Active splitting grouting device and grouting method suitable for reinforcing silty-fine sand layer

Abstract

The invention relates to the technical field of underground engineering grouting, in particular to an active splitting grouting device and method suitable for reinforcing a silty-fine sand layer. The splitting grouting device comprises a grouting assembly, a splitting assembly and a pushing assembly. The grouting assembly comprises a grouting pipe and a front flange, the front flange is fixedly installed on the grouting pipe, and a grout outlet hole is formed in the grouting pipe; the splitting assembly comprises a force transmission ring, a splitting pipe, a sliding sleeve and a supporting rod, the grouting pipe is sleeved with the force transmission ring, the inner end of the splitting pipe is hinged to a grout outlet of the grouting pipe, the splitting pipe is sleeved with the sliding sleeve, and the two ends of the supporting rod are hinged to the force transmission ring and the sliding sleeve respectively; the pushing assembly comprises a rear flange and a dowel bar, the grouting pipe is sleeved with the rear flange, and the two ends of the dowel bar are connected with the rear flange and the dowel ring respectively. Oriented split pulp veins are formed through the method, and the overall strength of the silty-fine sand layer is greatly enhanced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of underground engineering grouting, in particular to an active splitting grouting device and method suitable for reinforcing a silty fine sand layer. BACKGROUND

[0002] During the construction of underground projects, dense silty fine sand layers are often encountered. Due to the poor inter-particle bonding force, loose structure and strong water permeability of the silty fine sand layer, and especially its flow characteristics under the action of water, the construction of underground projects in the silty fine sand layer often faces the risk of collapse and outflow of the excavation surface, and the outflow of the silty fine sand layer leading to the "linkage" instability of the structure.

[0003] At present, there are the following technical problems in the grouting reinforcement of the silty fine sand layer, mainly in the following two aspects: 1. The particles in the silty fine sand layer are small, and the conventional grouting pipe grouting causes the water carried by the slurry to diffuse outward through the silty fine sand layer. The slurry particles are difficult to penetrate into the silty fine sand layer. With the progress of the grouting process, the slurry particles either form small slurry packages near the outlet of the grouting pipe and block the outlet, or flow back to the excavation surface of the underground project along the pores between the outlet and the stratum, forming a very thin reinforced layer. The grouting pressure rises rapidly during the grouting process, but the stratum consumes a small amount of slurry, and the overall reinforcement effect of the stratum is not good; 2. A small amount of slurry can form a splitting channel under pressure, but the slurry will extend indefinitely along the splitting channel during the grouting process, making it difficult to form a high-strength slurry vein system near the grouting pipe. When excavation is carried out after grouting is completed, it is difficult to find reinforced slurry veins in the excavation area, and the reinforcement of the silty fine sand layer cannot achieve the expected effect. SUMMARY

[0004] In view of the deficiencies of the prior art, the purpose of the embodiments of the present application is to provide an active splitting grouting device suitable for reinforcing a silty fine sand layer, which can actively split the slurry in the silty fine sand layer and form a slurry vein framework with supporting capacity, greatly improving the overall stability of the stratum.

[0005] In order to achieve the above-mentioned purpose, the embodiments of the present application provide the following technical solutions: An active splitting grouting device suitable for reinforcing a silty fine sand layer, comprising: a grouting assembly, a splitting assembly and a pushing assembly; the grouting assembly comprises a grouting pipe and a front flange, the front flange is fixedly installed on the outer wall of the grouting pipe, and a slurry outlet hole is formed in the wall of the grouting pipe; the splitting assembly comprises a force transmission ring, a splitting pipe, a sliding sleeve and a support rod, the force transmission ring is sleeved on the grouting pipe, the inner end of the splitting pipe is hingedly connected with the slurry outlet hole position of the grouting pipe, the sliding sleeve is sleeved on the splitting pipe, and the two ends of the support rod are hingedly connected with the force transmission ring and the sliding sleeve respectively; the pushing assembly comprises a rear flange and a force transmission rod, the rear flange is sleeved on the grouting pipe, and the two ends of the force transmission rod are connected with the rear flange and the force transmission ring respectively.

[0006] Optionally, the rear flange is located on the side of the front flange away from the splitting assembly, the front flange is provided with a through hole, and the force transmission rod is connected with the rear flange through the through hole of the front flange.

[0007] Optionally, in the initial state, the front flange and the rear flange have a set distance, and in the contact state of the front flange and the rear flange, the axis of the splitting pipe is perpendicular to the axis of the grouting pipe.

[0008] Optionally, the splitting assembly comprises a plurality of splitting pipes, and the plurality of splitting pipes are arranged in a circumferential array around the axis of the grouting pipe, and the inner end of each splitting pipe corresponds to a grouting hole.

[0009] Optionally, the splitting grouting device comprises a plurality of splitting assemblies, and the plurality of splitting assemblies are arranged along the length direction of the grouting pipe.

[0010] Optionally, the pushing assembly further comprises a pushing rod, the pushing rod is located between the front and rear splitting assemblies, and the two ends of the pushing rod are connected with the force transmission rings of the front and rear splitting assemblies respectively.

[0011] Optionally, the pushing rod between the two splitting assemblies is one group, and the pushing rods of the adjacent front and rear groups are arranged in a staggered manner in the circumferential direction.

[0012] Optionally, the force transmission rod has four, and the four force transmission rods are uniformly distributed on the outside of the grouting pipe in a circumferential array with the axis of the grouting pipe as the center; each group of pushing rods has three, and the three pushing rods are uniformly distributed on the outside of the grouting pipe in a circumferential array with the axis of the grouting pipe as the center.

[0013] The embodiment of the present application also provides a grouting method using the active splitting grouting device suitable for silt sand layer reinforcement, comprising the following steps: drilling a grouting hole in a region to be grouted and reinforced, inserting the splitting grouting device into the grouting hole to the silt sand layer region needing grouting; first fixing the front flange to push the rear flange forward, then driving the splitting pipe to rotate, so that the outer end of the splitting pipe contacts the inner wall of the grouting hole, then fixing the rear flange to pull the front flange backward until the front flange and the rear flange contact, at this time the outer end of the splitting pipe is inserted into the silt sand layer, and the inner end is connected with the grouting hole; starting grouting, the slurry first enters the grouting pipe, then enters each splitting pipe in turn, and continues to be pressurized, so that the slurry enters the silt sand layer through each splitting pipe, the silt sand layer is extruded and compacted, and after extrusion and compaction, splitting slurry veins are formed, and each splitting slurry vein constitutes a slurry vein skeleton with supporting capacity.

[0014] Optionally, the slurry is superfine cement-sodium silicate, the superfine cement is not less than 600 mesh, and the volume ratio of cement to sodium silicate is 1:1-4:1.

[0015] The one or more technical solutions provided in the embodiment of the present application have at least the following technical effects or advantages: 1、The splitting grouting device can accurately control the injection path and flow direction of the slurry through the design of active splitting. During the grouting process, the slurry enters the splitting pipe through the slurry outlet hole, ensuring that the slurry forms a directional splitting slurry vein, greatly enhancing the overall strength of the silty sand layer. Through this active control technology, the slurry injected into the formation forms a slurry vein skeleton with supporting capacity in the silty sand layer, improving the overall strength of the silty sand layer. At the same time, reinforcing more splitting slurry veins in the region can also have a compaction effect on the formation, reducing the permeability of the silty sand layer and ensuring the safety of underground engineering construction and operation in the silty sand layer.

[0016] 2、The splitting grouting device can effectively solve the problems of fast pressure rise during grouting in the silty sand layer, small formation slurry consumption, and low slurry retention rate in the reinforced area, avoiding the problem of slurry extending indefinitely along the splitting channel after entering the silty sand layer, which cannot form a splitting skeleton with supporting capacity.

[0017] 3、Through the design of the active splitting grouting device, artificial control of the number and direction of splitting slurry veins is achieved, reducing the unevenness and randomness of slurry diffusion in the traditional grouting process. At the same time, the generation of multiple splitting slurry veins also achieves compaction of the silty sand layer, reducing the permeability of the silty sand layer.

[0018] 4、The splitting grouting device can form radial splitting slurry veins in a single hole, and through the design of multiple holes in the silty sand layer, a splitting skeleton can be formed between two holes, forming a "network" structure of a self-stabilizing system, greatly increasing the self-stabilizing ability of the silty sand layer.

[0019] The advantages of the additional aspects of the present application will be given in the following description, some of which will become apparent from the following description, or will be understood by those skilled in the art through practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments described in the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings. In addition, the mutual distance or size is exaggerated for showing the position of each component, and the schematic diagram is only used for illustration.

[0021] Figure 1 is a whole schematic diagram of the splitting grouting device provided by the embodiment of the present application; Figure 2 is a schematic diagram of the splitting assembly in a folded state provided by the embodiment of the present application; Figure 3 is a schematic diagram of the splitting assembly in an unfolded state provided by the embodiment of the present application; Figure 4 is a schematic diagram of a cross section of a split vein provided by an embodiment of the present application; Figure 5 is a schematic diagram of a longitudinal section of a split vein provided by an embodiment of the present application; In the figure: 1, grouting assembly; 11, grouting pipe; 12, front flange; 13, grouting hole; 2, splitting assembly; 21, force transmission ring; 22, support rod; 23, sliding sleeve; 24, splitting pipe; 3, pushing assembly; 31, force transmission rod; 32, rear flange; 33, pushing rod; 4, fine sand layer; 5, split vein. DETAILED DESCRIPTION

[0022] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. 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 application belongs. Furthermore, it should be understood that the terms "comprise" and / or "comprising", when used in this specification, designate the presence of the stated features, steps, operations, devices, components and / or combinations thereof.

[0023] Embodiment 1 This embodiment is directed to the characteristics of grouting reinforcement that it is difficult for the grout to form multiple split veins 5 in the fine sand layer 4 near the grouting hole, and provides an active splitting grouting device suitable for reinforcement of the fine sand layer 4. As shown in Figure 1 , Figure 2 the splitting grouting device includes a grouting assembly 1, a splitting assembly 2 and a pushing assembly 3; the grouting assembly 1 includes a grouting pipe 11 and a front flange 12, the front flange 12 is fixedly installed on the outer wall of the grouting pipe 11, and the grouting pipe 11 has grouting holes 13 opened on the pipe wall; the splitting assembly 2 includes a force transmission ring 21, a splitting pipe 24, a sliding sleeve 23 and a support rod 22, the force transmission ring 21 is sleeved on the grouting pipe 11, the inner end of the splitting pipe 24 is hingedly connected with the grouting hole 13 of the grouting pipe 11, the sliding sleeve 23 is sleeved on the splitting pipe 24, and the two ends of the support rod 22 are respectively hingedly connected with the force transmission ring 21 and the sliding sleeve 23; the pushing assembly 3 includes a rear flange 32 and a force transmission rod 31, the rear flange 32 is sleeved on the grouting pipe 11, and the two ends of the force transmission rod 31 are respectively connected with the rear flange 32 and the force transmission ring 21.

[0024] The core of the grouting assembly 1 is the grouting pipe 11 and the front flange 12, the front flange 12 is fixed on the outer wall of the grouting pipe 11, and the grouting holes 13 are uniformly opened on the pipe wall of the grouting pipe 11, which plays a role in grout flow and diffusion. In actual use, the grout enters the splitting pipe 24 through these grouting holes 13.

[0025] The splitting assembly 2 is composed of a force transmission ring 21, a splitting pipe 24, a sliding sleeve 23 and a support rod 22. The force transmission ring 21 is sleeved on the grouting pipe 11, and the inner end of the splitting pipe 24 is connected with the position of the grouting hole 13 of the grouting pipe 11 through hinging. The sliding sleeve 23 is wrapped on the splitting pipe 24, and the two ends of the support rod 22 are hinged with the force transmission ring 21 and the sliding sleeve 23 respectively, which is used to open or fold the splitting pipe 24, and ensures the activity and stability of the splitting pipe 24.

[0026] The pushing assembly 3 includes a rear flange 32 and a force transmission rod 31. The rear flange 32 is sleeved on the grouting pipe 11, and the two ends of the force transmission rod 31 are connected with the rear flange 32 and the force transmission ring 21 respectively. Through the cooperation of the rear flange 32 and the force transmission rod 31, the splitting pipe 24 can be smoothly opened and inserted into the silty sand layer 4, forming an effective grout vein skeleton.

[0027] The rear flange 32 is located on the side of the front flange 12 away from the splitting assembly 2. The front flange 12 is provided with a through hole, and the force transmission rod 31 passes through the through hole of the front flange 12 to connect with the rear flange 32.

[0028] Through the through hole, the force transmission rod 31 can smoothly pass through the front flange 12, thereby realizing the pushing action on the force transmission ring 21 during the grouting process. The relative movement between the front flange 12 and the rear flange 32 ensures that the splitting pipe 24 can effectively expand in the grouting area, ensuring that the splitting pipe 24 can smoothly enter and stabilize in the silty sand layer 4 during construction operation, thereby enhancing the operability and reliability of the overall structure.

[0029] As shown in Figure 1 , in the initial state, the front flange 12 and the rear flange 32 have a set distance, as shown in Figure 3 , in the contact state of the front flange 12 and the rear flange 32, the axis of the splitting pipe 24 is perpendicular to the axis of the grouting pipe 11. By setting the distance between the front flange 12 and the rear flange 32, the opening angle of the splitting pipe 24 can be accurately controlled, ensuring that the splitting pipe 24 can be stably inserted into the silty sand layer 4 during grouting.

[0030] The splitting assembly 2 includes a plurality of splitting pipes 24, which are arranged in a circumferential array around the axis of the grouting pipe 11. The inner end of each splitting pipe 24 corresponds to a grouting hole 13, and the inner diameter of the splitting pipe 24 is equal to the diameter of the grouting hole 13. The grout enters the splitting pipe 24 from the grouting hole 13 of the grouting pipe 11, and then enters the formation through the opening at the outer end of the splitting pipe 24, forming a directional splitting grout vein 5. The design of multiple splitting pipes 24 improves the uniformity and accuracy of grout injection, avoiding uneven diffusion of grout during grouting. Through the circumferential array arrangement, the coverage of the splitting pipe 24 in the formation can be more extensive, thereby enhancing the reinforcement effect on the silty sand layer 4.

[0031] The splitting grouting device comprises a plurality of sets of splitting assemblies 2 arranged along the length direction of the grouting pipe 11. Through the arrangement of the plurality of sets of splitting assemblies 2, the grouting device can work simultaneously at multiple different positions, forming a more complex grout vein skeleton, improving the coverage density of the reinforced area, and effectively reinforcing the fine sand layer 4 in a larger range. At the same time, this structure can enhance the uniformity and stability of the grouting effect, further improving the support capacity of the reinforced layer.

[0032] As shown in Figure 2 The pushing assembly 3 further comprises a pushing rod 33 located between the front and rear splitting assemblies 2, and the two ends of the pushing rod 33 are respectively connected to the force transmission rings 21 of the front and rear splitting assemblies 2. The design of the pushing rod 33 can provide a pushing force during the grouting process, ensuring the coordinated movement between the plurality of sets of splitting assemblies 2, and through the step-by-step transmission of the pushing rod 33, the splitting pipes 24 are simultaneously opened and inserted into the fine sand layer 4.

[0033] The pushing rod 33 between the two sets of splitting assemblies 2 is one set, and the pushing rods 33 of the adjacent front and rear sets are arranged in a staggered manner in the circumferential direction. This arrangement enhances the stability and balance of the splitting assembly 2, and through the staggered arrangement of the pushing rod 33, the grouting device can work more stably, avoiding instability caused by uneven force between the pushing rods 33.

[0034] In this embodiment, the force transmission rod 31 has four, and the four force transmission rods 31 are arranged in a circumferential array on the outside of the grouting pipe 11 with the axis of the grouting pipe 11 as the center; each set of pushing rod 33 has three, and the three pushing rods 33 are arranged in a circumferential array on the outside of the grouting pipe 11 with the axis of the grouting pipe 11 as the center, ensuring the balance and stability of the grouting device, effectively avoiding the phenomenon of deviation or mechanical imbalance, and ensuring that the device can maintain a stable working state in actual work.

[0035] Embodiment 2 This embodiment provides a grouting method using the active splitting grouting device suitable for fine sand layer 4 reinforcement of embodiment 1, comprising: Hole is opened in the area to be grouted and reinforced, and the hole is sealed with a hole sealing pipe. After sealing and consolidation, drilling is continued to the fine sand layer 4 area to form a grouting hole, and the splitting grouting device is inserted into the grouting hole to the fine sand layer 4 area that needs to be grouted. As shown in Figure 2 The splitting pipe 24 on the grouting pipe 11 is in a retracted state before entering the stratum, and the diameter of the retracted splitting pipe 24 and the grouting pipe 11 is smaller than the diameter of the grouting hole, ensuring that the active splitting grouting device can smoothly enter the grouting area.

[0036] First, the front flange 12 is fixed to push the rear flange 32 forward, and the force transmission ring 21 is driven to move forward through the force transmission rod 31 and the pushing rod 33, and then the split pipe 24 is rotated, so that the outer end of the split pipe 24 contacts the inner wall of the grouting hole; then the rear flange 32 is fixed to pull the front flange 12 backward, the split pipe 24 continues to rotate until the front flange 12 and the rear flange 32 contact, at this time the split pipe 24 is perpendicular to the grouting pipe 11 (as shown in Figure 3 The outer end of the split pipe 24 is inserted into the fine sand layer 4, and the inner end is connected to the grouting hole 13.

[0037] The grouting pipe 11 is connected to the grouting joint, and the flange, the front flange 12 and the rear flange 32 of the orifice pipe are connected in turn by bolts, and the grouting pipe 11 and the split pipe 24 are fixed.

[0038] Start grouting, the slurry first enters the grouting pipe 11, then enters each split pipe 24 in turn, when the grouting pressure increases slightly, at this time the grouting pipe 11 and the split pipe 24 are filled with slurry; continue to pressurize, so that the slurry enters the fine sand layer 4 through each split pipe 24, and the fine sand layer 4 is compacted, and the split grout vein 5 is formed after compaction, and each split grout vein 5 constitutes a grout vein skeleton with supporting capacity (as shown in Figure 4 、 Figure 5 ).

[0039] The slurry is superfine cement-silicate, the superfine cement is not less than 600 mesh, and the volume ratio of cement-silicate is 1:1-4:1. The special formula of the slurry can provide strong reinforcement effect and ensure the fluidity and permeability of the slurry. Through the method, the slurry can be uniformly and directionally injected into the fine sand layer 4, so as to effectively form a grout vein skeleton with supporting capacity, and ensure the safety of underground engineering construction and operation in the fine sand layer 4.

[0040] Although the specific embodiments of the present application have been described above with reference to the drawings, it is not a limitation on the scope of protection of the present application, and those skilled in the art should understand that various modifications or changes made by those skilled in the art on the basis of the technical solutions of the present application without creative labor are still within the scope of protection of the present application.

Claims

1. An active splitting grouting device suitable for reinforcing fine sand layers, characterized in that, include: Grouting assembly, fracturing assembly, and propulsion assembly; The grouting assembly includes a grouting pipe and a front flange. The front flange is fixedly installed on the outer wall of the grouting pipe, and a grout outlet hole is provided on the pipe wall of the grouting pipe. The splitting assembly includes a force transmission ring, a splitting tube, a sliding sleeve, and a support rod. The force transmission ring is sleeved on the grouting tube, the inner end of the splitting tube is hinged to the grout outlet of the grouting tube, the sliding sleeve is sleeved on the splitting tube, and the two ends of the support rod are respectively hinged to the force transmission ring and the sliding sleeve. The pushing assembly includes a rear flange and a force transmission rod. The rear flange is sleeved on the grouting pipe, and the two ends of the force transmission rod are respectively connected to the rear flange and the force transmission ring.

2. The active splitting grouting device for reinforcing fine sand layers as described in claim 1, characterized in that, The rear flange is located on the side of the front flange away from the splitting assembly. The front flange has a through hole, and the force transmission rod passes through the through hole of the front flange and connects to the rear flange.

3. The active splitting grouting device for reinforcing fine sand layers as described in claim 2, characterized in that, In the initial state, there is a set distance between the front flange and the rear flange. When the front flange and the rear flange are in contact, the axis of the splitting pipe is perpendicular to the axis of the grouting pipe.

4. The active splitting grouting device for reinforcing fine sand layers as described in claim 1, characterized in that, The splitting assembly includes multiple splitting pipes, which are arranged in a circumferential array around the axis of the grouting pipe, with each splitting pipe having a corresponding grout outlet at its inner end.

5. The active splitting grouting device for reinforcing fine sand layers as described in claim 1, characterized in that, The splitting grouting device includes multiple sets of splitting components, which are arranged along the length of the grouting pipe.

6. The active splitting grouting device for reinforcing fine sand layers as described in claim 5, characterized in that, The pushing assembly also includes a push rod, which is located between the front and rear splitting assemblies, and the two ends of the push rod are respectively connected to the force transmission rings of the front and rear splitting assemblies.

7. The active splitting grouting device for reinforcing fine sand layers as described in claim 6, characterized in that, The push rods between the two sets of splitting components form a group, and the push rods of the two adjacent groups are staggered in the circumferential direction.

8. The active splitting grouting device for reinforcing fine sand layers as described in claim 7, characterized in that, The force transmission rods are four in number, and are evenly distributed in a circular array on the outside of the grouting pipe with the axis of the grouting pipe as the center. Each set of push rods has three in number, and are evenly distributed in a circular array on the outside of the grouting pipe with the axis of the grouting pipe as the center.

9. A grouting method using an active fracturing grouting device suitable for reinforcing fine sand layers as described in any one of claims 1-8, characterized in that, include: Drill grouting holes in the area to be reinforced by grouting, and insert the splitting grouting device into the grouting hole into the fine sand layer area that needs to be grouted; First, fix the front flange and push the rear flange forward, which will drive the splitting pipe to rotate, so that the outer end of the splitting pipe contacts the inner wall of the grouting hole. Then fix the rear flange and pull the front flange backward until the front flange and the rear flange contact each other. At this time, the outer end of the splitting pipe is inserted into the fine sand layer, and the inner end is connected with the grout outlet hole. Grouting begins with the grout entering the grouting pipe first, then sequentially entering each fracturing pipe. Pressurization continues, allowing the grout to pass through each fracturing pipe into the fine sand layer, compacting the fine sand layer and forming fracturing grout veins. Each fracturing grout vein constitutes a grout vein skeleton with supporting capacity.

10. The grouting method as described in claim 9, characterized in that, The slurry is an ultrafine cement-water glass mixture, wherein the ultrafine cement is not less than 600 mesh and the volume ratio of cement to water glass is 1:1-4:1.

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