Ground mixing preparation system and method for cemented sand gravel

Abstract

The invention discloses a ground mixing preparation system and method for cemented sand gravel, and the ground mixing preparation system comprises a sand gravel weighing and transporting subsystem which is used for conveying accurately metered sand gravel aggregate to a ground mixing operation subsystem; the centralized slurry preparation subsystem is used for preparing cementing slurry and conveying the cementing slurry to the ground mixing operation subsystem; the ground mixing operation subsystem is used for mixing the aggregate and the cementing slurry and comprises a mixing tank and a backhoe excavator; the plurality of mixing pools are arranged side by side in two rows, and the geometric dimensions of the mixing pools are standardized according to the production supply quantity; the plurality of backhoe excavators are arranged between the two rows of mixing pools, and the working surface of each backhoe excavator covers two adjacent mixing pools; a multi-tooth scarifier is arranged at the execution tail end of the backhoe excavator, and the tooth space of the scarifier is 1.3-1.6 times of the maximum particle size of the aggregate; and the intelligent control subsystem is used for monitoring the running state of each subsystem in real time and sending out an execution instruction.

Description

Technical Field

[0001] This invention belongs to the field of cemented gravel preparation technology, and more specifically, relates to a ground mixing preparation system and method for cemented gravel. Background Technology

[0002] Cemented sand and gravel, as an important material for water conservancy projects and infrastructure construction, is widely used in dams, embankments, road base courses, and other projects due to its advantages of convenient sourcing, low cost, and stable mechanical properties. Its preparation typically relies on stationary mixing plant systems, where aggregates (such as sand and gravel) are mixed with binders (such as cement and fly ash) in a specific ratio, and water is added to form a composite material with certain strength and stability. However, traditional methods of preparing cemented sand and gravel have significant limitations: on the one hand, stationary mixing plants require substantial investment in equipment purchase and infrastructure construction, and have high requirements for the flatness, bearing capacity, and spatial layout of the construction site; on the other hand, at construction sites far from the mixing plant, aggregates often need to undergo multiple transfers, which not only increases transportation costs but also easily causes aggregate segregation or fluctuations in moisture content, affecting the final mixing quality. These problems are particularly prominent in remote mountainous areas or emergency rescue projects.

[0003] To address these challenges, existing technologies primarily employ two improvement approaches. First, they develop upgrade solutions for stationary large-scale mixing plants. This involves optimizing the cavity structure and blade arrangement of the mixing host to improve the equipment's mixing efficiency for medium-sized aggregates, while simultaneously implementing an automated batching system to reduce manual intervention. Second, they promote the application of mobile mixing plants. Leveraging the flexible relocation capabilities of vehicle-mounted mixing equipment, they enable on-site mixing of cemented sand and gravel, thereby avoiding the cost losses associated with long-distance secondary transportation of aggregates.

[0004] Although existing technologies have made some progress in improving the mobility of cemented gravel preparation, they have not yet effectively resolved the contradiction between efficient mixing of oversized aggregates and large-scale continuous production. For example, while the flexibility of mobile mixing plants is evident, their mixing host power and chamber volume are limited, resulting in a production capacity far lower than that of stationary mixing plants, making it difficult to match the continuous construction rhythm of large-scale projects. Secondly, both existing stationary and mobile mixing systems suffer from poor aggregate size adaptability. Limited by the size of the feed inlet, the strength of the mixing blades, and the design of the discharge chute, they cannot achieve stable mixing of oversized gravel (over 200mm). Oversized aggregates are prone to clogging during feeding and discharging, which not only increases the frequency of mixing system shutdowns and significantly reduces production efficiency but also disrupts the uniformity of aggregate and binder mixing, affecting the final mechanical properties of cemented gravel. Summary of the Invention

[0005] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a system and method for preparing cemented sand and gravel through on-site mixing. Through modular, standardized, and intelligent collaborative design, it achieves efficient linkage between various subsystems, effectively overcoming technical bottlenecks such as high investment in traditional fixed mixing plants, low capacity of mobile equipment, and difficulties in mixing oversized aggregates. Simultaneously, the entire process is uniformly scheduled by an intelligent control subsystem, which monitors the operating status in real time and dynamically optimizes instructions, enabling on-site, continuous, and high-quality production of cemented sand and gravel, significantly improving the system's automation level and construction adaptability.

[0006] To achieve the above objectives, the present invention provides a ground mixing preparation system for cemented sand and gravel, comprising: a sand and gravel weighing and transportation subsystem for conveying precisely metered sand and gravel aggregate to the ground mixing operation subsystem; A centralized slurry preparation subsystem is used to prepare binder slurry and transport it to the ground mixing subsystem; The ground mixing subsystem is used to complete the mixing of aggregates and binder slurry, and includes: a mixing tank and a backhoe excavator; The multiple mixing tanks are arranged in two rows side by side, and their geometric dimensions are standardized according to the production supply volume, specifically: ; In the formula: The effective volume of the mixing tank; The volume factor; This is the weight of the binder; For aggregate quality; Design density for cemented gravel; Multiple backhoe excavators are positioned between two rows of mixing tanks, and the working face of each backhoe excavator covers two adjacent mixing tanks; The backhoe excavator is equipped with a multi-tooth ripper at its end of execution, and the tooth spacing of the ripper is 1.3-1.6 times the maximum particle size of the aggregate. The intelligent control subsystem is used to monitor the operating status of each subsystem in real time and issue execution commands.

[0007] Furthermore, the backhoe excavator includes GNSS for real-time acquisition of its precise three-dimensional position and attitude information within the working area; The backhoe excavator has a high-frequency piezoelectric acceleration sensor on the back of the ripper tooth seat to collect vibration acceleration signals when the ripper comes into contact with the material in real time.

[0008] Furthermore, each of the mixing tanks is equipped with at least one microwave moisture meter for real-time, non-contact measurement of the initial moisture content of the aggregate, and the data is fed back to the intelligent control subsystem.

[0009] Furthermore, the bottom of the mixing tank is provided with a two-way drainage slope with a slope of ≥3%; the end of the drainage slope is connected to a drainage pipe, and the outlet of the pipe is provided with a filter screen and a valve.

[0010] Furthermore, the gravel weighing and transportation subsystem includes: a transportation unit and a weighbridge device; the transportation unit includes multiple dump trucks, each equipped with a GPS weighing system and a vehicle-mounted terminal; the weighbridge device is fixedly installed at the inlet of the mixing tank and is communicatively connected to the intelligent control subsystem.

[0011] Furthermore, the centralized slurry preparation subsystem includes: a slurry mixing station, a constant-temperature slurry storage tank connected to the slurry mixing station, and a high-pressure slurry delivery pipeline connected to the constant-temperature slurry storage tank.

[0012] Furthermore, the inner wall of the constant temperature slurry storage tank is provided with a polyurethane insulation layer; The high-pressure slurry conveying pipeline is a DN100 type corrosion-resistant stainless steel pipeline. The outer wall of the pipeline is wrapped with a rock wool insulation layer and the outer layer is protected by iron sheet. The walls of the mixing tank are coated with a polyurethane elastic layer.

[0013] Furthermore, the ground mixing subsystem also includes: an annular spraying pipe; the annular spraying pipe corresponds one-to-one with the mixing tank and is located at the top of the mixing tank; the annular spraying pipe is connected to the high-pressure slurry conveying pipeline; and multiple 360° rotating nozzles are evenly arranged along the length of one side of the annular spraying pipe.

[0014] A second aspect of the present invention provides a ground mixing preparation method for cemented gravel, implemented using the ground mixing preparation system described above, comprising the following steps: S1: After weighing, the dump truck unloads the aggregate into the corresponding mixing tank. At the same time, according to the preset cemented gravel design density, the slurry preparation station prepares the cementing slurry, which is transported to the mixing tank through the high-pressure slurry conveying pipeline and injected into the tank through the annular spray pipe set on the top of the tank. S2: The material in the mixing tank within the range is turned over and mixed according to the preset path by the backhoe excavator until the material is evenly mixed; S3: After mixing, load the prepared cemented gravel onto trucks and transport it to the construction site.

[0015] Furthermore, in step S2, the planning method of the preset path is as follows: first, the mixing is carried out along the path around the work area, and then the mixing is carried out along the path inside the work area, and the mixing path includes at least two intersecting directions.

[0016] Further, step S2 includes the following steps: S21: Perform a short-time Fourier transform on the acceleration signal collected in real time by the high-frequency piezoelectric accelerometer sensor located on the back of the ripper tooth seat of the backhoe excavator to obtain the time spectrum, and obtain the instantaneous slurry damping characteristic index based on the time spectrum data; wherein: ; In the formula, for Instantaneous slurry damping characteristic index; This refers to the rigid impact frequency band of aggregates. , These are the lower and upper limits of the integral for the rigid collision frequency band of aggregates, respectively; For mechanical baseband; , These are the lower and upper limits of integration for the mechanical baseband, respectively. It is the time-frequency distribution function; S22: Discretize the mixing tank into a grid on a horizontal plane. Combine the GNSS coordinate information of the backhoe excavator and the instantaneous slurry damping characteristic index to calculate the average damping state within each grid cell. Determine whether the mixing is uniform by calculating the overall mixing uniformity loss function in real time. Wherein: ; ; In the formula, Spatial grid coordinates The average damping state value within; To ensure that the trajectory of the backhoe ripper falls within this grid during the statistical period. The total number of valid sampling points within the area; For the first The timestamp corresponding to each sampling point; This represents the loss due to mixing inhomogeneity. This is the overall compliance weighting coefficient; The target damping state threshold; This represents the average damping state of all grid cells in the entire pool; The local uniformity weighting coefficient; This represents the average damping value of the entire pool at the current moment. This represents the total number of effective grids within the mixing tank.

[0017] A third aspect of the present invention provides a computer-readable storage medium comprising a stored computer program, wherein the computer program, when executed by a processor, controls the device containing the storage medium to perform the ground mixing preparation method as described above.

[0018] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects: 1. The on-site mixing and preparation system of the present invention achieves efficient linkage of various subsystems through modular, standardized and intelligent collaborative design, effectively overcoming technical bottlenecks such as high investment of traditional fixed mixing plants, low production capacity of mobile equipment and difficulty in mixing oversized aggregates. At the same time, the entire process is uniformly scheduled by the intelligent control subsystem, which monitors the operating status in real time and dynamically optimizes instructions, enabling on-site, continuous and high-quality production of cemented sand and gravel, and greatly improving the system's automation level and construction adaptability.

[0019] 2. The ground mixing preparation system of the present invention utilizes the viscous damping effect of slurry on high-frequency elastic waves and directly characterizes the microscopic slurry coating state of the aggregate surface rather than the macroscopic mechanical resistance by monitoring the spectral redshift when the ripper touches the aggregate. This technical approach not only achieves complete decoupling of the detection signal and mechanical operation, but also cleverly transforms large-diameter aggregates from a source of hydraulic fluctuation interference in traditional calculation methods into a signal source reflecting coating quality. This fundamentally avoids false steady-state misjudgment in rheology and ensures absolute objectivity and accuracy in determining the uniformity of mixing under complex working conditions.

[0020] 3. The ground mixing preparation system of the present invention, by setting a microwave moisture meter, can dynamically adjust the water-cement ratio of the cementitious slurry delivered by the centralized slurry preparation subsystem, ensuring that the total water consumption of the final cemented gravel mixture meets the design requirements, thereby effectively overcoming the problem of inaccurate proportioning caused by fluctuations in the moisture content of natural aggregates, and avoiding strength reduction due to excessive moisture or uneven mixing due to insufficient moisture. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the ground mixing preparation system according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the intelligent control subsystem according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the steps in the mixing preparation method according to an embodiment of the present invention; Figure 4 This is a schematic diagram illustrating the logic of intelligent control based on vibration spectrum damping characteristics in an embodiment of the present invention.

[0022] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically: 1-processor, 2-communication bus, 3-user interface, 4-network interface, 5-memory. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0024] Example 1, please refer to Figure 1 and Figure 2 The present invention provides a ground mixing preparation system for cemented gravel, comprising: The gravel weighing and transport subsystem is used to deliver precisely measured gravel aggregates to the ground mixing subsystem. A centralized slurry preparation subsystem is used to prepare binder slurry and transport it to the ground mixing subsystem; The ground mixing subsystem is used to complete the mixing of aggregates and binder slurry, and includes: a mixing tank and a backhoe excavator; The multiple mixing tanks are arranged in two rows side by side, and their geometric dimensions are standardized according to the production supply volume, specifically: ; In the formula: The effective volume of the mixing tank; The volume factor; This is the weight of the binder; For aggregate quality; Design density for cemented gravel; Multiple backhoe excavators are positioned between two rows of mixing tanks, and the working face of each backhoe excavator covers two adjacent mixing tanks; The backhoe excavator is equipped with a multi-tooth ripper at its end of execution, and the tooth spacing of the ripper is 1.3-1.6 times the maximum particle size of the aggregate. The intelligent control subsystem is used to monitor the operating status of each subsystem in real time and issue execution commands.

[0025] Understandably, during operation, the ground mixing subsystem employs multiple standardized mixing tanks arranged in two parallel rows, facilitating continuous operation and efficient space utilization. Multiple backhoe excavators are positioned between the two rows of mixing tanks, with each excavator's working face covering two adjacent tanks, significantly improving equipment utilization and the continuity of mixing operations. Crucially, the backhoe excavators are equipped with multi-tooth rippers at the end effector, with tooth spacing set to 1.3 to 1.6 times the maximum aggregate diameter. This prevents aggregate breakage and blockage, ensuring uniform mixing and smooth discharge. The centralized slurry preparation subsystem ensures precise proportioning and stable delivery of the binder slurry, while the gravel weighing and transportation subsystem achieves accurate aggregate measurement and efficient supply. The entire process is uniformly scheduled by the intelligent control subsystem, which monitors the operating status in real time and dynamically optimizes commands, significantly improving the system's automation level and construction adaptability. In summary, this on-site mixing preparation system combines the advantages of flexibility, economy, and high production capacity, making it particularly suitable for cemented gravel engineering applications under large-scale, complex terrain conditions.

[0026] Furthermore, the gravel weighing and transportation subsystem includes: a transportation unit and a weighbridge device; the transportation unit includes multiple dump trucks, each equipped with a GPS weighing system and a vehicle-mounted terminal; the weighbridge device is fixedly installed at the inlet of the mixing tank and is communicatively connected to the intelligent control subsystem.

[0027] In an optional embodiment, the dump truck has a load capacity of 20t, a GPS positioning accuracy of ±5cm, a weighing system accuracy of ±1%, and its on-board terminal is connected to the intelligent control subsystem, which can upload vehicle location and load data in real time to achieve full monitoring of the transportation process.

[0028] In an optional embodiment, the weighbridge device includes two SCS-100 electronic weighbridges with a weighing range of 0-100t and an accuracy of ±0.1%. During use, the weighing data of the dump truck is automatically synchronized to the intelligent control subsystem. When the error between the GPS weighing system data and the weighing data exceeds ±2%, an audible and visual alarm is automatically triggered, and the vehicle is prohibited from unloading.

[0029] It is understandable that the gravel weighing and transportation subsystem can realize closed-loop monitoring and dynamic management of the entire process from loading, transportation to unloading, effectively avoid overloading, underloading or mix proportion deviation, ensure that the aggregate quality entering the mixing tank is stable and controllable, and provide reliable data support for the continuous and efficient operation of the system.

[0030] Furthermore, the centralized slurry preparation subsystem includes: a slurry mixing station, a constant-temperature slurry storage tank connected to the slurry mixing station, and a high-pressure slurry conveying pipeline connected to the constant-temperature slurry storage tank, thereby realizing the standardized production and long-distance transportation of high-quality binder slurry and ensuring the quality stability of the gel material.

[0031] In an optional embodiment, the slurry mixing plant is an HZS120 type concrete mixing plant, which integrates a precise automatic metering system for cement, fly ash, water-reducing agent, and water. Cement is metered using a screw conveyor in conjunction with a weighing sensor; fly ash is metered through a closed silo linked with a loss-in-weight weighing scale; water-reducing agent is metered using an electromagnetic flow meter; and water is metered using a high-precision water meter, thereby ensuring that the dosage of each component is accurate and controllable.

[0032] In an optional embodiment, the inner wall of the constant temperature slurry storage tank is provided with a polyurethane insulation layer, and the tank is also provided with a bidirectional spiral anti-sedimentation agitator.

[0033] In an optional embodiment, the polyurethane insulation layer inside the constant temperature slurry storage tank is 45-60mm thick, thereby ensuring that the slurry temperature is maintained within the range of 15-25°C and avoiding temperature fluctuations from affecting the slurry performance.

[0034] In an optional embodiment, the stirring speed of the bidirectional spiral anti-sedimentation stirrer is 25-30 r / min, which is used for continuous low-speed stirring to prevent slurry stratification and sedimentation.

[0035] In an optional embodiment, the high-pressure slurry conveying pipeline is a DN100 corrosion-resistant stainless steel pipeline, with a rock wool insulation layer wrapped around the outer wall and an outer iron sheet for protection. The high-pressure slurry conveying pipeline is equipped with a pressure sensor and a flow sensor, and is also equipped with a variable frequency high-pressure pump to ensure that the slurry pressure in the pipeline is stable at 0.5-0.8MPa, thereby avoiding slurry segregation.

[0036] It is understood that the centralized slurry preparation subsystem, by integrating a slurry mixing station, a constant-temperature slurry storage tank, and a high-pressure slurry delivery pipeline, achieves standardized, high-quality, continuous preparation and stable delivery of binder slurry. Furthermore, this structure not only improves the consistency and controllability of slurry quality but also provides a stable and reliable supply of binder to the ground mixing subsystem, thereby ensuring the overall mechanical properties and construction quality of the cemented gravel.

[0037] Furthermore, it should be noted that the backhoe excavator includes GNSS to acquire its precise three-dimensional position and attitude information within the work area in real time, and transmits the data to the onboard computing unit and the intelligent control subsystem. Understandably, through the above design, GNSS (Global Navigation Satellite System) supports the coordinated scheduling of multiple backhoe excavators between two mixing tanks, optimizing work paths, reducing empty runs and waiting time, and improving overall construction efficiency; simultaneously, it enhances the intelligence, standardization, and traceability of the ground mixing operation subsystem, providing reliable equipment support for large-scale continuous cemented gravel production.

[0038] The on-site mixing subsystem also includes: an annular spraying pipe; each annular spraying pipe corresponds one-to-one with the mixing tank and is located at the top of the mixing tank; the annular spraying pipe is connected to the high-pressure slurry conveying pipeline; multiple 360° rotating nozzles are evenly arranged along the length of one side of the annular spraying pipe. It can be understood that through the above design, full-section, multi-angle, and dead-angle-free slurry coverage can be achieved during the mixing process, significantly improving the uniformity of contact between the slurry and oversized aggregates, effectively avoiding localized dry material or slurry accumulation, and significantly improving the efficiency and automation level of the on-site mixing operation.

[0039] In an optional embodiment, the flow rate of the rotating nozzle is 27-30 L / s, and its spray angle is adjustable from 30° to 60°, thereby significantly optimizing the uniformity of distribution and penetration efficiency of the binder slurry in the mixing tank. At the same time, combined with its 360° rotation characteristic, the rotating nozzle can form a three-dimensional, multi-directional cross-spraying network in a limited space, greatly improving the coating rate and mixing uniformity of the slurry and aggregate, thereby ensuring the overall strength and construction quality stability of the cemented gravel.

[0040] In an optional embodiment, the bottom of the mixing tank is provided with a bidirectional drainage slope with a slope of ≥3%; the end of the drainage slope is connected to a drainage pipe, and the outlet of the pipe is equipped with a filter screen and a valve. It is understood that through the above design, rainwater or washing wastewater can be effectively guided to quickly converge on both sides and discharged in a timely manner, avoiding affecting the proportioning accuracy and mixing quality of the cemented gravel; furthermore, the filter screen is used to intercept fine aggregate particles or slurry residue discharged with the water flow, preventing blockage of downstream pipes and enabling material recovery; the valve facilitates flexible control of drainage opening and closing according to construction needs, taking into account both dry and wet management during operation and emergency drainage during the rainy season.

[0041] In an optional embodiment, the bottom of the mixing tank is made of C30 fine aggregate concrete and the surface is coated with an epoxy resin wear-resistant coating with a thickness of 2-3mm, thereby effectively extending the service life of the tank.

[0042] In an optional embodiment, the mixing tank wall is coated with a polyurethane elastic layer with a thickness of 2-3 mm and a Shore hardness of A85, which has good wear resistance and anti-adhesion properties to reduce the adhesion of sand and gravel to the tank wall.

[0043] In an optional embodiment, the volumetric coefficient is set to 1.2-1.3, optimized based on a comprehensive consideration of aggregate porosity, the space required for material movement during mixing, and operational margins. It is understood that this range ensures the actual volume of the mixing tank is slightly larger than the theoretical volume of cemented gravel, avoiding both overflow or insufficient mixing due to insufficient capacity, and preventing excessive tank size from causing material dispersion, increased energy consumption, and wasted space.

[0044] In an optional embodiment, each mixing tank is equipped with at least one microwave moisture meter to measure the initial moisture content of the aggregate in real time and non-contactly, and to feed the data back to the intelligent control subsystem. It is understood that, based on this moisture content information, the system can dynamically adjust the water-cement ratio of the binder slurry delivered by the centralized slurry preparation subsystem, ensuring that the total water consumption of the final cemented gravel mixture meets design requirements. This effectively overcomes the problem of inaccurate proportioning caused by fluctuations in the moisture content of natural aggregates, and avoids strength reduction due to excessive moisture or uneven mixing due to insufficient moisture.

[0045] In an optional embodiment, the back of the ripper tooth seat of the backhoe excavator is equipped with a high-frequency piezoelectric accelerometer sensor to collect vibration acceleration signals when the ripper comes into contact with the material in real time. The onboard computing unit performs time-frequency domain analysis on the signal to identify the degree of slurry coating on the aggregate. Specifically, a short-time Fourier transform is performed on the collected accelerometer signal to obtain the time spectrum, and the instantaneous slurry coating damping characteristic index is obtained based on this time spectrum data. ; In the formula, for Instantaneous slurry damping characteristic index; This refers to the rigid impact frequency band of aggregates. , These are the lower and upper limits of the integral for the rigid collision frequency band of aggregates, respectively; For mechanical baseband; , These are the lower and upper limits of integration for the mechanical baseband, respectively. This is the time-frequency distribution function.

[0046] In an optional embodiment, the rigid impact frequency band of the aggregate is in the range of 1500Hz-4000Hz, corresponding to the frequency range of elastic waves generated by the direct impact of the metal ripper with hard rock.

[0047] In an optional embodiment, the mechanical baseband ranges from 10Hz to 200Hz, to include excavator hydraulic pump pulsation, engine vibration, and structural low-frequency modes.

[0048] Furthermore, to avoid the local optimum trap of stopping the machine immediately after mixing at a single point, the mixing tank is discretized into a grid on the horizontal plane. Combining the GNSS coordinate information of the backhoe excavator and the instantaneous slurry damping characteristic index, the average damping state within each grid cell is calculated. The uniformity of mixing is determined by real-time calculation of the overall mixing uniformity loss function, the formula of which is: ; ; In the formula, Spatial grid coordinates The average damping state value within; To ensure that the trajectory of the backhoe ripper falls within this grid during the statistical period. The total number of valid sampling points within the area; For the first The timestamp corresponding to each sampling point; This represents the loss due to mixing inhomogeneity. This is the overall compliance weighting coefficient; The target damping state threshold; This represents the average damping state of all grid cells in the entire pool; The local uniformity weighting coefficient; This represents the average damping value of the entire pool at the current moment. This represents the total number of effective grids within the mixing tank.

[0049] In an optional embodiment, the target damping state threshold is 0.8; the overall compliance weighting coefficient is 0.6; and the local uniformity weighting coefficient is 0.4.

[0050] It should be noted that the high-frequency piezoelectric accelerometer in this embodiment is of the IEPE type. In other embodiments, other types of high-frequency piezoelectric accelerometers may be used, and no specific limitation is made here.

[0051] Furthermore, the intelligent control subsystem includes: a processor 1, at least one communication bus 2, a user interface 3, a network interface 4, and a memory 5; wherein: the communication bus 2 is used to realize the connection and communication between these components; the user interface 3 includes a display screen and a keyboard, and optionally, the user interface 3 also includes a standard wired interface and a wireless interface. The network interface 4 includes a standard wired interface and a wireless interface (such as a Wi-Fi interface). The memory 5 includes high-speed RAM or non-volatile memory, such as at least one disk storage device. Optionally, the memory 5 can also be at least one storage device located remotely from the aforementioned processor 1. The memory 5, as a computer-readable storage medium, may include an operating system, a network communication module, a user interface module, and a device control application program. The network interface 4 provides network communication functions; the user interface 3 is mainly used to provide an input interface for the user; and the processor 1 can be used to call the device control application program stored in the memory 5.

[0052] It should be understood that in some feasible implementations, the processor 1 described above can be a central processing unit (CPU), or it can be other general-purpose processors, DSPs, ASICs, FPGAs, or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor. The memory 5 can include read-only memory and random access memory, and provides instructions and data to the processor 1. For example, the memory can also store device type information.

[0053] Example 2, please refer to Figure 3 and Figure 4 The second aspect of the present invention provides a method for preparing cemented gravel by ground mixing, comprising the following steps: S1: After weighing, the dump truck unloads the aggregate into the corresponding mixing tank. At the same time, according to the preset cemented gravel design density, the slurry preparation station prepares the cementing slurry, which is transported to the mixing tank through the high-pressure slurry conveying pipeline and injected into the tank through the annular spray pipe set on the top of the tank. S2: The material in the mixing tank within the range is turned over and mixed according to the preset path by the backhoe excavator until the material is evenly mixed; S3: After mixing, load the prepared cemented gravel onto trucks and transport it to the construction site.

[0054] In an optional embodiment, in step S2, the planning method of the preset path is as follows: first, mixing is carried out along the path around the working area, and then mixing is carried out along the path inside the working area, and the mixing path includes at least two intersecting directions. It can be understood that by prioritizing the treatment of the boundary area of ​​the mixing tank, insufficient slurry distribution or aggregate accumulation caused by edge effects can be effectively eliminated; subsequently, the intersecting mixing paths are used to fully disturb, disperse and coat oversized aggregates (>200mm) and binder slurry in three-dimensional space, avoiding local agglomeration or dry material interlayering.

[0055] In an optional embodiment, the total number of mixing passes is not less than five, thereby meeting the minimum requirements for mixing uniformity in the specifications while also taking into account work efficiency.

[0056] In an optional embodiment, in step S2, the soil ripper's tooth entry angle is maintained at 35°, and the moving speed is controlled at 0.8 m / s. It is understood that through the above design, the set entry angle balances cutting resistance and disturbance depth, effectively embedding into the dense aggregate layer while avoiding excessive equipment load or accelerated tooth wear due to an excessively steep angle. Simultaneously, the set moving speed ensures that the soil ripper applies sufficient force per unit length, fully disintegrating the agglomerated aggregate and creating favorable conditions for subsequent slurry penetration and mixing.

[0057] In an optional embodiment, in order to achieve a unified balance between the number of mixing passes and energy consumption, eliminate ineffective work, and avoid excessive mechanical disturbance to the already mixed material, step S2 includes the following steps: S21: Perform a short-time Fourier transform on the acceleration signal collected in real time by the high-frequency piezoelectric accelerometer sensor located on the back of the ripper tooth seat of the backhoe excavator to obtain the time spectrum, and obtain the instantaneous slurry damping characteristic index based on the time spectrum data; wherein: ; In the formula, for Instantaneous slurry damping characteristic index; This refers to the rigid impact frequency band of aggregates. , These are the lower and upper limits of the integral for the rigid collision frequency band of aggregates, respectively; For mechanical baseband; , These are the lower and upper limits of integration for the mechanical baseband, respectively. It is the time-frequency distribution function; S22: Discretize the mixing tank into a grid on a horizontal plane. Combine the GNSS coordinate information of the backhoe excavator and the instantaneous slurry damping characteristic index to calculate the average damping state within each grid cell. Determine whether the mixing is uniform by calculating the overall mixing uniformity loss function in real time. Wherein: ; ; In the formula, Spatial grid coordinates The average damping state value within; To ensure that the trajectory of the backhoe ripper falls within this grid during the statistical period. The total number of valid sampling points within the area; For the first The timestamp corresponding to each sampling point; This represents the loss due to mixing inhomogeneity. This is the overall compliance weighting coefficient; The target damping state threshold; This represents the average damping state of all grid cells in the entire pool; The local uniformity weighting coefficient; This represents the average damping value of the entire pool at the current moment. This represents the total number of effective grids within the mixing tank.

[0058] In an optional embodiment, the target damping state threshold is 0.8; the overall compliance weighting coefficient is 0.6; and the local uniformity weighting coefficient is 0.4.

[0059] In an optional embodiment, when the mixing non-uniformity loss value is not greater than a preset threshold and the duration exceeds 5 seconds, the system determines that the aggregate in the entire pool has reached the specified coating thickness and uniformity, automatically issues a mixing completion command, and ends the operation. Preferably, the preset threshold ranges from 0.05 to 0.1.

[0060] In an optional embodiment, when the mixing unevenness loss value is greater than a preset threshold or the duration does not exceed 5 seconds, the system generates a corresponding heat map and mixes the unevenly mixed area again until it is uniformly mixed.

[0061] Understandably, the vibration frequency characteristics generated when the tips of a metal ripper impact gravel aggregate are highly correlated with the surface coating of the aggregate. When the tips directly impact a dry or uncoated rock surface, a quasi-elastic collision occurs, generating a high-frequency, crisp metallic ringing sound, with energy concentrated in the high-frequency range above 1.5kHz. When the aggregate surface is fully coated with viscous slurry, the slurry layer acts as a viscous damper at the moment of impact; according to the theory of vibration wave propagation, high-frequency waves attenuate fastest when passing through a viscous fluid layer; therefore, the high-frequency components of the impact signal are significantly absorbed, resulting in a muffled vibration response and energy transfer to lower frequencies. By utilizing the viscous damping effect of slurry on high-frequency elastic waves, the microscopic slurry coating state of the aggregate surface is directly characterized by monitoring the spectral redshift when the ripper touches the aggregate, rather than the macroscopic mechanical resistance. This technical approach not only achieves complete decoupling between the detection signal and the mechanical operation (the contact characteristics remain unchanged regardless of the speed of the operation), but also cleverly transforms large-diameter aggregates from a source of hydraulic fluctuation interference in traditional calculation methods into a signal source reflecting the coating quality. This fundamentally avoids false steady-state misjudgments in rheology and ensures the absolute objectivity and accuracy of the mixing uniformity determination under complex working conditions.

[0062] To further illustrate the present invention, the following detailed description of the ground mixing preparation method provided by the present invention is provided in conjunction with embodiments, but it should not be construed as a limitation on the scope of protection of the present invention. Specifically, the design parameters for the cemented gravel modulus enhancement zone of a certain project are: 90-day compressive strength of 6 MPa, strength guarantee rate of 80%; cement:fly ash ratio of 5:5; cementitious material mix proportion parameters are shown in Tables 1 to 3; and specific test results are shown in Table 4.

[0063] Table 1. Amount of cemented gravel material used per cubic meter (kg / m³) 3 ) Table 2 Slurry Properties Table 3 Mixing ratio for each batch of slurry Table 4. Results of on-site sampling performance tests of cemented gravel. The above-mentioned on-site mixing method was used to produce cemented sand and gravel. Forty-four samples were taken from the machine inlet on-site. Statistical results showed that the VC value and 90-day compressive strength of the specimens met the design requirements. Specifically, the modified VC value was 5-7s, the 90-day compressive strength ranged from 11.7 MPa to 19.7 MPa, and the average density was 2.40 g / cm³. 3 The relative density test value is 0.97 to 0.99 (meeting the design requirement of relative density ≥ 0.97).

[0064] Example 3: This embodiment of the invention also provides a computer-readable storage medium storing a computer program that is executed by a processor to implement the various steps in the above-described method for preparing cemented gravel by mixing. For details, please refer to the implementation methods provided for each of the above-described steps, which will not be repeated here.

[0065] It should be understood that although the steps in the flowcharts of the accompanying figures are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the accompanying figures may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0066] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0067] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0068] In this invention, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit it; those skilled in the art will readily understand that the above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A ground mixing preparation system for cemented sand and gravel, characterized in that, include: The gravel weighing and transport subsystem is used to deliver precisely measured gravel aggregates to the ground mixing subsystem. A centralized slurry preparation subsystem is used to prepare binder slurry and transport it to the ground mixing subsystem; The ground mixing subsystem is used to complete the mixing of aggregates and binder slurry, and includes: a mixing tank and a backhoe excavator; The multiple mixing tanks are arranged in two rows side by side, and their geometric dimensions are standardized according to the production supply volume, specifically: ； In the formula: The effective volume of the mixing tank; The volume factor; This is the weight of the binder; For aggregate quality; Design density for cemented gravel; Multiple backhoe excavators are positioned between two rows of mixing tanks, and the working face of each backhoe excavator covers two adjacent mixing tanks; The backhoe excavator is equipped with a multi-tooth ripper at its end of execution, and the tooth spacing of the ripper is 1.3-1.6 times the maximum particle size of the aggregate. The intelligent control subsystem is used to monitor the operating status of each subsystem in real time and issue execution commands.

2. The ground mixing preparation system according to claim 1, characterized in that, The backhoe excavator includes GNSS for real-time acquisition of its precise three-dimensional position and attitude information within the working area; The backhoe excavator has a high-frequency piezoelectric acceleration sensor on the back of the ripper tooth seat to collect vibration acceleration signals when the ripper comes into contact with the material in real time.

3. The ground mixing preparation system according to claim 1, characterized in that, Each of the mixing tanks is equipped with at least one microwave moisture meter for real-time, non-contact measurement of the initial moisture content of the aggregates and for feeding the data back to the intelligent control subsystem.

4. The ground mixing preparation system according to claim 1, characterized in that, The bottom of the mixing tank is provided with a two-way drainage slope with a slope of ≥3%; the end of the drainage slope is connected to a drainage pipe, and the outlet of the pipe is equipped with a filter screen and a valve.

5. The ground mixing preparation system according to claim 1, characterized in that, The gravel weighing and transportation subsystem includes: a transportation unit and a weighbridge device; the transportation unit includes multiple dump trucks, each equipped with a GPS weighing system and a vehicle terminal; the weighbridge device is fixedly installed at the inlet of the mixing tank and is communicatively connected to the intelligent control subsystem.

6. The ground mixing preparation system according to claim 1, characterized in that, The centralized slurry preparation subsystem includes: a slurry mixing station, a constant-temperature slurry storage tank connected to the slurry mixing station, and a high-pressure slurry delivery pipeline connected to the constant-temperature slurry storage tank.

7. The ground mixing preparation system according to claim 6, characterized in that, The inner wall of the constant temperature slurry storage tank is provided with a polyurethane insulation layer. The high-pressure slurry conveying pipeline is a DN100 type corrosion-resistant stainless steel pipeline. The outer wall of the pipeline is wrapped with a rock wool insulation layer and the outer layer is protected by iron sheet. The walls of the mixing tank are coated with a polyurethane elastic layer.

8. The ground mixing preparation system according to claim 6, characterized in that, The ground mixing subsystem further includes: an annular spraying pipe; the annular spraying pipe corresponds one-to-one with the mixing tank and is located at the top of the mixing tank; the annular spraying pipe is connected to the high-pressure slurry conveying pipeline; and multiple 360° rotating nozzles are evenly arranged along the length of one side of the annular spraying pipe.

9. A method for preparing cemented sand and gravel by ground mixing, implemented using the ground mixing preparation system as described in any one of claims 1-8, characterized in that, Includes the following steps: S1: After weighing, the dump truck unloads the aggregate into the corresponding mixing tank. At the same time, according to the preset cemented gravel design density, the slurry preparation station prepares the cementing slurry, which is transported to the mixing tank through the high-pressure slurry conveying pipeline and injected into the tank through the annular spray pipe set on the top of the tank. S2: The material in the mixing tank within the range is turned over and mixed according to the preset path by the backhoe excavator until the material is evenly mixed; S3: After mixing, load the prepared cemented gravel onto trucks and transport it to the construction site.

10. The method for preparing ground-mixed feed according to claim 9, characterized in that, In step S2, the planning method of the preset path is as follows: first, the mixing is carried out along the path around the work area, and then the mixing is carried out along the path inside the work area, and the mixing path includes at least two intersecting directions.

11. The method for preparing ground-mixed concrete according to claim 10, characterized in that, Step S2 includes the following steps: S21: Perform a short-time Fourier transform on the acceleration signal collected in real time by the high-frequency piezoelectric accelerometer sensor located on the back of the ripper tooth seat of the backhoe excavator to obtain the time spectrum, and obtain the instantaneous slurry damping characteristic index based on the time spectrum data; wherein: ； In the formula, for Instantaneous slurry damping characteristic index; This refers to the rigid impact frequency band of aggregates. , These are the lower and upper limits of the integral for the rigid collision frequency band of aggregates, respectively; For mechanical baseband; , These are the lower and upper limits of integration for the mechanical baseband, respectively. It is the time-frequency distribution function; S22: Discretize the mixing tank into a grid on a horizontal plane. Combine the GNSS coordinate information of the backhoe excavator and the instantaneous slurry damping characteristic index to calculate the average damping state within each grid cell. Determine whether the mixing is uniform by calculating the overall mixing uniformity loss function in real time. Wherein: ； ； In the formula, Spatial grid coordinates The average damping state value within; To ensure that the trajectory of the backhoe ripper falls within this grid during the statistical period. The total number of valid sampling points within the area; For the first The timestamps corresponding to each sampling point; This represents the loss due to mixing inhomogeneity. This is the overall compliance weighting coefficient; The target damping state threshold; This represents the average damping state of all grid cells in the entire pool; The local uniformity weighting coefficient; This represents the average damping value of the entire pool at the current moment. This represents the total number of effective grids within the mixing tank.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored computer program, which, when executed by a processor, controls the device containing the storage medium to perform the ground mixing preparation method as described in any one of claims 9-11.

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