - ramming device, 191 - adapter, 192 - winch hoisting frame, 193 - rammer. Detailed implementation manners

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part rather than all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0039] The purpose of the present invention is to provide a construction device and method for loess compaction piles, which integrates a humidification device, a pipe sinking device for hole expansion and compaction, a ramming device for ramming fillers, and a mixing bin, so as to solve many problems such as the need for cooperation of multiple machines in the past, cumbersome construction, high hourly rate, long humidification time, and uneven water diffusion, and promote the application and development of the wetland foundation treatment technology.

[0040] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the drawings and specific implementation manners.

[0041] Refer to Figures 1-4, in the construction device of lime soil compaction piles disclosed in the embodiments of the present invention, it at least includes a cab 13, a mixing bin 12 is arranged on the cab 13, and a filler conveying device is arranged in the cab 13, which is communicated with the mixing bin 12 and conveys the filler in the mixing bin 12 into the compaction pile holes. A water tank 4 is arranged on the cab 13 on one side of the mixing bin 12, and the water tank 4 is communicated with the mixing bin 12 for supplying water to the mixing bin 12. A lifting device is arranged at one end of the cab 13 far away from the mixing bin 12. The lifting device is detachably connected with a pipe sinking device 18 for hole expanding and compaction or a ramming device 19 for ramming the filler. A foundation humidifying device is also arranged at a position on the cab 13 close to the lifting device. In this embodiment, by integrating the humidifying device, the pipe sinking device 18 for hole expanding and compaction, the ramming device 19 for ramming the filler, and the mixing bin 12, many problems in the past, such as the need for cooperation of multiple machines, cumbersome construction, high shift costs, long humidifying time, and uneven moisture diffusion, are solved, promoting the application and development of the humidified foundation treatment technology.

[0042] It should be noted that a central control room 1 is also arranged on the cab 13, which is located on the left side of the walking direction of the whole mechanical equipment and is internally provided with mechanical working state regulation switches for overall control of the operation of various equipment.

[0043] Reference Figures 1-3 , as an implementation manner, crawler wheels 17 are installed below the cab 13 to facilitate maintaining the walking power in complex geological terrains. Legs 16 are installed at the four corners below the cab 13, and they are lowered in time after the working position is determined, so as to enhance the stability of mechanical operations.

[0044] Reference Figures 4-6 , in one embodiment, the foundation humidifying device includes an air compressor 2 arranged on the cab 13. The air compressor 2 is communicated with a high-pressure drilling steam humidifying device 6 arranged on the cab 13. A steam generator 3 and an air compressor 2 are also arranged on the cab 13. The water tank 4 is communicated with the air compressor 2 through the steam generator 3. Through the communication between the high-pressure drilling steam humidifying device 6 and the air compressor 2, the muck in the loess foundation can be blown out by the high-pressure gas in the air compressor 2, and then the humidification treatment of the loess foundation can be realized by the high-pressure steam generated by the steam generator 3.

[0045] It should be noted that the air compressor 2 is arranged below the central control room 1, which can pressurize the steam conveyed by the steam generator 3, and then pump it to the deep part of the loess foundation through the high-pressure drilling steam humidifying device 6. The steam generator 3 is externally designed with an operable adjustment device to adjust the steam generation temperature and rate, which is convenient for supplying to the air compressor 2. The water tank 4 supplies water sources to the steam generator 3 and the mixing bin 12 respectively. The high-pressure drilling steam humidifying device 6 is located between the air compressor 2 and the steam generator 3.

[0046] Reference Figures 4-6 As a preferred embodiment, the high-pressure drilling steam humidification device 6 includes a large slide rail 5 provided on the vehicle compartment 13. A vertical frame 62 is slidably connected to the slide rail. A small slide rail 63 is provided on the vertical frame 62. A directional clamp 65 is slidably connected to the small slide rail 63. A drill pipe 64 that is held vertically by the directional clamp 65 is surrounded by the directional clamp 65. One end of the drill pipe 64 is connected to a steam transmission pipe 61. The end of the steam transmission pipe 61 away from the drill pipe 64 is connected to the air compressor 2. One end of the steam transmission pipe 61 is connected to the air compressor 2 and the other end is connected to the end of the drill pipe 64, facilitating the injection of high-pressure water vapor into the deep part of the loess foundation through the drill pipe 64, thereby realizing the humidification of the arid loess foundation. The lower end of the vertical frame 62 is placed above the large slide rail 5, enabling the entire high-pressure drilling steam humidification device 6 to move freely. When foundation humidification is required, the high-pressure drilling steam humidification device 6 moves to the front end of the entire mechanical equipment through the large slide rail 5 for operation. When the humidification is completed, the high-pressure drilling steam humidification device 6 moves to the rear through the large slide rail 5 to provide an operation space for the pipe sinking device 18 and the tamping device 19. The small slide rail 63 is installed vertically on the vertical frame 62, facilitating the control of the lifting and lowering of the drill pipe 64. The directional clamp 65 is composed of two special semi-circular devices. When the two semi-circular devices are combined, the drill pipe 64 is clamped through bolts and screws to fix the direction of the drill pipe 64 and ensure that the drill pipe 64 remains vertical during the drilling process. At the same time, the directional clamp 65 is integrally installed on the small slide rail 63 and thus can freely move up and down with the small slide rail 63.

[0047] Reference Figures 4-6 As an implementation manner, the drill pipe 64 is of a hollow structure, and two or more through holes are uniformly arranged in the circumferential direction of the drill pipe 64. By uniformly arranging a plurality of through holes in the circumferential direction of the drill pipe 64, it is convenient for the high-pressure water vapor to spray out, thereby enabling uniform humidification of the loess foundation.

[0048] Reference Figure 1 As a preferred embodiment, the lifting device includes hydraulic lifting devices 7 provided on both sides of the end of the vehicle compartment 13. A cross beam 8 is provided at the top of the hydraulic lifting devices 7. A support frame 10 is fixedly provided on the cross beam 8. A motor 9 is provided above the support frame 10. A connection interface 11 for detachably connecting the pipe sinking device 18 or the tamping device 19 is provided below the support frame 10. By providing the hydraulic lifting devices 7, the heights of the pipe sinking device 18 and the tamping device 19 can be adjusted. By providing the motor 9, power can be provided for the rotation of the pipe sinking device 18 and the lifting of the tamping device 19. By providing the connection interface 11, the pipe sinking device 18 and the tamping device 19 can be replaced to realize the compaction and reaming of the loess foundation and the tamping of the fillers in the holes.

[0049] It should be noted that hydraulic lifting devices 7 are respectively installed on both sides of the front end of the entire mechanical equipment and are connected to each other through a cross beam 8.

[0050] Reference Figure 7 , as an implementation, the adapter 11 is integrally designed as a cylindrical structure and connected to the output shaft of the motor 9, and can rotate. Four locking devices 111 with the same specifications are evenly distributed on the inner wall of the adapter 11. The locking device 111 includes a support device connected to the inner wall of the adapter 11 and a support pipe arranged on the support device. There are two support pipes, and one end of the support pipe is open for detachably connecting to the pipe sinking device 18 and the ramming device 19.

[0051] Reference Figure 8 , as a preferred method, the pipe sinking device 18 includes a hollow cylinder and a conical structure arranged at the end of the hollow cylinder. A lock 181 is arranged at one end of the hollow cylinder away from the conical structure. The lock 181 is cooperatively connected with the adapter 11. The adapter 11 is rotationally connected to the motor 9. One end of the pipe sinking device 18 is designed as a cone, which is convenient for driving the entire pipe sinking device 18 deep into the loess foundation, so as to realize the hole expansion and compaction of the loess foundation. When it is necessary to use the pipe sinking device 18 to compact and expand the hole of the loess, the motor 9 can be started to drive the adapter 11 to rotate. The clockwise rotation of the adapter 11 will drive the pipe sinking device 18 to rotate. Under the action of the hydraulic lifting device 7, the pipe sinking device 18 is driven deep into the loess foundation in the form of "static pressure rotation".

[0052] It should be noted that the size specification of the lock 181 is the same as the opening of the locking device 111. One end of the lock 181 is fixed on the outer wall of the hollow cylinder, and the other end is a cylindrical body for cooperating with the support pipe, so that the pipe sinking device 18 is tightly connected to the adapter 11. When it is necessary to use the pipe sinking device 18 to compact and expand the hole of the loess, the motor 9 can be started to drive the adapter 11 to rotate. The rotation of the adapter 11 will drive the pipe sinking device 18 to rotate. The rotation direction of the motor should ensure that when the adapter 11 drives the pipe sinking device 18 to rotate, the lock 181 will not be disengaged from the adapter 11.

[0053] Reference Figure 11 , as an implementation method, the ramming device 19 includes a swivel joint 191 connected to the adapter 11. A winch lifting frame 192 is arranged below the swivel joint 191. The winch lifting frame 192 is connected with a rammer 193 through a cable. The winch lifting frame 192 realizes the lifting of the rammer 193 through the motor 9. The rammer 193 can be lifted by the motor 9 placed above the support frame 10, so as to realize the ramming and compaction of the filler in the hole.

[0054] It should be noted that the adapter 191 is fixed by an adapter 191 support device arranged above the hoist crane lifting frame 192. The size specification of the adapter 191 is consistent with the opening of the locking device 111. One end of the adapter 191 is fixed on the outer wall of the adapter 191 support device, and the other end is a cylindrical barrel body that cooperates with the support pipe, so that the tamping device 19 is tightly connected to the adapter 11.

[0055] Reference Figures 9-10 , as an implementation manner, the mixing bin 12 includes a polymer mixing bin 121 arranged on one side of the top of the mixing bin 12, a first filler mixing bin 123 arranged below the polymer mixing bin 121, and a second filler mixing bin 123 arranged on one side of the polymer mixing bin 121 and the first filler mixing bin 123. A polymer discharge port 122 is arranged at the bottom of the polymer mixing bin 121, a filler discharge port 124 is arranged at the bottom of the mixing bin 12. The size of the polymer mixing bin 121 is smaller than that of the first filler mixing bin 123 and the second filler mixing bin 123. A small mixing blade is installed in the middle of the bottom of the polymer mixing bin 121, and a polymer discharge port 122 is installed on the other side of the bottom. The polymer mixing bin 121 is used for mixing alkali-activated polymer solidifying materials, mainly including fly ash, slag, NaOH particles, water glass, etc. Mixing blades are installed at the bottoms of the first filler mixing bin 123 and the second filler mixing bin 123 for mixing loess and alkali-activated polymer solidifying materials to realize the "two-step method" for solidifying loess.

[0056] When the filler in the mixing bin 12 is polymer loess, the preparation method is specifically as follows: First, add sodium hydroxide to water glass to reduce the modulus of water glass to 1.2 and cool it to room temperature for standby, so as to prepare an alkali activator. Second, pour fly ash and slag powder into the polymer mixing bin 121 according to a mass percentage of 1:1, and add the prepared alkali activator; the dosage of the alkali activator (calculated as the percentage of the total mass of sodium silicate and sodium hydroxide solids in the total mass of the raw material powder) is 11%. Start the mixing blade to mix and prepare geopolymers. Then, through the polymer discharge port 122, the geopolymers are introduced into the filler mixing bin 123, so that the geopolymers and loess are mixed according to a mass ratio of (5-15):100. Add water through the water tank 4, start the mixing blade to mix and prepare polymer loess. Finally, open the filler discharge port 124 to transport the polymer loess to the inside of the pile hole through the conveyor belt 14 for ramming. When the mass ratio of the geopolymer material to loess is 5:100, the optimal moisture content of the polymer loess is 13.3%; when the mass ratio of the geopolymer material to loess is 10:100, the optimal moisture content of the polymer loess is 13.8%; when the mass ratio of the geopolymer material to loess is 15:100, the optimal moisture content of the polymer loess is 14.1%.

[0057] Under alkaline conditions, the hydration products of fly ash can effectively fill the pores in collapsible loess, significantly reduce the pore ratio, refine the pores and reduce the particle size, thereby optimizing the pore structure and interface properties of collapsible loess. In addition, in an alkaline environment, the hydroxide ions released by sodium hydroxide will continuously corrode the surface of fly ash and mineral powder, resulting in the breaking of covalent bonds such as Si-O-Si and Si-O-Al, thereby generating a certain amount of SiO2, CSH gel, CASH gel and a small amount of NASH gel. In the process of age growth, the polymerization reaction inside the geopolymer is also ongoing, in which the calcium ions in the CSH gel promote the continuous dissolution of silicon and aluminum monomers in fly ash and slag powder in an alkaline environment, and finally form a coexistence state of CSH gel, CASH gel, NASH gel and NaAlSi3O8 in the geopolymer system, jointly constructing a dense three-dimensional network polysilicate aluminate structure, which significantly improves the mechanical properties, water stability, frost resistance and erosion resistance of geopolymer loess.

[0058] refer to Figure 1 As an implementation mode, the filler conveying device includes a conveyor belt 14 arranged inside the cabin 13, and the conveyor belt 14 is located directly below the filling outlet 124 of the mixing bin. A discharge hopper 15 is arranged on the side wall of the cabin 13 near one end of the hydraulic lifting device 7. The discharge hopper 15 is connected to the material on the conveyor belt 14, and a baffle is arranged on the discharge hopper 15 to realize the opening and closing of the discharge hopper 15. It can also be connected by a rotatable shaft to facilitate its opening and closing, saving mechanical operating space.

[0059] The present invention also discloses a loess compaction pile construction method, the construction steps of which are:

[0060] Marking points: First, conduct a detailed geological survey on site to understand the nature of the soil, groundwater level, thickness and other geological conditions; then, based on the survey results, design the pile hole layout, pile spacing, pile length, filler type and other parameters of the compaction piles; finally, lay out on site according to the designed points to mark the points.

[0061] Mechanical preparation: First, start the mechanical equipment, check the working condition of the entire mechanical equipment, and ensure that the discharge hopper 15 is folded; secondly, control the machine in the central control room 1, adjust the hydraulic lifting device 7 to a suitable height, and align the front end of the mechanical equipment with the designed hole position, lower the legs 16 to stabilize the entire machine, and facilitate subsequent construction operations;

[0062] Hole-expanding and compaction: Install the pipe sinking device 18 on the adapter 11, and check whether the internal locking device 111 is locked. Start the motor 9 to make the pipe sinking device 18 rotate clockwise; control the hydraulic lifting device 7 to lower, and drive the pipe sinking device 18 into the specified depth of the loess foundation in the form of "static pressure rotation" and then slowly pull it out, so as to complete the hole-expanding and compaction operation of a single pile point. Compared with the previous form of driving the pipe by hammering, this hole-expanding and compaction form is more environmentally friendly, has less impact on the noise and vibration of the surrounding environment, and has a wider application range;

[0063] Mixing filler: First, load lime and loess in accordance with the corresponding ratio (such as 2:8 lime-soil) into the filler mixing bin 123, and start the mixing blades to complete the mixing. Secondly, open the filler discharge port 124, put in the volume of filler for a single ramming, and start the conveyor belt 14. Finally, open the discharge port and pour the lime-soil filler transported above the conveyor belt 14 into the compaction pile hole;

[0064] Ramming filler: Install the ramming device 19 on the adapter 11, and check whether the internal locking device 111 is locked. Start the motor 9 to make the hoist lift the rammer 193 to the specified ramming height to ensure that the ramming meets the design requirements, and repeatedly lift and release the rammer 193 to complete the ramming of the filler in the pile hole;

[0065] Inspection and acceptance: After the construction is completed, conduct acceptance on the strength, length, diameter, stability, bearing capacity, uniformity, etc. of the pile body to ensure that the quality of each pile body meets the design requirements. If there are quality problems, repairs or additional piles are required. The bearing capacity test can be carried out by the static load test or the standard penetration test.

[0066] It should be noted that wetting treatment can be carried out before hole expansion and compaction. Specifically: adjust the vertical frame 62 on the large slide rail 5 and the drill pipe 64 on the small slide rail 63 so that the drill pipe 64 is exactly aligned with the designed hole position, install the directional clamp 65 to fix the verticality of the drill pipe 64, ensure that no deviation occurs during the drilling process, and drill the drill pipe 64 into the loess foundation through the set instructions in the central control room 1. The muck is blown out by the high-pressure gas generated by the air compressor 2 (dry drilling). After drilling to the specified depth, connect the water tank 4 and the steam generator 3 so that the liquid in the water tank 4 is injected into the steam generator 3. Set the relevant programs of the steam generator 3 to control the rate and temperature of the generated water vapor, and introduce the water vapor into the air compressor 2. Set the pressure of the air compressor 2, and connect the steam to the drill pipe 64 through the steam transmission pipe 61. The surface of the drill pipe 64 is evenly provided with circular holes for evenly spraying the steam into the interior of the loess foundation to achieve the wetting treatment of the loess foundation. This method can significantly improve the efficiency and uniformity of water injection and wetting compared with the previous water injection and wetting method, and the high-temperature and high-pressure water vapor is convenient for the diffusion of the wetting water, thus playing a role in increasing the wetting range. When the steam-wetted foundation is completed, hole expansion and compaction and ramming of lime-soil filler can be continued.

[0067] As an implementation method, this embodiment analyzes the construction of a geopolymer loess compaction pile foundation after wetting treatment. Geopolymer loess filler is used when mixing the filler. Specifically: First, add sodium hydroxide to water glass to reduce the modulus of water glass to 1.2 and cool it to room temperature for standby, thus preparing an alkali activator. Second, pour fly ash and slag powder into the polymer mixing bin 121 according to the mass percentage of 1:1, and add the prepared alkali activator; the dosage of the alkali activator (calculated as the percentage of the total mass of sodium silicate and sodium hydroxide solids in the total mass of the raw material powder) is 11%. Start the stirring blade to prepare the geopolymer. Then, through the polymer discharge port 122, introduce the geopolymer into the filler mixing bin 123 so that the geopolymer and loess are mixed according to the mass ratio of 5:100. Add water through the water tank 4, start the stirring blade to prepare the geopolymer loess, and control the water content of the geopolymer loess to the optimal water content of 13.3%. Finally, open the filler discharge port 124 to transport the polymer loess to the inside of the pile hole through the conveyor belt 14 to complete ramming.

[0068] As another embodiment, the dosage of the geopolymer in this embodiment is changed. Specifically: First, sodium hydroxide is added to sodium silicate to reduce the modulus of sodium silicate to 1.2, and it is cooled to room temperature for standby, thereby preparing an alkali activator. Second, fly ash and slag powder are poured into the polymer mixing bin 121 according to a mass percentage of 1:1, and the prepared alkali activator is added. The dosage of the alkali activator (calculated as the total mass percentage of sodium silicate and solid sodium hydroxide in the total mass of the raw material powder) is 11%. The stirring blades are started to prepare the geopolymer. Then, through the polymer discharge port 122, the geopolymer is introduced into the filling mixing bin 123, so that the geopolymer and loess are mixed according to a mass ratio of 10:100. Water is added through the water tank 4, and the stirring blades are started to prepare the geopolymer loess. The moisture content of the geopolymer loess is controlled to be the optimal moisture content of 13.8%. Finally, the filling discharge port 124 is opened, and the polymer loess is transported to the inside of the pile hole through the conveyor belt 14 to complete ramming.

[0069] As one embodiment, the dosage of the geopolymer in this embodiment is changed. Specifically: First, sodium hydroxide is added to sodium silicate to reduce the modulus of sodium silicate to 1.2, and it is cooled to room temperature for standby, thereby preparing an alkali activator. Second, fly ash and slag powder are poured into the polymer mixing bin 121 according to a mass percentage of 1:1, and the prepared alkali activator is added. The dosage of the alkali activator (calculated as the total mass percentage of sodium silicate and solid sodium hydroxide in the total mass of the raw material powder) is 11%. The stirring blades are started to prepare the geopolymer. Then, through the polymer discharge port 122, the geopolymer is introduced into the filling mixing bin 123, so that the geopolymer and loess are mixed according to a mass ratio of 15:100. Water is added through the water tank 4, and the stirring blades are started to prepare the geopolymer loess. The moisture content of the geopolymer loess is controlled to be the optimal moisture content of 14.1%. Finally, the filling discharge port 124 is opened, and the polymer loess is transported to the inside of the pile hole through the conveyor belt 14 to complete ramming.

[0070] After sampling and testing the geopolymer solidified loess and ordinary loess prepared in the above embodiment, it is found that the unconfined compressive strength test results at 7d and 28d are shown in Table 1:

[0071] Table 1 Unconfined Compressive Strength Test

[0072]

[0073] As can be seen from the above table, with the increase of the alkali-activated polymer material, the unconfined compressive strength of the solidified loess at 7d and 28d gradually increases.

[0074] The CBR values of the geopolymer loess and plain loess prepared in the above embodiments were compared, as shown in Table 2 below. It can be seen from Table 2 that the geopolymer solidified loess > plain loess, that is, the alkali-activated geopolymer can significantly improve the mechanical properties of loess.

[0075] Table 2 Comparison of CBR indexes

[0076]

[0077] This device is designed with a multi-functional humidification-polymer loess compaction pile construction device integrating "high-pressure drilling steam humidification equipment 6", "compaction pile hole-forming equipment", "pile body filler ramming equipment", and "pile body filler mixing equipment", thus solving many problems such as the need for multiple machines to cooperate in the past, cumbersome construction, and high shift costs. The high-pressure drilling steam humidification equipment 6 can significantly improve the efficiency and uniformity of water injection humidification compared with the previous pre-drilled hole water injection humidification, and the high-temperature and high-pressure water vapor is convenient for the diffusion of humidification water, thus playing a role in increasing the humidification range. The compaction pile hole-forming equipment expands and compacts the loess foundation in the form of "static pressure rotation". Compared with the previous hammer-driven pipe sinking form, this kind of hole expansion and compaction form is more environmentally friendly, has less noise and vibration impact on the surrounding environment, and has a wider application range. The pile body filler mixing equipment is divided into a polymer mixing bin 121 and a filler mixing bin 123, thus realizing the on-site "two-step" mixing and preparation of the polymer solidified loess material, and this equipment can also be used for the mixing of conventional plain soil and lime soil fillers. In addition, the novel polymer solidified loess material designed in the present invention is more environmentally friendly, which is beneficial to reducing the carbon emissions of traditional materials, reducing the project cost, and improving the mechanical properties of loess. The active components such as aluminosilicates in industrial wastes such as fly ash and slag powder can react chemically with the water and other components in loess to generate C-S-H gel, etc., thus tightly bonding the loess particles together and enhancing the mechanical strength and water stability of loess; the sodium hydroxide particles play the role of an activator here; the alkaline environment can accelerate the hydration reaction of the active components in fly ash and slag powder and promote the generation of more cementitious substances. Sodium silicate, as an inorganic binder, has the functions of enhancing the uniformity, fluidity, adhesiveness, and constructability of materials. It can react chemically with the components in fly ash, slag powder, and loess to generate more stable compounds. In short, the combination of the novel geopolymer solidified loess material and the novel humidification-compaction pile construction equipment will help to better solve the treatment problem of collapsible loess foundation in arid areas.

[0078] It should be noted that for those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the invention. Any reference signs in the claims should not be construed as limiting the claimed invention.

Claims

1. A loess compaction pile construction device, characterized in that It includes a mixing bin arranged on the vehicle cabin, a filler conveying device arranged inside the vehicle cabin and communicating with the mixing bin to convey the filler into the compaction pile hole, a water tank arranged on one side of the mixing bin and communicating with the mixing bin, and a lifting device arranged at one end far from the mixing bin. The lifting device is detachably connected with a sinking pipe device for hole expansion and compaction or a tamping device for tamping the filler. It also includes a foundation humidifying device arranged on the vehicle cabin near one side of the lifting device.

2. The loess compaction pile construction device according to claim 1, characterized in that, The foundation humidifying device includes an air compressor arranged on the vehicle cabin, a high-pressure drilling steam humidifying device communicated with the air compressor, and a steam generator and an air compressor arranged on the vehicle cabin. The water tank is communicated with the air compressor through the steam generator.

3. The loess compaction pile construction device according to claim 2, wherein, The high-pressure drilling steam humidifying device includes a large slide rail arranged on the vehicle cabin, a vertical frame slidably connected with the large slide rail, a small slide rail arranged on the vertical frame, a directional clamp slidably connected with the small slide rail, a drill rod surrounded by the directional clamp to keep vertical through the directional clamp, and a steam transmission pipe with one end communicated with the end of the drill rod and the other end communicated with the air compressor.

4. The loess compaction pile construction device according to claim 3, characterized in that, Two or more through holes are evenly distributed circumferentially on the drill rod.

5. The loess compaction pile construction device according to claim 1, characterized in that, The lifting device includes hydraulic lifting devices arranged on both sides at the end of the vehicle cabin, a cross beam arranged on the top of the hydraulic lifting devices for connecting the hydraulic lifting devices, a support frame fixedly arranged on the cross beam, and a motor arranged above the support frame. A transfer interface for detachably connecting the sinking pipe device or the tamping device is arranged below the support frame.

6. The loess compaction pile construction device according to claim 5, characterized in that, The sinking pipe device includes a hollow cylinder, a conical structure arranged at the end of the hollow cylinder, and a lock arranged at one end of the hollow cylinder far from the conical structure and connected with the transfer interface. The transfer interface is rotationally connected with the motor.

7. The loess compaction pile construction device according to claim 5, characterized in that, The tamping device includes a connector connected with the transfer interface, a hoist lifting frame arranged below the connector, and a tamping hammer connected with the hoist lifting frame through a cable. The hoist lifting frame realizes the lifting of the tamping hammer through the motor.

8. The loess compaction pile construction device according to claim 1, characterized in that, The mixing bin includes a polymer mixing bin arranged on one side at the top of the mixing bin, a first filler mixing bin arranged below the polymer mixing bin, and a second filler mixing bin arranged on one side of the polymer mixing bin and the first filler mixing bin. A polymer discharge port is arranged at the bottom of the polymer mixing bin, and a filler discharge port is arranged at the bottom of the mixing bin.

9. The loess compaction pile construction device according to claim 1, characterized in that, The filler conveying device includes a conveyor belt arranged inside the vehicle cabin and directly below the mixing bin, and a discharge hopper arranged at one end of the vehicle cabin far from the mixing bin. The discharge hopper is communicated with the conveyor belt.

10. A construction method for loess compaction piles, characterized in that, Its construction steps are as follows: Mark the positions: Survey the site and design the layout form, pile spacing, pile length, and filler type of the compaction pile holes according to the results, and mark the positions. Prepare the machinery: Check the working conditions of the machinery and equipment. Expand the hole and compact: Complete the hole expansion and compaction operation through the sinking pipe device. Mix the filler: Pour the filler in the mixing device into the compaction pile hole. Tamping filler: Tamping the filler in the pile hole through a tamping device; Inspection and acceptance: Conducting acceptance inspection on the pile body.

Images