Drilling and grouting integrated device with automatic monitoring and grout return prevention functions and construction method

Abstract

The invention provides a drilling and grouting integrated device with automatic monitoring and grout return prevention functions and a construction method, and relates to the field of drilling and grouting, a first check valve and a second check valve are matched with each other, and flowing of grout is controlled from different positions and layers. The first check valve mainly aims at a channel between the inner pipe and the outer pipe to prevent slurry in the channel from flowing back; the second check valve focuses on guaranteeing the stability of the slurry at the joint of the inner pipes and preventing the slurry in the inner pipes from returning; all the components act together to form a complete grout return prevention system, so that the problem that grout returns along a pipeline when grouting is stopped is solved directly and effectively structurally, continuity, stability and high efficiency of drilling and grouting operation are ensured, and reliable technical guarantee is provided for engineering such as stratum reinforcement. Parameters in the slurry solidification process are obtained through the monitoring element, so that automatic monitoring of the slurry grouting process and the solidification process is achieved, the grouting quality is improved, and the grouting effect is guaranteed.

Description

Technical Field

[0001] The invention relates to the field of drilling and grouting, and in particular to a drilling and grouting integrated device with automatic monitoring and anti-return grouting functions and a construction method. Background Art

[0002] The integrated drilling and grouting device has been widely used in many scenarios such as tunnel advance support, coal mine tunnel support and urban underground space development. By integrating drilling and grouting functions, the traditional multi-step process is simplified to one step, greatly speeding up the construction speed. When constructing in soft and loose strata, the integrated drilling and grouting device can perform grouting in real time, effectively preventing problems such as hole collapse, ground collapse and soil erosion, and improving the stability of the stratum and the overall support effect. In addition, the integrated drilling and grouting device can grout immediately after the drilling is completed, avoiding the problem of inadequate grouting caused by time delay in traditional methods, and improving the accuracy and effectiveness of grouting.

[0003] A Chinese patent (publication number CN205918368U, publication date 20170201) discloses a drilling and grouting integrated retreating drill pipe, wherein the joint is connected to the outer tube, the core tube is located inside the outer tube, the outer tube joint is connected to the outer tube, the tail cap is connected to the core tube, the inner tube abdominal cavity is connected to the outer tube abdominal cavity by inner and outer tube fasteners, the steel washer is in close contact with the inner wall of the joint, the joint is located in the middle of the outer tube, the bearing, the steel hoop, and the outer tube joint are all fixed on the outer tube by a fastening cap, both ends of the core tube are connected to a rubber sealing ring, and the bottom of the core tube and the top of the rubber sealing ring are fixed by a tail cap. However, there are problems such as low water or slurry flow rate at the front end (drill bit direction) and uneven mixing of the two liquid slurries, and the slurry is easy to return along the pipeline during the grouting stop, which is inconvenient for real-time monitoring of the grouting effect inside the formation. Summary of the invention

[0004] The purpose of the present invention is to provide a drilling and injection device and construction method with automatic monitoring and anti-grouting in order to address the defects of the prior art. The first check valve and the second check valve cooperate with each other to control the flow of slurry from different positions and levels. The first check valve is mainly aimed at the channel between the inner pipe and the outer pipe to prevent the slurry in the channel from flowing back; the second check valve focuses on ensuring the stability of the slurry at the joint of the inner pipe and preventing the slurry in the inner pipe from flowing back. They work together to form a complete anti-slurry backflow system, which directly and effectively solves the problem of slurry returning along the pipeline during the period of stopping grouting from a structural point of view, ensures the continuity, stability and efficiency of the drilling and injection operation, and provides reliable technical guarantees for projects such as stratum reinforcement.

[0005] The first object of the present invention is to provide a drilling and injection device with automatic monitoring and anti-return slurry, which adopts the following scheme:

[0006] It comprises a plurality of drilling and injection pipes which are detachably connected along the axial direction, each drilling and injection pipe is provided with an inner pipe and an outer pipe which is sleeved outside the inner pipe, slurry channels are formed between the inner pipe and the inner pipe and the outer pipe respectively, the drilling and injection pipe located at the head end is the head end drilling and injection pipe, the drilling and injection pipe located at the tail end is the tail end drilling and injection pipe, a first check valve is provided between the inner pipe and the outer pipe of the drilling and injection pipe, a second check valve is provided at the position where the inner pipe is connected to the inner pipe of the different drilling and injection pipe, a drill bit is installed at the front end of the head end drilling and injection pipe, a water braid shaft is installed at the end of the tail end drilling and injection pipe, and a monitoring element is installed outside the end of the head end drilling and injection pipe close to the drill bit.

[0007] Furthermore, a Laval nozzle is provided at one end of the inner tube of the first-end drilling and injection pipe toward the drill bit, a space is formed inside the drill bit for the Laval nozzle and the slurry channel to output slurry mixing, and a slurry outlet hole is provided on the drill bit.

[0008] Furthermore, a support frame for maintaining the relative positions of the inner pipe and the outer pipe of the drilling and injection pipe is provided between the inner pipe and the outer pipe, and the slurry channels on both sides of the support frame are connected through the support frame.

[0009] Furthermore, the first check valve is provided with two valve plates in a fan-shaped shape, and the valve plates jointly open or block the slurry channel formed between the inner tube and the outer tube.

[0010] Furthermore, one end of the inner tube axially protrudes out of one end of the outer tube and is installed with a second check valve, and the other end of the inner tube is retracted into the other end of the outer tube to cooperate with the second check valve.

[0011] Furthermore, a threading tube is provided on the outside of the drilling and injection pipe, and the threading tubes corresponding to the connected drilling and injection pipes are butt-connected. The threading tube contains cables, one end of the cable extends to the first drilling and injection pipe and is connected to the monitoring element, and the other end extends to the rear drilling and injection pipe and is led out to access the communication terminal.

[0012] Furthermore, the monitoring element is located outside the threading tube and behind the drill bit.

[0013] Furthermore, the outer tube of the drilling and injection pipe is butt-jointed with the outer tube of a different drilling and injection pipe, and the inner tube of the drilling and injection pipe is butt-jointed with the inner tube of a different drilling and injection pipe, forming two isolated slurry channels in the drilling and injection pipe, and the two slurry channels are respectively connected to slurry supply pipes through water braid shafts.

[0014] The second object of the present invention is to provide a construction method of the drilling and injection device with automatic monitoring and anti-return grouting as described in the first object, comprising:

[0015] Multiple drilling and injection pipes are connected in sequence along the axial direction to form a drilling and injection rod, a drill bit is provided on the first end of the drilling and injection pipe, a water braid shaft of the drilling and injection pipe at the tail end is connected to a slurry supply source, and the drilling and injection rod is installed to a power device;

[0016] The power equipment drives the drilling rod to rotate and move forward at the same time, and the drill bit drills to form a borehole;

[0017] Slurry is injected into the drilling and injection pipe through the water braid axis, and the water glass slurry sprayed from the Laval nozzle is fully mixed with the cement slurry sprayed from the slurry channel, and then sprayed from the drill bit and injected into the formation;

[0018] After the grouting operation is completed, the drill rod will be pulled out.

[0019] Furthermore, water glass slurry is injected into the inner tube through the water braid shaft, and the water glass slurry flows in the slurry channel inside the inner tube. The prepared cement slurry is injected between the inner tube and the outer tube, and the cement slurry flows in the slurry channel between the inner tube and the outer tube.

[0020] Compared with the prior art, the present invention has the following advantages and positive effects:

[0021] The first check valve and the second check valve cooperate with each other to control the flow of slurry from different positions and levels. The first check valve is mainly used for the channel between the inner tube and the outer tube to prevent the slurry in the channel from flowing back; the second check valve focuses on ensuring the stability of the slurry at the joint of the inner tube and preventing the slurry in the inner tube from flowing back. They work together to form a complete anti-slurry backflow system, which directly and effectively solves the problem of slurry flowing back along the pipeline during the cessation of grouting from a structural perspective, ensuring the continuity, stability and efficiency of the drilling and injection operation, and providing reliable technical support for projects such as stratum reinforcement.

[0022] In view of the problems that the water or slurry flow rate in the drill bit direction of the current drilling and injection device is low and the double slurries are not mixed evenly, a Laval nozzle is arranged on the drilling and injection pipe at the head end of the entire drilling and injection pipe. The special structure of the Laval nozzle can accelerate the slurry, thereby solving the problem of low flow rate at the front end, and the slurry output by the Laval nozzle and the slurry channel is mixed in the space formed inside the drill bit, providing a special mixing space. Compared with the existing technology, it is more conducive to the uniform mixing of the double liquid slurry, solves the problem of uneven mixing of the double liquid slurry, makes the slurry performance more stable, thereby improving the grouting quality and ensuring the grouting effect.

[0023] The space inside the drill bit is connected to the slurry channel formed between the inner tube and the outer tube. The inner tube of the first end drilling and injection pipe is connected to the space inside the drill bit through the Laval nozzle, and the drill bit and the first end drilling and injection pipe are coaxially connected. There are multiple grouting holes that are connected to the space inside the drill bit, which optimizes the mixing process of the double liquid slurry at the drill bit, ensuring that the mixed slurry can be evenly output from multiple grouting holes, improving the uniformity and effect of grouting. Cement slurry releases heat during the hydration process, and the change in its hydration temperature is closely related to the consolidation process of cement. By measuring the temperature with a wireless temperature sensor and sending it to the communication terminal, construction personnel can understand the hydration process of cement slurry in real time. After the cement slurry is injected into the formation, the temperature will gradually increase, reach a peak, and then gradually decrease. If the temperature changes abnormally, such as the temperature rises too fast or too slowly, it may mean that the cement hydration reaction is abnormal, and factors such as the slurry ratio and ambient temperature need to be checked. Construction workers can roughly estimate the strength of the cement consolidation body based on temperature changes and relevant empirical formulas, and thus decide when to proceed with the next construction operation, such as dismantling the supporting structure and conducting subsequent drilling and injection operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0025] Figure 1 It is a schematic diagram of a drilling and injection device with automatic monitoring and anti-return grouting in one or more embodiments of the present invention.

[0026] Figure 2 Schematic diagram of a second check valve in one or more embodiments of the present invention.

[0027] Figure 3 Schematic diagram of a first check valve in one or more embodiments of the present invention.

[0028] Figure 4 Schematic diagram of a support frame in one or more embodiments of the present invention.

[0029] Among them, 1. slurry outlet hole; 2. drill bit; 3. Laval nozzle; 4. support frame; 5. inner pipe; 6. outer pipe; 7. first check valve; 8. second check valve; 9. first grouting pipe; 10. second grouting pipe; 11. monitoring element; 12. threading pipe; 13. cable; 14. communication terminal. DETAILED DESCRIPTION

[0030] Example 1

[0031] In a typical embodiment of the present invention, Figure 1-Figure 4 As shown, a drilling and injection device with automatic monitoring and anti-return slurry is provided.

[0032] In engineering scenarios such as tunnel advance support, coal mine roadway support, and urban underground space development that require integrated drilling and injection devices, the water or slurry flow rate at the front end (drill bit 2 direction) of the drilling and injection device in the prior art is insufficient, resulting in low drilling efficiency. It is difficult to drill quickly and effectively in some complex formations (such as hard or viscous formations), affecting the construction progress. Based on this, this embodiment provides an integrated drilling and injection device with automatic monitoring and anti-return slurry. By setting a Laval nozzle 3 in the inner tube 5 of the drilling and injection pipe at the head end, using its special gradually contracting and expanding structure, the pressure energy of the slurry is converted into kinetic energy when passing through the nozzle, which significantly improves the front end slurry flow rate, effectively solves this problem, and enhances the drilling ability in various formations.

[0033] In addition, during the grouting operation, the uneven mixing of the two liquid slurries will make the slurry solidification performance unstable, affecting the formation reinforcement effect. The previous technology lacked a special and effective mixing space and method. In this embodiment, a space for the Laval nozzle 3 and the slurry channel to output the slurry is constructed inside the drill bit 2, so that the two liquid slurries are fully mixed here, ensuring the stability of the slurry performance, improving the grouting quality, ensuring the reliability of the formation support, and reducing the risks of formation settlement and collapse caused by slurry quality problems.

[0034] like Figure 1-Figure 4 As shown, the integrated drilling and grouting device with automatic monitoring and anti-return grouting is composed of multiple drilling and grouting pipes that are detachably connected along the axial direction, which is convenient for flexible assembly and disassembly according to the drilling depth requirements of different projects. Each drilling and grouting pipe has an inner pipe 5 and an outer pipe 6, and independent slurry channels are formed between the inner pipe 5 and the outer pipe 6 and inside the inner pipe 5. The double slurry channel structure is conducive to the separate transportation of different slurries, such as cement slurry in one slurry channel and water glass slurry in another slurry channel. A drill bit 2 is set at the head end of the drilling and grouting pipe, and a water braid shaft is set at the tail end of the drilling and grouting pipe, realizing the integrated integration of drilling and grouting functions, and providing a structural basis for solving flow rate and mixing problems.

[0035] A Laval nozzle 3 is installed at the end of the inner tube 5 of the head-end drilling and injection pipe facing the drill bit 2. Its special geometric shape of first contraction and then expansion can accelerate the slurry during the flow process. When the slurry enters the gradually contracting section of the nozzle from a relatively large cross-section, the flow rate increases and the pressure decreases. After passing through the throat and entering the expansion section, the pressure further decreases and the flow rate increases sharply, thereby providing a high-speed slurry flow to the front end, solving the problem of insufficient flow rate at the front end, ensuring that the formation can be effectively impacted and rock cuttings can be carried during the drilling process, and improving the drilling efficiency.

[0036] A space is formed inside the drill bit 2, so that it is connected with the Laval nozzle 3 and the slurry channel. The high-speed slurry from the Laval nozzle 3 and the slurry transported by the slurry channel between the inner tube 5 and the outer tube 6 fully intersect and collide inside the drill bit 2, and the spatial structure inside the drill bit 2 is used to promote the uniform mixing of the two liquid slurries, ensuring that the slurry reaches a good mixing state before being injected into the formation, thereby improving the effect of grouting on the formation reinforcement.

[0037] The accelerated slurry from the Laval nozzle 3 has a stronger impact force at the drill bit 2, which can more efficiently break the formation rock, speed up the drilling speed, and reduce the construction time. Under the same construction conditions, compared with the traditional drilling and injection device, the drilling operation can be completed in a shorter time, improving the overall construction efficiency, especially in complex formations, reducing the construction cost and the risk of delays.

[0038] The stable and effective mixing space inside the drill bit 2 ensures that the two liquid slurries are evenly mixed, making the strength of the solidified body formed after the slurry solidifies more uniform and the performance more reliable. This significantly improves the formation reinforcement effect, enhances the bearing capacity and stability of the formation, effectively prevents formation deformation, collapse and other problems, improves the safety and durability of the project, and reduces subsequent maintenance costs and potential safety hazards.

[0039] After the grouting operation is suspended or a stage is completed, the slurry is prone to flow back along the pipeline due to pressure difference and other reasons, causing pipeline blockage, equipment damage and affecting the subsequent grouting effect. The traditional drilling and injection device lacks an effective anti-backflow mechanism. In this embodiment, a first check valve 7 is installed between the inner pipe 5 and the outer pipe 6 of the drilling and injection pipe, and a second check valve 8 is installed at the joint of the inner pipe 5 of different drilling and injection pipes. The structural design of the check valve allows the slurry to flow forward during normal grouting, and when the pressure changes in the opposite direction, the valve is immediately closed to prevent the slurry from flowing back.

[0040] By setting a first check valve 7 between the inner tube 5 and the outer tube 6 and setting a second check valve 8 at the connecting position of the inner tube 5, the one-way conduction characteristic of the check valve is utilized to effectively prevent the backflow of slurry, thereby ensuring the stability and reliability of the grouting system and avoiding a series of construction problems and equipment maintenance difficulties caused by the backflow of slurry.

[0041] It should be noted that the first check valve 7 is a special-shaped check valve adapted to the annular space between the inner tube 5 and the outer tube 6. Figure 3As shown, the first check valve 7 is provided with a fan-shaped valve plate, and the first check valve 7 is provided with two fan-shaped valve plates, which jointly open or block the slurry channel formed between the inner tube 5 and the outer tube 6. The second check valve 8 is a structure adapted to the end of the inner tube 5, and the sealing performance and opening pressure of the first check valve 7 and the second check valve 8 are adaptively adjusted to adapt to the pressure change range during the drilling and injection process, ensuring that the slurry can be effectively prevented from returning under various working conditions and ensuring the normal operation of the grouting system.

[0042] During the drilling and injection process, the inner tube 5 and the outer tube 6 may be relatively displaced due to vibration, uneven force and other factors, thereby affecting the patency of the slurry channel and the performance of the entire drilling and injection device. Figure 1 and Figure 4 As shown, a support frame 4 is arranged between the inner tube 5 and the outer tube 6 of the drilling and injection pipe. The support frame 4 is made of high-strength, corrosion-resistant material, and its shape and size are customized according to the structure of the inner tube 5 and the outer tube 6. The support frame 4 is firmly fixed between the inner tube 5 and the outer tube 6 by welding, clamping or bolting. The support frame 4 can stabilize the relative position of the inner tube 5 and the outer tube 6 to prevent them from shifting, shaking, etc. in a complex construction environment. In addition, sufficient space is reserved for the slurry channel to pass through, ensuring that the slurry can flow smoothly in the channel without affecting the grouting operation, ensuring the normal operation of the slurry channel, maintaining the structural integrity of the drilling and injection pipe, improving the durability and service life of the device, and reducing the number of failures and repairs caused by structural instability.

[0043] In order to achieve a better formation reinforcement effect, the dual-liquid slurry needs to be fully mixed and uniformly injected into the formation. Although the previous design has certain mixing measures, its mixing effect is still difficult to meet the needs. In this embodiment, the internal space of the drill bit 2 is structurally adjusted to form a close connection with the slurry channel between the inner tube 5 and the outer tube 6 and the Laval nozzle 3 of the first end drilling and injection pipe. Through the connection between the internal space of the drill bit 2 and the slurry channels of the inner tube 5 and the outer tube 6 and the connection between the Laval nozzle 3 and the internal space of the drill bit 2, the Laval nozzle 3 directly introduces the high-speed sprayed slurry into the internal mixing space of the drill bit 2, optimizing the mixing path and method of the dual-liquid slurry, so that the two slurries can be more fully mixed inside the drill bit 2, and are uniformly injected into the formation with the help of multiple connected grouting holes, which improves the uniformity and effectiveness of grouting and enhances the quality and stability of formation reinforcement.

[0044] In engineering practice, real-time understanding of the grouting effect inside the formation is crucial for adjusting construction parameters and ensuring project quality. Previous drilling and injection devices have difficulty in effectively monitoring the grouting process and the internal conditions of the formation. In this embodiment, a threading tube 12 is welded or installed on the outside of the drilling and injection pipe, and a cable 13 is arranged in the threading tube 12. The material of the threading tube 12 has good insulation and mechanical strength, and can protect the internal cable 13 from interference and damage from the external environment. The threading tube 12 is arranged on the outside of the drilling and injection pipe, and the monitoring element 11 and the communication terminal 14 are connected by the cable 13 to construct a real-time monitoring system.

[0045] The cable 13 is a wire with good signal transmission performance and corrosion resistance. One end is connected to the monitoring element 11 (such as a pressure sensor, a temperature sensor, etc.) located near the drill bit 2, and the other end is connected to the communication terminal 14 at the tail end through the drilling and injection pipe. The communication terminal 14 can directly send corresponding data signals and can upload them to the cloud for viewing and interaction from a smartphone or other mobile device.

[0046] The monitoring element 11 is located near the rear of the drill bit 2. The monitoring element 11 adopts a high-precision, miniaturized design, can accurately measure relevant parameters in the formation, and transmit the signal to the communication terminal 14 through the cable 13 for processing and display, thereby realizing real-time monitoring of the grouting process, and can accurately obtain key information related to the grouting effect in the formation (such as pressure, temperature, slurry distribution, etc.), and transmit it to the communication terminal 14 in time for construction personnel to analyze and make decisions, thereby realizing precise control of the grouting effect and intelligent management of the construction process.

[0047] The establishment of the monitoring system enables construction personnel to grasp the grouting situation inside the stratum in real time, and adjust the grouting parameters (such as slurry ratio, grouting pressure, grouting speed, etc.) in time according to the monitoring data, realizing the intelligent management of the construction process. This precise control method can improve the consistency and reliability of the grouting effect, avoid engineering quality problems caused by unreasonable construction parameters, and also provide data support for the tracing and analysis of engineering quality, improving the level and efficiency of engineering management.

[0048] During the dual-liquid grouting process, the supply and flow of the two slurries need to be controlled separately to ensure the accuracy of the mixing ratio. The design of traditional devices in this regard is not sophisticated enough, and it is easy to have slurry ratio imbalance. In this embodiment, when the inner tube 5 and the outer tube 6 of the drilling and injection pipe are connected, a connection method with good sealing performance (such as threaded connection, sealing rubber ring connection, etc.) is adopted to ensure that the two slurry channels formed are isolated from each other and have good sealing performance. The two slurry channels are connected to the corresponding slurry supply pipes through the water braid shaft, such as Figure 1As shown, the inner pipe 5 is connected to the second grouting pipe 10, the outer pipe 6 is connected to the first grouting pipe 9, the first grouting pipe 9 and the second grouting pipe 10 are respectively connected to the supply pipe, and the supply pipe is equipped with a flow regulating valve and a pressure gauge. The construction personnel can accurately control the flow and pressure of the two slurries according to the design requirements and actual construction conditions to ensure that the ratio of the double liquid slurry is accurate, thereby realizing effective management of the slurry supply.

[0049] By connecting the outer tube 6 of the drilling and grouting pipe with the outer tube 6 and the inner tube 5 with the inner tube 5 respectively, and forming two independent slurry channels, and connecting each of them to the slurry supply pipe, a clear separation and independent control of the two slurry supplies are achieved, which facilitates construction personnel to accurately adjust the flow and ratio of the slurry according to actual needs, improves the controllability and accuracy of the grouting operation, and ensures the stability of the grouting effect.

[0050] Independent slurry channels and precise supply pipe connection design enable construction personnel to accurately control the flow and ratio of dual-liquid slurry, ensuring that the performance of the grouting material meets the design requirements. Accurate slurry supply control helps improve the effect of stratum reinforcement, reduce material waste, reduce construction costs, improve the economic benefits and quality controllability of grouting construction, and ensure the smooth implementation of the project and quality compliance.

[0051] It is understandable that in other optional embodiments, the front end of the inner tube 5 protrudes from the outer tube 6 and the rear end is recessed in the outer tube 6, so that different drilling and injection pipes can be connected and connected. In addition, the size specifications of the inner tube 5 and the outer tube 6 can be configured according to needs and selected and used according to needs during construction.

[0052] Example 2

[0053] In another typical embodiment of the present invention, Figure 1-Figure 4 As shown, a construction method of a drilling and injection device with automatic monitoring and anti-return grouting is provided, using the drilling and injection device with automatic monitoring and anti-return grouting as in Example 1.

[0054] A construction method of a drilling and injection integrated device with automatic monitoring and anti-slurry return, comprising:

[0055] Multiple drilling and injection pipes are connected in sequence along the axial direction to form a drilling and injection rod, a drill bit 2 is provided on the first end of the drilling and injection pipe, a water braid shaft of the drilling and injection pipe at the tail end is connected to a slurry supply source, and the drilling and injection rod is installed to a power device;

[0056] The power device drives the drilling rod to rotate and move forward at the same time, and the drill bit 2 performs drilling operations to form a borehole;

[0057] Slurry is injected into the drilling and injection pipe through the water braid axis, and the water glass slurry sprayed from the Laval nozzle 3 is fully mixed with the cement slurry sprayed from the slurry channel, and then sprayed from the drill bit 2 and injected into the formation;

[0058] After the grouting operation is completed, the drill rod will be pulled out.

[0059] Water glass slurry is injected into the inner tube 5 through the water braid axis, and the prepared cement slurry is injected between the inner tube 5 and the outer tube 6.

[0060] Specific, combined Figure 1-Figure 4 , the construction method is explained in detail.

[0061] A. Weld the opposite sides of the slit iron threading tube 12 to each section of the outer tube 6.

[0062] B. Install the second check valve 8 , the support frame 4 , and the first check valve 7 on the inner tube 5 , and install them inside the outer tube 6 .

[0063] C. Assemble and connect the drill bit 2, the drilling and injection pipe, and the water braid, wherein the inner tube 5 of the tail end drilling and injection pipe is also assembled and connected with the inner tube 5 of the water braid. A wireless temperature sensor is installed at the rear of the drill bit 2 as a monitoring element 11, and its cable is pressed into the threading tube 12 through the slit of the threading tube 12.

[0064] D. Water can flow through the inner tube 5 and the outer tube 6 of the water braid, and then the drilling operation can be carried out. When the end of the tail drilling and injection pipe is reached, the grouting operation can be carried out, that is, water glass slurry is injected into the inner tube 5 of the water braid and the prepared cement slurry is injected into the outer tube 6. After the water glass slurry sprayed from the Laval nozzle 3 and the cement slurry are fully mixed, they are sprayed from the drill bit 2 and injected into the formation.

[0065] E. After the grouting operation is completed at the depth of the first section, the hydration temperature of the cement slurry and the strength of the cement consolidation body are monitored in real time through the wireless temperature sensor and the communication terminal 14. After that, other unit drilling and injection devices can be connected according to steps B and C, and drilling operations can be carried out. When the end of the drilling and injection pipe of other sections is drilled, the grouting operation at that depth can be continued according to step D. At the same time, as the treatment depth increases, the slurry ratio should be dynamically adjusted to extend the coagulation time of the double liquid slurry accordingly.

[0066] F. Continue the above steps until the designed depth of drilling and grouting is reached.

[0067] This embodiment solves the problems of low water flow rate of drill bit 2 during drilling, easy slurry backflow and pipe clogging during grouting, uneven mixing of double liquid slurry, and inability to monitor the grouting depth in real time. In engineering practice, it can ensure the continuous alternation of drilling and grouting, higher construction efficiency and better device safety.

[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A drilling and injection device with automatic monitoring and anti-return slurry, characterized in that: It comprises a plurality of drilling and injection pipes which are detachably connected along the axial direction, each drilling and injection pipe is provided with an inner pipe and an outer pipe which is sleeved outside the inner pipe, slurry channels are formed between the inner pipe and the inner pipe and the outer pipe respectively, the drilling and injection pipe located at the head end is the head end drilling and injection pipe, the drilling and injection pipe located at the tail end is the tail end drilling and injection pipe, a first check valve is provided between the inner pipe and the outer pipe of the drilling and injection pipe, a second check valve is provided at the position where the inner pipe is connected to the inner pipe of the different drilling and injection pipe, a drill bit is installed at the front end of the head end drilling and injection pipe, a water braid shaft is installed at the end of the tail end drilling and injection pipe, and a monitoring element is installed outside the end of the head end drilling and injection pipe close to the drill bit.

2. The drilling and injection device with automatic monitoring and anti-return grouting function as claimed in claim 1, characterized in that: The inner tube of the first-end drilling and injection pipe is provided with a Laval nozzle at one end facing the drill bit, and a space for the Laval nozzle and the slurry channel to output slurry mixing is formed inside the drill bit, and a slurry outlet hole is provided on the drill bit.

3. The drilling and injection device with automatic monitoring and anti-return grouting function as claimed in claim 1 or 2, characterized in that: A support frame for maintaining the relative positions of the inner pipe and the outer pipe is provided between the inner pipe and the outer pipe of the drilling and injection pipe, and slurry channels on both sides of the support frame are communicated through the support frame.

4. The drilling and injection device with automatic monitoring and anti-return grouting function as claimed in claim 3, characterized in that: The first check valve is provided with two valve plates in a fan-shaped shape, and the valve plates jointly open or block the slurry channel formed between the inner tube and the outer tube.

5. The drilling and injection device with automatic monitoring and anti-return grouting function as claimed in claim 4, characterized in that: One end of the inner tube axially protrudes out of one end of the outer tube and is installed with a second check valve, and the other end of the inner tube is retracted into the other end of the outer tube to cooperate with the second check valve.

6. The drilling and injection device with automatic monitoring and anti-return grouting function as claimed in claim 1, characterized in that: A threading tube is provided on the outside of the drilling and injection pipe, and the threading tubes corresponding to the connected drilling and injection pipes are butt-connected. The threading tube contains cables. One end of the cable extends to the first drilling and injection pipe and is connected to the monitoring element, and the other end extends to the rear drilling and injection pipe and is led out to access the communication terminal.

7. The drilling and injection integrated device with automatic monitoring and anti-return grouting according to claim 6, characterized in that: The monitoring element is located outside the threading tube and behind the drill bit.

8. The drilling and injection integrated device with automatic monitoring and anti-return grouting according to claim 1, characterized in that: The outer tube of the drilling and injection pipe is butted against the outer tube of another drilling and injection pipe, and the inner tube of the drilling and injection pipe is butted against the inner tube of another drilling and injection pipe, forming two isolated slurry channels in the drilling and injection pipe, and the two slurry channels are respectively connected to slurry supply pipes through water braid shafts.

9. A construction method of a drilling and injection device with automatic monitoring and anti-return grouting, using the drilling and injection device with automatic monitoring and anti-return grouting as claimed in any one of claims 1 to 8, characterized in that: include: Multiple drilling and injection pipes are connected in sequence along the axial direction to form a drilling and injection rod, a drill bit is provided on the first end of the drilling and injection pipe, a water braid shaft of the drilling and injection pipe at the tail end is connected to a slurry supply source, and the drilling and injection rod is installed to a power device; The power equipment drives the drilling rod to rotate and move forward at the same time, and the drill bit drills to form a borehole; Slurry is injected into the drilling and injection pipe through the water braid axis, and the water glass slurry sprayed from the Laval nozzle is fully mixed with the cement slurry sprayed from the slurry channel, and then sprayed from the drill bit and injected into the formation; After the grouting operation is completed, the drill rod will be pulled out.

10. The construction method of the drilling and injection integrated device with automatic monitoring and anti-return grouting according to claim 9, characterized in that: Water glass slurry is injected into the inner tube through the water braid axis, and the water glass slurry flows in the slurry channel inside the inner tube. The prepared cement slurry is injected between the inner tube and the outer tube, and the cement slurry flows in the slurry channel between the inner tube and the outer tube.

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