A protective pressure limiting device and grouting method in the grouting reinforcement process

Abstract

This invention discloses a protective pressure-limiting device and grouting method for grouting reinforcement process. The device includes a vertically arranged cylinder with a slider coaxially arranged in the upper part of the cylinder, the slider's length being less than the cylinder's length. The slider's outer wall is tightly fitted to the inner wall of the cylinder, and its lower end is connected to the bottom of the cylinder via multiple high-pressure springs. A grout inlet steel pipe, a grout return steel pipe, and a grout outlet steel pipe are arranged on the outer wall of the cylinder, with the inlet steel pipe located on the left side and the return and outlet steel pipes on the right side, spaced vertically. A pressure-feeding steel pipe is connected to the top of the cylinder, the distal end of which is connected to the portion of the inlet steel pipe near the cylinder. The distal end of the inlet steel pipe is divided into two paths: one for connecting to a grouting machine, and the other for extending to the stratum. This device and method enable pressure-limited grouting during the grouting reinforcement process, effectively determine the termination conditions of the grouting reinforcement, and reduce disturbance to the stratum.

Description

Technical Field

[0001] This invention belongs to the field of grouting construction technology, specifically relating to a protective pressure limiting device and grouting method in the grouting reinforcement process. Background Technology

[0002] The construction of urban underground spaces is mostly concentrated in residential areas or areas with dense buildings, which inevitably has a certain impact on many surrounding buildings. This includes uneven ground settlement caused by construction, leading to settlement, tilting, or collapse of buildings and structures. Therefore, ground reinforcement grouting is necessary when needed, which is beneficial for strengthening buildings and improving their stability.

[0003] Grouting reinforcement method uses grouting pipes to continuously permeate and harden the surrounding soil layers. The undisturbed soil is compressed, and the combination of the undisturbed soil and the permeated solidified material ultimately forms a composite stratum. The soil's water seepage channels are sealed, further achieving a tight and stable effect, increasing compressive strength, and reducing the probability of soil compression deformation. However, improper control of grouting pressure and flow rate, as well as the pulse pressure of the grouting machine, can cause excessive compression of the stratum, resulting in excessive disturbance and ground heave, which also poses certain risks. Summary of the Invention

[0004] The purpose of this invention is to provide a protective pressure limiting device and grouting method in the grouting reinforcement process. The device and method can realize pressure limiting grouting in the grouting reinforcement process, effectively determine the termination conditions of grouting reinforcement, reduce disturbance to the strata, and improve the grouting reinforcement effect and stability.

[0005] The present invention adopts the following technical solution: a protective pressure limiting device in the grouting reinforcement process, comprising a pressure limiting protection device body, the pressure limiting protection device body comprising a vertically arranged cylinder, a slider coaxially arranged in the upper part of the cylinder, the length of the slider being less than the length of the cylinder; its outer wall being tightly fitted with the inner wall of the cylinder, and its lower end being connected to the bottom of the cylinder through multiple high-pressure springs;

[0006] The cylinder body is equipped with an inlet steel pipe, a return steel pipe, and an outlet steel pipe. The inlet steel pipe is located on the left side, and the return and outlet steel pipes are located on the right side, with the return and outlet steel pipes spaced vertically apart. The top of the cylinder body is connected to a pressure-feeding steel pipe, and the far end of the pressure-feeding steel pipe is connected to the part of the inlet steel pipe near the cylinder body.

[0007] The far end of the grout inlet pipe is divided into two paths: one path is used to connect to the grouting machine, and the other path is used to extend to the formation; the far end of the grout outlet pipe is used to connect to the grouting machine; the outer end of the grout return pipe is connected to the grout outlet pipe.

[0008] When the pressure in the formation is too high, the pressure-feeding steel pipe is used to transport excess grout to the upper end of the cylinder, pushing the slider downward. When the high-pressure spring is compressed to the design pressure, the excess grout flows out through the grout outlet steel pipe, and the grouting pressure drops. At this time, the high-pressure spring is released, the slider moves upward, and the grout flows out through the grout return steel pipe and the grout outlet steel pipe. When the pressure continues to drop, the grout returns to the grout inlet steel pipe through the pressure-feeding steel pipe, and grouting continues.

[0009] Furthermore, the inner wall of the cylinder is stepped, and the diameter of the upper cavity is smaller than that of the lower cavity. From top to bottom, there are first and second steps, which form multiple interconnected cavities of different sizes. From top to bottom, there are first and second steps arranged at intervals, which are arranged opposite each other and surround half of the inner wall of the cylinder. The upper ends of the first and second steps are flush with the upper end of the cylinder, and the lower end of the second step extends beyond the lower end of the first step.

[0010] Furthermore, the slurry inlet pipe is located on the outer wall of the cylinder body, on the side where the second step is located, and below the slurry outlet pipe.

[0011] Furthermore, a second flow sensor is installed on the discharge steel pipe, at its far rear end where it connects to the return steel pipe.

[0012] Furthermore, a first flow sensor is installed on the pipeline connected to the grouting machine at the far end of the grouting steel pipe, close to the grouting machine; both the first and second flow sensors are connected to an automatic flow analysis recorder. The first and second flow sensors are used to measure the flow rate at the inlet and outlet ends, respectively, and the automatic flow analysis recorder is used to display the flow rate difference between the inlet and outlet ends.

[0013] The present invention also discloses a grouting reinforcement device, based on the above-mentioned protective pressure limiting device in the grouting reinforcement process. The far end of the grout inlet steel pipe is connected to a tee, and the other two ports of the tee are each connected to a connecting pipe. A ball valve is installed on one connecting pipe, and the far end of the connecting pipe extends into the stratum. The far end of the other connecting pipe is connected to the outlet of the grouting machine. The far end of the grout outlet steel pipe is connected to the grouting machine, and the grouting machine and the grouting machine are connected through a grout suction pipe.

[0014] This invention also discloses a grouting method for a grouting reinforcement device. The grouting machine draws grout from the grouting machine through a suction pipe and injects it through the grouting pipe. The grout is injected into the formation through the grouting pipe, a tee, and a ball valve, and simultaneously enters the inlet steel pipe and the pressure-feeding steel pipe. When the grouting pressure exceeds the design pressure for grouting reinforcement, the grout passes through the pressure-feeding steel pipe and presses the slider from above, compressing the high-pressure spring and causing the slider to move downwards until the high-pressure spring reaches the design pressure. The inlet and outlet steel pipes are connected through a cylinder body and are linked through the inner cavity of the cylinder body. The grout flows through the outlet steel pipe to the grouting machine. As the grouting pressure decreases, the high-pressure spring is released, the slider moves upwards, and the grout between the cylinder body and the slider flows back to the grouting machine through the return steel pipe and the outlet steel pipe. The grout at the top of the slider returns to the inlet steel pipe through the pressure-feeding steel pipe. As the grouting pressure decreases, the grouting machine continues to grout the formation.

[0015] The beneficial effects of this invention are: 1. The pressure limiting protection device can effectively regulate the grouting pressure, preventing excessive disturbance to the formation caused by high grouting pressure and pulse grouting pressure. 2. By selecting and matching the pressure and number of high-pressure springs in the pressure limiting protection device, it can well adapt to the grouting needs of various formations and environments. 3. The setting of the position and number of flow sensors reduces the impact of grout backflow on the formation grout injection flow when the pressure limiting protection device is closed, providing a new method for determining the end of grouting. 4. The setting of the grout return steel pipe in the pressure limiting protection device ensures that there is no grout residue between the cylinder and the slider when the pressure limiting protection device is closed, guaranteeing the accuracy of pressure control by the pressure limiting protection device. 5. The setting of the screw connection of the lower cover plate facilitates spring replacement and slider cleaning. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a protective pressure limiting device during the grouting reinforcement process;

[0017] Figure 2 This is a schematic diagram of the structure of a grouting reinforcement device;

[0018] The components include: 1. Grouting machine; 2. Grouting machine; 3. Grouting pipe; 4. Grout suction pipe; 5-1. First flow sensor; 5-2. Second flow sensor; 6. Automatic flow analysis recorder; 6-1. Display screen; 7. Tee; 8. Ball valve; 9. Formation; 10. Pressure limiting protection device body; 11. Monitoring cable;

[0019] 10-1. Cylinder body; 10-2. Screw; 10-3. Nut; 10-4. Lower cover plate; 10-5. Upper cover plate; 10-6. High-pressure anti-seepage rubber gasket; 10-7. High-pressure spring; 10-8. Slider; 10-9. Quick coupling; 10-10. Slurry inlet steel pipe; 10-11. Slurry outlet steel pipe; 10-12. Slurry return steel pipe; 10-13. Pressure supply steel pipe. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0021] This invention provides a protective pressure limiting device during the grouting reinforcement process, such as... Figure 1 As shown, the device includes a pressure limiting protection device body 10, which includes a vertically arranged cylinder 10-10-1. A slider 10-8 is coaxially arranged in the upper part of the cylinder 10-1. The outer wall of the slider 10-8 is tightly fitted with the inner wall of the cylinder 10-10-1. The length of the slider 10-8 is less than the length of the cylinder 10-10-1, and its shape is consistent with the shape of the inner cavity of the cylinder 4 part that is fitted with it.

[0022] The lower end of the slider 10-8 is connected to the bottom of the cylinder 10-10-1 via multiple high-pressure springs 10-7.

[0023] The inner wall of cylinder 10-1 is stepped, with the inner diameter of the upper part smaller than that of the lower part. Multiple interconnected cavities of varying sizes are formed inside. From top to bottom, there are two staircases, a first step and a second step, spaced apart and positioned opposite each other, each encircling half the inner wall of cylinder 10-1. The upper ends of both the first and second steps are flush with the upper end of cylinder 10-1, while the lower end of the second step extends beyond the lower end of the first step. The upper part of the second step and the first step together form a small-diameter cavity; the lower part of the second step and the lower inner wall of cylinder 10-1 together form a medium-diameter cavity; the cavity below the second step in cylinder 10-1 has the largest diameter. The shape of slider 10-8 matches the inner cavity of cylinder 10-1 to achieve a tight fit.

[0024] On the outer wall of cylinder 10-1, and on the side where the first step is located, a return steel pipe 10-12 and a discharge steel pipe 10-11 are sequentially arranged at the lower end of the first step. The return steel pipe 10-12 is attached to the lower end of the first step. The far outer end of the return steel pipe 10-12 is connected to the discharge steel pipe 10-11. The far outer end of the discharge steel pipe 10-11 is used to connect to the pulping machine 2.

[0025] On the outer wall of cylinder 10-1, on the side where the second step is located, and below the grout outlet steel pipe 10-11, there is a grout inlet steel pipe 10-10. The outer end of the grout inlet steel pipe 10-10 is divided into two paths, one for connecting to the grouting machine 1 and the other for extending to the stratum 9.

[0026] The top of the cylinder body 10-1 is connected to a pressure-feeding steel pipe 10-13, and the far end of the pressure-feeding steel pipe 10-13 is connected to the part of the slurry inlet steel pipe 10-10 near the cylinder body 10-1.

[0027] The discharge steel pipe 10-11, the inlet steel pipe 10-10, the return steel pipe 10-12, and the pressure supply steel pipe 10-13 are all connected to the opening on the cylinder body 10-1 via quick connectors 10-9.

[0028] When the pressure in formation 9 is too high, excess grout is transported to the upper end of cylinder 10-1 through pressure-feeding steel pipe 10-13, pushing slider 10-8 downward. When high-pressure spring 10-7 is compressed to the design pressure, inlet steel pipe 10-10 and outlet steel pipe 10-11 are connected through the inner cavity of cylinder 10-1, and grout flows to grouting machine 2 through outlet steel pipe 10-11. As the grouting pressure decreases, high-pressure spring 10-7 is released, slider 10-8 moves upward, and grout between cylinder 10-1 and slider 10-8 flows to grouting machine 2 through return steel pipe 10-12 and outlet steel pipe 10-11; grout at the upper end of slider 10-8 returns to inlet steel pipe 10-10 through pressure-feeding steel pipe 10-13. As the grouting pressure decreases, grouting machine 1 continues grouting formation 9. The above actions are then repeated.

[0029] The upper and lower ends of the cylinder body 10-1 are sealed by an upper cover plate 10-5 and a lower cover plate 10-4, respectively. Specifically, connecting holes are spaced apart on the side walls of the upper cover plate 10-5 and the lower cover plate 10-4. Simultaneously, through holes are also provided on the side walls of the upper and lower ends of the cylinder body 10-1. Screws 10-2 are inserted into the through holes and connecting holes to connect the cylinder body 10-1 to the upper cover plate 10-5 and the lower cover plate 10-4, respectively. Nuts 10-3 are screwed onto both ends of the screws 10-2 for fixation. High-pressure leak-proof rubber gaskets 10-6 are provided at the end contact surfaces of the upper cover plate 10-5 and the lower cover plate 10-4 with the cylinder body 10-1 to achieve a seal.

[0030] To prevent the pulse pressure from the grout returning to the grout inlet pipe 10-10 via the pressure-feeding steel pipe 10-13 from affecting the grout injection flow rate, a first flow sensor 5-1 is installed on the connecting pipe at the grout outlet of the grouting machine, and a second flow sensor 5-2 is installed on the grout outlet pipe 10-11, located at the far end of the pipe connected to the return grout pipe 10-12. Both the first flow sensor 5-1 and the second flow sensor 5-2 are connected to the automatic flow analysis recorder 6 via monitoring cable 11. The automatic flow analysis recorder 6 displays the flow difference between the first flow sensor 5-1 and the second flow sensor 5-2. When the flow difference reaches zero after the pressure limiting protection device has repeatedly opened and closed, it is determined that the grouting reinforcement has achieved the designed effect, and the grouting operation can be stopped.

[0031] This invention also discloses a grouting reinforcement device, based on the above-mentioned protective pressure limiting device in the grouting reinforcement process, such as... Figure 2As shown, the far end of the grout inlet steel pipe 10-10 is connected to a tee 7. The other two ports of the tee 7 are each connected to a connecting pipe. One connecting pipe is equipped with a ball valve 8, and the far end of the connecting pipe extends into the formation 9. The far end of the other connecting pipe is connected to the outlet of the grouting machine 1 through the grouting pipe 3. The far end of the grout outlet steel pipe 10-11 is connected to the grouting machine 2. The grouting machine 2 and the grouting machine 1 are connected through the grout suction pipe 4.

[0032] This invention also discloses a grouting method for the aforementioned grouting reinforcement device. First, the grout mixing machine 2 mixes the grout. The grouting machine 1 draws the grout from the mixing machine 2 through the suction pipe 4 and injects it through the grouting pipe 3. The grout is injected into the formation 9 through the grouting pipe 3, the tee 7, and the ball valve 8. Simultaneously, the grout also enters the grout inlet steel pipe 10-10 and the pressure supply steel pipe 10-13. As the grout is injected into the formation 9, the grouting pressure gradually increases. The number of high-pressure springs 10-7 calibrates the given grouting reinforcement design pressure. When the grouting pressure exceeds the grouting reinforcement design pressure, the grout is compressed from above by the pressure supply steel pipe 10-13, causing the high-pressure springs 10-7 to be compressed and the slider 10-8 to move downwards. The grouting machine moves until the high-pressure spring 10-7 is compressed to the design pressure. The grout inlet pipe 10-10 and the grout outlet pipe 10-11 are connected through the cylinder body 10-1. The grout inlet pipe 10-10 and the grout outlet pipe 10-11 are connected through the inner cavity of the cylinder body 10-1. The grout flows to the grouting machine 2 through the grout outlet pipe 10-11. The grouting pressure decreases, the high-pressure spring 10-7 is released, and the slider 10-8 moves upward. The grout between the cylinder body 10-1 and the slider 10-8 flows to the grouting machine 2 through the return grout pipe 10-12 and the grout outlet pipe 10-11. The grout at the upper end of the slider 10-8 returns to the grout inlet pipe 10-10 through the pressure supply pipe 10-13. The grouting pressure decreases, and the grouting machine 1 continues to grout the formation 9.

[0033] After stopping the grouting operation, close ball valve 8 to ensure that the grout leaks out in the middle of the formation, thus ensuring the grouting reinforcement effect. Then, fill the grouting machine 2 with clean water and connect the grout outlet steel pipe 10-11 to the outside of the grouting machine 2. Turn on the grouting machine 1 to continue operation and clean the entire pipeline and pressure limiting protection device.

Claims

1. A protective pressure limiting device during grouting reinforcement process, characterized in that, The device includes a pressure limiting protection device body (10), which includes a vertically arranged cylinder (10-1). A slider (10-8) is coaxially arranged in the upper part of the cylinder (10-1). The length of the slider (10-8) is less than the length of the cylinder (10-1). Its outer wall is tightly fitted with the inner wall of the cylinder (10-1), and its lower end is connected to the bottom of the cylinder (10-1) through multiple high-pressure springs (10-7). An inlet steel pipe (10-10), a return steel pipe (10-12), and an outlet steel pipe (10-11) are provided on the outer wall of the cylinder body (10-1). The inlet steel pipe (10-10) is located on the left side, and the return steel pipe (10-12) and the outlet steel pipe (10-11) are located on the right side, with the return steel pipe (10-12) and the outlet steel pipe (10-11) spaced apart vertically. A pressure-feeding steel pipe (10-13) is connected to the top of the cylinder body (10-1), and the far end of the pressure-feeding steel pipe (10-13) is connected to the portion of the inlet steel pipe (10-10) near the cylinder body (10-1). The outermost end of the grout inlet steel pipe (10-10) is divided into two paths, one for connecting to the grouting machine (1) and the other for extending to the stratum (9); the outermost end of the grout outlet steel pipe (10-11) is connected to the grouting machine (2); the outermost end of the grout return steel pipe (10-12) is connected to the grout outlet steel pipe (10-11); The upper and lower ends of the cylinder (10-1) are sealed by an upper cover plate (10-5) and a lower cover plate (10-4) respectively. Connection holes are opened at intervals on the side walls of the upper cover plate (10-5) and the lower cover plate (10-4). At the same time, through holes are also opened on the side walls of the upper and lower ends of the cylinder (10-1). Screws (10-2) are inserted into the through holes and the connection holes to connect the cylinder (10-1) to the upper cover plate (10-5) and the lower cover plate (10-4) respectively. When the pressure in the formation (9) is too high, the pressure-feeding steel pipe (10-13) is used to transport the excess grout to the upper end of the cylinder (10-1), pushing the slider (10-8) to move downward. When the high-pressure spring (10-7) is compressed to the design pressure, the excess grout flows out through the grout outlet steel pipe (10-11), and the grouting pressure drops. At this time, the high-pressure spring (10-7) is released, the slider (10-8) moves upward, and the grout flows out through the grout return steel pipe (10-12) and the grout outlet steel pipe (10-11). When the pressure continues to drop, the grout returns to the grout inlet steel pipe (10-10) through the pressure-feeding steel pipe (10-13) and continues grouting.

2. The protective pressure limiting device in the grouting reinforcement process as described in claim 1, characterized in that, The inner wall of the cylinder (10-1) is stepped, and the diameter of the upper cavity is smaller than that of the lower cavity. From top to bottom, there are first and second steps, and multiple interconnected cavities of different sizes are formed inside. From top to bottom, there are first and second steps arranged at intervals, which are arranged opposite each other and surround half of the inner wall of the cylinder (10-1). The upper ends of the first and second steps are flush with the upper end of the cylinder (10-1), and the lower end of the second step extends beyond the lower end of the first step.

3. The protective pressure limiting device in the grouting reinforcement process as described in claim 2, characterized in that, The slurry inlet steel pipe (10-10) is located on the outer wall of the cylinder body (10-1), on the side where the second step is located, and below the slurry outlet steel pipe (10-11).

4. The protective pressure limiting device in the grouting reinforcement process as described in claim 3, characterized in that, A second flow sensor (5-2) is provided on the discharge steel pipe (10-11) and at its far rear end where it connects to the return steel pipe (10-12).

5. A protective pressure limiting device during grouting reinforcement as described in claim 4, characterized in that, On the pipeline connected to the grouting machine (1) at the far end of the grouting steel pipe (10-10), and close to the grouting machine (1), a first flow sensor (5-1) is provided; the first flow sensor (5-1) and the second flow sensor (5-2) are both connected to the automatic flow analysis recorder (6). The first flow sensor (5-1) and the second flow sensor (5-2) are used to measure the flow rate at the inlet end and the outlet end, respectively. The automatic flow analysis recorder (6) is used to display the flow rate difference between the inlet end and the outlet end.

6. A grouting reinforcement device, characterized in that, According to any one of claims 1-5, a protective pressure limiting device in the grouting reinforcement process is provided, wherein the far end of the grout inlet steel pipe (10-10) is connected to a tee (7), and the other two ports of the tee (7) are each connected to a connecting pipe, a ball valve (8) is provided on one connecting pipe, and the far end of the connecting pipe extends into the stratum (9); the far end of the other connecting pipe is connected to the outlet of the grouting machine (1); the far end of the grout outlet steel pipe (10-11) is connected to the grouting machine (2), and the grouting machine (2) and the grouting machine (1) are connected through a grout suction pipe (4).

7. The grouting method of the grouting reinforcement device according to claim 6, characterized in that, The grouting machine (1) draws slurry from the slurry preparation machine (2) through the slurry suction pipe (4) and performs grouting through the grouting pipe (3); the slurry is injected into the formation (9) through the grouting pipe (3), the tee (7) and the ball valve (8), and at the same time the slurry will also enter the grout inlet steel pipe (10-10) and the pressure supply steel pipe (10-13); when the grouting pressure exceeds the grouting reinforcement design pressure, the slurry squeezes the slider (10-8) from above through the pressure supply steel pipe (10-13), the high pressure spring (10-7) is compressed, and the slider (10-8) moves downward until the high pressure spring (10-7) is compressed to the design pressure, and the grout inlet steel pipe (10-10) and the grout outlet steel pipe (10-11) pass through the cylinder (1) 0-1) Connect the slurry inlet steel pipe (10-10) and the slurry outlet steel pipe (10-11) through the inner cavity of the cylinder (10-1). The slurry flows to the slurry making machine (2) through the slurry outlet steel pipe (10-11). When the grouting pressure drops, the high pressure spring (10-7) is released, the slider (10-8) moves upward, and the slurry between the cylinder (10-1) and the slider (10-8) flows to the slurry making machine (2) through the slurry return steel pipe (10-12) and the slurry outlet steel pipe (10-11). The slurry at the upper end of the slider (10-8) returns to the slurry inlet steel pipe (10-10) through the pressure supply steel pipe (10-13). When the grouting pressure drops, the grouting machine (1) continues to grout the stratum (9).

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