Positioning targeted grouting plug and grouting construction method thereof

Abstract

This invention discloses a positioning and targeting grouting plug and its grouting construction method, including a grouting plug body (1) and a grout channel (2) inside the grouting plug body (1); an expansion sealing device (3) is arranged circumferentially on the outer periphery of the grouting plug body (1), and the inner cavity of the expansion sealing device (3) is connected to the grout channel (2); a pressure control and stabilizing valve (4) is provided at the grout outlet end of the grout channel (2), and the pressure control and stabilizing valve (4) has a preset opening pressure; this invention can drive the expansion sealing by the grouting fluid itself, with a simple structure, strong sealing pressure resistance, and good pore size adaptability, effectively improving the construction effect of seepage prevention and plugging.

Description

Technical Field

[0001] This invention relates to the field of engineering drilling grouting reinforcement technology, and in particular to a positioning and targeting grouting plug and its grouting construction method. Background Technology

[0002] In deep-hole drilling operations for projects such as tunnel excavation, mining, and water conservancy and hydropower, it is common to encounter geological sections with fractured and loose surrounding rock and poor strata stability. These conditions can easily lead to borehole wall collapse, borehole diameter shrinkage, and stuck drill bits, preventing normal drilling progress. The industry typically employs advanced grouting reinforcement technology, which uses grout to fill and bind the soil, improving the mechanical properties of the unfavorable strata and ensuring the continuous progress of drilling operations.

[0003] Currently used grouting and sealing devices are mostly split-type structures, requiring independent expansion medium pipelines and control systems. They rely on external media such as high-pressure water or compressed air to drive the expansion of the sealing capsule, achieving borehole wall sealing and grouting operations. Existing technologies have the following significant drawbacks in practical applications: First, the device structure is complex, resulting in low construction efficiency. Existing grouting plugs require separate expansion medium supply channels and control components, leading to a complex overall pipeline system. The adaptation and connection process with the grouting drill rod is cumbersome, and during deep hole placement, joint leakage and pipeline blockage are prone to occur, resulting in high construction risks and additional equipment costs and maintenance difficulties. Second, the adaptability and reliability of sealing are insufficient. The expansion coefficient and pressure-bearing strength of existing expansion sealing components are limited, making it difficult to adapt to irregular borehole diameters and borehole shrinkage caused by borehole collapse. During high-pressure grouting operations, sealing failure and grout backflow problems are likely to occur. Furthermore, after prolonged grouting operations, the expanded parts are prone to adhesion and solidification with the grout, causing the grouting plug to fail to retract properly, increasing construction losses. In addition, existing positioning and targeting grouting technology is usually only applicable to shallow holes within 100 meters. It is very difficult to reinforce deep holes (such as those exceeding 100 meters) under complex geological conditions. Often, due to the limitations of the grouting plug stopping process, the grout cannot accurately reach the predetermined depth, resulting in extremely high construction risks, poor grouting effect and high cost. Summary of the Invention

[0004] The purpose of this invention is to provide a positioning and targeting grouting plug and its grouting construction method. This invention relies on the grouting fluid itself to drive expansion and sealing, has a simple structure, strong sealing pressure resistance, and good pore size adaptability, effectively improving the construction effect of seepage prevention and plugging.

[0005] The technical solution of the present invention is as follows: A positioning and targeting grouting plug includes a grouting plug body, the grouting plug body having a grout channel; an expansion sealing device is circumferentially arranged on the outer periphery of the grouting plug body, the inner cavity of the expansion sealing device being connected to the grout channel; a pressure control and stabilizing valve is provided at the grout outlet end of the grout channel, the pressure control and stabilizing valve having a preset opening pressure; when the grouting pressure in the grout channel is lower than the preset opening pressure, the grout enters the internal cavity of the expansion sealing device, squeezing the expansion sealing device to expand radially; when the grouting pressure in the grout channel is higher than the preset opening pressure, the pressure control and stabilizing valve opens, and the grout flows out through the pressure control and stabilizing valve.

[0006] In the aforementioned positioning and targeting grouting plug, the grouting plug body includes a central column, with an inlet pipe and an outlet pipe respectively provided at both ends of the central column. The inlet pipe has an inlet hole on its side, and the outlet pipe has an outlet hole on its side. The grout channel is formed by the path of the inlet pipe, the inlet hole, the outlet hole, and the outlet pipe. Both the inlet hole and the outlet hole are connected to the inner cavity of the expansion sealing device. The pressure control and stabilizing valve is located at the end of the outlet pipe.

[0007] In the aforementioned positioning and targeting grouting plug, the expansion sealing device includes pressure plates disposed on the grout inlet pipe and the grout outlet pipe, and an elastic expansion sleeve is provided between the pressure plates to enclose the central column, the grout inlet hole and the grout outlet hole.

[0008] In the aforementioned positioning and targeting grouting plug, the corner of the pressure plate end has a chamfered transition.

[0009] In the aforementioned positioning and targeting grouting plug, the outer side of the grout inlet end of the grouting plug body is provided with connecting threads, which are sealed to the grouting drill rod.

[0010] The aforementioned grouting construction method for the targeted grouting plug is carried out according to the following steps:

[0011] Step S1: Carry out drilling operations according to the design parameters. When drilling reaches a section with poor geological conditions and the hole collapses, and repeated hole washing fails to pass, determine the location of the poor strata and record the depth of the hole collapse, then withdraw the drilling tools.

[0012] Step S2: Adjust the opening pressure of the pressure control and stabilizing valve of the positioning and targeting grouting plug according to the borehole depth and the water pressure coming out of the borehole; lower the positioning and targeting grouting plug to the design grouting depth corresponding to the collapsed section;

[0013] Step S3: Mix the grouting fluid, start the grouting pump to pump the grouting fluid into the positioning and targeting grouting plug, so that the pressure in the grout channel gradually increases; before the pressure reaches the preset opening pressure of the pressure control and stabilizing valve, the grouting fluid is filled into the expansion sealing device, driving the expansion sealing device to expand radially and press the hole wall to complete the sealing of the grout return channel;

[0014] Step S4: When the pressure in the grout channel exceeds the opening pressure of the pressure control and stabilizing valve, the pressure control and stabilizing valve opens, and the grout is injected into the unfavorable formation in front of the borehole until the design grouting pressure or design grouting volume is reached.

[0015] Step S5: After grouting is completed, use non-hardening liquid to push and replace the grouting fluid in the positioning and targeting grouting plug;

[0016] Step S6: Close the valve to maintain stable pressure inside the grouting plug and wait for the grouting fluid in the formation to solidify;

[0017] Step S7: After depressurizing the positioning and targeting grouting plug, pull it out to complete the positioning and targeting grouting reinforcement of the unfavorable strata.

[0018] In the aforementioned grouting construction method for the positioning and targeting grouting plug, the end of the positioning and targeting grouting plug is connected to a grouting drill rod via a connecting thread to extend the grouting depth of the positioning and targeting grouting plug.

[0019] In the aforementioned grouting construction method for the positioning and targeting grouting plug, the grouting fluid is selected from at least one of ordinary silicate cement grout, sulfoaluminate cement grout, modified water glass grout, ultrafine cement grout, bentonite grout, and acrylate grout.

[0020] In the aforementioned grouting construction method for the positioning and targeting grouting plug, the volume of the non-solidifying liquid in step S5 is greater than the total volume of the grouting liquid inside the positioning and targeting grouting plug.

[0021] In the aforementioned grouting construction method for the positioning and targeting grouting plug, a grouting effect evaluation step is included before step S6: if the grouting effect does not meet the design requirements, then steps S3 to S5 are repeated; if the design requirements are met, then step S6 is executed.

[0022] Compared with the prior art, the present invention relies on the pressure of the grouting fluid to drive the expansion sealing device to complete the hole wall sealing. There is no need to configure an additional independent expansion medium pipeline and control system. The device has a simple and reliable structure and can be connected to the grouting drill rod and lowered to any hole depth to realize fixed-point targeted grouting operation without limiting hole depth. Meanwhile, the expansion sealing device can adapt to irregular hole diameters and hole shrinkage caused by hole collapse, ensuring stable sealing performance and effectively avoiding grout backflow during high-pressure grouting. In particular, since deep hole grouting operations are usually lengthy, residual grout inside traditional devices is prone to solidification, making the grout plug unrecoverable. This invention, through an internal grout replacement process after grouting, completely replaces the solidifiable grout inside the device with a non-solidifying liquid, fundamentally preventing the grout from solidifying within the grout plug over a long period, thus ensuring the device can be successfully recovered and reused after long-term deep hole grouting operations. Furthermore, internal grout replacement after grouting prevents adhesion and solidification at the expansion sites, ensuring the device can be successfully recovered. Precise targeted grouting significantly reduces the consumption of ineffective grout in intact sections of the hole, significantly improving grout utilization and avoiding subsequent repeated hole sweeping operations. This shortens the construction cycle, reduces material costs and construction risks, and improves the engineering quality and overall economic benefits of deep hole pre-grouting reinforcement. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the positioning and targeting grouting plug of the present invention;

[0024] Figure 2 This is a schematic diagram of the grouting construction in step S1 of the present invention;

[0025] Figure 3 This is a schematic diagram of the grouting construction in step S2 of the present invention;

[0026] Figure 4 This is a schematic diagram of the grouting construction in steps S3 and S4 of the present invention;

[0027] Figure 5 This is a schematic diagram of the grouting construction in step S5 of the present invention;

[0028] Figure 6 This is a schematic diagram of the grouting construction in step S6 of the present invention;

[0029] Figure 7 This is a schematic diagram of the grouting construction in step S7 of the present invention.

[0030] The labels in the attached diagram are as follows: 1. Grout plug body; 2. Grout channel; 3. Expansion sealing device; 4. Pressure control and stabilizing valve; 5. Central column; 6. Grout inlet pipe; 7. Grout outlet pipe; 8. Grout inlet hole; 9. Grout outlet hole; 10. Pressure plate; 11. Elastic expansion sleeve; 12. Connecting thread; 13. Grouting drill rod. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0032] Example: A positioning and targeting grouting plug, as shown in the attached document. Figure 1 As shown, the device includes a grouting plug body 1, with a grout channel 2 inside the grouting plug body 1; an expansion sealing device 3 is arranged circumferentially on the outer periphery of the grouting plug body 1, and the inner cavity of the expansion sealing device 3 is connected to the grout channel 2; a pressure control and stabilizing valve 4 is installed at the grout outlet end of the grout channel 2, and the pressure control and stabilizing valve 4 is a spring-type pressure stabilizing structure that can be set with a preset opening pressure; preferably, the valve body can achieve stepless or stepped adjustment of the opening pressure by changing the spring with different stiffness or rotating the adjustment handle to adapt to the grouting requirements under different burial depths and water pressure conditions. When the grouting pressure in the grout channel 2 is lower than the preset opening pressure, the grout enters the internal chamber of the expansion sealing device 3, squeezing the expansion sealing device to expand radially; when the grouting pressure in the grout channel 2 is higher than the preset opening pressure, the pressure control and stabilizing valve 4 opens, and the grout flows out through the pressure control and stabilizing valve 4; the grout plug body 1 includes a solid central column 5, with an inlet pipe 6 and an outlet pipe 7 welded to both ends of the central column 5 respectively. Multiple inlet holes 8 are opened on the side of the inlet pipe 6, and multiple outlet holes 9 are opened on the side of the outlet pipe 7. The grout channel 2 is formed by the path of the inlet pipe 6, inlet holes 8, outlet holes 9, and outlet pipe 7. Both the inlet holes 8 and outlet holes 9 are connected to the... The expansion sealing device 3 has a connected inner cavity; the pressure control and stabilizing valve 4 is located at the end of the grout outlet pipe 7; the expansion sealing device 3 includes a pressure plate 10 located on the grout inlet pipe 6 and the grout outlet pipe 7, and a high-strength wear-resistant polyurethane rubber elastic expansion sleeve 11 is fixed between the pressure plates 10 to surround the central column 5, the grout inlet hole 8 and the grout outlet hole 9. The pressure plate and the elastic expansion sleeve form a cavity with the central column, part of the grout inlet pipe and part of the grout outlet pipe; the end corner of the pressure plate 10 has a chamfered transition to facilitate insertion into the borehole; the outer side of the grout inlet end of the grouting plug body 1 is fixed with a connecting thread 12, which has a tapered external thread that is compatible with the inner tapered thread of the standard grouting drill rod 13, and can achieve a quick sealing connection.

[0033] A grouting construction method for a targeted grouting plug is carried out according to the following steps:

[0034] Step S1: As attached Figure 2 As shown, drilling operations are carried out according to the design parameters. When drilling reaches a section with poor geological conditions and the hole collapses, and repeated hole washing fails to pass, the location of the poor strata is determined and the depth of the hole collapse is recorded, and the drilling tools are withdrawn.

[0035] Step S2: As attached Figure 3As shown, the opening pressure of the pressure control and stabilizing valve of the positioning and targeting grouting plug is adjusted according to the borehole depth and the water pressure in the borehole; the positioning and targeting grouting plug is sealed to the grouting drill rod through the connecting thread; the grouting drill rod is lengthened one by one according to the grouting depth requirement; and the grouting plug is lowered to the design grouting depth corresponding to the collapsed section of the hole.

[0036] Step S3: As attached Figure 4 As shown, the grouting fluid is prepared. The grouting fluid includes inorganic and organic grouting fluids such as ordinary silicate cement, sulfoaluminate cement, acrylate, modified water glass, ultrafine cement, and bentonite slurry, which are selected as needed according to the construction environment. The grouting pump is started to pump the grouting fluid into the grouting drill rod and the positioning and targeting grouting plug. The grouting fluid flows along the path of the grout inlet pipe, grout inlet hole, inner cavity of the expansion sealing device, grout outlet hole, and grout outlet pipe, so that the pressure in the grout channel gradually increases. Before the pressure reaches the preset opening pressure of the pressure control and stabilizing valve, the grouting fluid continues to fill the expansion sealing device, driving the expansion sealing device to expand radially and press against the hole wall, thus completing the sealing of the grout return channel.

[0037] Step S4: When the pressure in the grout channel exceeds the opening pressure of the pressure control and stabilizing valve, the pressure control and stabilizing valve opens, and the grout is injected into the unfavorable formation in front of the borehole until the design grouting pressure or design grouting volume is reached.

[0038] Step S5: As attached Figure 5 As shown, after grouting is completed, a non-solidifying liquid is used to push and replace the grouting fluid in the grouting drill rod and the positioning and targeting grouting plug. The volume of the non-solidifying liquid is greater than the total volume of the grouting fluid in the positioning and targeting grouting plug. The non-solidifying liquid refers to liquids such as water and hydraulic oil that do not react with the grouting fluid at normal temperature and pressure, remain liquid themselves, and do not have solidification properties. Its volume should be greater than the total volume of the grout channels inside the grouting drill rod and the grouting plug to ensure complete replacement. If the grouting effect does not meet the design requirements, steps S3 to S5 are repeated.

[0039] Step S6: As attached Figure 6 As shown, closing the valve maintains stable pressure inside the grouting plug, allowing for intermittent, small-volume replenishment of non-solidifying liquid to prevent the grouting liquid inside the plug from solidifying until the grouting liquid inside the formation solidifies.

[0040] Step S7: As attached Figure 7 As shown, the positioning and targeting grouting plug is depressurized and then pulled out to complete the positioning and targeting grouting reinforcement of the unfavorable strata.

[0041] In summary, this invention precisely controls the operation sequence through a preset pressure threshold of a pressure-regulating valve: during the low-pressure stage, grouting fluid is injected into the expansion sealing device, driving the elastic expansion sleeve to radially tighten, reliably sealing the annular gap in the borehole wall and preventing grouting fluid backflow; after pressure increase, the pressure-regulating valve automatically opens, and the grouting fluid is precisely injected into the target unfavorable stratum ahead. No additional independent expansion medium pipeline and control system are required throughout the process, resulting in a highly integrated device with simple operation. The device can be connected to standard grouting drill rods via connecting threads, and the lowering depth is not limited by the borehole depth, meeting the needs of targeted grouting in deep holes. The expansion sealing structure has high pressure resistance and strong expansion adaptability, effectively adapting to irregular borehole diameters and borehole shrinkage caused by borehole collapse, ensuring stable and reliable sealing performance. The accompanying construction method uses a grout replacement process to prevent the grouting fluid inside the device from solidifying and jamming, ensuring the smooth recovery and reuse of the grouting plug. Combined with grouting effect evaluation and replenishment grouting mechanisms, the quality of stratum reinforcement can be guaranteed. This invention significantly improves the accuracy and efficiency of deep hole grouting, reduces material consumption and construction risks, and has good application value in engineering fields such as tunnel reinforcement, mine water control, and water conservancy seepage prevention.

[0042] The above embodiments merely illustrate implementation methods of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. Furthermore, in these embodiments, "up," "down," "left," "right," "front," and "back" represent relative positions only, not absolute positions. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A positioning and targeting grouting plug, characterized in that: The device includes a grouting plug body (1), which has a grout channel (2) inside. An expansion sealing device (3) is arranged circumferentially around the grouting plug body (1), and the inner cavity of the expansion sealing device (3) is connected to the grout channel (2). A pressure control valve (4) is provided at the grout outlet of the grout channel (2), and the pressure control valve (4) has a preset opening pressure. When the grouting pressure in the grout channel (2) is lower than the preset opening pressure, the grout enters the internal cavity of the expansion sealing device (3) and squeezes the expansion sealing device (3) to expand radially. When the grouting pressure in the grout channel (2) is higher than the preset opening pressure, the pressure control valve (4) opens, and the grout flows out through the pressure control valve (4).

2. The positioning and targeting grouting plug according to claim 1, characterized in that: The grouting plug body (1) includes a central column (5), with a grout inlet pipe (6) and a grout outlet pipe (7) respectively at both ends of the central column (5). The grout inlet pipe (6) has a grout inlet hole (8) on its side, and the grout outlet pipe (7) has a grout outlet hole (9) on its side. The grout channel (2) is formed by the path of the grout inlet pipe (6), the grout inlet hole (8), the grout outlet hole (9), and the grout outlet pipe (7). The grout inlet hole (8) and the grout outlet hole (9) are both connected to the inner cavity of the expansion sealing device (3). The pressure control and stabilizing valve (4) is located at the end of the grout outlet pipe (7).

3. The positioning and targeting grouting plug according to claim 2, characterized in that: The expansion sealing device (3) includes a pressure plate (10) set on the slurry inlet pipe (6) and the slurry outlet pipe (7), and an elastic expansion sleeve (11) is provided between the pressure plates (10) to enclose the central column (5), the slurry inlet hole (8) and the slurry outlet hole (9).

4. The positioning and targeting grouting plug according to claim 3, characterized in that: The pressure plate (10) has a chamfered transition at the end corner.

5. The positioning and targeting grouting plug according to claim 1, characterized in that: The grouting plug body (1) has a connecting thread (12) on the outside of the grout inlet end, and the connecting thread (12) is sealed to the grouting drill rod.

6. The grouting construction method for the positioning and targeting grouting plug according to any one of claims 1-5, characterized in that: Follow these steps: Step S1: Carry out drilling operations according to the design parameters. When drilling reaches a section with poor geological conditions and the hole collapses, and repeated hole washing fails to pass, determine the location of the poor strata and record the depth of the hole collapse, then withdraw the drilling tools. Step S2: Adjust the opening pressure of the pressure control and stabilizing valve of the positioning and targeting grouting plug according to the borehole depth and the water pressure coming out of the borehole; lower the positioning and targeting grouting plug to the design grouting depth corresponding to the collapsed section; Step S3: Mix the grouting fluid, start the grouting pump to pump the grouting fluid into the positioning and targeting grouting plug, so that the pressure in the grout channel gradually increases; before the pressure reaches the preset opening pressure of the pressure control and stabilizing valve, the grouting fluid is filled into the expansion sealing device, driving the expansion sealing device to expand radially and press the hole wall to complete the sealing of the grout return channel; Step S4: When the pressure in the grout channel exceeds the opening pressure of the pressure control and stabilizing valve, the pressure control and stabilizing valve opens, and the grout is injected into the unfavorable formation in front of the borehole until the design grouting pressure or design grouting volume is reached. Step S5: After grouting is completed, use non-hardening liquid to push and replace the grouting fluid in the positioning and targeting grouting plug; Step S6: Close the valve to maintain stable pressure inside the grouting plug and wait for the grouting fluid in the formation to solidify; Step S7: After depressurizing the positioning and targeting grouting plug, pull it out to complete the positioning and targeting grouting reinforcement of the unfavorable strata.

7. The grouting construction method for the positioning and targeting grouting plug according to claim 6, characterized in that: In step S2, the end of the positioning and targeting grouting plug is connected to the grouting drill rod via a connecting thread to extend the grouting depth of the positioning and targeting grouting plug.

8. The grouting construction method for the positioning and targeting grouting plug according to claim 6, characterized in that: The grouting fluid is selected from at least one of ordinary silicate cement grout, sulfoaluminate cement grout, modified water glass grout, ultrafine cement grout, bentonite grout, and acrylate grout.

9. The grouting construction method for the positioning and targeting grouting plug according to claim 6, characterized in that: In step S5, the volume of the non-solidifying liquid is greater than the total volume of the grouting liquid in the positioning and targeting grouting plug.

10. The grouting construction method for the positioning and targeting grouting plug according to claim 6, characterized in that: Before step S6, there is also a grouting effect evaluation step: if the grouting effect does not meet the design requirements, then repeat steps S3 to S5; if the design requirements are met, then execute step S6.

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