Grouting head stretching device for soft soil subgrade grouting

Abstract

This utility model relates to the field of roadbed grouting technology, and more particularly to a grouting head extension device for soft soil roadbed grouting. It includes an extension tube, a grouting head connection mechanism, an adaptive pressure expansion mechanism, a connecting pipe, and a tapered pipe head. The upper end of the extension tube is equipped with a grouting head connection mechanism for connecting the grouting head. The lower end of the extension tube is equipped with a tapered pipe head for easy penetration into the soft soil roadbed. The outer end of the tapered pipe head is fitted with a spiral drill bit for separating the soft soil layer. Multiple sets of grouting ports are circumferentially opened around the outer end of the extension tube. Each grouting port is equipped with an adaptive pressure expansion mechanism for adjusting the grouting flow rate. This utility model achieves automatic adjustment of the grouting flow rate according to the actual conditions of the soft soil through the adaptive pressure expansion mechanism. Compared with traditional steel tubes with fixed holes, it greatly improves the uniformity of grouting and the reinforcement effect, ensuring that all parts of the soft soil roadbed receive a suitable amount of grout, effectively improving the foundation strength and stability.

Description

Technical Field

[0001] This utility model relates to the field of roadbed grouting technology, and in particular to a grouting head extension device for soft soil roadbed grouting. Background Technology

[0002] In road construction, the treatment of soft soil subgrades is a crucial step in ensuring project quality and stability. Soft soil subgrades are characterized by high water content, large void ratio, high compressibility, and low strength, directly affecting the bearing capacity and service life of roads. Grouting reinforcement technology, a common method for treating soft soil subgrades, involves injecting grout into the soft soil subgrade to fill voids, compact the soil, and improve its mechanical properties, thereby enhancing the strength and stability of the subgrade. It is widely used in the construction of infrastructure such as highways and railways. In practical applications, existing soft soil subgrade grouting equipment typically uses steel perforated pipes as the extension device for the grouting head.

[0003] Traditional grouting head extension devices, due to the fixed size of the holes on ordinary steel pipes, make it difficult to control the grout flow rate. During the grouting process, the grout flow rate is difficult to adaptively adjust according to the actual conditions of soft soil, which can easily affect the grouting effect.

[0004] Therefore, to address the problem that traditional grouting head extension devices cannot adaptively adjust the grout flow rate according to the actual conditions of soft soil, which easily affects the grouting effect, a grouting head extension device for soft soil subgrade grouting can be designed. By installing an adaptive pressure expansion mechanism in the grouting hole of the perforated pipe and automatically adjusting the grout flow rate according to the grouting pressure, the above problems can be easily solved. Utility Model Content

[0005] In order to overcome the shortcomings of traditional grouting head extension devices, which make it difficult to adaptively adjust the grout flow rate according to the actual conditions of soft soil and easily affect the grouting effect, this utility model provides a grouting head extension device for soft soil subgrade grouting.

[0006] The technical solution is as follows: a grouting head extension device for grouting soft soil subgrade includes an extension tube, a grouting head connection mechanism, an adaptive pressure expansion mechanism, a connecting pipe, and a tapered pipe head; the upper end of the extension tube is provided with a grouting head connection mechanism for connecting the grouting head, and the lower end of the extension tube is provided with a tapered pipe head for easy penetration into the soft soil subgrade. The outer end of the tapered pipe head is fitted with a spiral drill bit for easy separation of the soft soil layer. Multiple sets of grouting ports are opened around the outer end of the extension tube, and the interior of each grouting port is provided with an adaptive pressure expansion mechanism for adjusting the grouting flow rate.

[0007] Furthermore, the adaptive pressure reaming mechanism includes a reaming head located inside the grouting port. A fixing ring groove is provided on the inner edge of the grouting port, and a fixing retaining ring corresponding to the fixing ring groove is provided at the rear end of the reaming head.

[0008] Furthermore, the center of the reaming head is provided with a grouting hole, the inside of which is provided with an elastic grouting outer hopper, and the center of the elastic grouting outer hopper is provided with an elastic expansion hole.

[0009] Furthermore, the upper end of the extension tube is provided with a first inner ring groove, and the inner wall of the first inner ring groove is provided with multiple sets of first connecting holes. The lower end of the extension tube is provided with a first outer ring groove, and the outer wall of the first outer ring groove is provided with multiple sets of second connecting holes.

[0010] Furthermore, the enlarged head connection mechanism includes a transition tube, the lower end of which is provided with a second outer ring groove corresponding to the first inner ring groove, and the outer wall of the second outer ring groove is provided with multiple sets of third connection holes corresponding to the first connection hole.

[0011] Furthermore, the upper end of the transition pipe is provided with a bucket-shaped connecting cover, and the upper end of the bucket-shaped connecting cover is provided with a connecting flange ring.

[0012] Furthermore, multiple grouting grooves are opened around the outer end of the tapered pipe head, and a spiral drill bit is fitted onto the outer end of the tapered pipe head.

[0013] Furthermore, the lower end of the connecting tube is connected to the tapered tube head, and the upper end of the connecting tube is provided with a second inner ring groove corresponding to the first outer ring groove. The inner wall of the second inner ring groove is provided with multiple sets of fourth connecting holes corresponding to the second connecting hole.

[0014] The beneficial effect is that, compared with traditional grouting head extension devices, this application, through an adaptive pressure expansion mechanism composed of an elastic grouting outer hopper and an elastic expansion hole, achieves automatic adjustment of the grouting flow rate according to the actual conditions of the soft soil. Compared with traditional steel pipes with fixed holes, it greatly improves the uniformity of grouting and the reinforcement effect, ensuring that all parts of the soft soil subgrade receive appropriate grouting volume, effectively improving the foundation strength and stability. The use of embedded annular grooves and external annular grooves combined with bolt connections between the extension pipe, transition pipe, connecting pipe, and tapered pipe head allows for rapid assembly of the components. The device can be disassembled or reassembled, which not only facilitates flexible splicing and length adjustment of the equipment according to different engineering needs, but also allows for quick replacement and maintenance of specific components when equipment malfunctions, improving construction efficiency and reducing maintenance costs. The design of the bucket-shaped connecting cover effectively guides the grout to flow in evenly, reducing fluid resistance and pressure loss and ensuring stable transmission of grouting pressure. The combination of the spiral drill bit and the conical pipe head reduces the difficulty of inserting the device into soft soil, creating favorable conditions for grouting. At the same time, the seepage groove ensures the reinforcement effect of the bottom soil, comprehensively improving the quality and efficiency of grouting reinforcement. Attached Figure Description

[0015] Figure 1This is a three-dimensional structural diagram of the grouting head extension device for soft soil subgrade grouting according to this utility model.

[0016] Figure 2 This is a schematic diagram of the three-dimensional structure of the extension flower tube of this utility model;

[0017] Figure 3 This is a three-dimensional structural diagram of the grouting head connection mechanism of this utility model;

[0018] Figure 4 This is a three-dimensional structural diagram of the adaptive pressure expanding mechanism of this utility model;

[0019] Figure 5 This is a three-dimensional structural diagram of the combination of the connecting pipe and the tapered pipe head of this utility model.

[0020] Explanation of reference numerals in the attached drawings: 1. Extending perforated pipe; 101. Grouting port; 102. Fixed annular groove; 103. First inner annular groove; 104. First outer annular groove; 105. First connecting hole; 106. Second connecting hole; 2. Grouting head connecting mechanism; 201. Transition pipe; 202. Second outer annular groove; 203. Third connecting hole; 204. Bucket-shaped connecting cover; 205. Connecting flange ring; 3. Adaptive pressure reaming mechanism; 301. Reaming head; 302. Fixed retaining ring; 303. Grouting hole; 304. Elastic grouting outer bucket; 305. Elastic expansion hole; 4. Connecting pipe; 401. Second inner annular groove; 402. Fourth connecting hole; 5. Conical pipe head; 501. Spiral drill bit; 502. Grouting groove. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0022] Grouting of soft soil subgrade involves injecting a grout with good fluidity and cementitious properties into the soft soil foundation using specific grouting equipment. Under pressure, this grout will diffuse, penetrate, fill, and compact in the soil in different ways, depending on the pore characteristics and mechanical properties of the soft soil.

[0023] Infiltration grouting involves the grout, under pressure, flowing like water through a sponge and seeping into the pores between soft soil particles. Through filling, penetration, and compaction, it gradually removes moisture and air from between the soil particles. After solidification, the grout binds tightly with the soft soil particles, forming a high-strength, low-permeability stone-like mass, effectively improving the physical and mechanical properties of the soil and increasing its density and strength. Fracturing grouting, on the other hand, involves the grout forcibly splitting a channel in the soil when the grouting pressure exceeds the initial stress and tensile strength of the soft soil, forming vein-like or network-like grout veins. These veins act like a "skeleton" in the soil, providing support and compressing the soil under the grouting pressure, thereby increasing its density and strength. Compaction grouting uses a thick grout to compress the soft soil, forming grout bubbles around the injection point. As these bubbles expand, they compact the surrounding soil, reducing porosity and increasing density, thus improving the soil's bearing capacity.

[0024] Through these different grouting methods, soft soil subgrade grouting technology has been used to reinforce soft soil foundations, effectively reduce subgrade settlement, improve the overall stability and bearing capacity of the subgrade, and ensure the safe operation of engineering structures such as roads and bridges.

[0025] The performance of grouting materials directly affects the grouting effect. Therefore, it is crucial to select grouting materials appropriately. Currently, the grouting materials commonly used in soft soil subgrade grouting projects mainly include cement-based grouting materials, chemical grouting materials, and mixed grouting materials.

[0026] Cement-based grouting materials use cement as the main raw material, and their performance is adjusted by adding different admixtures. Ordinary Portland cement is the most commonly used type of cement, which has advantages such as high strength, good durability, and relatively low price. In actual engineering, in order to improve the fluidity, setting time, and other properties of cement grout, admixtures such as water-reducing agents, accelerators, and retarders are often added. For example, adding water-reducing agents can significantly improve the fluidity of the grout without changing the amount of water used, making it easier to diffuse in the soil. Adding accelerators can accelerate the setting and hardening speed of cement, shorten the construction cycle, and improve project efficiency. Cement-based grouting materials are suitable for most soft soil subgrade reinforcement projects, especially for projects with high strength requirements and relatively low environmental protection requirements.

[0027] There are many types of chemical grouting materials, the most common being polyurethane, epoxy resin, and acrylamide. These materials have good permeability and curing properties, allowing them to penetrate into tiny pores under relatively low pressure to form a high-strength, high-toughness solidified body. For example, polyurethane grouting materials undergo a chemical reaction upon contact with water, rapidly expanding in volume and effectively sealing cracks and pores, providing both waterproofing and reinforcement. Epoxy resin grouting materials, on the other hand, are characterized by high strength and strong adhesion, and are often used in soft soil subgrade reinforcement projects where high structural strength is required. However, chemical grouting materials are generally expensive, and some materials have certain toxicity and environmental pollution issues. Therefore, strict adherence to relevant environmental regulations and safe operating procedures is necessary when using them.

[0028] Hybrid grouting materials are grouting materials made by mixing cement-based materials with chemical materials or other materials in a certain proportion. They combine the advantages of different materials, possessing both the high strength and economy of cement-based materials and the good permeability and special properties of chemical grouting materials. For example, cement-water glass two-liquid grout, made by mixing cement and water glass in a certain proportion, has advantages such as short setting time, rapid strength increase, and good groutability. It is widely used in soft soil subgrade projects that require rapid water stopping and reinforcement.

[0029] The quality of grouting for soft soil subgrade directly affects the safety and service life of the entire project. Therefore, it is essential to strictly control the quality control points at each stage.

[0030] Before construction, a detailed geological survey of the soft soil subgrade is required to accurately determine the distribution range, thickness, physical and mechanical properties of the soft soil, providing a reliable basis for grouting design. At the same time, grouting materials and grouting processes should be rationally selected according to project requirements and geological conditions, and necessary indoor and field tests should be conducted to determine the optimal grouting parameters, such as grouting pressure, grouting volume, grout mix ratio, and grouting time interval. In addition, a comprehensive inspection and debugging of the grouting equipment is required to ensure that the equipment performs well and can meet the construction requirements.

[0031] Quality control during construction is crucial. Grouting must be carried out strictly in accordance with design requirements and construction specifications to ensure that the location, depth, and diameter of the grouting holes meet design standards. During grouting, close monitoring of grouting pressure, grout volume, and ground deformation is essential. Grouting parameters should be adjusted promptly to prevent problems such as excessive grouting pressure leading to ground heave and excessive grout loss, or insufficient grouting pressure and volume affecting the reinforcement effect. Simultaneously, the mixing quality of the grout must be ensured, with strict control over the grout mix ratio and mixing time to guarantee the uniformity and fluidity of the grout. For multiple grouting procedures, the grouting sequence should be rationally arranged to avoid mutual interference between adjacent grouting holes, which could affect the grouting effect.

[0032] After construction is completed, the quality of the grouting project needs to be inspected and evaluated. Commonly used quality inspection methods include core drilling, standard penetration test, static cone penetration test, and load test. Through these testing methods, the strength, density, uniformity of the grout and the bearing capacity of the soft soil subgrade can be directly understood, and it can be determined whether the grouting project meets the design requirements. For parts that fail the inspection, timely re-grouting and other treatment measures should be taken to ensure the quality of the entire project.

[0033] Example

[0034] like Figures 1-5 As shown, the grouting head extension device for grouting soft soil subgrade includes an extension tube 1, a grouting head connection mechanism 2, an adaptive pressure expansion mechanism 3, a connecting pipe 4, and a conical tube head 5. The upper end of the extension tube 1 is provided with the grouting head connection mechanism 2 for connecting the grouting head, and the lower end of the extension tube 1 is provided with a conical tube head 5 for easy penetration into the soft soil subgrade. The outer end of the conical tube head 5 is fitted with a spiral drill bit 501 for easy separation of the soft soil layer. Multiple sets of grouting ports 101 are opened around the outer end of the extension tube 1. The interior of each grouting port 101 is provided with an adaptive pressure expansion mechanism 3 for adjusting the grouting flow rate.

[0035] The adaptive pressure reaming mechanism 3 includes a reaming head 301, which is located inside the grouting port 101. A fixing ring groove 102 is provided on the inner edge of the grouting port 101. A fixing retaining ring 302 corresponding to the fixing ring groove 102 is provided at the rear end of the reaming head 301. Through the cooperation of the fixing ring groove 102 and the fixing retaining ring 302, the reaming head 301 can be quickly installed and positioned in the grouting port 101, which is convenient for later maintenance or replacement.

[0036] The center of the enlarged hole head 301 is provided with a grouting hole 303. The interior of the grouting hole 303 is provided with an elastic grouting outer bucket 304. The center of the elastic grouting outer bucket 304 is provided with an elastic expansion hole 305. By cooperating with the elastic grouting outer bucket 304 and the elastic expansion hole 305, the grouting flow rate can be adaptively adjusted to match different soft soil conditions and improve the uniformity of grouting and the reinforcement effect.

[0037] The upper end of the extension tube 1 is provided with a first inner ring groove 103, and the inner wall of the first inner ring groove 103 is provided with multiple sets of first connecting holes 105. The lower end of the extension tube 1 is provided with a first outer ring groove 104, and the outer wall of the first outer ring groove 104 is provided with multiple sets of second connecting holes 106. Through the cooperation of the first inner ring groove 103 and the first outer ring groove 104, it can be quickly assembled or disassembled with other components, which facilitates the flexible splicing and length adjustment of the equipment.

[0038] The reaming head 301 connection mechanism includes a transition tube 201. The lower end of the transition tube 201 is provided with a second outer ring groove 202 corresponding to the first inner ring groove 103. The outer wall of the second outer ring groove 202 is provided with multiple sets of third connecting holes 203 corresponding to the first connecting hole 105. The transition tube 201 serves as the connection medium between the extension tube 1 and the reaming head 301. The first inner ring groove 103 and the second outer ring groove 202 are nested together, and bolts pass through the first connecting hole 105 and the third connecting hole 203 for fixation, ensuring stable transmission of grouting pressure and avoiding leakage at the connection.

[0039] The upper end of the transition pipe 201 is provided with a bucket-shaped connecting cover 204, and the upper end of the bucket-shaped connecting cover 204 is provided with a connecting flange ring 205. The bucket-shaped connecting cover 204 expands the cross-sectional area of ​​the grouting inlet, guides the grout to flow evenly into the extension pipe 1, and reduces fluid resistance and pressure loss. The connecting flange ring 205 provides a standard interface for easy and quick connection with the grouting head.

[0040] Multiple grouting grooves 502 are opened around the outer end of the tapered pipe head 5. A spiral drill bit 501 is fitted on the outer end of the tapered pipe head 5. The tapered pipe head 5 reduces the resistance of the device when inserting into soft soil, making it easier for the equipment to be quickly positioned to the target depth. The spiral drill bit 501 cuts the soft soil and breaks up the soil structure during the rotation and insertion process, creating favorable conditions for subsequent grouting. The grouting grooves 502 ensure the reinforcement effect of the bottom soil.

[0041] The lower end of the connecting pipe 4 is connected to the tapered pipe head 5. The upper end of the connecting pipe 4 is provided with a second inner ring groove 401 corresponding to the first outer ring groove 104. The inner wall of the second inner ring groove 401 is provided with multiple sets of fourth connecting holes 402 corresponding to the second connecting holes 106. The extension flower tube 1 and the tapered pipe head 5 are connected through the connecting pipe 4. The first outer ring groove 104 and the second inner ring groove 401 are nested together, and the bolts pass through the fourth connecting holes 402 of the second connecting holes 106 to achieve a detachable connection.

[0042] In the treatment of soft soil subgrade in highways, construction workers need to reinforce a section of soft soil foundation with high water content and low strength by grouting. First, the grouting depth and the required length of the extension pipe 1 are determined according to the design requirements. Multiple extension pipes 1 are spliced ​​together by using the first inner ring groove 103 at the upper end and the first outer ring groove 104 at the lower end of the extension pipe 1. After splicing, the extension pipe 1 is then firmly connected to the first inner ring groove 103 at the lower end and the first outer ring groove 104 at the lower end, the hole enlarger head 301, the connecting pipe 4, and the tapered pipe head 5. The spiral drill bit 501 is welded to the outer end of the tapered pipe head 5.

[0043] The grouting head extension device is quickly connected to the grouting head by connecting flange ring 205. During the grouting process, the grouting pressure of the grouting head can be adjusted according to the actual situation of the soft soil to control the entire grouting process. After the grouting is completed, the grouting head is closed, the connecting flange ring 205 is removed, the grouting head extension device is separated from the grouting system, and the equipment is cleaned and maintained.

[0044] Its working principle is as follows: when the grouting head is started, the grout enters the bucket-shaped connecting cover 204 through the connecting flange ring 205. Since the bucket-shaped connecting cover 204 expands the cross-sectional area of ​​the grouting inlet, it can guide the grout to flow evenly into the transition pipe 201, reducing fluid resistance and pressure loss. Then the grout enters the extension perforated pipe 1 stably. In the extension perforated pipe 1, the grout enters the adaptive pressure expansion mechanism 3 through the multiple sets of grouting ports 101 that are opened around and through.

[0045] At this point, the elastic grouting hopper 304 and the elastic expansion hole 305 play a crucial role. When the resistance of the soft soil is high and the grouting pressure increases, the elastic grouting hopper 304 deforms under pressure, and the diameter of the elastic expansion hole 305 expands accordingly, allowing more grout to be injected into the soft soil quickly. Conversely, when the resistance of the soft soil is low and the grouting pressure is low, the elastic grouting hopper 304 and the elastic expansion hole 305 return to their original shape, reducing the grout flow rate. Through this adaptive adjustment mechanism, the grouting flow rate is matched with the actual situation of the soft soil.

[0046] During the insertion of the device into the soft soil subgrade, the tapered pipe head 5, due to its unique shape, can effectively reduce the insertion resistance and enable the device to be quickly positioned to the target depth. At the same time, the spiral drill bit 501 continuously cuts the soft soil and breaks up the soil structure during the rotation and insertion process, creating favorable conditions for subsequent grouting. Furthermore, the grouting groove 502 at the outer end of the tapered pipe head 5 ensures that the bottom soil can be fully grouted and reinforced.

[0047] Its beneficial effects are significant. The adaptive pressure expansion mechanism 3, composed of the elastic grouting outer hopper 304 and the elastic expansion hole 305, achieves automatic adjustment of the grouting flow rate according to the actual conditions of the soft soil. Compared with traditional steel pipes with fixed holes, it greatly improves the uniformity of grouting and the reinforcement effect, ensuring that all parts of the soft soil subgrade receive appropriate grouting volume, effectively improving the foundation strength and stability. The use of embedded and external annular grooves combined with bolts between the extension pipe 1, transition pipe 201, connecting pipe 4, and tapered pipe head 5 allows for quick assembly or disassembly of the components. The equipment is designed for flexible splicing and length adjustment according to different engineering needs. In the event of equipment failure, specific components can be quickly replaced and maintained, improving construction efficiency and reducing maintenance costs. The design of the bucket-shaped connecting cover 204 effectively guides the grout to flow in evenly, reducing fluid resistance and pressure loss and ensuring stable transmission of grouting pressure. The cooperation between the spiral drill bit 501 and the conical pipe head 5 reduces the difficulty of inserting the device into soft soil, creating favorable conditions for grouting. At the same time, the grouting groove 502 ensures the reinforcement effect of the bottom soil, comprehensively improving the quality and efficiency of grouting reinforcement.

Claims

1. A grouting head extension device for grouting soft soil subgrade, comprising an extension perforated pipe (1); characterized in that, It also includes a grouting head connection mechanism (2), an adaptive pressure expansion mechanism (3), a connecting pipe (4), and a tapered pipe head (5); the upper end of the extension tube (1) is provided with a grouting head connection mechanism (2) for connecting the grouting head, and the lower part of the extension tube (1) is provided with a tapered pipe head (5) for easy penetration into the soft soil subgrade. The outer end of the tapered pipe head (5) is fitted with a spiral drill bit (501) for easy separation of the soft soil layer. The outer end of the extension tube (1) is surrounded by multiple sets of grouting ports (101), and the interior of each grouting port (101) is provided with an adaptive pressure expansion mechanism (3) for adjusting the grouting flow rate.

2. The grouting head extension device for soft soil subgrade grouting according to claim 1, characterized in that, The adaptive pressure reaming mechanism (3) includes a reaming head (301), which is located inside the grouting port (101). A fixing ring groove (102) is provided on the inner edge of the grouting port (101), and a fixing ring (302) corresponding to the fixing ring groove (102) is provided at the rear end of the reaming head (301).

3. The grouting head extension device for grouting soft soil subgrade according to claim 2, characterized in that, The center of the enlarged head (301) is provided with a grouting hole (303), the inside of the grouting hole (303) is provided with an elastic grouting outer hopper (304), and the center of the elastic grouting outer hopper (304) is provided with an elastic expansion hole (305).

4. The grouting head extension device for soft soil subgrade grouting according to claim 3, characterized in that, The upper end of the extension tube (1) is provided with a first inner ring groove (103), and the inner wall of the first inner ring groove (103) is provided with multiple sets of first connecting holes (105) through the circumference. The lower end of the extension tube (1) is provided with a first outer ring groove (104), and the outer wall of the first outer ring groove (104) is provided with multiple sets of second connecting holes (106) through the circumference.

5. The grouting head extension device for soft soil subgrade grouting according to claim 4, characterized in that, The enlarged head (301) connection mechanism includes a transition tube (201), and the lower end of the transition tube (201) is provided with a second outer ring groove (202) corresponding to the first inner ring groove (103). The outer wall of the second outer ring groove (202) is provided with multiple sets of third connecting holes (203) corresponding to the first connecting hole (105).

6. The grouting head extension device for grouting soft soil subgrade according to claim 5, characterized in that, The upper end of the transition pipe (201) is provided with a bucket-shaped connecting cover (204), and the upper end of the bucket-shaped connecting cover (204) is provided with a connecting flange ring (205).

7. The grouting head extension device for grouting soft soil subgrade according to claim 1, characterized in that, Multiple grouting grooves (502) are opened around the outer end of the tapered pipe head (5), and a spiral drill bit (501) is fitted on the outer end of the tapered pipe head (5).

8. The grouting head extension device for grouting soft soil subgrade according to claim 4, characterized in that, The lower end of the connecting pipe (4) is connected to the tapered pipe head (5), and the upper end of the connecting pipe (4) is provided with a second inner ring groove (401) corresponding to the first outer ring groove (104). The inner wall of the second inner ring groove (401) is provided with multiple sets of fourth connecting holes (402) corresponding to the second connecting hole (106).

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