Method for controlling lifting deformation of earth-rock dam grouting based on intelligent grouting control system

Abstract

The application discloses a control method for lifting deformation of earth and rockfill dam grouting based on an intelligent grouting control system. The method comprises the following steps: connecting a lifting deformation observation device to the intelligent grouting control system; performing pre-grouting water pressure test; adopting different step-by-step pressure increasing strategies for shallow rock mass parts with prominent lifting deformation and deep rock mass parts without prominent lifting deformation to obtain an initial grouting pressure; when a real-time grouting pressure is less than the initial grouting pressure, increasing the grouting pressure according to a matching relationship between the grouting pressure and an injection rate; when the real-time grouting pressure is greater than the initial grouting pressure, increasing the grouting pressure according to a fixed-step pressure increasing strategy until the grouting pressure is gradually increased to a design grouting pressure; and if the rock mass is subjected to lifting deformation during a pressure stabilizing process, increasing the pressure to the design grouting pressure according to the steps of pressure reduction limit lifting, pressure stabilizing limit flow and fixed-step pressure increasing. The application can effectively control the lifting deformation of grouting and still normally increase the pressure to the design pressure for grouting.

Description

Technical Field

[0001] This invention relates to the field of water conservancy and hydropower engineering technology, specifically to a method for controlling the uplift deformation of earth-rock dams during grouting based on an intelligent grouting control system. Background Technology

[0002] Bedrock grouting is a common method for foundation treatment of dams in water conservancy and hydropower projects. It can improve the integrity, deformation resistance, and seepage prevention of the dam foundation rock mass, meeting the requirements of dam foundation and normal reservoir impoundment. Bedrock grouting requires a certain pressure to allow the grout to penetrate into the rock fissures and spread over a certain range. Grouting of earth-rock dams is generally carried out on the toe slab (0.5m to 1.0m thick) or the concrete surface of the dam core wall foundation (generally about 2m thick). Due to the thin overburden and the poorer condition of the foundation rock mass of earth-rock dams compared to concrete dams, shallow rock mass grouting is prone to uplift, making normal pressure injection difficult, which has always been a challenge in the grouting industry.

[0003] Current standard and conventional grouting practices are as follows: the pre-grouting water pressure is 80% of the grouting pressure and not more than 1 MPa; conventional grouting equipment is used, and the return grout flow rate is controlled by manually operating the gate valve on the return grout pipeline, thereby controlling the grouting pressure; grouting pressure is generally increased as quickly as possible or according to the matching relationship between grouting pressure and injection rate; uplift deformation monitoring devices are installed and read manually; after uplift deformation occurs, the pressure is reduced in time, and after the uplift stops, the pressure is increased normally for grouting. If uplift deformation continues or exceeds the allowable uplift deformation value (generally 200 μm), regrouting is carried out after setting.

[0004] The above processing method has the following main problems:

[0005] First, the response is not timely. Currently, uplift deformation is generally monitored by workers near the grouting hole, who read the dial gauge on the uplift deformation monitoring device. When uplift occurs during water pressure and grouting, workers verbally inform the pressure operator to reduce the pressure or suspend grouting. However, due to the sudden, instantaneous, and abrupt nature of uplift deformation, this conventional approach is insufficient for timely intervention.

[0006] Secondly, the control effect is poor. Manually operating the gate valves on the grout return pipeline to control pressure results in poor pressure stabilization due to pressure fluctuations and improper operation. Pressure fluctuations can reach 20% or even more of the grouting pressure, which is detrimental to controlling uplift deformation. For rock masses prone to uplift deformation, using 80% of the design grouting pressure before grouting easily leads to uplift, and the uplift during the water pressure process damages the rock mass, making the uplift even more pronounced during grouting. Even if pressure is reduced promptly after uplift deformation occurs, and grouting is resumed normally only after the uplift has stopped, grouting is still performed according to the pressure-injection rate relationship. This easily leads to continued uplift, resulting in poor uplift control and often preventing the grouting process from reaching the normal pressure control point.

[0007] Third, poor grouting quality. Due to poor control of uplift deformation, the pressure could not be properly increased to the required level for grouting, and the final grouting pressure did not reach the designed grouting pressure. Forced to use low-pressure grouting, the grout in the cracks could not be compressed and compacted under low pressure, nor could it diffuse sufficiently, resulting in incomplete or insufficient filling of the cracks. This directly affects the grouting quality and may even prevent the reservoir from storing water normally. Furthermore, excessive uplift deformation can also cause cracks or deformation in the upper toe slab and foundation, leading to structural quality problems.

[0008] Fourth, there is significant waste of grout and low grouting efficiency. The toe slab and foundation of earth-rock dams are only a few meters wide. Improper control of pressure and uplift during grouting can cause rock mass fracturing and grout leakage. This not only results in poor grouting quality but also renders the leaked grout ineffective, leading to waste. If measures such as waiting for curing and then re-grouting are adopted, it generally requires 24-48 hours of curing, making continuous grouting impossible. Furthermore, the effect of low-pressure grouting on improving the rock mass's bearing capacity after curing is uncertain, and re-grouting may still cause uplift. Repeated waiting for curing and re-grouting further reduces grouting efficiency. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention proposes a method for controlling uplift deformation during grouting in earth-rock dams based on an intelligent grouting control system. This method precisely monitors uplift deformation using an uplift deformation monitoring device and integrates the data into the intelligent grouting control system, enabling high-precision pressure control. Different pre-grouting water pressure processes are employed for shallow rock sections with significant uplift deformation and deep rock sections with less significant uplift deformation to achieve proactive anti-splitting and obtain the initial grouting pressure. During grouting, the real-time grouting pressure is compared with the initial grouting pressure to formulate different pressure-increasing grouting strategies. In the absence of uplift deformation, a step-by-step pressure-increasing grouting strategy is adopted until the designed grouting pressure is reached, after which grouting normally concludes. In the presence of uplift deformation, a pressure-reducing, uplift-limiting, pressure-stabilizing, and step-by-step pressure-increasing grouting strategy is adopted until the designed grouting pressure is reached, after which grouting normally concludes.

[0010] To achieve the above objectives, the present invention provides a method for controlling the grouting uplift deformation of earth-rock dams based on an intelligent grouting control system, characterized by the following steps:

[0011] S1) Complete the grouting preparation work, including drilling and flushing the grouting holes, connecting the mixing tank, grouting pump, pressure gauge, flow meter, blocker, and intelligent grouting control system in series through the grouting pipeline, and installing the lifting deformation observation device and connecting the lifting deformation observation device to the intelligent grouting control system.

[0012] The uplift deformation monitoring device is used to accurately monitor the grouting of the dam bedrock and to provide timely feedback and alarm when uplift occurs.

[0013] The intelligent grouting control system is used to receive the detected uplift value sent by the uplift deformation observation device, collect the flow rate, pressure, density and temperature signals of the grouting hole, control the water pressure construction and grouting construction, and has the functions of automatic grout preparation, automatic data recording, precise pressure control, grouting process control and grouting result processing.

[0014] S2) Pre-grouting water pressure is carried out, and different step-by-step pressure increase strategies are adopted for shallow rock mass parts with prominent uplift and deformation and deep rock mass parts with less prominent uplift and deformation to obtain the initial grouting pressure;

[0015] S3) Prepare cement grout with a suitable water-cement ratio, start the grouting pump to begin grouting. When grouting begins, the intelligent grouting control system controls the valve on the return grout pipeline to be fully open. After the grout pipeline and grouting hole are filled with grout, the valve on the return grout pipeline is controlled to slowly reduce the opening, increasing the pressure in the grouting hole, so that the grout is injected into the rock mass fissures. At the same time, the uplift deformation monitoring device automatically transmits the collected uplift data to the intelligent grouting control system.

[0016] The grouting process is as follows: When the real-time grouting pressure is less than the initial grouting pressure, pressurized grouting is carried out according to the matching relationship between grouting pressure and injection rate; when the real-time grouting pressure is greater than the initial grouting pressure, pressurized grouting is carried out according to the strategy of step-by-step pressurization, while closely monitoring the uplift value and injection rate. If the uplift value does not increase and the injection rate does not increase significantly during the pressure stabilization process, the pressure is increased by a fixed step and the pressure is stabilized until the grouting pressure is gradually increased to the design grouting pressure. After the injection rate reaches the end standard, the grouting of this section is normally completed; if the rock mass undergoes uplift deformation during the pressure stabilization process, then proceed to step S4);

[0017] The fixed-step pressurization refers to a fixed-step, step-by-step pressurization and pressure-stabilized grouting process.

[0018] S4) In response to the uplift and deformation that occurs during the grouting process, pressure control is carried out according to the steps of pressure reduction and uplift limitation, pressure stabilization and flow limitation, and step-by-step pressure increase.

[0019] S41) Pressure Reduction and Uplift Limitation: When the intelligent grouting control system detects uplift deformation, in order to avoid the uplift value from continuing to increase due to crack splitting, the system controls the uplift deformation by precisely adjusting the pressure, reducing the grouting pressure by one pressure level at a time, and simultaneously reducing the grouting injection rate, thus reducing the uplift effect of the grout on the rock mass; after the pressure is reduced, the uplift value is continuously monitored. If the uplift value still increases, the pressure is reduced by another pressure level to reduce the uplift effect of the grouting until the uplift no longer continues to increase;

[0020] S42) Pressure stabilization and flow restriction: After the grouting pressure is reduced to the point where the grouting uplift no longer increases, the grouting pressure is stabilized at the current grouting pressure. As grouting continues, the rock mass fissures are gradually filled, the grout injection rate gradually decreases, and the grout's uplift effect on the rock mass decreases. When the injection rate is less than the control value Q0, grouting continues for a period of time to fill the rock mass fissures to a certain extent, thereby enhancing the rock mass's resistance to uplift.

[0021] S43) Step-by-step pressure increase: As the grout fracturing effect decreases and the injection rate falls below the control value Q0, pressure increase grouting is carried out according to the step-by-step pressure increase strategy. At the same time, the uplift value and injection rate are closely monitored. If the uplift value does not increase and the injection rate does not increase significantly during the pressure stabilization process, the pressure is increased by a fixed step and the pressure is stabilized for grouting until the grouting pressure is gradually increased to the design grouting pressure. The grouting of this section is normally completed after the injection rate reaches the end standard.

[0022] If the lifting value continues to increase during the pressurization process, repeat the above process S41) to S43) until the design grouting pressure is reached and the grouting is completed normally.

[0023] Further, in S1), the lifting deformation observation device includes a lifting sensor embedded in the lifting observation hole, the lifting sensor having a resolution of 1μm and a range of not less than 10mm.

[0024] Further, in S1), the intelligent grouting control system includes a sensor cabinet, a control system, and a main control center. The sensor cabinet is used to collect flow rate, pressure, density, and temperature signals from the grouting holes. The control system is used to control the water pressure construction and grouting construction, and has functions such as automatic grout mixing, automatic data recording, precise pressure control, grouting process control, and grouting result processing. The main control center is used to receive the flow rate, pressure, density, and temperature signals sent by the sensor cabinet and the detection uplift values ​​sent by the uplift deformation observation device, and to control the control system.

[0025] Furthermore, in S1), the sensor cabinet includes a flow sensor, a pressure sensor, a density sensor, and a temperature sensor. The control system achieves precise pressure control by controlling the valves on the grout return pipeline. The automatic control range of the grouting pressure of the control system is 0-6 MPa, the pressure resolution is 0.01 MPa, and the injection rate resolution is 0.1 L / min.

[0026] Furthermore, in S2), the method for obtaining the initial grouting pressure is as follows:

[0027] If, during the water pressurization process, the injection rate does not exceed 10L / min to 15L / min and the detected uplift value is not ≥5μm, the pressure is gradually increased to the set water pressurization pressure, and the set water pressurization pressure is used as the initial grouting pressure.

[0028] If the injection rate exceeds 10L / min to 15L / min during the water pressure process, the set water pressure is no longer required. Instead, the pressure is reduced until the injection rate is between 10L / min and 15L / min. This water pressure is then maintained until the process ends, and this water pressure is used as the initial grouting pressure.

[0029] If, during the water pressure process, the detected uplift value is ≥5μm, it is determined that uplift has occurred, and pressure reduction is performed. If, during the subsequent process, the uplift value continues to rise by ≥2μm in real time, it is determined that the uplift has occurred, and pressure reduction is performed on the basis of the current water pressure until the uplift stops. Then, the water pressure is maintained until the end, and the water pressure is used as the initial grouting pressure.

[0030] The set pressure for the shallow rock mass is 60% of the design grouting pressure; the set pressure for the deep rock mass is 80% of the design grouting pressure.

[0031] Furthermore, in S2), the stepwise pressurization strategy for the shallow rock mass is as follows: each pressurization step increases by 0.02–0.03 MPa, stabilizes for 1–2 minutes, and then begins data recording. If, during the pressurization process, the injection rate exceeds 10–15 L / min, the set pressurization pressure is no longer required, and the pressure is reduced by 0.05 MPa, with each reduction interval of 4–5 seconds, until the injection rate is between 10–15 L / min. This pressurization pressure is maintained until the process ends. If a heave value ≥5 μm is detected during the recording process, heave is determined to have occurred, and a pressure reduction is performed. The pressure is reduced by 0.05 MPa from the pressurization pressure at the time of heave until the heave ceases, and this pressure is maintained until the process ends.

[0032] The stepwise pressurization strategy for the deep rock mass is as follows: pressurize by 0.04–0.05 MPa at each stage, stabilize for 1–2 minutes, and then start recording data. If the injection rate exceeds 10–15 L / min during the pressurization process, the set pressurization pressure is no longer required, and the pressure is reduced by 0.05 MPa. Each pressure reduction is spaced 4–5 seconds apart until the injection rate is between 10–15 L / min. Pressurization is then maintained at this pressure until the end. If a heave value ≥5 μm is detected during the recording process, heave is determined to have occurred, and a pressure reduction is performed. The pressure is reduced by 0.05 MPa from the pressurization pressure at the time of heave until the heave stops, and then pressurization is maintained at this pressure until the end.

[0033] Further, in S3), the fixed step size is a pressure increase of 0.03MPa to 0.1MPa every 2 to 5 minutes.

[0034] Furthermore, in S41), one pressure level is 0.05MPa to 0.1MPa.

[0035] Furthermore, in S42), the control value Q0 is 3L / min to 8L / min.

[0036] The advantages of this invention are:

[0037] 1. This invention uses a lifting deformation observation device to accurately monitor lifting deformation and provides timely feedback and alarm when lifting occurs;

[0038] 2. This invention controls water pressure and grouting construction through an intelligent grouting control system. The lifting deformation observation device is connected to the intelligent grouting control system to identify and record the lifting value in a timely manner. Then, the corresponding control strategy is activated to quickly process the lifting situation, realizing automatic pressure adjustment. The control is highly accurate and has a fast response speed. Grouting is carried out based on intelligent grouting process strategy, realizing digital and automated grouting, which is conducive to improving the level of intelligent construction of grouting projects.

[0039] 3. This invention employs different stepwise pressure-increasing strategies for shallow rock masses with prominent uplift deformation and deep rock masses with less prominent uplift deformation, achieving proactive anti-splitting and preventing excessive uplift of the rock mass due to splitting, which could affect the safety of structures such as the upper toe plate, foundation, and dam. Furthermore, the invention links the water pressure strategy with the grouting strategy, obtaining the initial grouting pressure from the pre-grouting water pressure. In contrast, existing technologies use the same pre-grouting water pressure for both shallow and deep rock masses. For rock masses prone to uplift deformation, the pre-grouting water pressure is set at 80% of the designed grouting pressure, making uplift highly likely. Moreover, the uplift during the water pressure process damages the rock mass, leading to more pronounced uplift during grouting. Additionally, the existing pre-grouting water pressure strategy is not linked to the grouting strategy.

[0040] 4. In the grouting process, this invention compares the real-time grouting pressure with the initial grouting pressure. When the real-time grouting pressure is less than the initial grouting pressure, pressure-increasing grouting is performed according to the matching relationship between grouting pressure and injection rate. When the real-time grouting pressure is greater than the initial grouting pressure, pressure-increasing grouting is performed according to a step-by-step pressure-increasing strategy. If no uplift deformation occurs, the grouting ends normally after reaching the design grouting pressure using this step-by-step pressure-increasing strategy. If uplift deformation occurs, a pressure-reducing-uplift-stabilizing-flow-step-increasing grouting strategy is adopted until the design grouting pressure is reached, after which the grouting ends normally. The grouting ends at the design grouting pressure. Appropriate grouting pressure is a crucial guarantee of grouting quality. Under the premise of controllable rock mass uplift, normal pressure-increasing to the design pressure and reaching the normal completion standard effectively ensures the grouting effect. However, current... In some grouting processes, the initial approach involves rapidly increasing the pressure or adjusting it according to the relationship between grouting pressure and injection rate. If uplift or deformation occurs, the pressure is reduced until the uplift stops before resuming normal grouting, still adhering to the pressure-injection rate relationship. This approach is highly prone to further uplift, resulting in poor uplift control. Consequently, grouting often fails to reach the designed grouting pressure before it can be completed normally. Because of the inability to properly increase the pressure, the final grouting pressure falls below the designed pressure, forcing the use of low-pressure grouting. At low pressure, the grout in the cracks cannot be compressed and compacted, nor can it diffuse sufficiently, resulting in incomplete or minimal filling of the cracks. This directly affects the grouting quality and can even prevent reservoirs from storing water normally. Furthermore, excessive uplift or deformation can cause cracks or deformation in the upper toe slab and foundation, leading to structural quality problems.

[0041] 5. This invention can still reach the normal completion standard and end grouting even after the grouting is lifted, avoiding the need for measures such as waiting for curing or re-grouting due to abnormal termination. The drilling and grouting of the next hole section can be carried out normally, which is conducive to improving construction efficiency and reducing grout waste.

[0042] This invention provides a control method for grouting uplift deformation of earth-rock dams based on an intelligent grouting control system. This method solves the problems of untimely handling measures, poor control effect, poor grouting quality, large grout waste, and low grouting efficiency in the past. It can effectively control grouting uplift while still pressurizing to the design pressure and reaching the normal completion standard. This can effectively ensure the grouting effect and avoid measures such as waiting for curing or re-grouting due to abnormal completion. Attached Figure Description

[0043] Figure 1 This is a flowchart of the control method for grouting uplift deformation of earth-rock dams based on an intelligent grouting control system according to the present invention;

[0044] Figure 2 This is a schematic diagram of the intelligent grouting control system in this invention;

[0045] Figure 3This is a schematic diagram illustrating the application of the present invention in an embodiment. Detailed Implementation

[0046] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0047] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention.

[0048] like Figure 1 As shown, the present invention provides a method for controlling the grouting uplift deformation of earth-rock dams based on an intelligent grouting control system, comprising the following steps:

[0049] S1) Complete the grouting preparation work, including drilling and flushing the grouting holes, connecting the mixing tank, grouting pump, pressure gauge, flow meter, blocker, and intelligent grouting control system in series through the grouting pipeline, and installing the lifting deformation observation device and connecting the lifting deformation observation device to the intelligent grouting control system.

[0050] The uplift deformation monitoring device is used to accurately monitor the grouting of the dam bedrock and to provide timely feedback and alarm when uplift occurs.

[0051] Specifically, the uplift deformation monitoring device includes a uplift sensor embedded in the uplift observation hole. A high-precision, high-stability uplift sensor is used and connected to the intelligent grouting control system via a data cable. The uplift sensor has a resolution of 1 μm and a measurement range of not less than 10 mm. The uplift sensor is embedded as follows... Figure 3 As shown.

[0052] The monitoring of uplift during dam bedrock grouting requires high precision, necessitating accurate monitoring of uplift and timely feedback and alarms upon detection. Uplift deformation monitoring devices are installed, employing high-precision, high-stability uplift sensors. Data is transmitted to the intelligent grouting control system via a data transmission line, enabling the system to promptly identify and record uplift values, and subsequently initiate appropriate control strategies for rapid response based on the uplift situation.

[0053] The intelligent grouting control system is used to receive the detection uplift value sent by the uplift deformation observation device, collect the flow rate, pressure, density and temperature signals of the grouting hole, control the water pressure construction and grouting construction, and has the functions of automatic grout preparation, automatic data recording, precise pressure control, grouting process control and grouting result processing.

[0054] Preferably, such as Figure 2 As shown, the intelligent grouting control system includes a sensor cabinet, a control system, and a main control center. The sensor cabinet is used to collect flow rate, pressure, density, and temperature signals from the grouting holes. The control system is used to control the water pressure construction and grouting construction, and has functions such as automatic grout mixing, automatic data recording, precise pressure control, grouting process control, and grouting result processing. The main control center is used to receive the flow rate, pressure, density, and temperature signals sent by the sensor cabinet and the detection uplift values ​​sent by the uplift deformation observation device, and to control the control system.

[0055] Specifically, the sensor cabinet includes a flow sensor, a pressure sensor, a density sensor, and a temperature sensor. The control system achieves precise pressure control by controlling the valves on the grout return pipeline. The automatic control range of the grouting pressure of the control system is 0-6 MPa, with a pressure resolution of 0.01 MPa, an injection rate resolution of 0.1 L / min, and good pressure stabilization effect.

[0056] The intelligent grouting control system boasts high pressure control precision, reaching up to 0.01 MPa, with fast response and minimal fluctuations. This precise and stable pressure control facilitates effective control of uplift deformation.

[0057] S2) Pre-grouting water pressure is carried out, and different step-by-step pressure increase strategies are adopted for shallow rock mass parts with prominent uplift and deformation and deep rock mass parts with less prominent uplift and deformation to obtain the initial grouting pressure.

[0058] Specifically, the method for obtaining the initial grouting pressure is as follows:

[0059] If, during the water pressurization process, the injection rate does not exceed 10L / min to 15L / min and the detected uplift value is not ≥5μm, the pressure is gradually increased to the set water pressurization pressure, and the set water pressurization pressure is used as the initial grouting pressure.

[0060] If the injection rate exceeds 10L / min to 15L / min during the water pressure process, the set water pressure is no longer required. Instead, the pressure is reduced until the injection rate is between 10L / min and 15L / min. This water pressure is then maintained until the process ends, and this water pressure is used as the initial grouting pressure.

[0061] If, during the water pressure process, the detected uplift value is ≥5μm, it is determined that uplift has occurred, and pressure reduction is performed. If, during the subsequent process, the uplift value continues to rise by ≥2μm in real time, it is determined that the uplift has occurred, and pressure reduction is performed on the basis of the current water pressure until the uplift stops. Then, the water pressure is maintained until the process ends, and this water pressure is used as the initial grouting pressure.

[0062] The set pressure for the shallow rock mass is 60% of the design grouting pressure; the set pressure for the deep rock mass is 80% of the design grouting pressure.

[0063] The purpose of pre-grouting water pressure is to initially obtain the permeability of the rock mass and guide grouting. For areas with significant uplift and deformation, the pre-grouting water pressure should be appropriately reduced, to about 60% of the design grouting pressure, and the injection rate should be controlled to no more than 10L / min to 15L / min to prevent uplift and deformation during the water pressure process. For areas with minimal uplift and deformation, the conventional practice should be followed, with the pre-grouting water pressure set at 80% of the design grouting pressure.

[0064] This invention employs different stepwise pressure-increasing strategies for shallow rock masses with prominent uplift deformation and deep rock masses with less prominent uplift deformation, achieving proactive anti-splitting and preventing excessive uplift of the rock mass due to splitting, which could affect the safety of structures such as the upper toe plate, foundation, and dam. Furthermore, it links the water pressure strategy with the grouting strategy, obtaining the initial grouting pressure from the pre-grouting water pressure. In contrast, existing technologies use the same pre-grouting water pressure for both shallow and deep rock masses. For rock masses prone to uplift deformation, the pre-grouting water pressure is set at 80% of the designed grouting pressure, making uplift highly likely. Moreover, the uplift during the water pressure process damages the rock mass, leading to more pronounced uplift during grouting. Additionally, existing technologies do not link the pre-grouting water pressure strategy with the grouting strategy.

[0065] Specifically, the stepwise pressurization strategy for the shallow rock mass (generally the first two or three sections) is as follows: each pressurization step increases by 0.02–0.03 MPa, stabilizes for 1–2 minutes, and then begins data recording. If, during the pressurization process, the injection rate exceeds 10–15 L / min, the set pressurization pressure is no longer required, and the pressure is reduced by 0.05 MPa, with each reduction occurring at 4–5 seconds intervals, until the injection rate is between 10–15 L / min. This pressurization pressure is then maintained until the process ends. If a heave value ≥5 μm is detected during the recording process, heave is considered to have occurred, and a pressure reduction is implemented. The pressure is reduced by 0.05 MPa from the pressurization pressure at the time of heave until the heave ceases, and this pressure is then maintained until the process ends.

[0066] The stepwise pressurization strategy for the deep rock mass is as follows: pressurize by 0.04–0.05 MPa at each stage, stabilize for 1–2 minutes, and then start recording data. If the injection rate exceeds 10–15 L / min during the pressurization process, the set pressurization pressure is no longer required, and the pressure is reduced by 0.05 MPa. Each pressure reduction is spaced 4–5 seconds apart until the injection rate is between 10–15 L / min. Pressurization is then maintained at this pressure until the end. If a heave value ≥5 μm is detected during the recording process, heave is determined to have occurred, and a pressure reduction is performed. The pressure is reduced by 0.05 MPa from the pressurization pressure at the time of heave until the heave stops, and then pressurization is maintained at this pressure until the end.

[0067] S3) Prepare cement grout with a suitable water-cement ratio, start the grouting pump to begin grouting. When grouting begins, the intelligent grouting control system controls the valve on the return grout pipeline to be fully open. After the grout pipeline and grouting hole are filled with grout, the valve on the return grout pipeline is controlled to slowly reduce the opening, increasing the pressure in the grouting hole, so that the grout is injected into the rock mass fissures. At the same time, the uplift deformation observation device automatically transmits the collected uplift data to the intelligent grouting control system.

[0068] The grouting process is as follows: When the real-time grouting pressure is less than the initial grouting pressure, pressure-increasing grouting is carried out according to the matching relationship between grouting pressure and injection rate; when the real-time grouting pressure is greater than the initial grouting pressure, pressure-increasing grouting is carried out according to the strategy of step-by-step pressure increase, while closely monitoring the uplift value and injection rate. If the uplift value does not increase and the injection rate does not increase significantly during the pressure stabilization process, the pressure is increased by a fixed step and the pressure is stabilized for grouting until the grouting pressure is gradually increased to the design grouting pressure and the injection rate reaches the end standard, and the grouting of this section is normally completed; if the rock mass undergoes uplift deformation during the pressure stabilization process, then proceed to step S4).

[0069] Specifically, the matching relationship between grouting pressure and injection rate is shown in Table 1.

[0070] Table 1 Relationship between Injection Rate and Grouting Pressure

[0071]

[0072] Specifically, the fixed step size is a pressure increase of 0.03 MPa to 0.1 MPa every 2 to 5 minutes.

[0073] The fixed-step pressurization refers to a step-by-step pressurization and pressure-stabilized grouting process with a fixed step size.

[0074] To address the tendency for uplift and fracturing to occur in shallow layers, different grouting strategies are developed for easily uplifted shallow rock masses and less easily uplifted deep rock masses. In addition to ensuring the matching relationship between grouting pressure P and injection rate Q, it is also necessary to implement injection rate control grouting, employing a fixed-step pressure increase grouting method. Preferably, the injection rate for shallow rock masses is controlled at a maximum of approximately 15 L / min, and the injection rate for deep rock masses is controlled at a maximum of approximately 30 L / min. The pressure increase control conditions are to simultaneously meet the following three principles: no uplift deformation occurs, the injection rate does not exceed the limit value, and the matching relationship between grouting pressure P and injection rate Q is satisfied. The pressure increase method is as follows: gradually increase the pressure by 0.03 MPa to 0.1 MPa, stabilize for a period of time, and closely monitor the uplift value and injection rate. If the pressure increase control conditions are met, continue increasing the pressure until the design pressure is reached, at which point normal grouting is completed.

[0075] S4) In case of uplift and deformation during grouting, pressure control is carried out according to the steps of pressure reduction and uplift limitation, pressure stabilization and flow limitation, and step-by-step pressure increase.

[0076] S41) Pressure Reduction and Heave Limitation: When the intelligent grouting control system detects heave deformation, in order to avoid the heave value from continuing to increase due to crack splitting, the system controls the heave deformation by precisely adjusting the pressure, reducing the grouting pressure by one pressure level each time, and at the same time reducing the grouting injection rate, thus reducing the heave effect of the grout on the rock mass; after the pressure is reduced, the heave value is continuously monitored. If the heave value still increases, the pressure is reduced by another pressure level to reduce the heave effect of grouting until the heave no longer continues to increase.

[0077] Specifically, one pressure rating is 0.05 MPa to 0.1 MPa.

[0078] S42) Pressure stabilization and flow restriction: After the grouting pressure is reduced to the point where the grouting uplift no longer increases, the grouting pressure is stabilized at the current grouting pressure. As grouting continues, the rock mass fissures are gradually filled, the grout injection rate gradually decreases, and the grout's uplift effect on the rock mass decreases. When the injection rate is less than the control value Q0, grouting continues for a period of time to fill the rock mass fissures to a certain extent, thereby enhancing the rock mass's resistance to uplift.

[0079] Specifically, the control value Q0 is 3L / min to 8L / min.

[0080] S43) Step-by-step pressure increase: As the grout fracturing effect decreases and the injection rate falls below the control value Q0, pressure increase grouting is carried out according to the step-by-step pressure increase strategy. At the same time, the uplift value and injection rate are closely monitored. If the uplift value does not increase and the injection rate does not increase significantly during the pressure stabilization process, the pressure is increased by a fixed step and the pressure is stabilized for grouting until the grouting pressure is gradually increased to the design grouting pressure. The grouting of this section is normally completed after the injection rate reaches the end standard.

[0081] If the lifting value continues to increase during the pressurization process, repeat the above process S41) to S43) until the design grouting pressure is reached and the grouting is completed normally.

[0082] At this point, with the uplift value under control, the grouting was successfully completed. After the grouting of this section was finished, the same steps were followed to continue drilling and grouting for the next section.

[0083] This invention compares the real-time grouting pressure with the initial grouting pressure during the grouting process. When the real-time grouting pressure is lower than the initial grouting pressure, pressure-increase grouting is performed according to the matching relationship between grouting pressure and injection rate. When the real-time grouting pressure is higher than the initial grouting pressure, pressure-increase grouting is performed according to a step-by-step pressure-increase strategy. If no uplift or deformation occurs, the grouting ends normally after reaching the design grouting pressure using this step-by-step pressure-increase strategy. If uplift or deformation occurs, a pressure-reduction-uplift-stabilization-flow-step-increase grouting strategy is adopted to reach the design grouting pressure before grouting ends normally. The grouting ends at the design grouting pressure. Appropriate grouting pressure is a crucial guarantee of grouting quality. Under the premise of controllable rock mass uplift, normal pressure-increase to the design pressure and normal completion criteria can effectively ensure the grouting effect. In contrast, existing... In the grouting process, the initial approach involves rapidly increasing the pressure or adjusting it according to the relationship between grouting pressure and injection rate. If uplift deformation occurs, the pressure is reduced until the uplift stops before resuming normal grouting. However, this method, which still follows the pressure-injection rate relationship, makes it highly susceptible to continued uplift. Poor uplift control often results in grouting failing to reach the designed grouting pressure before it can be properly completed. Due to the inability to increase the pressure during grouting, the final grouting pressure does not reach the designed pressure, forcing the use of low-pressure grouting. At low pressure, the grout in the cracks cannot be compressed and compacted, nor can it spread sufficiently, resulting in incomplete or insufficient filling of the cracks. This directly affects the grouting quality and can even prevent the reservoir from storing water normally. Furthermore, excessive uplift deformation can cause cracks or deformation in the upper toe plate and foundation, leading to structural quality problems.

[0084] This invention provides a control method for grouting uplift deformation of earth-rock dams based on an intelligent grouting control system. This method solves the problems of untimely handling measures, poor control effect, poor grouting quality, large grout waste, and low grouting efficiency in the past. It can effectively control grouting uplift while still pressurizing to the design pressure and reaching the normal completion standard. This can effectively ensure the grouting effect and avoid measures such as waiting for curing or re-grouting due to abnormal completion.

[0085] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for controlling the uplift deformation of earth-rock dams during grouting based on an intelligent grouting control system, characterized in that, Includes the following steps: S1) Complete the grouting preparation work, including drilling and flushing the grouting holes, connecting the mixing tank, grouting pump, pressure gauge, flow meter, blocker, and intelligent grouting control system in series through the grouting pipeline, and installing the lifting deformation observation device and connecting the lifting deformation observation device to the intelligent grouting control system. The uplift deformation monitoring device is used to accurately monitor the grouting of the dam bedrock and to provide timely feedback and alarm when uplift occurs. The intelligent grouting control system is used to receive the detected uplift value sent by the uplift deformation observation device, collect the flow rate, pressure, density and temperature signals of the grouting hole, control the water pressure construction and grouting construction, and has the functions of automatic grout preparation, automatic data recording, precise pressure control, grouting process control and grouting result processing. S2) Pre-grouting water pressure is carried out, and different step-by-step pressure increase strategies are adopted for shallow rock mass parts with prominent uplift and deformation and deep rock mass parts with less prominent uplift and deformation to obtain the initial grouting pressure; S3) Prepare cement grout with a suitable water-cement ratio, start the grouting pump to begin grouting. When grouting begins, the intelligent grouting control system controls the valve on the return grout pipeline to be fully open. After the grout pipeline and grouting hole are filled with grout, the valve on the return grout pipeline is controlled to slowly reduce the opening, increasing the pressure in the grouting hole, so that the grout is injected into the rock mass fissures. At the same time, the uplift deformation monitoring device automatically transmits the collected uplift data to the intelligent grouting control system. The grouting process is as follows: When the real-time grouting pressure is less than the initial grouting pressure, pressurized grouting is carried out according to the matching relationship between grouting pressure and injection rate; when the real-time grouting pressure is greater than the initial grouting pressure, pressurized grouting is carried out according to the strategy of step-by-step pressurization, while closely monitoring the uplift value and injection rate. If the uplift value does not increase and the injection rate does not increase significantly during the pressure stabilization process, the pressure is increased by a fixed step and the pressure is stabilized until the grouting pressure is gradually increased to the design grouting pressure. After the injection rate reaches the end standard, the grouting of this section is normally completed; if the rock mass undergoes uplift deformation during the pressure stabilization process, then proceed to step S4); The fixed-step pressurization refers to a fixed-step, step-by-step pressurization and pressure-stabilized grouting process. S4) In case of uplift and deformation during grouting, pressure control shall be carried out in accordance with the steps of pressure reduction and uplift limitation, pressure stabilization and flow limitation, and step-by-step pressure increase. S41) Pressure Reduction and Uplift Limitation: When the intelligent grouting control system detects uplift deformation, in order to avoid the uplift value from continuing to increase due to crack splitting, the system controls the uplift deformation by precisely adjusting the pressure, reducing the grouting pressure by one pressure level at a time, and simultaneously reducing the grouting injection rate, thus reducing the uplift effect of the grout on the rock mass; after the pressure is reduced, the uplift value is continuously monitored. If the uplift value still increases, the pressure is reduced by another pressure level to reduce the uplift effect of the grouting until the uplift no longer continues to increase; S42) Pressure stabilization and flow restriction: After the grouting pressure is reduced to the point where the grouting uplift no longer increases, the grouting pressure is stabilized at the current grouting pressure. As grouting continues, the rock mass fissures are gradually filled, the grout injection rate gradually decreases, and the grout's uplift effect on the rock mass decreases. When the injection rate is less than the control value Q0, grouting continues for a period of time to fill the rock mass fissures to a certain extent, thereby enhancing the rock mass's resistance to uplift. S43) Step-by-step pressure increase: As the grout fracturing effect decreases and the injection rate falls below the control value Q0, pressure increase grouting is carried out according to the step-by-step pressure increase strategy. At the same time, the uplift value and injection rate are closely monitored. If the uplift value does not increase and the injection rate does not increase significantly during the pressure stabilization process, the pressure is increased by a fixed step and the pressure is stabilized for grouting until the grouting pressure is gradually increased to the design grouting pressure. The grouting of this section is normally completed after the injection rate reaches the end standard. If the lifting value continues to increase during the pressurization process, repeat the above process S41) to S43) until the design grouting pressure is reached and the grouting is completed normally.

2. The method for controlling the uplift deformation of earth-rock dams based on an intelligent grouting control system according to claim 1, characterized in that: In S1), the lifting deformation observation device includes a lifting sensor embedded in the lifting observation hole, the lifting sensor having a resolution of 1μm and a range of not less than 10mm.

3. The method for controlling the uplift deformation of earth-rock dams based on an intelligent grouting control system according to claim 1, characterized in that: In S1), the intelligent grouting control system includes a sensor cabinet, a control system, and a main control center. The sensor cabinet is used to collect flow rate, pressure, density, and temperature signals from the grouting holes. The control system is used to control the water pressure construction and grouting construction, and has functions such as automatic grout mixing, automatic data recording, precise pressure control, grouting process control, and grouting result processing. The main control center is used to receive the flow rate, pressure, density, and temperature signals sent by the sensor cabinet and the detection uplift values ​​sent by the uplift deformation observation device, and to control the control system.

4. The method for controlling the uplift deformation of earth-rock dams based on an intelligent grouting control system according to claim 3, characterized in that: In S1), the sensor cabinet includes a flow sensor, a pressure sensor, a density sensor, and a temperature sensor. The control system achieves precise pressure control by controlling the valves on the grout return pipeline. The automatic control range of the grouting pressure of the control system is 0-6 MPa, the pressure resolution is 0.01 MPa, and the injection rate resolution is 0.1 L / min.

5. The method for controlling the uplift deformation of earth-rock dams based on an intelligent grouting control system according to claim 1, characterized in that: In S2), the method for obtaining the initial grouting pressure is as follows: If, during the water pressurization process, the injection rate does not exceed 10L / min to 15L / min and the detected uplift value is not ≥5μm, the pressure is gradually increased to the set water pressurization pressure, and the set water pressurization pressure is used as the initial grouting pressure. If the injection rate exceeds 10L / min to 15L / min during the water pressure process, the set water pressure is no longer required. Instead, the pressure is reduced until the injection rate is between 10L / min and 15L / min. This water pressure is then maintained until the process ends, and this water pressure is used as the initial grouting pressure. If, during the water pressure process, the detected uplift value is ≥5μm, it is determined that uplift has occurred, and pressure reduction is performed. If, during the subsequent process, the uplift value continues to rise by ≥2μm in real time, it is determined that the uplift has occurred, and pressure reduction is performed on the basis of the current water pressure until the uplift stops. Then, the water pressure is maintained until the end, and the water pressure is used as the initial grouting pressure. The set pressure for the shallow rock mass is 60% of the design grouting pressure; the set pressure for the deep rock mass is 80% of the design grouting pressure.

6. The method for controlling the grouting uplift deformation of earth-rock dams based on an intelligent grouting control system according to claim 5, characterized in that: In S2), the stepwise pressurization strategy for the shallow rock mass is as follows: pressurize by 0.02-0.03 MPa at each stage, stabilize for 1-2 minutes, and then start recording data. If the injection rate exceeds 10-15 L / min during the pressurization process, the set pressurization pressure is no longer required, and the pressure is reduced by 0.05 MPa. Each pressure reduction is spaced 4-5 seconds apart until the injection rate is between 10-15 L / min. The pressurization pressure is then maintained until the end. If a heave value ≥5 μm is detected during the recording process, heave is determined to have occurred, and a pressure reduction is performed. The pressure is reduced by 0.05 MPa from the pressurization pressure at the time of heave until the heave stops, and then the pressure is maintained until the end. The stepwise pressurization strategy for the deep rock mass is as follows: pressurize by 0.04–0.05 MPa at each stage, stabilize for 1–2 minutes, and then start recording data. If the injection rate exceeds 10–15 L / min during the pressurization process, the set pressurization pressure is no longer required, and the pressure is reduced by 0.05 MPa. Each pressure reduction is spaced 4–5 seconds apart until the injection rate is between 10–15 L / min. Pressurization is then maintained at this pressure until the end. If a heave value ≥5 μm is detected during the recording process, heave is determined to have occurred, and a pressure reduction is performed. The pressure is reduced by 0.05 MPa from the pressurization pressure at the time of heave until the heave stops, and then pressurization is maintained at this pressure until the end.

7. The method for controlling the uplift deformation of earth-rock dams based on an intelligent grouting control system according to claim 1, characterized in that: In S3), the fixed step size is a pressure increase of 0.03MPa to 0.1MPa every 2 to 5 minutes.

8. The method for controlling the uplift deformation of earth-rock dams based on an intelligent grouting control system according to claim 1, characterized in that: In S41), one pressure rating is 0.05MPa to 0.1MPa.

9. The method for controlling the uplift deformation of earth-rock dams based on an intelligent grouting control system according to claim 8, characterized in that: In S42), the control value Q0 is 3L / min to 8L / min.

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