Sand box supporting structure calibration equipment and method

Abstract

The sand box supporting structure calibration method at least comprises the following steps that S1, sample sand of a sand box supporting structure needing to be calibrated is selected, the loose accumulation state of the sample sand or the compaction degree Y1 of the sample sand in the certain compaction degree state is measured, and the height H1 of the sample sand in a sand box model in the loose accumulation state or the certain compaction degree state is measured; s2, reducing the void ratio of the sample sand and increasing the compaction degree of the sample sand in a pressurizing manner; s3, maintaining the pressure in the step S2 for a certain time, and recording the height H2 of the sample sand when the height difference at a certain time interval is smaller than a certain range; and S4, calibrating the sand box supporting structure. According to the calibration equipment for the sand box supporting structure, in order to measure the relative relation between the sand body bearing capacity and the sand body bearing capacity under different conditions and different sand physical properties, the supporting strength of the actually-used sand box supporting structure is predicted through a sand box model, and the supporting strength of the actually-used sand box supporting structure can be calibrated according to the height change.

Description

Technical Field

[0001] The invention belongs to the field of building construction auxiliary equipment, and in particular relates to sand box support structure calibration equipment and method. Background Art

[0002] The existing beam dropping equipment mainly includes sand box support system, unloading blocks and hydraulic jacks, but in terms of safety factor, the sand box support system is the safest. The sand box support system includes round sand cylinders and square sand beams. Sand cylinders are generally used on bridges, and sand beams are generally used on beams with lower intervals, such as basement construction. The domestic patent announcement number "CN113482043B" and the patent name "A prefabricated splicing frame of a basement roof steel truss and its installation method" use this sand beam structure. Transition floors where the floor structure changes also need to use a sand beam structure. These sand box support systems all have a problem. During construction, the sand box support system may settle, but there is currently no relatively complete method to detect or predict the settlement of the relevant sand box support system and the bearing capacity of the sand box support system. Chinese Patent Publication No. "CN101775783B" and the patent name "A construction method using a sand box as a temporary support for a continuous beam" provide a construction method for a sand box support system, but it directly uses a heavy object that can generate a certain pressure to pre-press the sand box. However, when the pressure exceeds the pre-pressing pressure, or when the moisture content of the sand box changes, it is impossible to confirm whether the sand box will settle and how much settlement will occur. Summary of the invention

[0003] In view of the above-mentioned prior art, the purpose of the present invention is to provide a sand box support structure calibration device and method to predict the maximum bearing capacity of the sand box support structure and the range of settlement of the sand box support structure after exceeding the bearing capacity, so as to determine whether there are safety hazards during and after the construction process.

[0004] The technical solution of the present invention is implemented as follows: a sand box support structure calibration method includes at least the following steps: S1 selecting sample sand of the sand box support structure to be calibrated, placing the sample sand in a sand box model similar to or the same as the sand box support structure, scraping the top and measuring the height H1 of the sample sand in the sand box model in a loose stacking state or a state with a certain degree of compaction, and measuring the compaction Y1 of the sample sand in a loose stacking state or a state with a certain degree of compaction; S2 reducing the porosity of the sample sand and increasing the compaction of the sample sand by pressurizing; S 3. Maintain the pressure of step S2 for a certain time, and measure the height of the sample sand at a certain interval. When the height difference at a certain interval is less than a certain range, record the height H2 of the sample sand. S4. Calibrate the sand box support structure. After the height of the sample sand drops from H1 to H2, the compaction degree Y2=Y1×H1÷H2, and the corresponding bearing load is F2, or the ring knife mass Z2=Z1×H1÷H2, and the corresponding bearing load is F2, that is, when the compaction degree of the sand box support structure is Y2 or the ring knife mass is Z2, the corresponding bearing load is F2.

[0005] Further, repeat steps S2 and S3 to record multiple sets of heights and corresponding bearing load data; repeat step S4 to calibrate the sand box support structure, calculate the corresponding compaction degree or ring knife mass from the height change, calibrate the corresponding relationship between the compaction degree or ring knife mass and the bearing load, or use data to fit a simulation function to predict the relationship between height change and bearing load, including the height and bearing load data of sample sand at different humidity and temperature, and obtain the height range and bearing load range.

[0006] Furthermore, the sand box model and the sand box support structure are placed in the same environment to ensure that the humidity, temperature, air flow and time factors of the sand box model and the sand box support structure environment are basically the same or identical. The bearing capacity of the sand box model is retested before construction, the bearing load is increased by a certain value and the height value of the sample sand is measured.

[0007] Furthermore, the sample sand is a simulated sample having the same or similar fineness modulus, the same or similar humidity and the same or similar origin as the engineering sand used in the sand box support structure.

[0008] Furthermore, the sand box model maintains a certain load for 6 hours to obtain the height change. When the height change ΔH is less than 0.5 mm, the height H6 of the sand box model and the corresponding load F6 are recorded. The corresponding compaction degree Y6 is calculated by the height H6, that is, when the compaction degree of the sand box support structure is Y6, the corresponding bearing load is F6.

[0009] The sand box support structure calibration equipment includes a sand box model, a frame, a pressure head, a driving structure and a sand box seat. The sand box model is made into a cylindrical or cubic sand box with the sand box support structure to be calibrated as the original model. The frame is provided with a driving structure that can provide a certain pressure to the pressure head. A sand box seat is provided under the frame to place or fix the sand box model.

[0010] Furthermore, the sand box model includes a barrel, a bottom plate and a limiting hook, the barrel has an upper opening and a lower opening, the bottom plate matches the lower opening, the limiting hook is hinged to the side wall of the barrel, and the hook portion of the limiting hook limits the bottom plate.

[0011] Furthermore, the upper opening of the sand box model is provided with a pier cover, and at least a part of the pier cover can enter the sand box model. The side wall of the pier cover is provided with a scale to display the depth of the pier cover entering the sand box model.

[0012] Furthermore, the frame is provided with a first vibration module and a second vibration module, the first vibration module is located at the pressure head, the second vibration module is located at the sand box seat, the pier cover includes a cylinder and a cylinder cover, and sand or soil with a certain degree of compaction is placed in the cylinder.

[0013] Furthermore, the equipment also includes a temperature and humidity monitoring structure, the sand box seat is provided with a heating device capable of heating the sand box model, the frame is provided with a water adding device capable of adding water to the sand box model, and the equipment also includes a timing structure capable of ensuring that the equipment maintains a certain pressure for a certain period of time.

[0014] The beneficial effect of such a design is: the support strength of the actual sand box support structure can be predicted by using the sand box model, and the support strength of the actual sand box support structure can be calibrated according to the change in height. As long as the actual construction strength does not exceed this strength, settlement will generally not occur, which can provide guidance for construction. Ordinary method calibration requires multiple compaction tests or ring knife tests, which is very labor-intensive. This application obtains the ring knife mass or compaction degree under the corresponding load by calculating the height change, and the calibration speed is greatly improved. Even continuous numerical calibration can be performed using mathematical models, which greatly reduces the workload of calibration. For some load-bearing parts that are large or the load-bearing parts change within a certain range, the sand box model data can be used to predict the range of settlement before or during construction to determine whether the construction is safe, and construction risks can be avoided or predicted. In addition, the sand box model data can be used to determine whether the settlement of the sand box support structure is within the normal range. If it is within the abnormal range, it may be that there are foreign objects or other abnormal conditions in the sand box, which can be discovered and avoided early to improve the safety of construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a three-dimensional schematic diagram of a sand box support structure calibration device in Example 1; Figure 2This is a schematic diagram of the sand box support structure calibration device in Example 1 without the sand box model placed therein; Figure 3 This is a schematic diagram of a sand box model of a sand box support structure calibration device in Example 1; Figure 4 It is a schematic diagram of an explosion of a sand box model of a sand box support structure calibration device in Example 1; Figure 5 This is a schematic diagram of the sand box support structure calibration device in Example 2 without the sand box model placed therein; Figure 6 A schematic diagram of a sand box model of a sand box support structure calibration device according to Example 2; Figure 7 This is a schematic diagram of the cylinder and cylinder cover of the sand box support structure calibration device in Example 3; Figure 8 This is a three-dimensional schematic diagram of the sand box support structure calibration equipment in Example 3. DETAILED DESCRIPTION

[0016] As required, detailed embodiments of the present invention are disclosed herein, but it should be understood that the disclosed embodiments are merely exemplary of the present invention, and the present invention may be implemented in different and alternative forms. The accompanying drawings may not be drawn to scale, and certain features may be exaggerated or reduced to show the details of specific components. Therefore, the specific structural and functional details disclosed herein should not be understood as having a limiting meaning, but only as a representative basis to teach those skilled in the art to adopt the present invention differently. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention.

[0017] The sand box support structure calibration method includes at least the following steps: S1 selects sample sand of the sand box support structure to be calibrated, places the sample sand in a sand box model 1 that is similar to or the same as the sand box support structure, scrapes the top and measures the height H1 of the sample sand in the sand box model 1 in a loose stacking state or a state with a certain degree of compaction. In this embodiment, the height is the height of the loose stacking state. For the convenience of comparison, H1=150mm is taken for measurement, and the compaction Y1 of the sample sand in the loose stacking state or the state with a certain degree of compaction is measured. For the convenience of comparison, it can be directly scraped with the sand box model 1; S2 uses a pressurized method to The formula reduces the porosity of the sample sand and increases the compaction of the sample sand; S3 maintains the pressure of step S2 for a certain time, and measures the height of the sample sand at a certain interval, and records the height H2 of the sample sand when the height difference at a certain interval is less than a certain range; S4 calibrates the sand box support structure, and after the sample sand height drops from H1 to H2, the compaction degree Y2=Y1×H1÷H2, and the corresponding bearing load is F2, or the ring knife mass Z2=Z1×H1÷H2, and the corresponding bearing load is F2, that is, when the compaction degree of the sand box support structure is Y2 or the ring knife mass is Z2, the corresponding bearing load is F2.

[0018] Repeat steps S2 and S3, record multiple sets of heights and corresponding load data; repeat step S4 to calibrate the sand box support structure, for example, the load is F3 after the height drops from H1 to H3, calculate the corresponding compaction degree or ring knife mass from the height change, calibrate the corresponding relationship between the compaction degree or ring knife mass and the load, or use data to fit a simulation function to predict the relationship between height change and load, including the height and load data of sample sand at different humidity and temperature, and obtain the height range and load range. These calibrations all require recording the corresponding environmental parameters. Changes in multiple parameters will make the relationship complicated. For example, temperature has little effect on pressure, so you can choose a more extreme temperature to measure, that is, the changes in pressure and height at the highest temperature, lowest temperature and average temperature of the place. The function of one variable is also easier to fit using software.

[0019] Place the sand box model 1 and the sand box support structure in the same environment, ensure that the humidity, temperature, air flow and time factors of the sand box model 1 and the sand box support structure environment are basically the same or identical, and re-test the bearing capacity of the sand box model 1 before construction.

[0020] The sample sand is a simulated sample with the same or similar fineness modulus, humidity and origin as the engineering sand used in the sand box support structure. The most ideal sample sand should be directly extracted from the sand box support structure production site. If the data of the sand box model 1 needs to be tracked and monitored later, the storage adjustment of the sand box model 1 should be the same or similar to the storage conditions after the sand box support structure is produced, such as ambient temperature, humidity and air flow. If the detection site is far away from the construction site, it is difficult to ensure the synchronization of various environmental factors. In this case, extreme data can be tested to obtain extreme ranges, such as data of sample sand with zero or near zero humidity, data of sample sand with the lowest density. Generally, the density of sand is the lowest when the humidity is 3%-7%, and the density of raw sand is the lowest when the humidity is 7%. The data with the highest humidity has no actual reference value. Of course, if the construction is outdoors and it happens to be rainy, the data of the maximum humidity is also of reference value. Generally, the maximum humidity of raw sand is about 20%.

[0021] The sand box model 1 and the sand box support structure can adopt the same structure, but some cubic sand box support structures are larger. Therefore, in order to facilitate testing, a smaller sand box model 1 is made to calibrate the sand box support structure. For structures with the same cross-sectional area, the volume change ratio is the same as the height change ratio. Therefore, the height change and bearing capacity data can be directly measured, that is, a sand box model 1 is taken, and sample sand with a loose stacking height H1=150mm is piled up in the sand box model 1. The loose stacking is to slowly pour the sample sand into the sand box model 1 and scrape the excess sand flat. Then, pressurize it on the designated equipment, select a sand box model with a diameter of 150mm, and calibrate five groups of sea fine sand, sea sand, river fine sand, river sand and machine-made medium sand respectively. Maintain a certain load on the sand box model 1 for 6 hours to obtain the height change. When the height change ΔH is less than 0.5mm, record the height H6 and the corresponding load F6 of the sand box model 1, and calculate the corresponding compaction degree Y6 or ring knife mass Z6 through the height H6, that is, when the compaction degree of the sand box support structure is Y6 or the ring knife mass is Z6, the corresponding bearing load is F6. The compaction degree or the mass of the ring cutter does not necessarily have to take the value at the height of H1. A set of values ​​can be obtained at any other height to calculate other values, which are all proportional to the height change. Due to the large height change in the early stage of loose accumulation and the small load, there is no practical use value. Therefore, the load is counted from 20KN and above, and finally the following calibration data are obtained, as shown in Table 1 below. Some measuring devices are convenient for recording height differences, and some measuring devices can directly obtain the height of the sand box model 1, which does not affect the test results. The volume of the ring cutter sampling is 200 cubic centimeters, and the mass of the ring cutter is the mass of the sample, excluding the mass of the measured ring cutter itself. The maximum dry density of sea fine sand is 2.012 grams per cubic centimeter, the maximum dry density of sea sand is 2.150 grams per cubic centimeter, the maximum dry density of river fine sand is 2.031 grams per cubic centimeter, the maximum dry density of river sand is 2.188 grams per cubic centimeter, and the maximum dry density of machine-made medium sand is 2.121 grams per cubic centimeter.

[0022] #imgpt1#

[0023] In this way, during the actual use of the sand box, the load capacity of the sand box can be determined according to the change in volume or height based on the calibrated value. Knowing the load of the sand box can estimate the change in volume or height of the sand box. For example, when the volume or height of the sand box using the same batch of sea sand is reduced by 16.14% from 126.16mm, that is, when the compaction degree or ring knife density increases by 19.24% accordingly, the load of the sea sand increases from 21.1KN to about 198.9KN. Conversely, if it is known that the sand box of the sea sand bears a load of about 198.9KN, it can be inferred that the compaction degree of the sea sand at this time refers to the dry density of the sea sand, which is 2.150 Grams per cubic centimeter is 1.169234705. If the mass of the ring knife of a sand box model 1 of this batch of sea sand is 502.77 grams, then the bearing capacity of the sand box model is also 198.9KN. If the compaction degree of a sand box model 1 of this batch of sea sand is 1.169234705, then the bearing capacity of the sand box model is also 198.9KN. During the calibration process, the loads need to be measured one by one. A set of data such as height, height difference, volume, compaction degree, and ring knife mass corresponding to the load can be measured. The other data are in a certain proportional relationship and can be directly calculated. The height and height difference are easier to obtain than other data. Therefore, the height or height difference of the sand box model 1 under each test constant pressure is detected during calibration.

[0024] The sand box can also be calibrated using the height difference, that is, the bearing load corresponding to different height differences can be calibrated, which is convenient for determining the load capacity according to the height difference during construction or estimating the height difference according to the load. Of course, for the sand box support structure, the height difference needs to be calculated at a certain ratio to obtain the value of the compaction degree or the ring knife density change. Sand boxes made by different processes may not be convenient to measure the change in height or volume. The theoretical load capacity of the sand box support structure can also be estimated by measuring the actual compaction degree or ring knife density.

[0025] During the actual construction of the same batch of sand box support structures, it is necessary to predict the load size of the sand box support structures. The compaction degree or ring cutter quality of the same batch of sand box support structures can be tested. After obtaining relevant data, the approximate load can be estimated by querying the above table. Of course, if the change in volume or height is known, the above table can also be queried, but it is difficult to obtain height change data during actual construction. The height data is only easy to obtain in the calibration stage, but the compaction degree or ring cutter quality can be obtained in the construction stage.

[0026] Embodiment 1: like Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, the sand box support structure calibration equipment includes a sand box model 1, a frame 2, a pressure head 3, a driving structure 4 and a sand box seat 5. The sand box model 1 is made into a cylindrical or cubic sand box with the sand box support structure to be calibrated as the original model. The frame 2 is provided with a driving structure 4 that can provide a certain pressure to the pressure head 3. A sand box seat 5 is provided under the frame 2 to place or fix the sand box model 1. The frame 2 or the pressure head 3 is provided with a sliding ruler 6 to obtain the moving distance of the pressure head 3. The sliding ruler 6 can be a purely mechanical ruler or an electronic displacement measuring device, such as a grating ruler.

[0027] The sand box support structure calibration equipment can be directly improved on the basis of the hydraulic press, which makes manufacturing more convenient. That is, the same function can be achieved by setting a sand box seat 5 on the hydraulic press. The hydraulic press is also equipped with pressure monitoring elements, height change monitoring, etc., which can directly obtain pressure and height data. The customized sand box support structure calibration equipment can achieve more functions and can of course be customized as needed, so that the structure is more reasonable.

[0028] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the sand box model 1 is cylindrical and includes a barrel 11, a bottom plate 12 and a limit hook 13. The barrel 11 has an upper opening 14 and a lower opening 15. The bottom plate 12 matches the lower opening 15. The limit hook 13 is hinged to the side wall of the barrel 11, and the hook portion of the limit hook 13 limits the bottom plate 12. The bottom plate 12 can be set to a stepped structure so that at least part of the position can be inserted into the lower opening 15, and the size of the bottom plate 12 and the lower opening 15 must match.

[0029] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, a relatively protruding hook portion 16 is provided at the lower end of the limit hook 13, and the middle position of the limit hook 13 is hinged to the barrel portion 11. A threaded hole 17 is provided at the upper end of the limit hook 13, and a locking screw 18 is provided in the threaded hole 17. In the locked state, the head of the locking screw 18 abuts against the barrel portion 11 to ensure that the limit hook 13 does not rotate.

[0030] like Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, the frame 2 is in an arched U-shaped structure, and it can also be in a C-shaped structure. However, the C-shaped structure has higher requirements for the strength of the frame 2. The arched U-shaped structure includes a left column 21, a right column 22, and a cross beam 23. A hydraulic cylinder 24 is arranged on the cross beam 23, and the hydraulic cylinder 24 pushes the pressure head 3 to move. A sliding seat 25 is arranged on the pressure head 3. A sliding scale 6 is arranged inside the sliding seat 25. The sliding scale 6 can slide relative to the sliding seat 25. The upper end of the sliding scale 6 can be fixed on the frame 2. The sliding scale is provided with scales. According to the change of the sliding scale at the same position of the sliding seat 25, the dimension difference can be obtained. In this way, when the sliding seat 25 moves, the moving distance can be displayed on the sliding scale 6. A separate observation hole 30 can also be arranged on the sliding seat to observe the change of the sliding scale.

[0031] As Figure 1 , Figure 2 , Figure 3 and Figure 4 shown, a plurality of limiting hooks 13 are circumferentially arranged outside the cylinder part 11, generally at least three are provided. If there are too many, it will be more troublesome to disassemble.

[0032] As Figure 1 , Figure 2 , Figure 3 and Figure 4 shown, the sand box seat 5 is provided with a plurality of limiting holes 7 that match the limiting hooks 13 for installing the sand box model 1. The limiting holes also have the function of significantly positioning the sand box model 1.

[0033] As Figure 1 , Figure 2 , Figure 3 and Figure 4 shown, the sand box model 1 is provided with a pier cover 19. At least part of the pier cover 19 can enter the sand box model 1. The side wall of the pier cover 19 is provided with scales to display the depth of the pier cover 19 entering the sand box model 1. The pressure head 3 can directly act on the pier cover 19. The pier cover 19 is made of a relatively thick metal plate or solid steel structure.

[0034] As Figure 1 , Figure 2 , Figure 3 and Figure 4 shown, the frame 2 is provided with a sand box limiting plate 26 that can limit the position of the sand box model 1. A left air cylinder 27 and a right air cylinder 28 can be arranged on the cross beam 23 of the frame 2. A left limiting plate 29 and a right limiting plate 20 are respectively arranged at the lower ends of the left air cylinder 27 and the right air cylinder 28. In this way, an auxiliary positioning function can be achieved.

[0035] As a further optimized structure, the equipment also includes a temperature and humidity monitoring structure. Generally speaking, the ambient temperature is the same as the temperature of the sandbox model 1, so it is sufficient to detect one temperature. The humidity mainly monitors the ambient humidity, and the moisture content of the sample sand should also be monitored, but it can be directly monitored using special equipment and methods. The sandbox seat 5 is provided with a heating device to heat the sandbox model 1, and the frame 2 is provided with a water adding device to add water to the sandbox model 1. The equipment also includes a timing structure to ensure that the equipment maintains a certain pressure for a certain period of time. Temperature monitoring and humidity monitoring can obtain more specific environmental information. The density of sand will change under different temperatures and humidities, and the bearing capacity will also be different. The heating device can heat the sandbox model 1 to reduce the humidity of the sand, which is convenient for measuring the load change of the sandbox model 1 under extreme conditions. The other limit is the pressure change of the sandbox model 1 when the humidity is the highest. In this way, a range of changes in the bearing strength of the sandbox model 1 can be obtained, and the changes in the height of the sandbox model 1 under these extreme conditions can be recorded.

[0036] Embodiment 2: like Figure 5 and Figure 6 As shown, the sand box support structure calibration equipment includes a sand box model 1, a frame 2, a pressure head 3, a driving structure 4 and a sand box seat 5. The sand box model 1 is made into a cylindrical or cubic sand box with the sand box support structure to be calibrated as the original model. The frame 2 is provided with a driving structure 4 that can provide a certain pressure to the pressure head 3. A sand box seat 5 is provided below the frame 2 to place or fix the sand box model 1. The sand box model 1 is a cubic structure, and the pressure head 3 is also a square structure. The sand box model 1 includes a barrel 11, a bottom plate 12 and a limit hook 13. The barrel 11 has an upper opening 14 and a lower opening 15. The bottom plate 12 matches the lower opening 15. The limit hook 13 is hinged to the side wall of the barrel 11, and the hook 16 of the limit hook 13 limits the bottom plate 12. The frame 2 is provided with a displacement sensor and a pressure sensor to obtain the displacement and load of the pressure head, so that it is more convenient to obtain pressure data and displacement data.

[0037] Embodiment 3: like Figure 7 and Figure 8As shown, the frame 2 is provided with a first vibration module 8 and a second vibration module 9. The first vibration module 8 is located at the pressure head 3, and the second vibration module is located at the sand box seat 5. The pier cover 19 includes a cylinder 38 and a cylinder cover 39. Sand or soil with a certain degree of compaction is placed in the cylinder 38. The first vibration module 8 is mainly used to simulate the vibration during the construction process. During the pouring process of concrete, a vibrator is required to increase the compaction of concrete. Therefore, the sand box support structure is equivalent to being under the action of a dynamic load. Therefore, when calibrating the sand box support structure, it is also carried out in a vibration environment. The power of the vibration can be selected according to the actual construction situation. The compaction of the sand or soil placed in the cylinder 38 should be close to the compaction of the concrete. Such data is closer to the real data, and the calibrated data is also more accurate. A second vibration module 9 is provided at the bottom of the sand box seat 5, which can drive the sand box model 1 on the sand box seat 5 to vibrate. The vibration structure can be an eccentric structure that rotates at high speed. The rotation speed can be changed, that is, it rotates at different frequencies. Multiple vibration structures in multiple directions can be set, such as up and down vibration, left and right vibration, front and back vibration and other directions. It can vibrate in multiple directions at the same time, or it can vibrate in one direction alone. The vibration frequency is between 50HZ-100HZ, and the acceleration is between 5g-25g. Of course, in order to improve efficiency, a larger acceleration can be selected.

Claims

1. The sand box support structure calibration method is characterized by: At least the following steps are included: S1 selects the sample sand of the sand box support structure to be calibrated, places the sample sand in a sand box model (1) that is similar to or the same as the sand box support structure, scrapes the top and measures the height H1 of the sample sand in the sand box model (1) in a loose stacking state or in a state with a certain degree of compaction, measures the compaction Y1 of the sample sand in a loose stacking state or in a state with a certain degree of compaction, or selects a standard ring knife and uses the standard ring knife to take samples in the sand box model (1) and obtains the ring knife mass of the sample sand of the standard ring knife volume as Z1; S2 uses a pressurized method to reduce the porosity of the sample sand and increase the compaction of the sample sand, and measures the height H2 of the sample sand; S3 maintains the pressure of step S2 for a certain time, and measures the height H2 of the sample sand at a certain interval, and records the height H2 of the sample sand when the height difference ΔH at a certain interval is less than a certain range; S4 calibrates the sand box support structure. After the sample sand height drops from H1 to H2, the compaction degree is Y2=Y1×H1÷H2, and the corresponding bearing load is F2, or the ring knife mass is Z2=Z1×H1÷H2, and the corresponding bearing load is F2, that is, when the compaction degree of the sand box support structure is Y2 or the ring knife mass is Z2, the corresponding bearing load is F2.

2. The method for calibrating a flask support structure according to claim 1, characterized in that: Repeat steps S2 and S3 to record multiple sets of heights and corresponding bearing load data; repeat step S4 to calibrate the sand box support structure, calculate the corresponding compaction degree or ring knife mass from the height change, calibrate the corresponding relationship between the compaction degree or ring knife mass and the bearing load, or use data to fit a simulation function to predict the relationship between the height change and the bearing load, including the height and bearing load data of sample sand at different humidity and temperature, and obtain the height range and bearing load range.

3. The method for calibrating a flask support structure according to claim 2, characterized in that: The sand box model (1) and the sand box support structure are placed in the same environment to ensure that the humidity, temperature, air flow and time factors of the sand box model (1) and the sand box support structure are substantially the same or identical. Before construction, the bearing capacity of the sand box model (1) is retested by increasing the bearing load by a certain value and measuring the height value of the sample sand.

4. The method for calibrating a flask support structure according to claim 3, characterized in that: The sample sand is a simulated sample having the same or similar fineness modulus, the same or similar humidity and the same or similar origin as the engineering sand used in the sand box support structure.

5. The method for calibrating a flask support structure according to claim 4, characterized in that: The sand box model (1) is maintained at a certain load for 6 hours to obtain a height change. When the height change ΔH is less than 0.5 mm, the height H6 of the sand box model (1) and the corresponding load F6 are recorded. The corresponding ring knife mass Z6 or compaction degree Y6 is calculated by the height H6, that is, when the ring knife mass of the sand box support structure is Z6 or the compaction degree is Y6, the corresponding bearing load is F6.

6. A sand box support structure calibration device, using the sand box support structure calibration method according to any one of claims 1 to 5, characterized in that: The invention comprises a sand box model (1), a frame (2), a pressure head (3), a driving structure (4) and a sand box seat (5); the sand box model (1) is made into a cylindrical or cubic sand box with a sand box support structure to be calibrated as the original model; the frame (2) is provided with the driving structure (4) capable of providing a certain pressure to the pressure head (3); and the sand box seat (5) is provided below the frame (2) capable of placing or fixing the sand box model (1).

7. The sand box support structure calibration device according to claim 5, characterized in that: The sand box model (1) comprises a barrel (11), a bottom plate (12) and a limiting hook (13); the barrel (11) has an upper opening (14) and a lower opening (15); the bottom plate (12) matches the lower opening (15); the limiting hook (13) is hinged to the side wall of the barrel (11); and a hook portion (16) of the limiting hook (13) limits the bottom plate (12).

8. The sand box support structure calibration device according to claim 5, characterized in that: The sand box model (1) is provided with a pier cover (19), and at least a portion of the pier cover (19) is able to enter the sand box model (1), and a scale is provided on the side wall of the pier cover (19) to display the depth of the pier cover (19) entering the sand box model (1).

9. The sand box support structure calibration device according to claim 5, characterized in that: The frame (2) is provided with a first vibration module (8) and a second vibration module (9), the first vibration module (8) is located on the pressure head (3), the second vibration module (9) is located on the sand box seat (5), the pier cover (19) comprises a cylinder (38) and a cylinder cover (39), and sand or soil with a certain degree of compaction is placed in the cylinder (38).

10. The sand box support structure calibration device according to any one of claims 5 to 9, characterized in that: The device also includes a temperature and humidity monitoring structure. The sand box seat (5) is provided with a heating device capable of heating the sand box model (1). The frame (2) is provided with a water adding device capable of adding water to the sand box model (1). The device also includes a timing structure capable of ensuring that the device maintains a certain pressure for a certain period of time.

Images