Underground water level control method and system

Abstract

The invention provides an underground water level control method and system, and relates to the technical field of foundation pit dewatering. The precipitation data comprises underground water level elevations of an observation well and a precipitation well in the to-be-excavated area and the water yield of the precipitation well; according to the rainfall data, a water level drawdown predicted value of underground water in the to-be-excavated area is calculated; the water level drawdown predicted value is a correction factor calculated according to the rainfall data and the water level drawdown predicted value; according to the correction factor, obtaining a corrected water level prediction model; the water level prediction model is configured to calculate a water level drawdown correction value of underground water in the to-be-excavated area according to the water yield of the dewatering well; and inputting the target water level drop depth of the underground water in the to-be-excavated area into the water level prediction model, and determining the target water yield of each dewatering well when the total water displacement of the dewatering wells is minimum, so that the water level elevation of the underground water is accurately controlled, and the problems of energy consumption increase caused by excessive adoption of the underground water and potential safety hazards caused by water level rise are avoided.

Description

Technical Field

[0001] This application relates to the technical field of foundation pit dewatering, and particularly relates to a method and system for controlling the groundwater level. Background Art

[0002] Foundation pit dewatering refers to the work of dewatering when the groundwater level is higher than the excavation bottom surface during the excavation of the foundation pit. Groundwater will continuously seep into the pit. To ensure that the foundation pit can be constructed under dry conditions and prevent slope instability, base quicksand, bottom heave, bottom piping, and a decrease in foundation bearing capacity.

[0003] Currently, the common dewatering control methods usually include: setting drainage wells, using pumps, manual monitoring, and manual adjustment. By pumping out the groundwater under the foundation pit, the water level elevation of the groundwater is made to meet the depth requirements of the foundation pit.

[0004] Since the drainage equipment such as pumps is adjusted manually, it is impossible to accurately control the water level elevation of the groundwater. Generally, the power of the pump is modulated to the maximum or the pump is operated according to the calculated set power. However, due to the large area of the foundation pit and the large number of pumps used, the power consumption of the pumps is extremely large, and it is impossible to control the operating power of the pumps in real time according to the water level elevation of the groundwater, resulting in the inability to accurately control the water level elevation of the groundwater and easily causing potential safety hazards. Summary of the Invention

[0005] This application provides a method and system for controlling the groundwater level to solve the technical problem that it is currently impossible to accurately control the water level elevation of the groundwater, which easily causes potential safety hazards.

[0006] In the first aspect of this application, a method for controlling the groundwater level is provided, which is applied to the area to be excavated. A number of dewatering wells are arranged outside the area to be excavated, and pumps are arranged in the dewatering wells. The pumps are used to pump out the water in the dewatering wells. The method includes: Obtain dewatering data; the dewatering data includes: the water level elevation of the groundwater in the area to be excavated and the water output of the dewatering wells; According to the dewatering data, calculate the predicted value of the groundwater level drawdown in the area to be excavated; the predicted value of the water level drawdown is: S i = ; In the formula, S i is the groundwater level drawdown in the area to be excavated; H is the thickness of the aquifer in the area to be excavated; is the water output of the j th dewatering well; k is the permeability coefficient of the aquifer in the area to be excavated; Ris the influence radius; is the j distance from the center of the precipitation well at the n th opening to the center of the area to be excavated; Calculate a correction factor according to the precipitation data and the predicted value of the water level drawdown; the correction factor is: α = S 实 ÷ ; In the formula, S 实 is the measured value of the water level drawdown of the groundwater in the area to be excavated; Obtain a water level prediction model according to the correction factor; the water level prediction model is configured to calculate the corrected value of the water level drawdown of the groundwater in the area to be excavated according to the water output of the precipitation well; the corrected value of the water level drawdown is: S 修 = α × ( ); Input the target water level drawdown of the groundwater in the area to be excavated into the water level prediction model, and determine the target water output of each precipitation well when the total water output of the precipitation well is the smallest; the total water output is: Q 总 = q 1 + q 2 + q 3 + …… q j .

[0007] In some embodiments, the water level prediction model is further configured to: Obtain the water level elevations of any two adjacent precipitation wells; Obtain the water level elevation of the observation well; the observation well is arranged in the middle area outside two adjacent precipitation wells; the horizontal distances between the observation well and the two adjacent precipitation wells are the first distance and the second distance respectively; the depth of the observation well is the same as that of the precipitation well; Obtain the hydraulic gradient in the area of the observation well according to the water level elevations of the observation well and the two precipitation wells on both sides; the hydraulic gradient is: J = [(h 1降 - h 观 ) ÷ L 11 + (h 2降 - h 观 ) ÷ L 12 ÷ 2; In the formula, h 观 is the water level elevation of the observation well; h 1降 and h 2降 are the water level elevations of the two precipitation wells adjacent to the observation well respectively; L 11is the first distance; L 12 is the second distance; When determining that the water level drawdown of the observation well is the target water level drawdown of the groundwater in the area to be excavated, the target water level drawdown of the precipitation wells adjacent to both sides of the observation well; the target water level drawdown of the precipitation well is: S 降 = S 观 + L 观降 × J; In the formula, L 观降 is the horizontal distance between the observation well and the precipitation wells adjacent to both sides; J is the hydraulic gradient of the observation well area; Based on the target water level drawdown and the initial water level elevation of the precipitation well, obtain the target water level elevation of the precipitation well; Based on the target water level elevation of the precipitation well, adjust the target operating power and water output of the water pump so that the real-time water level elevation of the precipitation well is maintained within the target water level elevation control range.

[0008] In some embodiments, the measured value of the water level drawdown of the groundwater in the area to be excavated is obtained through the following steps: Obtain the real-time water level elevation of the observation well; Based on the initial water level elevation and the real-time water level elevation of the observation well, calculate the water level drawdown of the observation well; the water level drawdown of the observation well is: S 观 = h 观初 - h 观实 ; In the formula, h 观初 is the initial water level elevation of the observation well; h 观实 is the real-time water level elevation of the observation well; Based on the minimum water level drawdown of the observation well; determine the measured value of the water level drawdown of the groundwater in the area to be excavated.

[0009] In some embodiments, the method further includes: Based on the water level drawdown of the observation well, obtain the target water level drawdown of the precipitation wells adjacent to both sides of the observation well; the target water level drawdown of the precipitation well is: S 降 = S 观 + L 观降 × J; In the formula, L 观降 is the horizontal distance between the observation well and the precipitation wells adjacent to both sides; J is the hydraulic gradient of the observation well area; Based on the target water level drawdown and the initial water level elevation of the precipitation well, obtain the target water level elevation of the precipitation well; Adjust the target operating power and water output of the water pump according to the target water level elevation.

[0010] In some embodiments, the step of adjusting the target operating power and water output of the water pump according to the target water level elevation includes: Obtain the water level control index of the precipitation well according to the target water level elevation of the precipitation well; Adjust the target operating power and water output of the water pump according to the water level control index and the real-time water level elevation of the precipitation well, so that the real-time water level elevation of the precipitation well is maintained within the target water level elevation control range. The target water level elevation control range is below the target water level elevation.

[0011] In some embodiments, the water level control index includes: Target water level, safety water level, frequency increase water level, frequency decrease water level, stop water level; The safety water level is: h1 = h j -0.5; where h j is the target water level, and the target water level is equal to the target water level elevation of the precipitation well; The frequency increase water level is: h2 = h1 - 1; The frequency decrease water level is: h3 = h2 - 2; The stop water level is: h4 = h3 - 3; where the safety water level is greater than the frequency increase water level, the frequency increase water level is greater than the frequency decrease water level, and the frequency decrease water level is greater than the stop water level.

[0012] In some embodiments, the step of adjusting the target operating power and water output of the water pump according to the water level control index and the real-time water level elevation of the precipitation well, so that the real-time water level elevation of the precipitation well is maintained within the target water level elevation control range includes: If the real-time water level elevation of the precipitation well is greater than or equal to the safety water level, control the water pump to operate at full frequency; If the real-time water level elevation of the precipitation well is less than the safety water level and greater than or equal to the frequency increase water level, control the power of the water pump to gradually increase according to the set power until the real-time water level elevation of the precipitation well is less than the frequency decrease water level; If the real-time water level elevation of the precipitation well is less than the frequency increase water level and greater than or equal to the frequency decrease water level, control the water pump to operate at the preset power; If the real-time water level elevation of the precipitation well is less than the frequency decrease water level and greater than or equal to the stop water level, control the power of the water pump to gradually decrease according to the set power until the real-time water level elevation of the precipitation well is greater than the frequency decrease water level; If the real-time water level elevation of the precipitation well is less than the stop water level, control the water pump to stop running until the real-time water level elevation of the precipitation well rises to the frequency increase water level, start the water pump and control the power of the water pump to gradually increase according to the set power.

[0013] In some embodiments, before the step of obtaining precipitation data, it includes: Dividing the area to be excavated into multiple partitions; the partitions are divided according to the depth to be excavated and the construction sequence; the length of the partition is less than the preset length; Setting the precipitation wells on the periphery of the partition; the distance between the precipitation wells is less than the preset distance.

[0014] The second aspect of the present application provides a groundwater level control system, which is applied to the area to be excavated. A number of precipitation wells are arranged on the periphery of the area to be excavated, and a water pump is arranged in the precipitation well. The water pump is used to pump out the water in the precipitation well. It includes: A data acquisition module, which is configured as: Obtaining precipitation data; the precipitation data includes: the water level elevation of the groundwater in the area to be excavated and the water output of the precipitation well; A data processing module, which is configured as: According to the precipitation data, calculating the predicted value of the groundwater level drawdown in the area to be excavated; the predicted value of the groundwater level drawdown is: S i = ; In the formula, S i is the groundwater level drawdown in the area to be excavated; H is the thickness of the aquifer in the area to be excavated; is the water output of the j th precipitation well; k is the permeability coefficient of the aquifer in the area to be excavated; R is the radius of influence; is the distance from the center of the j th precipitation well to the center of the area to be excavated; n is the number of precipitation wells; According to the precipitation data and the predicted value of the groundwater level drawdown, calculating a correction factor; the correction factor is: α= S 实 ÷ ; In the formula, S 实 is the measured value of the groundwater level drawdown in the area to be excavated; According to the correction factor, a water level prediction model is obtained; the water level prediction model is configured to calculate a corrected value of the groundwater level drawdown in the area to be excavated according to the water output of the precipitation wells; the corrected value of the groundwater level drawdown is: S 修 = α × ( ); A data output module, the data output module is configured to: Input the target groundwater level drawdown in the area to be excavated into the water level prediction model to determine the target water output of each precipitation well when the total water discharge of the precipitation wells is minimized; the total water discharge is: Q 总 = q 1 + q 2 + q 3 + …… q j ; An early warning module, the early warning module is configured to: When the real-time water level elevation of the precipitation well is greater than the early warning water level, an alarm sound is emitted and the early warning information is sent to the set device; the early warning water level is greater than the safety water level; the early warning information includes: the well number and water level status of the precipitation well where the real-time water level elevation is greater than the early warning water level; the water level status includes: the real-time water level elevation and the safety water level of the precipitation well.

[0015] In some embodiments, the early warning module is configured with an early warning light; the early warning module is further configured to: When the real-time water level elevation of the precipitation well is greater than or equal to the safety water level, control the early warning light to display red; When the real-time water level elevation of the precipitation well is less than the safety water level and greater than or equal to a preset value, control the early warning light to display yellow; the preset value is: X = h1 - 0.5; Wherein, h1 is the safety water level; When the real-time water level elevation of the precipitation well is less than the preset value, control the early warning light to display green.

[0016] The present application provides a groundwater level control method and system, which is applied to an area to be excavated. A plurality of precipitation wells are arranged outside the area to be excavated, and a water pump is arranged in each precipitation well for pumping out the water in the precipitation well; the method includes: obtaining precipitation data; the precipitation data includes: the water level elevation of the groundwater in the area to be excavated and the water output of the precipitation wells; according to the precipitation data, calculating a predicted value of the groundwater level drawdown in the area to be excavated; the predicted value of the groundwater level drawdown is: S i = ; In the formula, S i is the drawdown of the groundwater level in the area to be excavated; H is the thickness of the aquifer in the area to be excavated; is the j discharge of the k th precipitation well; R is the coefficient of permeability of the aquifer in the area to be excavated; is the j distance from the center of the n th precipitation well to the center of the area to be excavated; According to the precipitation data and the predicted drawdown value, calculate the correction factor; the correction factor is: α = S 实 ÷ ; In the formula, S 实 is the measured value of the drawdown of the groundwater level in the area to be excavated; According to the correction factor, obtain the water level prediction model; the water level prediction model is configured to calculate the corrected value of the drawdown of the groundwater level in the area to be excavated according to the discharge of the precipitation well; the corrected value of the drawdown is: S 修 = α × ( ) Input the target drawdown of the groundwater level in the area to be excavated into the water level prediction model, and determine the target discharge of each precipitation well when the total discharge of the precipitation wells is the smallest; the total discharge is: Q 总 = q 1 + q 2 + q 3 +... q j , so as to solve the problem that the current groundwater level elevation cannot be accurately controlled, which easily leads to potential safety hazards.

[0017] The present application provides a groundwater level control method and system, which has the following beneficial effects: accurately controlling the thickness of the aquifer in the area to be excavated, and at the same time enabling the pump operation power in the precipitation well to reach the minimum value, reducing the power consumption of the pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the present application, the drawings required for the embodiments will be briefly introduced below. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0019] Figure 1 This is the flow chart of the groundwater level control method in this application; Figure 2 This is the schematic diagram of the water level index of the precipitation well in this application; Figure 3 This is the first schematic diagram of the distribution structure of the precipitation well and the observation well in this application; Figure 4 This is the second schematic diagram of the distribution structure of the precipitation well and the observation well in this application; Figure 5 This is the schematic diagram of the hydraulic gradient in the observation well area in this application; Figure 6 This is the specific application scenario diagram of the groundwater level control method in this application. Detailed implementation manners

[0020] In order to enable those skilled in the art to better understand the technical solutions in this application, the following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0021] Since in some technologies, the groundwater level elevation cannot be accurately controlled, which easily leads to potential safety hazards. To solve this technical problem, this application provides a groundwater level control method and system. The following will explain the groundwater level control method and system: As Figure 1 shown, this is the flow chart of the groundwater level control method in this application.

[0022] In the first aspect of this application, a groundwater level control method is provided, which is applied to an area to be excavated. A plurality of precipitation wells are arranged outside the area to be excavated, and a water pump is arranged in each precipitation well. The water pump is used to pump out the water in the precipitation well; the method includes the following steps: S100: Obtain precipitation data; the precipitation data includes: the groundwater level elevation in the area to be excavated and the water output of the precipitation well; among them, the groundwater level elevation in the area to be excavated is obtained by a liquid level sensor arranged in the observation well, and the water output of the precipitation well is obtained by a flow sensor arranged at the water outlet end of the water pump. Among them, the water level elevation is the height from the free water surface in the well to the wellhead.

[0023] Before the step of obtaining precipitation data, the following steps are included: S80: Divide the area to be excavated into multiple partitions; the partitions are divided according to the depth to be excavated and the construction sequence; the length of the partition is less than the preset length; define multiple precipitation partitions according to parameters such as the excavation depth of the area to be excavated, the construction sequence, and the precipitation period, and the length of each partition is not more than 50 meters, and then input the basic parameters of the precipitation design such as the well location coordinates, wellhead elevation, initial water level elevation, pump volume, power, etc. into the system for subsequent calculation of the target water output of the precipitation well.

[0024] It is understandable that the area to be excavated may occupy a large area, resulting in inconsistent groundwater level elevation in the area to be excavated. Therefore, the area to be excavated needs to be divided according to the groundwater level elevation in the area to be excavated to ensure that the difference between the maximum and minimum groundwater levels in the divided areas is within the preset range. The area to be excavated can be further divided according to parameters such as the specific construction sequence and precipitation cycle. In order to ensure that the groundwater level elevation can be accurately controlled, the length of the partition is generally less than the preset length, and the length of each partition is generally not more than 50 meters.

[0025] S90: The precipitation wells are arranged at the periphery of the partitions; the distance between the precipitation wells is less than the preset distance. The precipitation wells are arranged at the periphery of the partitions, and are used to extract groundwater in the area to be excavated, so that the groundwater level in the area to be excavated is lower than the depth to be excavated in the area to be excavated. In order to ensure that the water extracted through the precipitation wells can affect the thickness of the aquifer in the area to be excavated, the distance between the precipitation wells is less than the preset distance, so as to ensure that the groundwater is extracted through the precipitation wells arranged at the periphery of the area to be excavated, thereby reducing the thickness of the aquifer in the area to be excavated.

[0026] The thickness of the aquifer in the area to be excavated is obtained by the following steps: The water level of the observation well is obtained; the observation well is set outside the precipitation well, and the thickness of the aquifer in the area to be excavated is obtained according to the maximum water level of the observation well. The observation well is used to indicate the groundwater level in the area to be excavated.

[0027] like Figure 3 and Figure 4 As shown, it is a schematic diagram of the structure in which the observation well and the precipitation well are distributed outside the area to be excavated in this application.

[0028] Exemplarily, before carrying out the precipitation work, it is first necessary to divide the area to be excavated into multiple sub-areas. The division criteria include parameters such as the excavation depth of the area to be excavated, the construction sequence, and the precipitation cycle. By dividing the sub-areas, not only can the efficiency and safety of subsequent construction be improved, but also the precipitation effect can be ensured to meet the expected basis. After each sub-area of the area to be excavated is divided, observation wells are first set up. Generally, the well depth of the observation wells is set to be greater than the excavation depth of the area to be excavated. The number of observation wells is determined by the size of the area to be excavated. Usually, the observation wells are set outside the precipitation wells, so that the dynamic of the groundwater level can be effectively monitored, and the interference of construction activities on the observation data can be avoided. The elevation of the groundwater level in the observation wells is obtained by setting liquid level sensors in the observation wells. Generally, the maximum water level elevation data among the water level elevation data of each observation well is used as the thickness of the aquifer in the area to be excavated, so as to improve the accuracy of the aquifer thickness data in the area to be excavated and lay a solid foundation for subsequent excavation operations.

[0029] Exemplarily, by setting precipitation wells, such as Figure 3 and Figure 4 shown, the precipitation well is Jn; a water pump is set in the precipitation well, and the groundwater in the precipitation well is pumped out through the water pump, so as to reduce the elevation of the groundwater level in the area to be excavated. Among them, the precipitation wells are set outside the area to be excavated, and the observation wells are set outside the precipitation wells, as Figure 3 and Figure 4 shown, the observation well is Gm; and the wellhead width of the precipitation well is much larger than that of the observation well. It can be understood that since the main task of the precipitation well is to reduce the groundwater level in the area to be excavated, it is necessary to ensure that as much groundwater as possible can penetrate and converge into the precipitation well. The wide wellhead design can effectively increase the infiltration area of groundwater and improve the precipitation efficiency. At the same time, the wide wellhead also helps the water pump to pump groundwater more efficiently, so as to ensure the rapidity and stability of the precipitation process. The main task of the observation well is to obtain accurate data on the elevation of the groundwater level in the area to be excavated. Therefore, the wellhead width of the observation well does not need to be set too large. An overly large wellhead will not only increase the construction difficulty and cost, but may also cause unnecessary interference to the setting work of the precipitation well. It is only necessary to ensure that the wellhead width of the observation well is large enough to accommodate monitoring equipment such as liquid level sensors and can provide accurate and reliable groundwater precipitation data. Among them, the number of precipitation wells is set according to the size of the area to be excavated, based on being able to accurately and quickly reduce the groundwater level in the area to be excavated.

[0030] S200: Calculate the predicted value of the groundwater level drawdown in the area to be excavated according to the precipitation data; the predicted value of the groundwater level drawdown is: S i = ; In the formula,S i is the drawdown of the groundwater level in the area to be excavated, that is, the drawdown of the groundwater level at any point in the foundation pit; H is the thickness of the aquifer in the area to be excavated, that is, the thickness of the unconfined aquifer; is the j discharge (m³ / d) of the k th precipitation well; is the hydraulic conductivity of the aquifer in the area to be excavated; R is the radius of influence; is the j distance from the center of the j th precipitation well to the center of the area to be excavated, that is, the distance from the center of the n th well to the groundwater level calculation point (m); is the number of precipitation wells; Among them, the hydraulic conductivity of the aquifer in the area to be excavated k can be measured by the water level gradient method. According to Darcy's law k =frac{v}{I} (where v is the groundwater flow velocity and I is the water level gradient) to calculate the hydraulic conductivity. Among them, the groundwater flow velocity can be measured by the indicator method (putting indicators such as dye substances and salt solutions, measuring the time when they appear in the downstream observation wells, and calculating the flow velocity in combination with the distance) or the electrical charging method, etc. The water level gradient can be obtained through the unified measurement of the groundwater level in the area to be excavated, obtaining the water levels at each position point in the area to be excavated, and calculating the water level gradient by calculating the ratio of the water level difference to the distance.

[0031] Specifically, the hydraulic conductivity of the aquifer in the area where the precipitation well is located is obtained through the following methods: First, obtain the groundwater flow velocity in the precipitation well to be measured. By obtaining the upstream precipitation well or observation well at the location of the precipitation well to be measured, put the indicator (such as dye substances and salt solutions) into the upstream precipitation well or observation well, measure the time when it appears in the precipitation well to be measured, and calculate the groundwater flow velocity in combination with the distance; groundwater flow velocity = the distance between the precipitation well to be measured and the upstream precipitation well or observation well ÷ the time from when the indicator is put into the upstream precipitation well or observation well to when it reaches the precipitation well to be measured; Second, obtain the water level gradient of the precipitation well to be measured. By obtaining the water levels of each precipitation well, calculate the water level gradient by calculating the ratio of the water level difference of each precipitation well to the distance. Finally, calculate the hydraulic conductivity of the groundwater in each precipitation well according to Darcy's law, that is, the hydraulic conductivity of the aquifer in the area to be excavated.

[0032] Among them, the measured value of the drawdown of the groundwater level in the area to be excavated is measured in real time by the liquid level sensor in the observation well, and the measured value of the minimum drawdown of the groundwater level in the area to be excavated is used as the measured value of the drawdown of the groundwater level in the area to be excavated.

[0033] S300: Calculate the correction factor according to the precipitation data and the predicted value of the drawdown; the correction factor is: α =S 实 ÷ ; In the formula, S 实 is the measured value of the groundwater level drawdown in the area to be excavated.

[0034] It should be noted that the correction factor is constantly changing. For example, the system obtains the water output data of the precipitation well and the measured value of the groundwater level drawdown in the area to be excavated every hour, and then modifies the correction factor according to the predicted value of the groundwater level drawdown in the area to be excavated, and continuously updates the correction factor to ensure that the aquifer thickness in the area to be excavated is controlled near the target thickness value.

[0035] S400: Obtain a water level prediction model according to the correction factor; the water level prediction model is configured to calculate a corrected value of the groundwater level drawdown in the area to be excavated according to the water output of the precipitation well; the corrected value of the groundwater level drawdown is: S 修 =α × ( ).

[0036] It can be understood that there is a certain difference between the predicted value of the groundwater level drawdown in the area to be excavated obtained through the above formula and the measured value of the groundwater level drawdown in the area to be excavated. The above formula obtains the predicted value of the groundwater level drawdown in the area to be excavated according to the proportional relationship between the water output of the precipitation well and the groundwater level elevation in the area to be excavated. However, due to the permeability of the soil to water and the error value of the water output measurement, there is a certain error in the predicted value of the groundwater level drawdown in the area to be excavated measured by the above calculation.

[0037] The measured value of the groundwater level drawdown in the area to be excavated is obtained through the following steps: Obtain the initial water level elevation of the observation well; obtain the real-time water level elevation of the observation well; calculate the water level drawdown of the observation well according to the initial water level elevation and the real-time water level elevation; the water level drawdown of the observation well is: S 观 =h 观初 -h 观实 ; In the formula, h 观初 is the initial water level elevation of the observation well; h 观实 is the real-time water level elevation of the observation well; determine the measured value of the groundwater level drawdown in the area to be excavated according to the minimum water level drawdown of the observation well. For safety reasons, generally, the minimum water level drawdown of the observation well is used as the measured value of the groundwater level drawdown in the area to be excavated.

[0038] In this embodiment, the water level value of the groundwater in the area to be excavated can be obtained more accurately through the observation well. By using the theoretical value of the groundwater level drawdown and the measured value of the groundwater level drawdown in the area to be excavated, the correction coefficient for the theoretical value of the groundwater level drawdown in the area to be excavated can be obtained by using the correction factor formula, which lays a foundation for obtaining the target water output of the precipitation well subsequently.

[0039] S500: Input the target water level drawdown of the groundwater in the area to be excavated into the water level prediction model, and determine the target water output of the precipitation well when the total drainage volume of the precipitation well is the smallest; the total drainage volume is: Q 总 = q 1 + q 2 + q 3 + …… q j 。

[0040] Among them, through the theoretical value of the groundwater level drawdown and the measured value of the groundwater level drawdown in the area to be excavated, the correction value of the groundwater level drawdown in the area to be excavated is obtained. Through the correction value and the formula corresponding to the theoretical value of the groundwater level drawdown in the area to be excavated, more accurate groundwater level drawdown data in the area to be excavated can be obtained, so as to obtain the linear relationship between the water output of the precipitation well and the groundwater level drawdown in the area to be excavated, and then the water output of the precipitation well can be obtained according to the target water level drawdown.

[0041] Specifically, when the user inputs the target water level drawdown into the water level prediction model, it is equivalent to determining the value of S 修 in the model. At this time, the model requires that the total drainage volume of the precipitation well satisfies that the groundwater level drawdown in the area to be excavated is greater than the target water level drawdown of the groundwater in the area to be excavated. It can be understood that at this time, the water output results of each precipitation well corresponding to the model are multiple, but the water output of each precipitation well corresponding to the minimum total drainage volume of the precipitation well is the only value, that is, the target water output. In the above process, every once in a while (such as one hour), the model will update the correction factor in the model according to the predicted value of the water level drawdown and the measured value of the water level drawdown, so as to ensure that the target water output of each precipitation well is always at the best value.

[0042] It should be noted that because the permeability coefficient of each precipitation well k is different, the water output of each precipitation well is not the same.

[0043] Among them, the target water output, the water output of the water pump, and the operating power are all at their minimum values. When the groundwater level drawdown in the area to be excavated reaches the drawdown of the target groundwater level in the area to be excavated, the electricity consumption of the water pump can be saved. Moreover, the less the water output of the water pump, the more the transportation and storage costs of groundwater can be saved.

[0044] This application provides a method for controlling the groundwater level, and the steps are as follows: The first step: Obtain precipitation data; the precipitation data includes: the thickness of the aquifer in the area to be excavated, the water level elevation of the regional observation well, the water level elevation of the precipitation well, the water output of the precipitation well, the distance between the precipitation well and the observation well, etc.; The second step: According to the precipitation data, calculate the predicted value of the groundwater level drawdown in the area to be excavated; the predicted value of the groundwater level drawdown is: according to parameters such as the measured water output of the precipitation well, the distance between the observation point and the precipitation well, and the permeability coefficient, calculate the theoretical predicted value of the water level drawdown at the observation point through the interference drawdown theoretical formula; The third step: Compare the measured precipitation data with the theoretical predicted value of the water level drawdown, and calculate the correction factor; The fourth step: According to the correction factor, obtain the corrected water level prediction model; according to the corrected water level prediction model and the measured water output of each precipitation well, calculate the corrected value of the groundwater level drawdown in the area to be excavated; The fifth step: Input the target water level drawdown of the groundwater in the area to be excavated into the corrected water level prediction model, and determine the target water output of each precipitation well when the total drainage volume of the precipitation well is the smallest. In order to accurately control the water level elevation of the groundwater, avoid the problem of increased energy consumption caused by excessive extraction of groundwater, and the safety hazards caused by rising water levels.

[0045] This application provides a method for controlling the groundwater level. First, set up observation wells outside the area to be excavated, and then set up precipitation wells outside the observation wells. The number of the observation wells and the precipitation wells is determined according to the size of the area to be excavated. After the groundwater penetrates into the observation well area and stabilizes, use a liquid level sensor to obtain the maximum water level elevation in the observation well as the thickness of the aquifer in the area to be excavated. Start the water pump to pump out the groundwater in the precipitation well. When the maximum water level elevation in the observation well is greater than the depth to be excavated in the area to be excavated and is stable, it means that the thickness of the aquifer in the area to be excavated meets the excavation requirements, and the excavation work can be carried out on the area to be excavated. Among them, the water level elevation of the observation well determines the water output of the water pump, that is, the water output of the precipitation well, and the water output of the precipitation well determines the water level elevation of the precipitation well, so as to determine the groundwater level elevation in the area to be excavated. Through the linear relationship between the above data, continuously update the operating power of the water pump, so as to control the thickness of the aquifer in the area to be excavated, and at the same time, the operating power of the water pump in the precipitation well can reach the minimum value, reducing the power consumption of the water pump.

[0046] The present application provides a method for controlling the groundwater level. Rainfall data is input into the rainfall system in real time through sensors such as liquid level sensors and flow sensors. The rainfall system can calculate the predicted value of the groundwater level drawdown in the area to be excavated based on the rainfall data. There is a certain error in the predicted value of the water level drawdown. In the present application, the measured value of the groundwater level drawdown in the area to be excavated is obtained every preset time (such as every 1 h). A correction factor is obtained through the measured value of the water level drawdown and the predicted value of the water level drawdown. Thus, the rainfall system obtains a water level prediction model through the correction factor. The water level drawdown value obtained through the water level prediction model has a certain accuracy compared with the predicted value of the water level drawdown, thereby improving the precise control of the water output of each water pump. The user can input the target water level drawdown of the groundwater in the area to be excavated into the water level prediction model. Thus, the water level prediction model can obtain the target water output of each rainfall well, that is, the target operating power of the water pump. The rainfall system controls each water pump to operate at the target operating power, and can control the water level drawdown of the groundwater in the area to be excavated within the target water level drawdown range.

[0047] It can be understood that the target water output of each rainfall well obtained through the water level prediction model, on the one hand, improves the accuracy of water level control, and the target water output data of each rainfall well can be corrected in real time through the water level prediction model; on the other hand, it reduces the operating power of the water pump. It can be understood that when the water pump operates at the maximum power, it may also be able to meet the rainfall demand, but the required electricity consumption of the water pump is large and the energy consumption is high. The water level prediction model provided by the present application can not only meet the rainfall demand, but also control the water pump to operate at the minimum power to meet the rainfall demand, that is, the total drainage volume of the rainfall well reaches the minimum value, thereby reducing the required electricity consumption and energy consumption of the water pump.

[0048] As Figure 5 shown, it is a schematic diagram of the hydraulic gradient of the observation well area in the present application.

[0049] The method further includes the following steps: S600: Obtain the water level elevations of any two adjacent rainfall wells; S700: Obtain the water level elevation of the observation well; the observation well is arranged in the outer middle area between two adjacent rainfall wells; the horizontal distances between the observation well and the two adjacent rainfall wells are the first distance L 11 and the second distance L 12 ; the depth of the observation well is the same as that of the rainfall well; wherein, the water level elevation data of the rainfall well and the observation well are measured when there is a water level difference between the water level in the observation well and the water level of the rainfall well when the water pump is turned on; S800: Obtain the hydraulic gradient in the observation well area according to the water level elevations of the observation well and the two adjacent rainfall wells; the hydraulic gradient in the observation well area is used to calculate the target water level drawdown of the adjacent rainfall well, and the hydraulic gradient is: J = [(h 1降 - h 观 ) ÷ L 11 + (h 2降 - h 观 ) ÷ L 12 ÷ 2。

[0050] Wherein, h 1降 - h 观 = Δh1; h 2降 - h 观 = Δh2。

[0051] In the formula, h 观 is the water level elevation of the observation well; h 1降 and h 2降 are respectively the water level elevations of two adjacent dewatering wells to the observation well; L 11 is the first distance; L 12 is the second distance.

[0052] Wherein, the hydraulic gradient is the head loss per unit distance along the flow path when the fluid flows from a cross-section with larger mechanical energy to a cross-section with smaller mechanical energy, that is, the gradient of the total head line, and represents the hydraulic gradient in the area where the observation well is located in this embodiment.

[0053] S900: When determining that the drawdown of the observation well is the target drawdown of the groundwater in the area to be excavated, the target drawdowns of the dewatering wells adjacent to both sides of the observation well; the target drawdowns of the dewatering wells are: S 降 = S 观 + L 观降 × J; In the formula, L 观降 is the horizontal distance between the observation well and the adjacent dewatering wells on both sides; J is the hydraulic gradient of the observation well area.

[0054] S1000: Obtain the target water level elevation of the dewatering well according to the target drawdown and the initial water level elevation of the dewatering well; the target water level elevation of the dewatering well can both satisfy that the water level elevation of the groundwater in the area to be excavated is greater than the depth to be excavated in the area to be excavated and achieve the minimum total operating power.

[0055] S1100: Adjust the target operating power and water output of the water pump according to the target water level elevation of the dewatering well, so that the real-time water level elevation of the dewatering well is maintained within the target water level elevation control range. The water pump can both satisfy that the water level elevation of the groundwater in the area to be excavated is less than the depth to be excavated in the area to be excavated and achieve the minimum total operating power according to the target operating power and water output.

[0056] Specifically, when obtaining the target water output of the precipitation well, it is necessary to determine the target water level drawdown of each precipitation well, so as to control the operating power of the water pump and maintain the real-time water level elevation of the precipitation well within the target water level elevation control range. Maintaining the real-time water level elevation of the precipitation well within the target water level elevation control range means: maintaining the real-time water level elevation of the precipitation well below the target water level. Among them, calculating the target water level drawdown of each precipitation well requires obtaining the hydraulic gradient in the observation well area. Through the hydraulic gradient, the water level drawdown of two adjacent precipitation wells can be calculated. It can be understood that the purpose of this application is to make the water level drawdown of the groundwater in the area to be excavated reach above the target water level drawdown. Therefore, ideally, the water level drawdown of each observation well should reach the target water level drawdown of the groundwater in the area to be excavated. Therefore, using the target water level drawdown of the groundwater in the area to be excavated, the target water level elevation of each precipitation well can be obtained, and thus the water level control index of each precipitation well can be obtained. Through the water level control index, the operating power of the water pump can be adjusted to maintain the real-time water level elevation of each precipitation well within the target water level elevation control range, which not only meets the precipitation demand but also makes the operating power of the water pump reach the lowest value.

[0057] As Figure 2 shown, it is a schematic diagram of the water level index of the precipitation well in this application.

[0058] The step of adjusting the target operating power and water output of the water pump according to the target water level elevation of the precipitation well to maintain the real-time water level elevation of the precipitation well within the target water level elevation control range includes the following sub-steps: S1200: Obtain the water level control index of the precipitation well according to the target water level elevation of the precipitation well; the water level index includes: target water level, safety water level, frequency increase water level, frequency decrease water level, stop water level.

[0059] The safety water level is: h1 = h j - 0.5; In the formula, h j is the target water level, and the target water level is equal to the target water level elevation of the precipitation well; The frequency increase water level is: h2 = h1 - 1; The frequency decrease water level is: h3 = h2 - 2; Among them, the safety water level is greater than the frequency increase water level, the frequency increase water level is greater than the frequency decrease water level, and the frequency decrease water level is greater than the stop water level. The water level index is used to control the index of the operating power of the water pump.

[0060] S1300: Adjust the target operating power and water output of the water pump according to the water level control index and the real-time water level elevation of the precipitation well, so that the real-time water level elevation of the precipitation well is maintained within the target water level elevation control range. The water pump can meet the requirement that the water level elevation of the groundwater in the area to be excavated is less than the depth to be excavated in the area to be excavated according to the target operating power and water output, and can also minimize the total operating power.

[0061] The step of adjusting the target operating power and water output of the water pump according to the water level control index and the real-time water level elevation of the precipitation well, so that the real-time water level elevation of the precipitation well is maintained within the target water level elevation control range, includes the following sub-steps: S1310: If the real-time water level elevation of the precipitation well is greater than or equal to the safety water level, control the water pump to operate at full frequency; when the real-time water level elevation of the precipitation well is greater than or equal to the safety water level, it means that the water level elevation of the groundwater in the area to be excavated is about to be less than the depth to be excavated in the area to be excavated, which is likely to cause potential safety hazards. Therefore, it is necessary to control the water pump to operate at full frequency to quickly pump out the water in the precipitation well and lower the water level in the precipitation well below the safety water level.

[0062] S1320: If the real-time water level elevation of the precipitation well is less than the safety water level and greater than or equal to the frequency-increasing water level, control the power of the water pump to gradually increase according to the set power until the real-time water level elevation of the precipitation well is less than the frequency-decreasing water level; when the real-time water level elevation of the precipitation well is less than the safety water level and greater than or equal to the frequency-increasing water level, it means that the water level elevation of the groundwater in the area to be excavated is about to reach the safety water level and has an upward trend. Therefore, it is necessary to control the operating power of the water pump to gradually increase according to the set power to lower the water level in the precipitation well to the frequency-decreasing water level to prevent potential safety hazards.

[0063] S1330: If the real-time water level elevation of the precipitation well is less than the frequency-increasing water level and greater than or equal to the frequency-decreasing water level, control the water pump to operate at the preset power; when the real-time water level elevation of the precipitation well is less than the frequency-increasing water level and greater than or equal to the frequency-decreasing water level, it means that the real-time water level elevation of the precipitation well meets the requirements, which can ensure that the water level elevation of the groundwater in the area to be excavated is greater than the depth to be excavated in the area to be excavated. Therefore, it is only necessary to control the water pump to operate constantly at the preset power, which can ensure that the water level elevation of the groundwater in the area to be excavated tends to be stable and can also ensure that the power consumption of the water pump is within the minimum range, saving the power consumption of the water pump.

[0064] S1340: If the real-time water level elevation of the precipitation well is less than the frequency-reducing water level and greater than or equal to the stop water level, control the power of the water pump to gradually decrease according to the set power until the real-time water level elevation of the precipitation well is greater than the frequency-reducing water level; when the real-time water level elevation of the precipitation well is less than the frequency-reducing water level and greater than or equal to the stop water level, it means that the real-time water level elevation of the precipitation well has fully met the target water level elevation of the groundwater in the area to be excavated. Therefore, there is no need to operate at too high an operating power, and it is only necessary to control the power of the water pump to gradually decrease according to the set power, saving the electricity consumption of the water pump.

[0065] S1350: If the real-time water level elevation of the precipitation well is less than the stop water level, control the water pump to stop running until the real-time water level elevation of the precipitation well rises to the frequency-increasing water level, start the water pump and control the power of the water pump to gradually increase according to the set power. When the real-time water level elevation of the precipitation well is less than the stop water level, it means that the water level elevation of the groundwater in the area to be excavated is much greater than the excavation depth of the area to be excavated. Therefore, control the water pump to stop running. When the real-time water level elevation of the precipitation well rises to the frequency-increasing water level, start the water pump. After starting the water pump, control the power of the water pump to gradually increase according to the set power to prevent the power of the water pump from not meeting the pumping volume requirement due to a sudden rise in the water level.

[0066] This application provides a method for controlling the groundwater level, and the specific application scenario is as follows: Known conditions: Assume that a foundation pit is 35m long, 55m wide, with an excavation depth h = 15.0m, and the ground is at ±0.00m; the initial water level in the exploration report and preliminary investigation is -5.0m, the aquifer thickness H = 20.0m, the permeability coefficient K = 50m / d, and the minimum drawdown S = h + 1 = 16.0m.

[0067] Design calculation: The groundwater influence radius R = 2S = 2×16.0× = 1012m; The area A of the area to be excavated = 35×55m = 1925m 2 ; The equivalent radius r0 of the area to be excavated = = 612.7m; According to the unconfined complete well formula: ; Among them, as Figure 6 shown, a total of 11 wells are arranged, the single-well discharge q = 1.1Q / n = 1.1×14545 / 11 = 1202m³ / d, and the pumping volume is 60m³ / h; the designed operating power of the configured water pump is 80m³ / h, and the head is 35m; the water output of the water pump is adjusted through the intelligent system.

[0068] Among them, 11 dewatering wells J1 - J11 are arranged with a well spacing of 20m and a well depth of 30m; the distances between the observation well G1 and each dewatering well are r1 - r11 respectively.

[0069] As shown in the following table, it is the water output of each water pump.

[0070]

[0071] When the water output of the water pump is adjusted to be the same as the theoretical calculated value of 60m³, the theoretically predicted interference drawdown is: S i = ; The interference drawdown at point G1 is S1 = 18.65m; If the measured drawdown is S 1实 = 17.5m; Then the correction coefficient is α1 = S 1实 ÷ = 17.5 / 18.65 = 0.9384; Similarly, calculate that at point G2, S2 = 17.83m; at point G3, S1 = 18.65m; at point G4, S1 = 17.83m; Measured data: S 2实 = 16.9m; S 3实 = 17.6m; S 4实 = 17.0m; Then, similarly calculate that the correction coefficients are α2 = 0.9478; α3 = 0.9437; α4 = 0.9534; The weighted average gives: α = (α1 + α2 + α3 + α4) / 4 = 0.9458; The adjusted prediction formula is: S 修 = α × ( )= 0.9458 × ( ); Adjust the water output of the water pump to 50m³ / h, and the water level recovers.

[0072] As shown in the following table, it is the water output of each water pump.

[0073]

[0074] Predict according to the corrected formula: S 1修 = 0.9458 × ( )= 17.85m; The measured value through the monitoring system is S1 = 17.80m; Error = 17.75 - 17.85 = -0.1m. When the error is less than ±0.3m, no repeated correction is required.

[0075] Accuracy = 17.8 / 17.85 × 100% = 99.44%.

[0076] The second aspect of the present application provides an application for a to-be-mined area. A number of precipitation wells are arranged around the to-be-mined area, and a water pump is arranged in each precipitation well. The water pump is used to pump out the water in the precipitation well, including: A data acquisition module, the data acquisition module is configured to: Obtain precipitation data; the precipitation data includes: the water level elevation of the groundwater in the to-be-mined area and the water output of the precipitation well. A data processing module, the data processing module is configured to: According to the precipitation data, calculate the predicted value of the groundwater level drawdown in the to-be-mined area; the predicted value of the groundwater level drawdown is: S i = ; In the formula, S i is the groundwater level drawdown in the to-be-mined area; H is the thickness of the aquifer in the to-be-mined area; is the j water output of the k th precipitation well; R is the permeability coefficient of the aquifer in the to-be-mined area; is the j distance from the center of the n th precipitation well to the center of the to-be-mined area; is the number of precipitation wells; α = S 实 ÷ ; In the formula, S 实 is the measured value of the groundwater level drawdown in the to-be-mined area; According to the correction factor, obtain a water level prediction model; the water level prediction model is configured to calculate the corrected value of the groundwater level drawdown in the to-be-mined area according to the water output of the precipitation well; the corrected value of the groundwater level drawdown is: S 修 = α × ( ); A data output module, the data output module is configured to: Input the target water level drawdown of the groundwater in the area to be excavated into the water level prediction model to determine the target water output of each precipitation well when the total drainage volume of the precipitation well is minimized; the total drainage volume is: Q 总 = q 1 + q 2 + q 3 + …… q j ; An early warning module, which is configured as: When the real-time water level elevation of the precipitation well is greater than the early warning water level, an alarm sound is emitted and the early warning information is sent to the set device; the early warning water level is greater than the safety water level; the early warning information includes: the well number of the precipitation well where the real-time water level elevation is greater than the early warning water level and the water level status; the water level status includes: the real-time water level elevation and the safety water level of the precipitation well.

[0077] In this embodiment, to prevent the real-time water level elevation of the precipitation well from being greater than the early warning water level due to the damage of the water pump installed in the precipitation well, an early warning device is installed in the precipitation well to obtain the water level elevation of the precipitation well in real time. When the water level elevation of the precipitation well is greater than the early warning water level, an alarm is issued and the early warning information is sent to the set device. Among them, the set device can be the observation platform of the precipitation well or a mobile device, such as: mobile phones and other electronic devices. Construction personnel can obtain the model number of the precipitation well with the water level elevation exceeding the early warning water level according to the early warning information, so as to obtain its location, and take actions immediately to prevent the water level elevation of the groundwater in the area to be excavated from being less than the excavation depth of the area to be excavated, and the groundwater seeps into the area to be excavated, causing potential safety hazards.

[0078] In this embodiment, the early warning module is configured with an early warning light; the early warning module is also configured as: When the real-time water level elevation of the precipitation well is greater than or equal to the safety water level, control the early warning light to display red; When the real-time water level elevation of the precipitation well is less than the safety water level and greater than or equal to the preset value, control the early warning light to display yellow; the preset value is: X = h1 - 0.5; In the formula, h1 is the safety water level; When the real-time water level elevation of the precipitation well is less than the preset value, control the early warning light to display green.

[0079] Among them, the early warning light can be set at the observation panel of the precipitation well, and users can quickly and accurately obtain the water level status of the precipitation well through the color of the early warning light corresponding to each precipitation well.

[0080] It should be noted that for the effects achieved when the above system embodiments are running, reference may be made to the effects of the above method embodiments, which will not be elaborated herein.

[0081] The above specific implementation manners further elaborate in detail the objectives, technical solutions, and beneficial effects of the embodiments of the present application. It should be understood that the above are only the specific implementation manners of the embodiments of the present application, and are not used to limit the protection scope of the embodiments of the present application. Any modifications, equivalent replacements, improvements, etc. made on the basis of the technical solutions of the embodiments of the present application shall be included within the protection scope of the embodiments of the present application.

Claims

1. A groundwater level control method is applied to an area to be excavated. A number of precipitation wells are arranged around the area to be excavated, and a water pump is arranged in each precipitation well. The water pump is used to pump out the water in the precipitation well. It is characterized in that, Including: Obtain precipitation data; the precipitation data includes: the water level elevation of the groundwater in the area to be excavated, and the water output of the precipitation well; According to the precipitation data, calculate the predicted value of the groundwater level drawdown in the area to be excavated; the predicted value of the water level drawdown is: S i = ； In the formula, S i To lower the groundwater level in the area to be excavated; H is the thickness of the aquifer in the area to be excavated; For the j The water output of the precipitation well; k is the permeability coefficient of the aquifer in the area to be excavated; R is the influence radius; For the j The distance from the center of the drainage well to the center of the area to be excavated; n is the number of precipitation wells; According to the precipitation data and the predicted value of the water level drawdown, calculate the correction factor; the correction factor is: α= S 实 ÷ ； In the formula, S 实 is the measured value of the groundwater level drawdown in the area to be mined; According to the correction factor, obtain a water level prediction model; the water level prediction model is configured to calculate the corrected value of the groundwater level drawdown in the area to be excavated according to the water output of the precipitation well; the corrected value of the water level drawdown is: S 修 =α×（ ）； Input the target water level drawdown of the groundwater in the area to be mined into the water level prediction model to determine the target water output of each precipitation well when the total drainage volume of the precipitation well is minimized; the total drainage volume is: Q 总 = q 1+ q 2+ q 3+…… q j 。 2. The groundwater level control method according to claim 1, characterized in that, The water level prediction model is further configured to: Obtain the water level elevations of any two adjacent precipitation wells; Obtain the water level elevation of the observation well; the observation well is arranged in the middle area outside two adjacent precipitation wells; the horizontal distances between the observation well and the two adjacent precipitation wells are the first distance and the second distance respectively; the depth of the observation well is the same as that of the precipitation well; According to the water level elevations of the observation well and the two precipitation wells on both sides, the hydraulic gradient within the area of the observation well is obtained; the hydraulic gradient is: J = [(h 1降 - h 观 ) ÷ L 11 + (h 2降 - h 观 ) ÷ L 12 ) ÷ 2; where h 观 is the water level elevation of the observation well; h 1降 and h 2降 are the water level elevations of two adjacent precipitation wells to the observation well respectively; L 11 is the first distance; L 12 is the second distance; When it is determined that the water level drawdown of the observation well is the target water level drawdown of the groundwater in the area to be excavated, determine the target water level drawdown of the precipitation wells adjacent to both sides of the observation well; the target water level drawdown of the precipitation well is: S 降 = S 观 + L 观降 × J; Where L 观降 is the horizontal distance between the observation well and the adjacent precipitation wells on both sides; J is the hydraulic gradient of the observation well area; According to the target water level drawdown and the initial water level elevation of the precipitation well, obtain the target water level elevation of the precipitation well; According to the target water level elevation of the precipitation well, adjust the target operating power and water output of the water pump so that the real-time water level elevation of the precipitation well is maintained within the target water level elevation control range.

3. The groundwater level control method according to claim 2, characterized in that, The measured value of the groundwater level drawdown in the area to be excavated is obtained through the following steps: Obtain the real-time water level elevation of the observation well; According to the initial water level elevation and the real-time water level elevation of the observation well, calculate the water level drawdown of the observation well; the water level drawdown of the observation well is: S 观 =h 观初 -h 观实 ; where h 观初 is the initial water level elevation of the observation well; h 观实 is the real-time water level elevation of the observation well; According to the minimum water level drawdown of the observation well, determine the measured value of the groundwater level drawdown in the area to be excavated.

4. The groundwater level control method according to claim 2, characterized in that, The step of adjusting the target operating power and water output of the water pump according to the target water level elevation of the precipitation well so that the real-time water level elevation of the precipitation well is maintained within the target water level elevation control range includes: According to the target water level elevation of the precipitation well, obtain the water level control index of the precipitation well; According to the water level control index and the real-time water level elevation of the precipitation well, adjust the target operating power and water output of the water pump so that the real-time water level elevation of the precipitation well is maintained within the target water level elevation control range.

5. The groundwater level control method according to claim 4, characterized in that, The water level control index includes: Target water level, safety water level, frequency increase water level, frequency decrease water level, stop water level; The safe water level is: h1 = h j -0.5; where h j is the target water level, and the target water level is equal to the elevation of the target water level of the precipitation well; The frequency increase water level is: h2 = h1 - 1; The frequency decrease water level is: h3 = h2 - 2; The stop water level is: h4 = h3 - 3; Wherein, the safety water level is greater than the frequency increase water level, the frequency increase water level is greater than the frequency decrease water level, and the frequency decrease water level is greater than the stop water level.

6. A groundwater level control method according to claim 5, characterized in that, The step of adjusting the target operating power and water output of the water pump according to the water level control index and the real-time water level elevation of the precipitation well so that the real-time water level elevation of the precipitation well is maintained within the target water level elevation control range includes: If the real-time water level elevation of the precipitation well is greater than or equal to the safety water level, control the water pump to operate at full frequency; If the real-time water level elevation of the precipitation well is less than the safety water level and greater than or equal to the frequency increase water level, control the power of the water pump to gradually increase according to the set power until the real-time water level elevation of the precipitation well is less than the frequency decrease water level; If the real-time water level elevation of the precipitation well is less than the frequency increase water level and greater than or equal to the frequency decrease water level, control the water pump to operate at the preset power; If the real-time water level elevation of the precipitation well is less than the frequency decrease water level and greater than or equal to the stop water level, control the power of the water pump to gradually decrease according to the set power until the real-time water level elevation of the precipitation well is greater than the frequency decrease water level; If the real-time water level elevation of the precipitation well is less than the stop water level, control the water pump to stop operating until the real-time water level elevation of the precipitation well rises to the frequency increase water level, start the water pump and control the power of the water pump to gradually increase according to the set power.

7. A groundwater level control method according to claim 1, characterized in that, Before the step of obtaining precipitation data, it includes: Dividing the area to be excavated into multiple partitions; the partitions are divided according to the depth to be excavated and the construction sequence; the length of the partition is less than the preset length; Setting the precipitation wells on the periphery of the partition; the distance between the precipitation wells is less than the preset distance.

8. A groundwater level control system is applied to an area to be excavated. A number of dewatering wells are arranged around the area to be excavated, and a water pump is arranged in each dewatering well. The water pump is used to pump out the water in the dewatering well; characterized in that, It includes: A data acquisition module, the data acquisition module is configured to: Obtain precipitation data; the precipitation data includes: the water level elevation of the groundwater in the area to be excavated and the water output of the precipitation well; A data processing module, the data processing module is configured to: According to the precipitation data, calculate the predicted value of the water level drawdown of the groundwater in the area to be excavated; the predicted value of the water level drawdown is: S i = ； In the formula, S i To lower the groundwater level in the area to be excavated; H is the thickness of the aquifer in the area to be excavated; For the j The water output of the precipitation well; k is the permeability coefficient of the aquifer in the area to be excavated; R is the influence radius; For the j The distance from the center of the drainage well to the center of the area to be excavated; n is the number of precipitation wells; According to the precipitation data and the predicted value of the water level drawdown, calculate the correction factor; the correction factor is: α= S 实 ÷ ； In the formula, S 实 is the measured value of the groundwater level drawdown in the area to be mined; According to the correction factor, obtain a water level prediction model; the water level prediction model is configured to calculate the corrected value of the water level drawdown of the groundwater in the area to be excavated according to the water output of the precipitation well; the corrected value of the water level drawdown is: S 修 =α×（ ）； A data output module, the data output module is configured to: Input the target water level drawdown of the groundwater in the area to be mined into the water level prediction model to determine the target water output of each precipitation well when the total drainage volume of the precipitation well is minimized; the total drainage volume is: Q 总 = q 1+ q 2+ q 3+…… q j ; An early warning module, the early warning module is configured to: When the real-time water level elevation of the precipitation well is greater than the early warning water level, emit an alarm sound and send the early warning information to the set device; the early warning water level is greater than the safety water level; the early warning information includes: the well number of the precipitation well with the real-time water level elevation greater than the early warning water level and the water level status; the water level status includes: the real-time water level elevation of the precipitation well and the safety water level.

9. The groundwater level control system according to claim 8, characterized in that, The early warning module is configured with an early warning light; the early warning module is also configured to: When the real-time water level elevation of the precipitation well is greater than or equal to the safety water level, control the early warning light to display red; When the real-time water level elevation of the precipitation well is less than the safety water level and greater than or equal to the preset value, control the early warning light to display yellow; the preset value is: X = h1 - 0.5; In the formula, h1 is the safety water level; When the real-time water level elevation of the precipitation well is less than the preset value, control the early warning light to display green.

Images