In-situ soil foundation construction device based on advanced pre-grouting reinforcement

Abstract

The utility model relates to power transmission line foundation technical field discloses a kind of in-situ soil foundation construction devices based on advance pre-grouting reinforcement, including drilling and grouting equipment;Drilling and grouting equipment includes grouting drill bit, push rod section, gear, driving equipment, grouting pump, grouting pipe and grout tank;The side of grouting drill bit is set annular cutter head, and the other side of grouting drill bit is set the clamping groove matched with push rod section;Grouting hole is set on the grouting drill bit;The two sides of push rod section are respectively set clamping groove, one side clamping groove corresponds with the clamping groove of grouting drill bit, and the other side clamping groove corresponds with the clamping groove of next push rod section;The push rod section farthest from grouting drill bit is set external thread, and push rod section is driven with gear screw rod.The utility model aims at improving the strength and stability of soil body, providing solid foundation for subsequent construction, reducing safety risk in construction process, avoiding soil body collapse and deformation in excavation process, improving construction efficiency and quality.

Description

Technical Field

[0001] This utility model relates to the field of power transmission line foundation technology, and in particular to a construction device for undisturbed soil foundations based on advanced pre-grouting reinforcement. Background Technology

[0002] In recent years, with the increasing scale of development and utilization of clean energy such as photovoltaic and wind power in Northwest China, power transmission lines have inevitably entered desert, Gobi and other barren areas, and the complex geological environment has brought great challenges to the construction of power transmission lines.

[0003] In deserts, desert edges, Gobi, and some loess areas, where the soil has a high sand content, the use of undisturbed soil foundations (such as bored foundations or excavated foundations) for power transmission lines can easily lead to hole collapse accidents, causing repeated changes to the engineering plan and significantly increasing the construction period and investment.

[0004] Because sandy soil is characterized by its loose structure, low strength, and poor stability, saturated fine sand particles are tightly packed together during construction disturbances, making it impossible to drain pore water in time. This causes a sudden increase in pore water pressure, reducing the contact force between sand particles and decreasing frictional resistance, making it highly susceptible to localized liquefaction, strength loss, and ultimately, significant foundation pit collapse. To address this, the power transmission line industry often uses excavated foundations in sandy soil conditions. However, excavated foundations cause significant damage to the topography and vegetation, which is detrimental to environmental protection. In-situ foundations (such as bored foundations and excavated foundations) have a small working area, cause less damage to the topography, and can maximize the bearing capacity of the undisturbed soil. However, they are prone to borehole collapse when used in sandy soil conditions. Therefore, there is an urgent need for a construction device that can use in-situ foundations in sandy soil conditions. Utility Model Content

[0005] To address existing problems, this utility model provides a construction device for undisturbed soil foundations based on advanced pre-grouting reinforcement. It aims to fully utilize the bearing capacity advantage of undisturbed soil while avoiding the damage to the original topography and vegetation caused by large-scale foundation excavation, reducing construction risks, saving production costs, and reducing the amount of earthwork, thereby achieving the effects of resource conservation, environmental friendliness, and significant economic benefits.

[0006] To achieve the above objectives, the present invention provides the following technical solution.

[0007] This utility model discloses a construction device for undisturbed soil foundations based on pre-grouting reinforcement, including a drilling and grouting device. The drilling and grouting device includes a grouting drill bit, a push rod section, a gear, a drive device, a grouting pump, a grouting pipe, and a grout tank. The grouting drill bit has a circumferential cutter head on one side and a groove on the other side that mates with the push rod section. The grouting drill bit has grouting holes. The push rod section has grooves on both sides, one groove corresponding to the groove of the grouting drill bit, and the other groove corresponding to the groove of the next push rod section. The push rod section furthest from the grouting drill bit has an external thread, and the push rod section is driven by a gear and screw. The drive device rotates the gear. Both the grouting drill bit and the push rod section have hollow cavities, which are interconnected and connected to the grouting pump and the grout tank sequentially through the grouting pipe.

[0008] As a further improvement of this utility model, it also includes excavation equipment; the excavation equipment is a rotary drilling rig or a mechanical Luoyang shovel.

[0009] As a further improvement of this utility model, there are several push rod segments; the several push rod segments are connected to each other through corresponding slots to form a push rod assembly that can be installed and removed along the length direction.

[0010] As a further improvement of this utility model, the spacing of the grouting holes is 1.5 times the preset grouting penetration range.

[0011] As a further improvement of this utility model, the grouting pipe includes a front section, which is made of seamless steel pipe with a diameter of 50mm or 70mm.

[0012] As a further improvement of this utility model, a circumferential cutter head is provided on one side of the grouting drill bit. The circumferential cutter head includes a cutter head body, a cutting edge, and a chip removal groove. The cutting edge is located at the front end of the cutter head body, while the chip removal groove is distributed on the side of the cutter head body.

[0013] As a further improvement of this utility model, the grouting pump, grouting pipe and grout tank are set on a grouting mobile platform, which is convenient for pump trucks and trailers to carry.

[0014] As a further improvement of this utility model, it also includes a cyclone slurry mixer and special grouting equipment; the special grouting equipment includes a grouting valve, a high-pressure hose and monitoring instruments; the monitoring instruments include a pressure gauge, a flow meter and an automatic grouting recorder.

[0015] As a further improvement of this utility model, it also includes a drive linkage; the drive device transmits rotational power to the gear through a drive linkage.

[0016] As a further improvement of this utility model, the drive device is one of a diesel engine, a gasoline engine or an electric motor; the output power of the drive device is between 20kW and 40kW.

[0017] This utility model has the following beneficial effects: The construction device disclosed in this utility model can achieve precise grouting of soil, ensuring uniform distribution of grouting material and improving grouting efficiency and quality; the circumferential cutter head can cut the soil and provide immediate support after drilling, reducing the natural healing of sand and soil after drilling and providing stable structural support for the penetration of grouting material; the grouting hole is used to inject grouting material into the soil to achieve grouting reinforcement; the design of the slot and external thread facilitates the connection and disassembly of the push rod section, and the length of the push rod section can be adjusted according to actual needs, improving the flexibility and applicability of the equipment; the hollow inner cavity design can ensure that the grouting material passes smoothly through the grouting drill bit and the push rod section, improving grouting efficiency.

[0018] Preferably, the excavation equipment is easy to operate and can achieve rapid and efficient excavation of soil, thereby improving construction efficiency and quality.

[0019] Alternatively, the push rod section made of lightweight steel pipe is easy to handle and install, while the snap-fit ​​design allows the overall length of the push rod to be adjusted according to the drilling depth, improving the flexibility and applicability of the equipment.

[0020] Preferably, the grouting material is ensured to fully penetrate and fill the voids in the soil, thereby improving the grouting effect.

[0021] Preferably, seamless steel pipes have advantages such as high strength and good corrosion resistance, which can ensure the grouting pressure during the grouting process and improve the stability and durability of the grouting pipe.

[0022] Preferably, a circumferential cutter head is provided on one side of the grouting drill bit, which can cut the soil more effectively and facilitate the drilling of the grouting drill bit. At the same time, the design of the chip removal groove helps to remove the soil chips generated by cutting in a timely manner and keep the borehole unobstructed.

[0023] Preferably, the grouting pump, grouting pipe and grout tank are set on a grouting mobile platform, which facilitates overall movement and transportation, and improves the flexibility and convenience of the construction site.

[0024] Preferably, the cyclone grout mixer can efficiently prepare the grout required for grouting, while the special grouting equipment ensures precise control and monitoring of the grouting process, thereby improving the construction quality.

[0025] Preferably, the rotational force is transmitted to the gears via a drive linkage, which simplifies the transmission structure and improves the reliability and stability of the transmission.

[0026] Preferably, the drive equipment, such as diesel engine, gasoline engine or electric motor, provides a variety of power options, which can be flexibly selected according to the actual conditions of the construction site, improving the applicability and economy of the device, and also meeting the power requirements of grouting operations. Attached Figure Description

[0027] The accompanying drawings described herein are for illustrative purposes only and do not limit the scope of this invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely schematic to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. In the drawings: Figure 1 This is a schematic diagram of the space plan drilled out by the pre-grouting reinforcement method for undisturbed soil foundation construction described in Example 1. Figure 2 This is a schematic diagram of a construction device for an undisturbed soil foundation based on pre-grouting reinforcement as described in Example 1. The components include: 1. Grouting drill bit; 2. Push rod section; 3. Gear; 4. Drive equipment; 5. Grouting pump; 6. Grouting pipe; 7. Grout tank; 8. Grouting hole; 9. Slot; 10. External thread; 11. Grouting moving platform; and 12. Front section of grouting pipe. Detailed Implementation

[0028] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0029] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0031] This utility model proposes a pre-reinforced undisturbed soil foundation construction device, which solves the problem of using undisturbed soil foundation construction in areas such as deserts, Gobi, and soil layers with high sand content. It can give full play to the high bearing capacity of undisturbed soil foundation, and use soil instead of formwork to reduce damage to the original landform and vegetation. It can make full use of mechanized equipment for foundation pit excavation, reduce construction risks, and save project investment.

[0032] Example 1 like Figure 1 As shown, a method for constructing an undisturbed soil foundation based on pre-grouting reinforcement involves inserting a set of grouting pipes into the soil foundation in a quincunx pattern, then grouting the soil foundation for reinforcement. Grout is filled into the voids in the soil foundation around the pipes, and the reinforcement is completed around the pipes after the grout has solidified. Generally, excavation is carried out around the pipes and in the central part of the quincunx pattern.

[0033] like Figure 2 As shown, this utility model also discloses a construction device for undisturbed soil foundations based on pre-grouting reinforcement, including a drilling and grouting device. The drilling and grouting device includes a grouting drill bit 1, a push rod section 2, a gear 3, a drive device 4, a grouting pump 5, a grouting pipe 6, and a grout tank 7. The construction device disclosed in this utility model can achieve precise grouting of the soil, ensuring uniform distribution of grouting material and improving grouting efficiency and quality. The circumferential cutter head can cut the soil and provide immediate support after drilling, reducing the natural healing of sand after drilling and providing stable structural support for the penetration of grouting material. The grouting hole 8 is used to inject grouting material into the soil to achieve grouting reinforcement. The design of the slot 9 and the external thread 10 facilitates the connection and disassembly of the push rod section 2, and the length of the push rod section 2 can be adjusted according to actual needs, improving the flexibility and applicability of the equipment. The hollow inner cavity design ensures that the grouting material passes smoothly through the grouting drill bit 1 and the push rod section 2, improving grouting efficiency. The grouting pump 5, grouting pipe 6 and grout tank 7 can be mounted on a grouting mobile platform 11, which can be carried by a pump truck and a trailer.

[0034] Specifically, the grouting drill bit 1 has a circumferential cutter head on one side, which can consist of a cutter head body, a cutting edge, and a chip removal groove. The diameter of the circumferential cutter head can be 80mm to 120mm; the cutting edge is located at the front end of the cutter head body and is responsible for cutting soil or rock. The chip removal groove is distributed on the side of the cutter head body to guide the cut soil or rock chips out. The cutter head shape can be conical, cylindrical, flat, or a special shape, such as with helical blades. The cutter head material usually includes steel, cemented carbide, and diamond; for gravelly soil, steel can be selected. The other side of the grouting drill bit 1 has a groove 9 that mates with the push rod section 2; the groove 9 can be semi-circular, square, elliptical, or polygonal; the grouting drill bit 1 has a grouting hole 8; the push rod section 2 has grooves 9 on both sides, one side of the groove 9 corresponding to the groove 9 of the grouting drill bit 1, and the other side of the groove 9 corresponding to the groove 9 of the next push rod section 2. Push rod section 2 can be made of lightweight hollow steel tubing.

[0035] The push rod section 2, located furthest from the grouting drill bit 1, is provided with an external thread 10. The push rod section 2 is driven by the gear 3 via a screw drive. A dustproof hose or a flexible cover can be installed on the outside of the screw drive part to avoid dust contamination. The pitch of the external thread 10 can be 1 / 4 to 1 / 2 of the number of teeth of the gear 3, and the number of teeth can be selected between 20 and 60. The drive device 4 rotates the gear 3. The drive device 4 can be a diesel engine, a gasoline engine, or an electric motor. The output power of the drive device 4 can be between 20kW and 40kW, and the output torque can be between 200Nm and 600Nm.

[0036] Both the grouting drill bit 1 and the push rod section 2 are provided with hollow inner cavities. The hollow inner cavities of the grouting drill bit 1 and the push rod section 2 are interconnected and connected to the grouting pump 5 and the grout tank 7 in sequence through the grouting pipe 6. The grouting pipe 6 can also be designed in sections, including the front section 12 and the remaining grouting pipe, with the two sections connected by a telescopic bend. The grouting pipe 6 can be recycled and reused.

[0037] like Figure 2 As shown, the device of this utility model is arranged vertically, requiring the grouting pipe 6 to be built inside the drill bit. The drill bit is used to break through the soil in the foundation to form a support structure. Then, the grouting liquid is injected into the surrounding area of ​​the structure through the inner cavity of the drill bit and the grouting hole 8 for solidification, so as to reduce the need to repeatedly insert multiple grouting pipes 6 into the foundation for grouting. After solidification, further excavation can be carried out in the hole excavated by the original drill bit.

[0038] The front section 12 of the grouting pipe is made of seamless steel pipe with a diameter of 50mm or 70mm. Seamless steel pipe has the advantages of high strength and good corrosion resistance, which can ensure the grouting pressure during the grouting process and improve the stability and durability of the front section 12 of the grouting pipe.

[0039] There are several push rod sections 2, which can be 1m to 5m in length and can be manufactured according to splicing requirements; several push rod sections 2 are connected to each other through corresponding slots 9 to form a push rod assembly that can be installed and removed along the length direction.

[0040] This device also includes excavation equipment; the excavation equipment is a rotary drilling rig or a mechanical Luoyang shovel. The excavation equipment is simple to operate and can achieve rapid and efficient excavation of soil, improving construction efficiency and quality.

[0041] The spacing of the grouting holes 8 is 1.5 times the preset grouting penetration range. In clay and silt, due to the finer soil particles and smaller pores, the penetration range of the grout is usually small, generally between 0.5 meters and 2 meters. In sand and gravel, due to the larger soil particles and more pores, the penetration range of the grout is usually larger, generally between 2 meters and 5 meters, or even further. Under some special geological conditions, such as the presence of groundwater or a large amount of organic matter in the soil, the penetration range of the grout may be limited and needs to be determined through field tests, laboratory tests, or numerical simulations. The properties of the grouting material (such as viscosity and setting time) and the grouting process (such as grouting pressure and grouting speed) also affect the penetration range. For example, using low-viscosity grouting materials and higher grouting pressure can increase the penetration range.

[0042] Specifically, the usage steps of the undisturbed soil foundation device based on pre-grouting reinforcement described in this embodiment are as follows: A comprehensive geological survey was conducted before construction to understand the soil structure, groundwater level, and soil type of the foundation, in order to determine a suitable grouting scheme. Based on the geological survey results, a specific grouting scheme was designed, including the selection of grouting materials, the setting of grouting pressure, and the arrangement of grouting holes. Considering the dry climate and loess characteristics of Northwest China, grouting materials with good water retention and anti-drying shrinkage properties were selected, such as cement grout with added fiber reinforcement or modified cement grout, and water-soluble polyurethane grout. Environmentally friendly grouting materials were given priority to reduce the impact on the local ecological environment. Modified cement grout has good water retention and anti-drying shrinkage properties, making it suitable for dry environments; water-soluble polyurethane grout has good fluidity and permeability, enabling it to penetrate into tiny cracks in the soil and form an effective reinforcement effect. The grouting pressure was controlled between 0.2 and 0.6 MPa. Grouting can be carried out using a retractable or segmented forward grouting method with the grouting drill bit 1. In the later stages of grouting, the grouting pressure can be appropriately increased to between 1 and 3 MPa.

[0043] The working face is enclosed, and a grouting mobile platform 11 (including grout tank 7, grouting pump 5, and grouting pipe 6) is arranged. The grouting mobile platform 11 should be placed behind and against the side of the working face to reduce mutual interference between drilling and grouting and improve work efficiency. According to the designed grouting volume, the grout should be piled up in a position close to the working face but not affecting the construction of the working face.

[0044] Drill holes at predetermined locations using drilling and grouting equipment. The drilling depth should meet design requirements, typically exceeding the foundation bottom surface by a certain depth to ensure grouting effectiveness. After drilling, install grouting pipes 6 inside the cavities of the grouting drill bit 1 and push rod section 2. Grouting pipes 6 should extend to the grouting drill bit 1 to ensure even distribution of grout into the drilled soil holes. During grouting, strictly control the grouting pressure to avoid soil cracking or grout loss due to excessive pressure. In dry, loose loess and sand, appropriately reduce the grouting pressure to prevent soil breakage or grout loss, especially for very loose soil layers where the initial pressure can be even lower to avoid soil breakage. Simultaneously, control the grouting speed to prevent insufficient penetration and solidification of the grout. The grouting speed should be controlled between 10 and 30 cubic meters per hour. For highly permeable sand, the speed can be appropriately increased, while for loess, it should be slowed down to ensure sufficient penetration and solidification of the grout. Based on the looseness and moisture content of the soil, the density and depth of the grouting holes 8 on the grouting drill bit 1 should be rationally arranged to ensure that the grout can be evenly distributed throughout the reinforced area. The number of grouting holes 8 should be determined according to the diameter of the undisturbed soil foundation and the spacing of the grouting holes 8; the distance between the grouting hole 8 and the edge of the undisturbed soil foundation should be 0.5 times the grout penetration range; the burial depth of the grouting holes 8 should be greater than the burial depth of the undisturbed soil foundation; during the grouting process, ground-penetrating radar, seismic wave method and other technical means should be used for real-time monitoring, and grouting parameters should be adjusted in a timely manner to ensure the reinforcement effect. Considering the possible impact of the rainy season in Northwest China, such as flash floods and hail in high-altitude mountainous areas, grouting construction should be carried out in the dry season as much as possible to reduce the impact of moisture on the grouting effect. The grouting end standard can be based on the grouting time or the grouting volume; grouting can be stopped when the grouting time reaches the grout setting time but the grouting volume has not yet reached the design value, or when the grouting volume reaches the design value but the grout has not reached the setting time or the grouting pressure does not fluctuate significantly. During the grouting process, keep good records of the grouting, including the grouting time, grouting pressure, and grouting volume for each hole.

[0045] After grouting is completed, a certain period of time is required to allow the grout to fully solidify in the soil and form a stable aggregate. The length of this period depends on the setting time of the grouting material used. After the aggregate has formed, a strength test is performed to ensure it meets design requirements. It is recommended to allow at least 24 to 48 hours for solidification after grouting; if the grout sets quickly, the next grouting stage can begin after 4 to 12 hours. The specific time should be adjusted according to the type of grouting material and the ambient temperature. In cold seasons, a longer solidification time may be required. Strength testing methods can include core sampling: after the solidification time, a core drill is used to randomly sample the reinforced area to obtain soil samples after grouting, or visual inspection and pressure testing can be performed, relying on experience to make judgments, with the primary goal of facilitating excavation. Observe the surface for any obvious deformation characteristics; if necessary, use methods such as standard penetration testing, light dynamic penetration testing, static penetration testing, or surface wave testing to monitor the uniformity of the formation.

[0046] Finally, properly dispose of waste generated during construction, especially the packaging and residue of grouting materials, to avoid polluting soil and water sources. After construction is completed, carry out ecological restoration of the construction area by planting plants suitable for the local climate to restore the ecological environment.

[0047] The above embodiments are merely one of the implementation methods for achieving the technical solution of this utility model. The scope of protection claimed by this utility model is not limited to this embodiment, but also includes any variations, substitutions, and other implementation methods that are easily conceived by those skilled in the art within the scope of the technology disclosed in this utility model. Although embodiments of this utility model have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of this utility model. The scope of this utility model is defined by the appended claims and their equivalents.

Claims

1. A construction device for in-situ soil foundation based on advanced pre-grouting reinforcement, characterized in that, The equipment includes a drilling and grouting device; the drilling and grouting device includes a grouting drill bit (1), a push rod section (2), a gear (3), a drive device (4), a grouting pump (5), a grouting pipe (6), and a grout tank (7); the grouting drill bit (1) is provided with a circumferential cutter head on one side and a groove (9) that cooperates with the push rod section (2) on the other side; the grouting drill bit (1) is provided with a grouting hole (8); the push rod section (2) is provided with grooves (9) on both sides respectively, and one groove (9) is connected to the groove of the grouting drill bit (1). (9) Correspondingly, the slot (9) on the other side corresponds to the slot (9) of the next push rod section (2); the push rod section (2) that is furthest from the grouting drill bit (1) is provided with an external thread (10), and the push rod section (2) is driven by the gear (3) screw; the drive device (4) rotates the gear (3); the grouting drill bit (1) and the push rod section (2) are both provided with hollow inner cavities, and the hollow inner cavities of the grouting drill bit (1) and the push rod section (2) are interconnected and connected to the grouting pump (5) and the grout tank (7) in sequence through the grouting pipe (6).

2. The in-situ soil foundation construction device based on advance pre-grouting reinforcement according to claim 1, characterized in that, It also includes excavation equipment; the excavation equipment is a rotary drilling rig or a mechanical Luoyang shovel.

3. The in-situ soil foundation construction device based on advance pre-grouting reinforcement according to claim 1, characterized in that, There are several push rod segments (2); the several push rod segments (2) are connected to each other through corresponding slots (9) to form a push rod assembly that can be installed and removed along the length direction.

4. The in-situ soil foundation construction device based on advance pre-grouting reinforcement according to claim 1, characterized in that, The spacing of the grouting holes (8) is 1.5 times the preset grouting penetration range.

5. The in-situ soil foundation construction device based on pre-grouting reinforcement according to claim 1, characterized in that, The grouting pipe (6) includes a grouting pipe front section (12), which is made of seamless steel pipe with a diameter of 50mm or 70mm.

6. The in-situ soil foundation construction device based on advance pre-grouting reinforcement according to claim 1, characterized in that, The grouting drill bit (1) has a circumferential cutter head on one side, which includes a cutter head body, a cutting edge and a chip removal groove; the cutting edge is located at the front end of the cutter head body; and the chip removal groove is distributed on the side of the cutter head body.

7. The in-situ soil foundation construction device based on advance pre-grouting reinforcement according to claim 1, characterized in that, The grouting pump (5), grouting pipe (6) and grout tank (7) are mounted on a grouting mobile platform (11), which is convenient for pump trucks and trailers to carry.

8. The undisturbed soil foundation construction device based on pre-grouting reinforcement as described in claim 1, characterized in that, It also includes a cyclone slurry mixer and special grouting equipment; the special grouting equipment includes grouting valves, high-pressure hoses and monitoring instruments; the monitoring instruments include pressure gauges, flow meters and automatic grouting recorders.

9. The in-situ soil foundation construction device based on advance pre-grouting reinforcement according to claim 1, characterized in that, It also includes a drive linkage; the drive device (4) transmits rotational power to the gear (3) through a drive linkage.

10. The in-situ soil foundation construction device based on advance pre-grouting reinforcement according to claim 1, characterized in that, The drive device (4) is one of a diesel engine, a gasoline engine or an electric motor; the output power of the drive device (4) is between 20kW and 40kW.

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