Device and method for testing early settlement stability of HECC material rock-fill dam panel

Abstract

The invention relates to a device and a method for testing early settlement stability of an HECC material rock-fill dam panel. The device comprises an angle adjusting support, a panel mold, a movable baffle, a movable reinforcing mesh, a movable pressing plate and a settlement monitoring device. When a stability test is carried out, a movable reinforcing mesh is placed in a simulation panel pouring groove, an HECC material is poured and flattened through a movable pressing plate to form an HECC material simulation panel, a movable baffle is placed on the top face of the HECC material simulation panel, the early settlement condition of the HECC material simulation panel is monitored through a settlement monitoring device, and a time-settlement relation curve of the HECC material is obtained. And the settlement ratio is calculated, and the settlement stability of the HECC material is determined through the settlement ratio, so that the matched slip form ascending speed is selected during construction, and the flatness and related performance of the panel are ensured. According to the method, the engineering construction working condition of the HECC material is effectively simulated, the early settlement stability of the HECC material is accurately represented, and theoretical guidance is provided for application of the HECC material in panel concrete engineering.

Description

Technical Field

[0001] This application relates to the field of performance testing of high ductility concrete in hydraulic engineering, specifically to a testing device and method for early settlement stability of HECC material rockfill dam panels. Background Technology

[0002] Concrete-faced rockfill dams are a general term for dams constructed by layering and compacting riprap or gravel, with concrete faces serving as the seepage barrier. In recent years, they have been widely used in water-retaining structures of water conservancy and hydropower projects. In concrete-faced rockfill dams, the concrete face, as the main seepage barrier structure, bears a significant head difference and is crucial for the safety and stability of the dam's seepage flow. However, concrete exhibits significant asymmetry in its mechanical properties; its compressive strength is much higher than its tensile strength, and it is prone to brittle fracture under tension and compression. Therefore, the mismatch between the deformation of the dam body and the concrete face caused by dam settlement can easily lead to cracking of the concrete face, thus affecting the safety and stability of the dam. Currently, controlling the later-stage deformation of the concrete face is the main means of preventing cracking. However, passive deformation control methods can only solve the problem of cracking at a certain stage; throughout the entire operation period, cracking of the concrete face will still occur.

[0003] To address the aforementioned problem of cracking in concrete panels, the inventors of this application researched a high-toughness cement-based composite material suitable for hydraulic structures and applied for an invention patent on March 23, 2022, with authorization publication number CN114685117B. This patent discloses the formulation and preparation method of the material, which includes 25-34 wt% cement, 23-30 wt% fly ash, 15-20 wt% silica fume, 26-32 wt% fine aggregate, 1.25-1.7% composite fiber mesh, 0.1-0.24 wt% water-reducing agent, and 0.03-0.07 wt% thickener. The composite fiber mesh is prepared by impregnating composite fibers in water-based epoxy resin and a curing agent, mixing them evenly, removing the composite fibers, spreading them out, and then cutting or breaking them into small mesh structures. Based on traditional engineered cementitious composite (ECC) materials, this material utilizes geographically sourced materials, breaks through aggregate particle size limitations, and incorporates flowability design as needed. This results in a material with advantages such as high ductility, high toughness, and high durability. Therefore, this material is named Hydraulic Engineered Cementitious Composite (HECC) for hydraulic structures. By incorporating composite fiber mesh, HECC material is tightly interwoven with other raw materials, significantly improving its crack resistance and impermeability. It also possesses very high compressive and flexural strengths, making it highly suitable for use in hydraulic engineering projects where seepage prevention and crack resistance are required.

[0004] HECC (Heated Concrete Cement) materials have been applied in rockfill dams with concrete panels. Specifically, using HECC panels instead of traditional concrete panels significantly improves stress distribution, enhances deformation adaptability, and effectively prevents panel cracking. Generally, when pouring rockfill dam panels on the dam slope, a slipform system is installed from the dam base onto the slope, and concrete is continuously poured along a track. The formwork slides and lifts at a uniform speed, resulting in a dense panel formed in one go. However, because HECC is composed of cement, mineral admixtures, fine sand, fibers, additives, and water, it does not contain coarse aggregate and belongs to the cement mortar category. Lacking a coarse aggregate skeleton, the slipform construction speed directly affects the HECC panel forming effect during continuous slipform construction. An inappropriate slipform construction speed, such as too fast, can easily lead to settlement on the slope, causing bulging or even plastic cracks, affecting panel quality and operational safety. As HECC is a novel material, there is currently a lack of research on its performance, particularly regarding its early settlement stability. There are no suitable devices or methods for testing and studying this material, resulting in a lack of data to guide the application and construction of HECC in rockfill dam panels. Consequently, it is impossible to select parameters for later slipform construction based on the early settlement stability of HECC.

[0005] One method in asphalt concrete slope flow tests involves mounting asphalt concrete Marshall specimens on supports along a slope with the designed gradient, and then measuring the slope flow deformation over 48 hours using a micrometer. However, asphalt concrete slope tests require a 70°C oven, necessitate manual micrometer readings, and are characterized by small specimen sizes, cumbersome operation, and susceptibility to errors. This method is not suitable for testing and evaluating the settlement of HECC (Heated Iron Cemented Concrete) panels in rockfill dams. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a testing device and method for early settlement stability of HECC material rockfill dam panels. This device can test the early settlement stability of HECC material rockfill dam panels, classify the tested stability, and select different sliding speeds according to different levels, thereby providing construction guidance for the sliding membrane construction of rockfill dam panels and improving the quality and operational safety of HECC material rockfill dam panels.

[0007] This invention also provides a testing device for early settlement stability of HECC material rockfill dam panels. The testing device includes an angle adjustment bracket, a panel mold, a movable baffle, a movable steel mesh, a movable pressure plate, and a settlement monitoring device. The panel mold is located on the angle adjustment bracket, and its tilt angle is adjusted by the angle adjustment bracket, with the adjustment range controlled between 20° and 75°. A simulated panel casting groove is provided on the panel of the panel mold. The settlement monitoring device includes a control device and a displacement sensor fixedly installed on the top surface of the simulated panel casting groove. During the early settlement stability test of HECC material rockfill dam panels, the movable steel mesh is placed in the simulated panel casting groove, and HECC material is poured into the simulated panel casting groove. After the groove opening is smoothed by the movable pressure plate, a simulated HECC material panel is formed in the simulated panel casting groove. The distance between the top surface of the simulated HECC material panel and the top surface of the simulated panel casting groove is greater than the thickness of the movable baffle. The movable baffle is placed on the top surface of the simulated HECC material panel, and the early settlement of the simulated HECC material panel is monitored by the settlement monitoring device.

[0008] The preferred technical solution of the present invention is as follows: The settlement monitoring device includes two continuously readable laser displacement sensors fixed at the top of the casting tank of the simulated panel. The signal output terminal of the laser displacement sensor is connected to the signal input terminal of the control device. The two laser displacement sensors continuously collect the displacement data of the movable pressure plate, i.e., the settlement data of the HECC material simulated panel, and transmit the collected displacement data to the control device. The control device sets the time to generate the time-settlement curve of the HECC material simulated panel, and obtains the settlement parameters from the time-settlement curve of the HECC material simulated panel to calculate the differential settlement amount ΔS and the settlement ratio δ.

[0009] The preferred technical solution of the present invention is as follows: the angle adjustment bracket includes a support base plate and an adjustment frame, the panel mold is rotatably connected to the support base plate, and the adjustment frame supports and adjusts the angle of the simulated slope to change the angle of the slope.

[0010] The preferred technical solution of the present invention is that the length of the movable steel mesh is less than the length of the simulated panel casting groove, and when the HECC material is poured to form the HECC material simulated panel, the HECC material completely wraps the movable steel mesh.

[0011] The preferred technical solution of the present invention is as follows: the width and length of the movable baffle are respectively matched with the depth and width of the simulated panel casting groove, the width of the movable pressure plate is matched with the width of the simulated panel casting groove, and the length is less than the length of the simulated panel casting groove; handles are respectively provided on the movable baffle and the movable pressure plate.

[0012] This invention also provides a method for testing the early settlement stability of HECC material rockfill dam panels. The method uses the aforementioned HECC material rockfill dam panel early settlement stability testing device to simulate and test the stability of the HECC material rockfill dam panel to be poured before its casting. The specific steps are as follows:

[0013] S1. First, determine the actual slope of the HECC material rockfill dam panel to be poured, and prepare the same HECC material slurry as the actual HECC material rockfill dam panel to be poured according to the design requirements.

[0014] S2. Adjust the panel mold to the actual slope of the rockfill dam panel to be poured using the angle adjustment bracket. Then pour the HECC material slurry mixed in step S1 into the simulated panel pouring groove of the panel mold. During the pouring process, the surface is fixed by the movable pressure plate and the HECC material simulated panel is formed by layered pouring. The top surface of the HECC material simulated panel is a certain distance away from the top surface of the simulated panel pouring groove for installing the movable baffle.

[0015] S3. Insert the movable baffle into the casting groove of the simulation panel and make it fit tightly against the top surface of the newly cast HECC material simulation panel;

[0016] S4. Open the monitoring device, remove the movable pressure plate, continuously monitor the displacement data of the movable baffle through the displacement sensor, and set a fixed time to continuously record the displacement data of the movable baffle, thereby obtaining the time-settlement relationship curve of the HECC material simulation panel.

[0017] S4. Obtain settlement parameters from the HECC material simulation panel: initial settlement value S0, instantaneous settlement S t The length L of the simulated HECC material panel is determined, and the differential settlement ΔS and settlement ratio δ are calculated through settlement parameters. The early settlement stability of the simulated HECC material panel is judged by the settlement ratio δ, so as to select the matching slipform lifting speed of the rockfill dam panel for the actual HECC material rockfill dam panel pouring.

[0018] The preferred technical solution of this invention: In step S4, the specific formulas for calculating the differential settlement ΔS and settlement ratio δ using settlement parameters are as follows: ; .

[0019] A further technical solution of the present invention: The specific criteria for judging the early settlement stability of HECC material rockfill dams by the settlement ratio δ in step S4 are as follows: The stability of the HECC material simulation panel is judged to be Grade A, and the sliding form lifting speed of the rockfill dam panel is no more than 3m / h. 4‰, the stability of the HECC material simulation panel is judged to be grade B, and the sliding form lifting speed of the rockfill dam panel is not greater than 2m / h; The stability of the HECC material simulation panel is judged to be grade C, and the sliding form lifting speed of the rockfill dam panel is no more than 1.2 m / h.

[0020] The beneficial effects of this invention are:

[0021] (1) The testing device in this invention can change the angle of the test slope through an adjustable bracket. The panel is fixed on the adjustable bracket and has a built-in movable steel mesh, which together form a slope component; the movable metal pressure plate and baffle form a molding component; two laser displacement sensors are fixed with reserved holes on the left and right sides of the top of the panel to form a monitoring component; the slope component can be adjusted to the test slope, the movable pressure plate is used to fix the surface to pour the mixed slurry in layers, and then the laser displacement sensor is turned on, the movable pressure plate is removed in sequence, and the time-settlement relationship curve of HECC material is obtained by continuous monitoring through the sensor, and the settlement ratio is calculated. The settlement ratio index is used to classify the settlement stability of HECC material. This device is easy to operate, effectively simulates the engineering construction conditions of HECC material, accurately characterizes the early settlement stability of HECC material, makes up for the lack of existing HECC material testing devices, provides theoretical guidance for the application of HECC material in panel concrete engineering, and ensures construction quality.

[0022] (2) This invention classifies the settlement stability of HECC materials into three levels, A, B, and C, based on the settlement ratio index. For different stability levels, the slipform construction corresponds to a specific construction speed, thereby guiding the slipform construction of HECC material rockfill dam panels. When the stability rating is A, the stability of HECC materials is good, and the slipform construction speed should not exceed 3 m / h. When the stability rating is B, the stability of HECC materials decreases, and the slipform construction speed should be controlled to not exceed 2 m / h. When the stability rating of HECC materials is C, the slipform construction speed should be strictly controlled to not exceed 1.2 m / h. By controlling the slipform construction speed, the probability of HECC materials settling on the slope, producing bulges and plastic cracks is reduced, which greatly improves the quality and operational safety of HECC material rockfill dam panels. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the testing device in this invention;

[0024] Figure 2 This is a reference diagram showing the usage status of the testing device in this invention;

[0025] Figures 3 to 8 These are the time-sedimentation curves from Examples 1 to 6, respectively.

[0026] Figures 9 to 14These are schematic diagrams of HECC material molding panels from Examples 1 to 6.

[0027] In the diagram: 1. Panel mold; 2. Movable baffle; 3. Angle adjustment bracket; 4. Simulated panel pouring trough; 5. Settlement monitoring device; 6. Movable steel mesh; 7. Movable pressure plate; 8. HECC material simulation panel; 9. Handle. Detailed Implementation

[0028] The technical solutions of the embodiments of this application will now be described with reference to the accompanying drawings. It should be noted that similar reference numerals and letters in the following drawings indicate similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments. The technical solutions shown in the drawings are specific embodiments of the present invention and are not intended to limit the scope of the claimed invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0030] The embodiment provides an early settlement stability testing device for HECC material rockfill dam panels, such as... Figure 1 and Figure 2As shown, the testing device includes an angle adjustment bracket 3, a panel mold 1, a movable baffle 2, a movable steel mesh 6, a movable pressure plate 7, and a settlement monitoring device 5. The panel mold 1 is located on the angle adjustment bracket 3, and its tilt angle is adjusted by the angle adjustment bracket 3. The adjustment range is controlled between 20° and 75°. The angle adjustment bracket 3 includes a support base plate and an adjustment frame. The panel mold 1 is rotatably connected to the support base plate, and is supported and its angle is adjusted by the adjustment frame to change the angle of the simulated slope. The angle adjustment bracket 3 can adopt an existing structure, and its main purpose is to adjust the tilt angle of the panel mold. A simulated panel casting groove 4 is provided on the panel of the panel mold 1. The settlement monitoring device 5 includes a control device and a displacement sensor fixedly installed on the top surface of the simulated panel casting groove 4. During the early settlement stability test of the HECC material rockfill dam panel, a movable steel mesh 6 is placed in the simulated panel casting groove 4, and HECC material is poured into the simulated panel casting groove 4. After the groove opening is smoothed by the movable pressure plate 7, a simulated HECC material panel 8 is formed in the simulated panel casting groove 4. The distance between the top surface of the simulated HECC material panel 8 and the top surface of the simulated panel casting groove 4 is greater than the thickness of the movable baffle 2. The movable baffle 2 is placed on the top surface of the simulated HECC material panel 8, and the early settlement of the simulated HECC material panel 8 is monitored by the settlement monitoring device 5. The length of the movable steel mesh 6 is less than the length of the simulated panel casting groove 4, and when the HECC material is poured to form the simulated HECC material panel 8, the HECC material completely wraps the movable steel mesh 6. The width and length of the movable baffle 2 are matched with the depth and width of the simulated panel casting groove 4, respectively. The width of the movable pressure plate 7 is matched with the width of the simulated panel casting groove 4, and its length is less than the length of the simulated panel casting groove 4. Handles 9 are provided on the movable baffle 2 and the movable pressure plate 7, respectively.

[0031] In this embodiment, the settlement monitoring device 5 includes two continuously readable laser displacement sensors fixed to the top of the simulated panel casting tank 4. The signal output terminals of the laser displacement sensors are connected to the signal input terminals of the control device. The two laser displacement sensors continuously collect the displacement data of the movable pressure plate 7, i.e., the settlement data of the HECC material simulated panel 8, and transmit the collected displacement data to the control device. The control device sets the time to generate the HECC material simulated panel time-settlement curve, and obtains the settlement parameters from the HECC material simulated panel time-settlement curve to calculate the differential settlement amount ΔS and the settlement ratio δ.

[0032] The following will refer to the appendix. Figure 1 This application will be described in detail with reference to exemplary embodiments. The embodiments use the apparatus of this application to conduct early settlement stability tests on HECC rockfill dam panels, and compare the results with construction effects:

[0033] HECC material mixtures were prepared, and their slump was recorded. A portion of the material was sampled and its slope stability was tested using the early settlement stability testing device provided by this invention. The remaining mixtures were used for panel slipforming construction. The slipforming lifting speed was controlled, and the panel surface flatness was observed to evaluate the panel construction quality. This was used to determine the guiding role of the evaluation method proposed in this invention.

[0034] In the following embodiments, the specific criteria for judging the early settlement stability of HECC material rockfill dams by the settlement ratio δ are as follows: The stability of the HECC material simulation panel is judged to be Grade A, and the sliding form lifting speed of the rockfill dam panel is no more than 3m / h. 4‰, the stability of the HECC material simulation panel is judged to be grade B, and the sliding form lifting speed of the rockfill dam panel is not greater than 2m / h; The stability of the HECC material simulation panel is judged to be grade C, and the sliding form lifting speed of the rockfill dam panel is no more than 1.2 m / h.

[0035] Implementation Case 1 provides a method for testing the early settlement stability of HECC material rockfill dam panels. Before the pouring of the HECC material rockfill dam panels, the stability of the HECC material rockfill dam panels to be poured is simulated and tested. The specific steps are as follows:

[0036] S1. First, determine the actual slope of the HECC material rockfill dam panel to be poured as 45°.

[0037] S2. Prepare a metal panel mold 1, which simulates the panel casting groove 4 with a length of 1m, a width of 0.5m, and a depth of 0.1m. Brush a layer of oil inside the simulated panel casting groove 4 to facilitate the later demolding process.

[0038] S3. Prepare HECC material slurry identical to the actual HECC material rockfill dam panel to be poured according to the design requirements, record the slump as 6cm, take a sample and put it into the simulated panel pouring groove 4 of the panel mold 1, and use a high-frequency vibrator to compact it. During vibration, the surface is fixed by the movable pressure plate 7 and the prepared slurry is poured in layers. The surface is smoothed, and the top surface of the HECC material simulated panel is a certain distance away from the top surface inside the simulated panel pouring groove for installing the movable baffle 2.

[0039] S4. Adjust the panel mold 1 to a tilt angle of 45° using the angle adjustment bracket 3, turn on the laser displacement sensor, record the initial test value S0:0, remove the movable pressure plate 7, and continuously monitor the moving distance of the movable baffle 2 through the laser displacement sensor, i.e. the settlement value of the HECC material simulated panel.

[0040] When the S5 HECC panel reaches final set, save the data, close the testing software, and obtain the curve showing the relationship between the HECC material simulation panel test time and the corresponding settlement, as shown below. Figure 3 As shown.

[0041] S6. Obtain settlement parameters from the time-settlement curve of the HECC material simulation panel: initial settlement value S0=0, instantaneous settlement S t =1.24mm, HECC material simulation panel length L=800mm, and differential settlement ΔS and settlement ratio δ are calculated using settlement parameters as follows:

[0042] =1.24-0=1.24mm;

[0043] ‰;

[0044] The early settlement stability of the simulated HECC material panel was determined by the settlement ratio δ, and the matching slipform lifting speed of the rockfill dam panel was selected for the actual casting of the HECC material rockfill dam panel.

[0045] S7. Stability Analysis: Calculations show that the settlement ratio δ of the HECC panel in Example 1 is 1.55‰, and the settlement stability of the HECC panel in Example 1 is determined to be Grade A.

[0046] S8. During actual construction, a slipform simulation device was used to ascend at a constant speed of 2.5 m / h. The smoothness of the HECC surface after slipform construction was observed. Figure 9 .

[0047] Implementation Case 2 provides a method for testing the early settlement stability of HECC material rockfill dam panels. Before the pouring of the HECC material rockfill dam panels, the stability of the HECC material rockfill dam panels to be poured is simulated and tested. The specific steps are as follows:

[0048] S1. First, determine the actual slope of the HECC material rockfill dam panel to be poured as 45°.

[0049] S2. Prepare a metal panel mold 1, which simulates the panel casting groove 4 with a length of 1m, a width of 0.5m, and a depth of 0.1m. Brush a layer of oil inside the simulated panel casting groove 4 to facilitate the later demolding process.

[0050] S3. Prepare HECC material slurry identical to the actual HECC material rockfill dam panel to be poured according to the design requirements, record the slump of 10cm, take a sample and put it into the simulated panel pouring groove 4 of the panel mold 1, and use a high-frequency vibrator to compact it. During vibration, the surface is fixed by the movable pressure plate 7 and the prepared slurry is poured in layers. The surface is smoothed, and the top surface of the HECC material simulated panel is a certain distance away from the top surface of the simulated panel pouring groove for installing the movable baffle 2.

[0051] S4. Adjust the panel mold 1 to a tilt angle of 45° using the angle adjustment bracket 3, turn on the laser displacement sensor, record the initial test value S0:0, remove the movable pressure plate 7, and continuously monitor the moving distance of the movable baffle 2 through the laser displacement sensor, i.e. the settlement value of the HECC material simulated panel.

[0052] When the S5 HECC panel reaches final set, save the data, close the testing software, and plot the curve showing the relationship between the HECC material simulation panel test time and the corresponding settlement, as shown below. Figure 4 As shown.

[0053] S6. Obtain settlement parameters from the time-settlement curve of the HECC material simulation panel: initial settlement value S0=0, instantaneous settlement S t =2.88mm, HECC material simulation panel length L=800mm, and differential settlement ΔS and settlement ratio δ are calculated using settlement parameters as follows:

[0054] ;

[0055] ;

[0056] The early settlement stability of the simulated HECC material panel was determined by the settlement ratio δ, and the matching slipform lifting speed of the rockfill dam panel was selected for the actual casting of the HECC material rockfill dam panel.

[0057] S7. Stability Analysis: Calculations show that the settlement ratio of the HECC panel is 3.6‰, classifying the panel's settlement stability as Grade B.

[0058] S8. Using a synovial membrane simulation device, the surface of the HECC was observed to be relatively smooth after the synovial membrane construction, with a constant upward speed of 1.7 m / h. Figure 10 As shown.

[0059] Implementation Case 3 provides a method for testing the early settlement stability of HECC material rockfill dam panels. Before the pouring of the HECC material rockfill dam panels, the stability of the HECC material rockfill dam panels to be poured is simulated and tested. The specific steps are as follows:

[0060] S1. First, determine the actual slope of the HECC material rockfill dam panel to be poured as 45°.

[0061] S2. Prepare a metal panel mold 1, which simulates the panel casting groove 4 with a length of 1m, a width of 0.5m, and a depth of 0.1m. Brush a layer of oil inside the simulated panel casting groove 4 to facilitate the later demolding process.

[0062] S3. Prepare HECC material slurry identical to the actual HECC material rockfill dam panel to be poured according to the design requirements, record the slump as 5.5cm, take a sample and put it into the simulated panel pouring groove 4 of panel mold 1, and compact it with a high-frequency vibrator. During vibration, the prepared slurry is poured in layers on the surface by fixing it with movable pressure plate 7, and the surface is smoothed. The top surface of the HECC material simulated panel is a certain distance away from the top surface inside the simulated panel pouring groove for installing movable baffle 2.

[0063] S4. Adjust the panel mold 1 to a tilt angle of 45° using the angle adjustment bracket 3, turn on the laser displacement sensor, record the initial test value S0:0, remove the movable pressure plate 7, and continuously monitor the moving distance of the movable baffle 2 through the laser displacement sensor, i.e. the settlement value of the HECC material simulated panel.

[0064] When the S5 HECC panel reaches final set, save the data, close the testing software, and plot the curve showing the relationship between the HECC material simulation panel test time and the corresponding settlement, as shown below. Figure 5 As shown.

[0065] S6. Obtain settlement parameters from the time-settlement curve of the HECC material simulation panel: initial settlement value S0=0, instantaneous settlement S t =0.87mm, HECC material simulation panel length L=800mm, and differential settlement ΔS and settlement ratio δ are calculated using settlement parameters as follows:

[0066]

[0067]

[0068] The early settlement stability of the simulated HECC material panel was determined by the settlement ratio δ, and the matching slipform lifting speed of the rockfill dam panel was selected for the actual casting of the HECC material rockfill dam panel.

[0069] S7. Stability Analysis: Calculations show that the settlement ratio of the HECC panel is 1.1‰, and the settlement stability of the panel is classified as Grade A.

[0070] S8. Using a synovial membrane simulation device, ascend at a constant speed of 2.5 m / h and observe the smoothness of the HECC surface after synovial membrane construction. Figure 11 .

[0071] Implementation Case 4 provides a method for testing the early settlement stability of HECC material rockfill dam panels. Before the pouring of the HECC material rockfill dam panels, the stability of the HECC material rockfill dam panels to be poured is simulated and tested. The specific steps are as follows:

[0072] S1. First, determine the actual slope of the HECC material rockfill dam panel to be poured as 45°.

[0073] S2. Prepare a metal panel mold 1, which simulates the panel casting groove 4 with a length of 1m, a width of 0.5m, and a depth of 0.1m. Brush a layer of oil inside the simulated panel casting groove 4 to facilitate the later demolding process.

[0074] S3. Prepare HECC material slurry identical to the actual HECC material rockfill dam panel to be poured according to the design requirements, record the slump as 5.5cm, take a sample and put it into the simulated panel pouring groove 4 of panel mold 1, and compact it with a high-frequency vibrator. During vibration, the prepared slurry is poured in layers on the surface by fixing it with movable pressure plate 7, and the surface is smoothed. The top surface of the HECC material simulated panel is a certain distance away from the top surface inside the simulated panel pouring groove for installing movable baffle 2.

[0075] S4. Adjust the panel mold 1 to a tilt angle of 45° using the angle adjustment bracket 3, turn on the laser displacement sensor, record the initial test value S0:0, remove the movable pressure plate 7, and continuously monitor the moving distance of the movable baffle 2 through the laser displacement sensor, i.e. the settlement value of the HECC material simulated panel.

[0076] When the S5 HECC panel reaches final set, save the data, close the testing software, and plot the curve showing the relationship between the HECC material simulation panel test time and the corresponding settlement, as shown below. Figure 6 As shown.

[0077] S6. Obtain settlement parameters from the time-settlement curve of the HECC material simulation panel: initial settlement value S0=0, instantaneous settlement S t =2.2mm, HECC material simulation panel length L=800mm, and differential settlement ΔS and settlement ratio δ were calculated using settlement parameters, as follows:

[0078]

[0079]

[0080] The early settlement stability of the simulated HECC material panel was determined by the settlement ratio δ, and the matching slipform lifting speed of the rockfill dam panel was selected for the actual casting of the HECC material rockfill dam panel.

[0081] S7. Stability Analysis: Calculations show that the settlement ratio of the HECC panel is 2.75‰, classifying the panel's settlement stability as Grade B.

[0082] S8. Using a synovial membrane simulation device, ascend at a constant speed of 1.5 m / h and observe the smoothness of the HECC surface after synovial membrane construction. Figure 12 As shown.

[0083] Implementation Case 5 provides a method for testing the early settlement stability of HECC material rockfill dam panels. Before the pouring of the HECC material rockfill dam panels, the stability of the HECC material rockfill dam panels to be poured is simulated and tested. The specific steps are as follows:

[0084] S1. First, determine the actual slope of the HECC material rockfill dam panel to be poured as 45°.

[0085] S2. Prepare a metal panel mold 1, which simulates the panel casting groove 4 with a length of 1m, a width of 0.5m, and a depth of 0.1m. Brush a layer of oil inside the simulated panel casting groove 4 to facilitate the later demolding process.

[0086] S3. Prepare HECC material slurry identical to the actual HECC material rockfill dam panel to be poured according to the design requirements, record the slump of 10cm, take a sample and put it into the simulated panel pouring groove 4 of the panel mold 1, and use a high-frequency vibrator to compact it. During vibration, the surface is fixed by the movable pressure plate 7 and the prepared slurry is poured in layers. The surface is smoothed, and the top surface of the HECC material simulated panel is a certain distance away from the top surface of the simulated panel pouring groove for installing the movable baffle 2.

[0087] S4. Adjust the panel mold 1 to a tilt angle of 45° using the angle adjustment bracket 3, turn on the laser displacement sensor, record the initial test value S0:0, remove the movable pressure plate 7, and continuously monitor the moving distance of the movable baffle 2 through the laser displacement sensor, i.e. the settlement value of the HECC material simulated panel.

[0088] When the S5 HECC panel reaches final set, save the data, close the testing software, and plot the curve showing the relationship between the HECC material simulation panel test time and the corresponding settlement, as shown below. Figure 7 As shown.

[0089] S6. Obtain settlement parameters from the time-settlement curve of the HECC material simulation panel: initial settlement value S0=0, instantaneous settlement S t =2.52mm, HECC material simulation panel length L=800mm, and differential settlement ΔS and settlement ratio δ were calculated using settlement parameters as follows:

[0090]

[0091]

[0092] The early settlement stability of the simulated HECC material panel was determined by the settlement ratio δ, and the matching slipform lifting speed of the rockfill dam panel was selected for the actual casting of the HECC material rockfill dam panel.

[0093] S7. Stability Analysis: Calculations show that the settlement ratio of the HECC panel is 3.15‰, classifying the panel's settlement stability as Grade B.

[0094] S8. Using a synovial membrane simulation device, the membrane was raised at a constant speed of 2.5 m / h. The HECC settlement after synovial membrane construction was observed; the surface was uneven. Figure 13 .

[0095] Implementation Case 6 provides a method for testing the early settlement stability of HECC material rockfill dam panels. Before the pouring of the HECC material rockfill dam panels, the stability of the HECC material rockfill dam panels to be poured is simulated and tested. The specific steps are as follows:

[0096] S1. First, determine the actual slope of the HECC material rockfill dam panel to be poured as 45°.

[0097] S2. Prepare a metal panel mold 1, which simulates the panel casting groove 4 with a length of 1m, a width of 0.5m, and a depth of 0.1m. Brush a layer of oil inside the simulated panel casting groove 4 to facilitate the later demolding process.

[0098] S3. Prepare HECC material slurry identical to the actual HECC material rockfill dam panel to be poured according to the design requirements, record the slump as 15cm, take a sample and put it into the simulated panel pouring groove 4 of the panel mold 1, and use a high-frequency vibrator to compact it. During vibration, the surface is fixed by the movable pressure plate 7 and the prepared slurry is poured in layers. The surface is smoothed, and the top surface of the HECC material simulated panel is a certain distance away from the top surface inside the simulated panel pouring groove for installing the movable baffle 2.

[0099] S4. Adjust the panel mold 1 to a tilt angle of 45° using the angle adjustment bracket 3, turn on the laser displacement sensor, record the initial test value S0:0, remove the movable pressure plate 7, and continuously monitor the moving distance of the movable baffle 2 through the laser displacement sensor, i.e. the settlement value of the HECC material simulated panel.

[0100] When the S5 HECC panel reaches final set, save the data, close the testing software, and plot the curve showing the relationship between the HECC material simulation panel test time and the corresponding settlement, as shown below. Figure 8 As shown.

[0101] S6. Obtain settlement parameters from the time-settlement curve of the HECC material simulation panel: initial settlement value S0=0, instantaneous settlement S t =2.66mm, HECC material simulation panel length L=800mm, and differential settlement ΔS and settlement ratio δ are calculated using settlement parameters as follows:

[0102]

[0103]

[0104] The early settlement stability of the simulated HECC material panel was determined by the settlement ratio δ, and the matching slipform lifting speed of the rockfill dam panel was selected for the actual casting of the HECC material rockfill dam panel.

[0105] S7. Stability Analysis: Calculation. The settlement ratio of the HECC panel is 3.325‰, and the settlement stability of the panel is determined to be Grade B.

[0106] S8. Using a synovial membrane simulation device, the panel was raised at a constant speed of 2.3 m / h to observe the settlement and surface unevenness of the HECC panel after synovial membrane construction. (See details...) Figure 14 .

[0107] The settlement ratio, stability rating, slipform lifting rate selected during construction, and surface smoothness of the concrete panels obtained from the experiments in Examples 1 to 6 above were statistically analyzed and compiled into a statistical table, as shown in Table 1:

[0108] Table 1. Comparison of test results from Examples 1 to 6

[0109] Example Settlement ratio Stability rating Sliding mode lifting rate Panel surface flatness Example 1 1.55‰ A 2.5 smooth Example 2 3.6‰ B 1.7 smooth Example 3 1.1‰ A 2.5 smooth Example 4 2.75‰ B 1.5 smooth Example 5 3.15‰ B 2.5 Uneven Example 6 3.325‰ B 2.3 Uneven

[0110] The statistical results in the table above show that the slipform lift rate selected in Examples 1 to 4 was based on stability rating requirements, resulting in a high degree of surface smoothness in the constructed concrete panels. However, in Examples 5 and 6, the slipform lift rate was not selected according to stability rating requirements, leading to uneven concrete surfaces. Therefore, it can be seen that the stability test results and the subsequent selection of the slipform lift rate in this application have a direct impact on the slab construction effect. Thus, this invention can provide theoretical guidance for the application of HECC materials in slab concrete engineering, ensuring construction quality.

[0111] The above description is merely one embodiment of the present invention, and while it is detailed and specific, it should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A testing device for early settlement stability of HECC material rockfill dam panels, characterized in that: The testing device includes an angle adjustment bracket (3), a panel mold (1), a movable baffle (2), a movable steel mesh (6), a movable pressure plate (7), and a settlement monitoring device (5). The panel mold (1) is located on the angle adjustment bracket (3), and its tilt angle is adjusted by the angle adjustment bracket (3). The adjustment range is controlled between 20° and 75°. A simulated panel casting groove (4) is provided on the panel of the panel mold (1). The settlement monitoring device (5) includes a control device and a displacement sensor fixedly installed on the top surface of the simulated panel casting groove (4). The device is used to monitor the early settlement stability of HECC material rockfill dam panels. During the test, the movable steel mesh (6) is placed in the simulated panel casting groove (4), and HECC material is poured into the simulated panel casting groove (4). After the groove opening is smoothed by the movable pressure plate (7), a simulated HECC material panel (8) is formed in the simulated panel casting groove (4). The distance between the top surface of the simulated HECC material panel (8) and the top surface of the simulated panel casting groove (4) is greater than the thickness of the movable baffle (2). The movable baffle (2) is placed on the top surface of the simulated HECC material panel (8), and the early settlement of the simulated HECC material panel (8) is monitored by the settlement monitoring device (5).

2. The testing device for early settlement stability of HECC material rockfill dam panels according to claim 1, characterized in that: The settlement monitoring device (5) includes two continuously readable laser displacement sensors fixed at the top of the simulation panel casting tank (4). The signal output end of the laser displacement sensor is connected to the signal input end of the control device. The displacement data of the movable pressure plate (7), i.e. the settlement data of the HECC material simulation panel (8), is continuously collected by the two laser displacement sensors. The collected displacement data is transmitted to the control device. The control device sets the time to generate the HECC material simulation panel time-settlement curve. The settlement parameters are obtained from the HECC material simulation panel time-settlement curve. The differential settlement amount ΔS and the settlement ratio δ are calculated.

3. A testing device for early settlement stability of HECC material rockfill dam panels according to claim 1 or 2, characterized in that: The angle adjustment bracket (3) includes a support base plate and an adjustment frame. The panel mold (1) is rotatably connected to the support base plate and is supported and its angle is adjusted by the adjustment frame to change the angle of the simulated slope.

4. A testing device for early settlement stability of HECC material rockfill dam panels according to claim 1 or 2, characterized in that: The length of the movable steel mesh (6) is less than the length of the simulated panel pouring groove (4), and when the HECC material is poured to form the HECC material simulated panel (8), the HECC material completely wraps the movable steel mesh (6).

5. A testing device for early settlement stability of HECC material rockfill dam panels according to claim 1 or 2, characterized in that: The width and length of the movable baffle (2) are matched with the depth and width of the simulated panel casting groove (4), respectively. The width of the movable pressure plate (7) is matched with the width of the simulated panel casting groove (4), and its length is less than the length of the simulated panel casting groove (4). Handles (8) are provided on the movable baffle (2) and the movable pressure plate (7).

6. A method for testing the early settlement stability of HECC material rockfill dam panels, characterized in that, The test method uses the early settlement stability test device for HECC material rockfill dam panels as described in any one of claims 1 to 5 to simulate and test the stability of the HECC material rockfill dam panels to be poured before the casting of the HECC material rockfill dam panels. The specific steps are as follows: S1. First, determine the actual slope of the HECC material rockfill dam panel to be poured, and prepare the same HECC material slurry as the actual HECC material rockfill dam panel to be poured according to the design requirements. S2. Adjust the panel mold to the actual slope of the rockfill dam panel to be poured using the angle adjustment bracket. Then pour the HECC material slurry mixed in step S1 into the simulated panel pouring groove of the panel mold. During the pouring process, the surface is fixed by the movable pressure plate and the HECC material simulated panel is formed by layered pouring. The top surface of the HECC material simulated panel is a certain distance away from the top surface of the simulated panel pouring groove for installing the movable baffle. S3. Insert the movable baffle into the casting groove of the simulation panel and make it fit tightly against the top surface of the newly cast HECC material simulation panel; S4. Open the monitoring device, remove the movable pressure plate, continuously monitor the displacement data of the movable baffle through the displacement sensor, and set a fixed time to continuously record the displacement data of the movable baffle, thereby obtaining the time-settlement relationship curve of the HECC material simulation panel. S4. Obtain settlement parameters from the HECC material simulation panel: initial settlement value S0, instantaneous settlement S t The length L of the simulated HECC material panel is determined, and the differential settlement ΔS and settlement ratio δ are calculated through settlement parameters. The early settlement stability of the simulated HECC material panel is judged by the settlement ratio δ, so as to select the matching slipform lifting speed of the rockfill dam panel for the actual HECC material rockfill dam panel pouring.

7. The method for testing the early settlement stability of HECC material rockfill dam panels according to claim 6, characterized in that: In step S4, the specific formulas for calculating the differential settlement ΔS and settlement ratio δ using settlement parameters are as follows: ； 。 8. A method for testing the early settlement stability of HECC material rockfill dam panels according to claim 6 or 7, characterized in that, The specific criteria for determining the early settlement stability of HECC material rockfill dams in step S4, based on the settlement ratio δ, are as follows: The stability of the HECC material simulation panel is judged to be Grade A, and the sliding form lifting speed of the rockfill dam panel is no more than 3m / h. 4‰, the stability of the HECC material simulation panel is judged to be grade B, and the sliding form lifting speed of the rockfill dam panel is not greater than 2m / h; The stability of the HECC material simulation panel is judged to be grade C, and the sliding form lifting speed of the rockfill dam panel is no more than 1.2 m / h.

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