Anti-segregation device for pouring and filling of water-filled goaf and evaluation method

Abstract

The anti-segregation device comprises a material storage unit, a metering unit, a stirring unit, a slurrying control table, a slurry conveying unit, an anti-segregation grouting pipe and an electric control system, and a grouting pump is connected with the inlet end of the anti-segregation grouting pipe in a sealed mode through a slurry conveying pipe. The anti-segregation grouting pipe comprises a grouting pipe body, a plurality of spiral guide vanes and butterfly-shaped gravity valves, the spiral guide vanes are sequentially arranged in the grouting pipe body at equal intervals along the grouting pipe body, and the butterfly-shaped gravity valves are arranged on the lower sides of the spiral guide vanes. According to the method, the comprehensive segregation evaluation model is constructed, data collected by multiple sensors are fused with various parameter weights, the slurry segregation degree is dynamically monitored in real time, feedback regulation and control of parameters of the slurry water cement ratio and the grouting pressure are achieved, the weight coefficient is regularly adjusted through the collected data, accurate monitoring and evaluation are achieved, and the method is suitable for large-scale popularization and application. The purpose of preventing concrete from being disintegrated in the backfill grouting process is achieved.

Description

Technical Field

[0001] This invention relates to the field of goaf backfilling technology, specifically to an anti-segregation device and evaluation method for water-filled goaf grouting and backfilling. Background Technology

[0002] Coal mining provides crucial support for energy supply and economic development. However, large-scale mining creates goaf areas that are prone to surface subsidence, groundwater pollution, and secondary geological disasters. Water-filled goaf areas, in particular, are susceptible to water inrush accidents and backfill failure due to the interaction between accumulated water and the geological structure. Currently, goaf remediation primarily employs grouting technology, which reinforces the goaf by injecting concrete grout. However, during the transportation of concrete through grouting pipes to the goaf, the grout and aggregate are prone to separation due to gravity. Combined with the presence of water in the goaf, the concrete is prone to segregation (aggregate settling, grout stratification), leading to uneven strength and even cementation failure of the backfill. Existing prevention methods, such as optimizing the water-cement ratio, adding admixtures, or controlling mixing time, are limited to surface pre-control and cannot monitor the impact of dynamic changes in the underground environment on concrete performance in real time. Furthermore, there is a lack of proactive intervention measures to address segregation. In addition, the detection of grouting effect mainly relies on post-drilling, geophysical exploration or long-term surface subsidence monitoring, which has problems such as poor timeliness, high destructiveness and difficulty in implementation in deep mining areas, resulting in low treatment efficiency and difficulty in eradicating safety hazards.

[0003] Chinese patent application number 2020107869916 discloses a method for full-pipe grouting in goaf areas and real-time monitoring of its effects. This method ensures full-pipe grout flow by setting buffer devices at each grouting hole, and uses surrounding borehole fluid level monitoring devices and three quantitative indicators (height coefficient, attenuation coefficient, and downward flow coefficient) to evaluate the grouting effect in real time. However, its shortcomings include reliance on specialized equipment and complex parameter calculations, resulting in high implementation costs, inability to monitor segregation in real time, and insufficient verification of its adaptability to geological conditions. Therefore, there is an urgent need to develop an intelligent system capable of buffering concrete pouring, real-time monitoring of concrete segregation, dynamic adjustment of grouting parameters, and closed-loop management of filling quality. This system would overcome the limitations and lag of traditional surface technologies, comprehensively improving the reliability and timeliness of goaf treatment. Summary of the Invention

[0004] To address the shortcomings of the prior art, one objective of this invention is to provide an anti-segregation device for backfilling water-filled goaf areas, which solves the problem of concrete not filling the grouting pipe during the backfilling process of water-filled goaf areas in coal mines, which easily leads to segregation in the grouting pipe, and the difficulty in real-time monitoring whether concrete segregation occurs in the water body of the goaf area.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] An anti-segregation device for grouting and filling water-filled goaf areas includes a material storage unit, a metering unit, a mixing unit, a slurry preparation control console, a slurry conveying unit, an anti-segregation grouting pipe, and an electrical control system. The material storage unit includes a cement silo, an aggregate silo, an admixture tank, and a water tank. The metering unit includes a cement scale, an aggregate scale, and an admixture scale. The outlet of the cement silo is connected to the inlet of the mixing unit via a screw conveyor and the cement scale.

[0007] The aggregate bin outlet is connected to the mixing unit inlet via a belt conveyor and aggregate scale. The admixture tank outlet is connected to the mixing unit inlet pipe via an admixture scale. The water tank is connected to the mixing unit inlet pipe via a metering pump.

[0008] The slurry delivery unit includes a grouting pump and a slurry transport pipe. The grouting pump is located at the outlet end of the mixing unit, and the outlet of the grouting pump is fixedly and sealed to the inlet end of the anti-segregation grouting pipe through the slurry transport pipe.

[0009] The anti-segregation grouting pipe includes a grouting pipe body, spiral guide vanes, and butterfly gravity valves. The grouting pipe body is vertically arranged inside the mine, with its lower end extending into the water body of the goaf. There are multiple spiral guide vanes, which are fixed at equal intervals along the axial direction of the grouting pipe body inside the grouting pipe body. Each spiral guide vane is accompanied by a butterfly gravity valve on its lower side.

[0010] The electrical control system includes a PLC controller, ultrasonic sensors, pressure sensors, flow sensors, and temperature sensors. There are multiple ultrasonic sensors, which are arranged in a spiral pattern on the outer circumference of the grouting pipe.

[0011] There are multiple pressure sensors and flow sensors. One pressure sensor 82 and one flow sensor are located at the outlet end of the grouting pump. The remaining pressure sensors and flow sensors are arranged sequentially and at intervals along the vertical direction on the inner wall of the grouting pipe.

[0012] There are multiple temperature sensors, which are fixed at equal intervals along the vertical direction on the outside of the grouting pipe and are staggered with the ultrasonic sensors. The signal terminals of all ultrasonic sensors, pressure sensors, flow sensors and temperature sensors are connected to the PLC controller for communication.

[0013] Furthermore, the cement silo is vertically fixed above the ground by a steel frame. The outlet of the cement silo is located at its bottom and is connected to one end of a screw conveyor. The other end of the screw conveyor is connected to the inlet of a cement scale. The cement scale is located above the mixing unit, and its bottom outlet is connected to the pipeline of the mixing unit.

[0014] One end of the belt conveyor is located below the bottom outlet of the aggregate bin, and the other end of the belt is located above the inlet of the aggregate scale. The bottom outlet of the aggregate scale is connected to the mixing unit pipeline. The signal terminals of the screw conveyor and the belt conveyor are respectively connected to the pulping control console.

[0015] Furthermore, the outlet of the admixture tank is connected to the inlet of the admixture scale via a pipeline, and the outlet of the admixture scale is connected to the inlet pipeline of the mixing unit.

[0016] The metering pump is fixedly installed at the outlet end of the water tank. The outlet end of the metering pump is connected to the inlet pipe of the mixing unit. The signal terminals of the metering pump and the admixture scale are respectively connected to the pulping control console for communication.

[0017] Furthermore, the mixing unit includes a primary mixing tank and a secondary mixing tank, and the outlet ends of the cement scale, aggregate scale, admixture scale and metering pump are all connected to the top of the primary mixing tank.

[0018] The secondary mixing tank is located below the primary mixing tank, and its top is connected to the bottom of the primary mixing tank through a pipeline with a gate valve. The bottom outlet of the secondary mixing tank is connected to the inlet of the grouting pump. In addition, both the primary and secondary mixing tanks are equipped with a mixer.

[0019] Furthermore, the grouting pipe body has a vertical shaft with a circular cross-section inside. The vertical shaft is arranged coaxially with the grouting pipe body, and all spiral guide vanes are sleeved on the outside of the vertical shaft. Their inner sides are fixedly welded to the outer wall of the vertical shaft.

[0020] Furthermore, the grouting pipe body is composed of multiple steel pipe segments connected end to end in sequence. The butterfly gravity valve includes a valve body, a horizontal shaft, a valve plate, and a torsion spring. The valve body is fixedly and sealed to the corresponding ends of two adjacent steel pipe segments.

[0021] The two ends of the horizontal shaft are fixedly connected to the side wall of the valve body. The vertical shaft passes through the middle position of each horizontal shaft and is fixedly connected to it in a cross shape. There are two valve plates, which are symmetrically arranged and rotated on both sides of the horizontal shaft axis. The valve plates are semi-circular flat plates. The torsion spring is sleeved on the outside of the horizontal shaft, and its end is fixedly connected to the bottom surface of the valve plate.

[0022] Another objective of this invention is to provide an anti-segregation assessment method for injection and backfilling of water-filled goaf areas.

[0023] An anti-segregation assessment method for injection and backfilling of water-filled goaf areas, based on the aforementioned anti-segregation device for injection and backfilling of water-filled goaf areas, the assessment method includes the following steps:

[0024] Step 1: Construct a comprehensive segregation evaluation model. The comprehensive segregation index formula used in this model is as follows:

[0025] SCI=α·SA+β·ΔP+γQ var +δ·T dev

[0026] In the formula, SCI is the comprehensive segregation index, SA is the ultrasonic segregation degree, ΔP is the pressure fluctuation rate, and Q is the total segregation index. var T is the coefficient of variation of flow rate. dev The percentage of temperature deviation from the reference value; α is the weighting coefficient of the ultrasonic sensor; β is the weighting coefficient of the pressure sensor; γ is the weighting coefficient of the flow sensor; δ is the weighting coefficient of the temperature sensor.

[0027] Step 2: Each ultrasonic sensor collects the propagation time t of the ultrasonic wave in the injected concrete at unit time intervals. The propagation time t is processed by the controller to obtain SA.

[0028] The time points t1, t2, ... t of a single pressure sensor per unit time. u Collect the pressure values ​​of the grouting pipeline and record them as P1, P2, ... P u All pressure sensors will obtain the grouting pipeline pressure value per unit time, which will be processed by the controller to obtain ΔP;

[0029] The time points t1, t2, ... t of a single flow sensor within a unit of time. u Collect the concrete flow rate values ​​in the grouting pipe and record them as Q1, Q2, ..., Q u The system then sends the concrete flow rate values ​​collected by all flow sensors per unit time to the controller, which processes the data to obtain Q. var ;

[0030] The time points t1, t2, ... t of a single temperature sensor within a unit of time. u Collect the temperature values ​​outside the grouting pipe body and record them as T1, T2, ..., T u The system then sends the temperature values ​​collected by all flow sensors within a unit of time to the controller, which processes the data to obtain the temperature value (T). dev u represents the number of times the sensor collects data per unit time, and the duration between any two adjacent time points is equal.

[0031] Step 3: Calculate SA, ΔP, and Q obtained in Step 2. var T dev Substitute the values ​​into the comprehensive segregation index formula to calculate the current comprehensive segregation index;

[0032] Then, the current comprehensive segregation index is compared with the set comprehensive segregation threshold. If the current comprehensive segregation index is greater than or equal to the comprehensive segregation threshold, it is determined that the concrete injected into the goaf water has segregated. The controller feeds back the result to the slurry control console. The slurry control console adjusts the concrete raw material ratio according to the feedback result and continues to pour concrete.

[0033] If the current comprehensive segregation index is less than the comprehensive segregation threshold, it is determined that the concrete injected into the goaf water has not segregated, and concrete pouring continues according to the original concrete raw material ratio.

[0034] Step 4: During the concrete pouring process, in order to adapt to the dynamic changes in the goaf environment, the weight coefficients in the comprehensive segregation evaluation model are dynamically updated by combining the entropy method and the time-lapse method.

[0035] Before concrete pouring, an initial weighting coefficient is set, and the statistical period is set to a day and the transition period is set to b days. The statistical data of the four sensors are extracted from each statistical period and input into the comprehensive segregation index formula to calculate and update the weighting coefficient used in the transition period.

[0036] When the next time period is reached, the weight coefficients are updated in the same way, and so on, until the concrete pouring is completed.

[0037] Furthermore, in step two, the propagation time at the critical state of concrete segregation is defined as t0, and |S| is calculated using the segregation degree formula, which is:

[0038]

[0039] After processing the data collected by each ultrasonic sensor in the same instance, the maximum value of |S| is selected as SA.

[0040] Calculate the average pressure of each pressure sensor per unit time. In the formula, P i Given the pressure value of the pressure sensor at any point within a unit of time, the standard deviation σ of the pressure at each point in time for all pressure sensors is calculated using the sample standard deviation formula. P And sort them in ascending order: σ Pi <σ P2 <σ P3 <…<σ Pn Then, the standard deviation σ of the pressure from all pressure sensors per unit time was calculated. P The sample data were processed using the 95th percentile, and the pressure standard deviation σ was... P The 95th percentile is used as ΔP, and the formula for calculating the pressure standard deviation is:

[0041]

[0042] Calculate the average flow rate of each flow sensor per unit time. The calculation formula is:

[0043]

[0044] In the formula, Q i The flow sensor measures the flow rate of concrete at any point in time within a unit of time.

[0045] The standard deviation of flow rate σ at each time point for all flow sensors was calculated using the formula for standard deviation of flow rate. Q The formula for calculating the standard deviation of flow rate is:

[0046]

[0047] The standard deviation of the flow rate σ Q Substituting the values ​​into the formula for the coefficient of variation of flow rate, the coefficient of variation (CV) of flow rate for each flow sensor per unit time is calculated. Q The formula for the coefficient of variation of flow rate is:

[0048]

[0049] The coefficient of variation (CV) of flow rate for all flow sensors per unit time Q Sort in ascending order, then analyze the coefficient of variation (CV) of the flow rate. Q The sample data was processed using the 95th percentile to determine the coefficient of variation (CV) of the flow rate. Q The 95th percentile as Q var ;

[0050] Preset reference temperature T ref The reference value is T; the actual measured temperature is T. i Calculate the difference ΔT between the measured temperature obtained by the temperature sensor and the reference value per unit time. i The difference ΔT i The calculation formula is as follows:

[0051] ΔT i =T i -T ref

[0052] Calculate the percentage relative deviation AT of each measured temperature by the temperature sensor per unit time. The formula for calculating the percentage relative deviation is:

[0053]

[0054] The relative deviation percentage AT of the temperature sensors per unit time is sorted in ascending order. Then, the sample data of the relative deviation percentage AT are processed by the 95th percentile, and the 95th percentile of the relative deviation percentage AT is taken as T. dev .

[0055] Furthermore, in step one, the original data matrix X of the comprehensive analysis evaluation model is constructed. The original data matrix X consists of m types of sensors, with each type of sensor consisting of n sensors, denoted as X = (X... ij ) m*n After standardizing X, a new data matrix is ​​obtained.

[0056]

[0057] Calculate the data weight P of the j-th sensor of the i-th sensor type. ij :

[0058]

[0059] In the formula, (i = 1, 2, ..., m; j = 1, 2, ..., n), P ij Substituting into the following formula, the entropy value e of the j-th sensor is calculated. j :

[0060] In the formula,

[0061] The exponent of variation for the j-th sensor is: d j =1-e j ;

[0062] The weight of the j-th sensor is:

[0063] Calculate the comprehensive evaluation value Z of the i-th sensor. i ,

[0064] Z1 is used as the weighting coefficient α for the ultrasonic sensor, Z2 as the weighting coefficient β for the pressure sensor, Z3 as the weighting coefficient γ for the flow sensor, and Z4 as the weighting coefficient δ for the temperature sensor.

[0065] By adopting the above technical solution, the beneficial technical effects of this invention are as follows: This invention, by setting spiral guide vanes and gravity valves inside the grouting pipe, slows down the flow rate of concrete, ensuring the grouting pipe remains full at all times. This prevents segregation of concrete during long-distance downward transport along the grouting pipe, ensuring that the concrete maintains a good aggregate and grout condition after falling into the goaf. By constructing a comprehensive segregation evaluation model, data collected from multiple sensors are fused with parameter weights to dynamically monitor the degree of grout segregation in real time. The entropy method combined with the time-lapse method is used to monitor grout segregation through a multi-sensor monitoring system, and adjustments are made through a feedback system. This forms a fully automated chain from material storage, proportioning, mixing, transportation, grouting to monitoring feedback, thereby achieving the effect of resisting and monitoring concrete segregation. Attached Figure Description

[0066] Figure 1 This is a schematic diagram of the structure of an anti-segregation device for filling and grouting water-filled goaf areas according to the present invention.

[0067] Figure 2 This is a schematic diagram of the combined structure of the grouting pipe body and the electrical control system of the present invention.

[0068] Figure 3 yes Figure 2 A magnified view of part A in the middle.

[0069] Figure 4 This is a schematic diagram of the time-shifting method table for updating weight coefficients according to the present invention.

[0070] The diagram shows: 1. Material storage unit; 11. Cement silo; 12. Aggregate silo; 13. Admixture tank; 14. Water tank; 21. Screw conveyor; 22. Belt conveyor; 3. Metering unit; 31. Cement scale; 32. Aggregate scale; 33. Admixture scale; 34. Metering pump; 4. Mixing unit; 41. Primary mixing tank; 42. Secondary mixing tank; 5. Grouting pipe body; 51. Grouting pipe body; 52. Spiral guide vane; 53. Vertical shaft; 54. Horizontal shaft; 55. Valve plate; 56. Torsion spring; 6. Slurry control console; 61. First side plate; 7. Slurry conveying unit; 71. Grouting pump; 72. Slurry transport pipe; 81. Ultrasonic sensor; 82. Pressure sensor; 83. Flow sensor; 84. Temperature sensor. Detailed Implementation

[0071] To make the advantages and technical solutions of the present invention clearer and more explicit, the present invention will be described in detail below with reference to specific embodiments.

[0072] Example 1, combined with Figures 1 to 3An anti-segregation device for grouting and filling water-filled goaf areas includes a material storage unit 1, a metering unit 3, a mixing unit 4, a slurry preparation control console 6, a slurry conveying unit 7, an anti-segregation grouting pipe 5, and an electrical control system. The material storage unit 1 includes a cement silo 11, an aggregate silo 12, an admixture tank 13, and a water tank 14. The metering unit 3 includes a cement scale 31, an aggregate scale 32, and an admixture scale 33. The outlet of the cement silo 11 is connected to the inlet of the mixing unit 4 via a screw conveyor 21 and the cement scale 31.

[0073] Specifically, the cement silo 11 is vertically fixed above the ground by a steel frame. The interior of the cement silo 11 is used to temporarily store cement. The outlet of the cement silo 11 is located at its bottom and is connected to one end of the screw conveyor 21. The other end of the screw conveyor 21 is connected to the inlet of the cement scale 31. The cement scale 31 is located above the mixing unit 4, and its bottom outlet is connected to the pipeline of the mixing unit 4. The screw conveyor 21 transports the cement stored in the cement silo 11 through the outlet at the bottom of the cement silo 11 to the interior of the cement scale 31. After being weighed by the cement scale 31, the outlet valve of the cement scale 31 is opened, and the weighed cement is quantitatively added into the primary mixing tank 41.

[0074] The outlet of aggregate bin 12 is connected to the inlet of mixing unit 4 via belt conveyor 22 and aggregate scale 32. The outlet of admixture tank 13 is connected to the inlet pipe of mixing unit 4 via admixture scale 33. Water tank 14 is connected to the inlet pipe of mixing unit 4 via metering pump 34. Metering pump 34 is fixedly installed at the outlet end of water tank 14, and the outlet end of metering pump 34 is connected to the inlet pipe of mixing unit 4. The signal terminals of metering pump 34 and admixture scale 33 are respectively connected to the pulping control console 6 for communication.

[0075] Aggregate bin 12 holds aggregate, which is conveyed by belt conveyor 22 to aggregate scale 32. After being weighed by aggregate scale 32, the aggregate enters the primary mixing tank 41 for quantitative addition. Admixture in admixture tank 13 is weighed by admixture scale 33 and also quantitatively added to primary mixing tank 41. Simultaneously, water in water tank 14 is quantitatively supplied to primary mixing tank 41 by metering pump 34. The pulping control console 6 controls the addition of cement, aggregate, admixture, and water through program instructions. According to the instructions, the addition ratio of the above raw materials and water can be adjusted, and the status of screw conveyor 21, belt conveyor 22, metering pump 34, and corresponding valves can be controlled to realize the automated control of raw material and water addition.

[0076] Specifically, one end of the belt conveyor 22 is located below the bottom outlet of the aggregate bin 12, and the other end is located above the inlet of the aggregate scale 32. The bottom outlet of the aggregate scale 32 is connected to the pipeline of the mixing unit 4. The signal terminals of the screw conveyor 21 and the belt conveyor 22 are respectively connected to the pulping control console 6 for communication. The outlet of the admixture tank 13 is connected to the inlet of the admixture scale 33 through a pipeline connection, and the outlet of the admixture scale 33 is connected to the inlet pipeline of the mixing unit 4.

[0077] The mixing unit 4 includes a primary mixing tank 41 and a secondary mixing tank 42. The outlets of the cement scale 31, aggregate scale, admixture scale 33, and metering pump 34 are all connected to the top of the primary mixing tank 41. The secondary mixing tank 42 is located below the primary mixing tank 41, and its top is connected to the bottom of the primary mixing tank 41 via a pipeline with a gate valve. The bottom outlet of the secondary mixing tank 42 is connected to the inlet of the grouting pump 71. Both the primary and secondary mixing tanks 41 and 42 are equipped with a mixer. After the raw materials are added to the primary mixing tank 41 according to a set ratio, the mixer in the primary mixing tank 41 starts working, thoroughly mixing the raw materials and water. The mixed concrete is then transported to the secondary mixing tank 42 via a pipeline with a gate valve for further mixing, maintaining the homogeneity of the concrete and preventing grout segregation. After the outlet of the primary mixing tank 41 is closed, raw materials and water are continuously added to the primary mixing tank 41 in the same manner to continuously produce concrete, ensuring continuous concrete preparation and supply.

[0078] The slurry conveying unit 7 includes a grouting pump 71 and a slurry transport pipe 72. The grouting pump 71 is located at the outlet end of the mixing unit 4, and the outlet of the grouting pump 71 is fixedly and sealed to the inlet end of the anti-segregation grouting pipe 5 through the slurry transport pipe 72. Specifically, the anti-segregation grouting pipe 5 includes a grouting pipe body 51, a spiral guide vane 52, and a butterfly gravity valve. The grouting pipe body 51 is composed of multiple steel pipe segments fixedly connected end to end. The grouting pipe body 51 is vertically arranged inside the mine. The upper end of the grouting pipe body 51 is fixedly and sealed to the end of the slurry transport pipe 72 away from the grouting pump 71, and its lower end extends into the water body of the goaf.

[0079] Multiple spiral guide vanes 52 are fixed at equal intervals along the axial direction of the grouting pipe body 51 inside the grouting pipe body 51. Each spiral guide vane 52 has a butterfly gravity valve arranged adjacent to it on its lower side. Specifically, the grouting pipe body 51 has a vertical shaft 53 with a circular cross-section inside. The vertical shaft 53 is coaxially arranged with the grouting pipe body 51. All spiral guide vanes 52 are sleeved on the outside of the vertical shaft 53, and their inner sides are fixedly welded to the outer wall of the vertical shaft 53. During operation, the grouting pump 71 continuously transports the concrete inside the secondary mixing tank 42 to the upper end of the grouting pipe body 51 through the grout transport pipe 72. After entering the grouting pipe body 51, the concrete is output downward to the goaf area under the action of pressure and gravity along the internal cavity of the grouting pipe body 51. As the concrete moves downward along the grouting pipe body 51, the spiral guide vanes 52 force the concrete to move along the spiral trajectory, generating centrifugal force and shearing action to reduce the kinetic energy of the grout, thereby making the aggregate and grout evenly mixed and reducing the effect of segregation.

[0080] The spiral guide vane 52 and the butterfly gravity valve intermittently slow down the flow rate of aggregate in concrete, so that the aggregate and grout maintain the same flow rate. This effectively prevents segregation of concrete during long-distance downward transportation along the grouting pipe 51, ensuring that the aggregate and grout remain in good condition after the concrete falls to the goaf.

[0081] The butterfly gravity valve includes a valve body, a horizontal shaft 54, valve plates 55, and a torsion spring 56. The valve body is fixedly and sealed to the corresponding ends of two adjacent steel pipe sections. The two ends of the horizontal shaft 54 ​​are fixedly connected to the side walls of the valve body. A vertical shaft 53 passes through the middle of each horizontal shaft 54 ​​and is fixedly connected to it in a cross shape. There are two valve plates 55 arranged symmetrically on both sides of the horizontal shaft 54. Each valve plate 55 is a semi-circular flat plate. The torsion spring 56 is sleeved on the outside of the horizontal shaft 54, and its end is fixedly connected to the bottom surface of the valve plate 55. Because the concrete pressure varies at different heights inside the grouting pipe 51, during operation, the appropriate size of the torsion spring 56 can be selected based on its height. The torsion spring 56 controls the opening and closing of the valve plates 55 through its elasticity, thereby slowing down the concrete flow rate to achieve full pipe filling and further reducing the possibility of segregation.

[0082] The electrical control system includes a PLC controller, ultrasonic sensors 81, pressure sensors 82, flow sensors 83, and temperature sensors 84. Multiple ultrasonic sensors 81 are arranged in a spiral pattern on the outer circumference of the grouting pipe body 51. Multiple pressure sensors 82 and flow sensors 83 are also present; one pressure sensor 82 and one flow sensor 83 are located at the outlet end of the grouting pump 71, while the remaining pressure sensors 82 and flow sensors 83 are arranged vertically at intervals on the inner sidewall of the grouting pipe body 51.

[0083] Multiple temperature sensors 84 are fixed at equal intervals along the vertical direction on the outside of the grouting pipe 51, and are staggered with the ultrasonic sensors 81. The signal terminals of all ultrasonic sensors 81, pressure sensors 82, flow sensors 83, and temperature sensors 84 are connected to the PLC controller. These four types of sensors monitor the state of the concrete during transport and after it reaches the goaf, as well as data from the external environment. After data analysis, the state of the concrete in the goaf water is determined, and the result is fed back to the grouting control console 6. This forms a fully automated chain from raw material storage, proportioning, mixing, transporting, grouting to monitoring feedback, thereby achieving the purpose of monitoring and preventing concrete segregation.

[0084] Example 2, combined with Figures 1 to 4 A method for assessing segregation prevention during injection and backfilling of water-filled goaf areas, based on the aforementioned anti-segregation device for injection and backfilling of water-filled goaf areas, includes the following steps:

[0085] Step 1: Construct a comprehensive segregation evaluation model. The comprehensive segregation index formula used in this model is as follows:

[0086] SCI=α·SA+β·ΔP+γQ var +δ·T dev

[0087] In the formula, SCI is the comprehensive segregation index, SA is the ultrasonic segregation degree, ΔP is the pressure fluctuation rate, and Q is the total segregation index. var T is the coefficient of variation of flow rate. dev The percentage of temperature deviation from the reference value; α is the weighting coefficient of the ultrasonic sensor; β is the weighting coefficient of the pressure sensor; γ is the weighting coefficient of the flow sensor; δ is the weighting coefficient of the temperature sensor.

[0088] Ultrasonic segregation degree SA: Calculated by the difference in sound velocity; Pressure fluctuation rate ΔP: Pressure fluctuation rate refers to the amplitude of pressure change in the system per unit time, usually calculated using the standard deviation; Flow rate variation coefficient Q var The stability of grout flow is reflected by the ratio of the standard deviation of the grout flow rate per unit time to the average flow rate; the percentage T of temperature deviation from the reference value is also considered. dev Calculated by the degree of deviation of the actual temperature from the set reference temperature.

[0089] Step 2: Each ultrasonic sensor 81 collects the propagation time t of the ultrasonic wave in the injected concrete at unit time intervals. The propagation time t is processed by the controller to obtain SA.

[0090] In step two, the propagation time at the critical state of concrete segregation is defined as t0, and |S| is calculated using the segregation degree formula, which is:

[0091]

[0092] After processing the data collected by each ultrasonic sensor in the same instance, the maximum value of |S| is selected as SA.

[0093] One of the pressure sensors 82 is installed inside the outlet of the grouting pump casing to monitor pump pressure fluctuations and the initial grouting pressure. The remaining pressure sensors 82 are arranged spirally around the grouting pipe 51, with one pressure sensor installed every 50 meters. They are screwed into the side wall of the grouting pipe through threaded interfaces, and the pressure inside the pipe is monitored in full coverage by the established comprehensive segregation evaluation model.

[0094] The time points t1, t2, ... t of a single pressure sensor 82 within a unit of time. u Collect the pressure values ​​of the grouting pipeline and record them as P1, P2, ... P u All pressure sensors 82 will obtain the grouting pipeline pressure value per unit time and then process it through the controller to obtain ΔP;

[0095] Specifically, the average pressure of each pressure sensor 82 per unit time is calculated. In the formula, P i Given the pressure value of pressure sensor 82 at any point within a unit of time, the standard deviation σ of pressure for all pressure sensors 82 at each point of time is calculated using the sample standard deviation calculation formula. P And sort in ascending order: v P1 <σ P2 <σ P3 <…<σ Pn .

[0096] Then, the pressure standard deviation σ of all pressure sensors 82 per unit time is calculated. P The sample data was processed using the 95th percentile to exclude outliers, reflecting the upper limit of fluctuation for 95% of pressure sensors, and the pressure standard deviation σ was calculated. P The 95th percentile is used as ΔP, and the formula for calculating the pressure standard deviation is:

[0097]

[0098] The time points t1, t2, ... t of a single flow sensor 83 within a unit of time. u Collect the concrete flow rate values ​​in the grouting pipe and record them as Q1, Q2, ..., Q u The system then sends the concrete flow rate values ​​collected by all flow sensors 83 per unit time to the controller, which processes the data to obtain Q. var .

[0099] Specifically, the average flow rate of each flow sensor 83 per unit time is calculated. The calculation formula is:

[0100]

[0101] In the formula, Q i The flow rate of concrete is measured by flow sensor 83 at any sampling time point within a unit time; the standard deviation of flow rate σ of all flow sensors 83 at each time point is calculated using the standard deviation formula for flow rate. Q The formula for calculating the standard deviation of a single flow rate is:

[0102]

[0103] The standard deviation of the flow rate σ Q Substituting the values ​​into the formula for the coefficient of variation of flow rate, the coefficient of variation (CV) of flow rate for each flow sensor 83 per unit time is calculated. Q The formula for the coefficient of variation of flow rate is:

[0104]

[0105] The coefficient of variation (CV) of flow rate per unit time for all flow sensors 83 Q Sort in ascending order, then analyze the coefficient of variation (CV) of the flow rate. Q The sample data was processed using the 95th percentile to remove outliers, reflecting the upper limit of fluctuation for 95% of flow sensors, and the coefficient of variation (CV) of the flow rate was then calculated. Q The 95th percentile as Q var .

[0106] A single temperature sensor 84 at time points t1, t2, ... t within a unit of time. u Collect the temperature values ​​outside the grouting pipe 51 and record them as T1, T2, ..., T u The temperature values ​​collected by all flow sensors 83 per unit time are sent to the controller, which processes them to obtain T. dev , u is the number of times the sensor collects data per unit time, and the duration between any two adjacent time points is equal.

[0107] Specifically, the preset reference temperature T ref The reference value is T; the actual measured temperature is T. i Calculate the difference ΔT between the measured temperature measured by temperature sensor 84 and the reference value per unit time. i The difference ΔT i The calculation formula is as follows:

[0108] ΔT i =T i -T ref

[0109] Calculate the relative deviation percentage AT of each measured temperature of temperature sensor 84 per unit time. The formula for calculating the relative deviation percentage is:

[0110]

[0111] The relative deviation percentage AT of temperature sensor 84 per unit time is sorted in ascending order. Then, the sample data of the relative deviation percentage AT is processed by the 95th percentile to remove outliers, reflecting the upper limit of the temperature sensor's fluctuation by 95%. The 95th percentile of the relative deviation percentage AT is taken as T. dev .

[0112] Step 3: Calculate SA, ΔP, and Q obtained in Step 2. var T dev Substitute the values ​​into the comprehensive segregation index formula to calculate the current comprehensive segregation index.

[0113] Then, the current comprehensive segregation index is compared with the set comprehensive segregation threshold. If the current comprehensive segregation index is greater than or equal to the comprehensive segregation threshold, it is determined that the concrete injected into the goaf water has segregated. The controller feeds back the result to the slurry control console 6. The slurry control console 6 adjusts the concrete raw material ratio according to the feedback result and continues to pour concrete.

[0114] If the current comprehensive segregation index is less than the comprehensive segregation threshold, it is determined that the concrete injected into the goaf water has not segregated, and concrete pouring continues according to the original concrete raw material ratio.

[0115] Step 4: During the concrete pouring process, in order to adapt to the dynamic changes in the goaf environment, the weight coefficients in the comprehensive segregation evaluation model are dynamically updated by combining the entropy method and the time-lapse method.

[0116] The original data matrix X for constructing the comprehensive analysis evaluation model consists of m types of sensors, each consisting of n sensors, denoted as X = (X... ij ) m*n After standardizing X, a new data matrix is ​​obtained.

[0117]

[0118] Calculate the data weight P of the j-th sensor of the i-th sensor type. ij :

[0119]

[0120] In the formula, (i = 1, 2, ..., m; j = 1, 2, ..., n), Pij Substituting into the following formula, the entropy value e of the j-th sensor is calculated. j :

[0121] In the formula,

[0122] The variation index of the j-th sensor is: d j =1-e j ;

[0123] The weight of the j-th sensor is:

[0124] Calculate the comprehensive evaluation value of the i-th sensor: Let Z1 be the weighting coefficient α of the ultrasonic sensor, Z2 be the weighting coefficient β of the pressure sensor, Z3 be the weighting coefficient γ of the flow sensor, and Z4 be the weighting coefficient δ of the temperature sensor.

[0125] In laboratory simulations, slurry segregation tests were conducted by adjusting parameters such as the water-cement ratio, grouting pressure, and aggregate particle size. Data was collected using multiple sensors, and initial weights were designed. In actual engineering projects, a multi-sensor fusion monitoring system was installed. A statistical period was designed using an entropy method combined with a time-lapse method to periodically collect real-world data and reset the weight coefficients.

[0126] Before concrete pouring, initial weighting coefficients are set, and the statistical period is set to 'a' days and the transition period to 'b' days (where b < a). Statistical data from the four sensors are extracted from each statistical period and input into the comprehensive segregation index formula to calculate and update the weighting coefficients used within the transition period. For example... Figure 4 As shown, the statistical period is selected as 7 days, with a transition period of 2 days. The data from the most recent 7 days is used for entropy-based weighting. Every two days, the data from the most recent 7 days is selected again for entropy-based weighting, and the weights obtained from the re-weighting are used for the next two days. This process is repeated to ensure timely updates of real-time data and achieve accurate sensor monitoring.

[0127] When the next time period is reached, the weight coefficients are updated in the same way, and so on, until the concrete pouring is completed.

[0128] This embodiment constructs a comprehensive segregation evaluation model, integrates data collected by multiple sensors and weights of various parameters, and monitors the degree of grout segregation in real time. This enables feedback control of parameters such as the water-cement ratio and grouting pressure of the grout. Furthermore, by periodically adjusting the weight coefficients based on data collected by the subsequent control system, precise monitoring is achieved, effectively preventing segregation during concrete backfilling and grouting.

[0129] For any parts not mentioned in this invention, existing technologies can be used or referenced.

[0130] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0131] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", 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 this invention.

[0132] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A device for preventing segregation during injection and filling of water-filled goaf areas, characterized in that, It includes a material storage unit, a metering unit, a mixing unit, a slurry control console, a slurry conveying unit, an anti-segregation grouting pipe, and an electrical control system. The material storage unit includes a cement silo, an aggregate silo, an admixture tank, and a water tank. The metering unit includes a cement scale, an aggregate scale, and an admixture scale. The outlet of the cement silo is connected to the inlet of the mixing unit through a screw conveyor and a cement scale. The aggregate bin outlet is connected to the mixing unit inlet via a belt conveyor and aggregate scale; the admixture tank outlet is connected to the mixing unit inlet pipe via an admixture scale; and the water tank is connected to the mixing unit inlet pipe via a metering pump. The slurry delivery unit includes a grouting pump and a slurry transport pipe. The grouting pump is located at the outlet end of the mixing unit, and the outlet of the grouting pump is fixedly and sealed to the inlet end of the anti-segregation grouting pipe through the slurry transport pipe. The anti-segregation grouting pipe includes a grouting pipe body, spiral guide vanes, and butterfly gravity valves. The grouting pipe body is vertically arranged inside the mine, with its lower end extending into the water body of the goaf. There are multiple spiral guide vanes, which are arranged at equal intervals along the axial direction of the grouting pipe body inside the grouting pipe body. Each spiral guide vane is adjacent to a butterfly gravity valve arranged on its lower side. The electrical control system includes a PLC controller, ultrasonic sensors, pressure sensors, flow sensors, and temperature sensors. There are multiple ultrasonic sensors, which are arranged in a spiral pattern on the outer circumference of the grouting pipe. There are multiple pressure sensors and flow sensors. One pressure sensor and one flow sensor are located at the outlet end of the grouting pump, and the remaining pressure sensors and flow sensors are arranged at intervals along the vertical direction on the inner wall of the grouting pipe. There are multiple temperature sensors, which are fixed at equal intervals along the vertical direction on the outside of the grouting pipe and are staggered with the ultrasonic sensors. The signal terminals of all ultrasonic sensors, pressure sensors, flow sensors and temperature sensors are connected to the PLC controller for communication.

2. The anti-segregation device for injection and filling of water-filled goaf areas according to claim 1, characterized in that, The cement silo is vertically fixed above the ground by a steel frame. The outlet of the cement silo is located at its bottom and is connected to one end of a screw conveyor. The other end of the screw conveyor is connected to the inlet of the cement scale. The cement scale is located above the mixing unit, and its bottom outlet is connected to the pipeline of the mixing unit. One end of the belt conveyor is located below the bottom outlet of the aggregate bin, and the other end of the belt is located above the inlet of the aggregate scale. The bottom outlet of the aggregate scale is connected to the mixing unit pipeline. The signal terminals of the screw conveyor and the belt conveyor are respectively connected to the pulping control console.

3. The anti-segregation device for injection and filling of water-filled goaf areas according to claim 1, characterized in that, The outlet of the admixture tank is connected to the inlet of the admixture scale via a pipeline, and the outlet of the admixture scale is connected to the inlet pipeline of the mixing unit. The metering pump is fixedly installed at the outlet end of the water tank. The outlet end of the metering pump is connected to the inlet pipe of the mixing unit. The signal terminals of the metering pump and the admixture scale are respectively connected to the pulping control console for communication.

4. The anti-segregation device for injection and filling of water-filled goaf areas according to claim 1, characterized in that, The mixing unit includes a primary mixing tank and a secondary mixing tank. The outlets of the cement scale, aggregate scale, admixture scale, and metering pump are all connected to the top of the primary mixing tank. The secondary mixing tank is located below the primary mixing tank, and its top is connected to the bottom of the primary mixing tank through a pipeline with a gate valve. The bottom outlet of the secondary mixing tank is connected to the inlet of the grouting pump. In addition, both the primary and secondary mixing tanks are equipped with a mixer.

5. The anti-segregation device for injection and filling of water-filled goaf areas according to claim 1, characterized in that, The grouting pipe body has a vertical shaft with a circular cross-section inside. The vertical shaft is arranged coaxially with the grouting pipe body. All spiral guide vanes are sleeved on the outside of the vertical shaft, and their inner sides are fixedly welded to the outer wall of the vertical shaft.

6. The anti-segregation device for injection and filling of water-filled goaf areas according to claim 5, characterized in that, The grouting pipe body is composed of multiple steel pipe segments connected end to end. The butterfly gravity valve includes a valve body, a horizontal shaft, a valve plate, and a torsion spring. The valve body is fixedly and sealed to the corresponding ends of two adjacent steel pipe segments. The two ends of the horizontal shaft are fixedly connected to the side wall of the valve body. The vertical shaft passes through the middle position of each horizontal shaft and is fixedly connected to it in a cross shape. There are two valve plates, which are symmetrically arranged and rotated on both sides of the horizontal shaft axis. The valve plates are semi-circular flat plates. The torsion spring is sleeved on the outside of the horizontal shaft, and its end is fixedly connected to the bottom surface of the valve plate.

7. A method for assessing segregation prevention during injection and backfilling of water-filled goaf areas, characterized in that, The segregation prevention device for injection and backfilling of water-filled goaf areas as described in any one of claims 1 to 6, the segregation prevention assessment method includes the following steps: Step 1: Construct a comprehensive segregation evaluation model. The comprehensive segregation index formula used in this model is as follows: SCI=α·SA+β·ΔP+γQ var +δ·T dev In the formula, SCI is the comprehensive segregation index, SA is the ultrasonic segregation degree, ΔP is the pressure fluctuation rate, and Q is the total segregation index. var T is the coefficient of variation of flow rate. dev The percentage of temperature deviation from the reference value; α is the weighting coefficient of the ultrasonic sensor; β is the weighting coefficient of the pressure sensor; γ is the weighting coefficient of the flow sensor; δ is the weighting coefficient of the temperature sensor. Step 2: Each ultrasonic sensor collects the propagation time t of the ultrasonic wave in the injected concrete at unit time intervals. The propagation time t is processed by the controller to obtain SA. The time points t1, t2, ... t of a single pressure sensor per unit time. u Collect the pressure values ​​of the grouting pipeline and record them as P1, P2, ... P u All pressure sensors will obtain the grouting pipeline pressure value per unit time, which will be processed by the controller to obtain ΔP; The time points t1, t2, ... t of a single flow sensor within a unit of time. u Collect the concrete flow rate values ​​in the grouting pipe and record them as Q1, Q2, ..., Q u The system then sends the concrete flow rate values ​​collected by all flow sensors per unit time to the controller, which processes the data to obtain Q. var ; The time points t1, t2, ... t of a single temperature sensor within a unit of time. u Collect the temperature values ​​outside the grouting pipe body and record them as T1, T2, ..., T u The system then sends the temperature values ​​collected by all flow sensors within a unit of time to the controller, which processes the data to obtain the temperature value (T). dev ; Step 3: Calculate SA, ΔP, and Q obtained in Step 2. var T dev Substitute the values ​​into the comprehensive segregation index formula to calculate the current comprehensive segregation index; Then, the current comprehensive segregation index is compared with the set comprehensive segregation threshold. If the current comprehensive segregation index is greater than or equal to the comprehensive segregation threshold, it is determined that the concrete injected into the goaf water has segregated. The controller feeds back the result to the slurry control console. The slurry control console adjusts the concrete raw material ratio according to the feedback result and continues to pour concrete. If the current comprehensive segregation index is less than the comprehensive segregation threshold, it is determined that the concrete injected into the goaf water has not segregated, and concrete pouring continues according to the original concrete raw material ratio. Step 4: During the concrete pouring process, in order to adapt to the dynamic changes in the goaf environment, the weight coefficients in the comprehensive segregation evaluation model are dynamically updated by combining the entropy method and the time-lapse method. Before concrete pouring, an initial weighting coefficient is set, and the statistical period is set to a day and the transition period is set to b days. The statistical data of the four sensors are extracted from each statistical period and input into the comprehensive segregation index formula to calculate and update the weighting coefficient used in the transition period. When the next time period is reached, the weight coefficients are updated in the same way, and so on, until the concrete pouring is completed.

8. The method for assessing segregation prevention during injection and backfilling of water-filled goaf areas according to claim 7, characterized in that, In step two, the propagation time at the critical state of concrete segregation is defined as t0, and |S| is calculated using the segregation degree formula, which is: After processing the data collected by each ultrasonic sensor in the same instance, the maximum value of |S| is selected as SA. Calculate the average pressure of each pressure sensor per unit time. In the formula, P i Given the pressure value of the pressure sensor at any point within a unit of time, the standard deviation σ of the pressure at each point in time for all pressure sensors is calculated using the sample standard deviation formula. P And sort them in ascending order: σ P1 <σ P2 <σ P3 <…<σ Pn Then, the standard deviation σ of the pressure from all pressure sensors per unit time was calculated. P The sample data were processed using the 95th percentile, and the pressure standard deviation σ was... P The 95th percentile is used as ΔP, and the formula for calculating the pressure standard deviation is: Calculate the average flow rate of each flow sensor per unit time. The calculation formula is: In the formula, Q i The flow sensor measures the flow rate of concrete at any point in time within a unit of time. The standard deviation of flow rate σ at each time point for all flow sensors was calculated using the formula for standard deviation of flow rate. Q The formula for calculating the standard deviation of flow rate is: The standard deviation of the flow rate σ Q Substituting the values ​​into the formula for the coefficient of variation of flow rate, the coefficient of variation (CV) of flow rate for each flow sensor per unit time is calculated. Q The formula for the coefficient of variation of flow rate is: The coefficient of variation (CV) of flow rate for all flow sensors per unit time Q Sort in ascending order, then analyze the coefficient of variation (CV) of the flow rate. Q The sample data was processed using the 95th percentile to determine the coefficient of variation (CV) of the flow rate. Q The 95th percentile as Q var ; Preset reference temperature T ref The reference value is T; the actual measured temperature is T. i Calculate the difference ΔT between the measured temperature obtained by the temperature sensor and the reference value per unit time. i The difference ΔT i The calculation formula is as follows: ΔT i =T i -T ref Calculate the percentage relative deviation AT of each measured temperature by the temperature sensor per unit time. The formula for calculating the percentage relative deviation is: The relative deviation percentage AT of the temperature sensors per unit time is sorted in ascending order. Then, the sample data of the relative deviation percentage AT are processed by the 95th percentile, and the 95th percentile of the relative deviation percentage AT is taken as T. dev .

9. The method for assessing segregation prevention in water-filled goaf injection and backfilling according to claim 7, characterized in that, The original data matrix X for constructing the comprehensive analysis evaluation model consists of m types of sensors, each consisting of n sensors, denoted as X = (X... ij ) m*n After standardizing X, a new data matrix is ​​obtained. Calculate the data weight P of the j-th sensor of the i-th sensor type. ij : In the formula, (i = 1, 2, ..., m; j = 1, 2, ..., n), P ij Substituting into the following formula, the entropy value e of the j-th sensor is calculated. j : In the formula, The exponent of variation for the j-th sensor is: d j =1-e j ; The weight of the j-th sensor is: Calculate the comprehensive evaluation value Z of the i-th sensor. i , Z1 is used as the weighting coefficient α for the ultrasonic sensor, Z2 as the weighting coefficient β for the pressure sensor, Z3 as the weighting coefficient γ for the flow sensor, and Z4 as the weighting coefficient δ for the temperature sensor.

Images