A test device for simulating submerged evaporation

Abstract

The invention discloses a test device for simulating submerged evaporation, which overcomes the problems of being unable to simulate submerged evaporation and cumbersome evaporation measurement. The test device comprises a light-proof box, a test cylinder, an evaporation temperature exhaust control system, a submerged evaporation monitoring system, a soil moisture and salt temperature monitoring system, a water level dynamic control system, an image acquisition system, a data acquisition system and a computer; the test cylinder is installed in the light-proof box, and the evaporation temperature exhaust control system is installed on the light-proof box; the submerged evaporation monitoring system is installed on the light-proof box and the test cylinder; the soil moisture and salt temperature monitoring system is inserted into the soil sample; the water level dynamic control system is installed directly below the test cylinder; the image acquisition system is installed on the right side of the light-proof box; the data acquisition system and the computer are located on the right side of the light-proof box, the data acquisition system is connected to the soil moisture and salt temperature monitoring system line, and the computer and the data acquisition system, the image acquisition system and the water level dynamic control system are connected.

Description

Technical Field

[0001] The invention relates to a test device in the field of geotechnical engineering geotechnical test technology, environmental science and engineering, and in particular to a test device for simulating the dynamic change of groundwater level and evaporation of water. Background Art

[0002] Phreatic evaporation refers to the phenomenon that shallow groundwater is transported and moved to the surface through the soil and then vaporized and lost. Phreatic evaporation is related to the retention and loss of water in the soil and land salinization, and has an adverse effect on the growth of vegetation and crops in the agricultural field. In the field of geotechnical engineering, phreatic evaporation is the direct cause of many engineering problems, which can easily cause problems such as roadbed slurrying and slope instability. Therefore, the study of phreatic evaporation is of great significance for the prevention and control of land salinization, the stability research of geotechnical engineering, the formulation of irrigation systems, vegetation restoration and ecological restoration.

[0003] The existing domestic phreatic evaporation indoor test equipment generally sets a water supply cylinder outside the soil sample, manually controls the water level in the water supply cylinder, and supplies water to the soil sample at a constant pressure through the water supply cylinder to simulate phreatic evaporation under a constant groundwater level. However, the existing equipment cannot simulate phreatic evaporation under dynamic changes in groundwater level, which is very different from the actual field.

[0004] In the process of submerged evaporation, the measurement of evaporation is of great significance. Currently, many submerged evaporation indoor test devices can only measure evaporation at various time points in the evaporation process by weighing or drying methods. However, the weighing method requires manual reading of data, which is cumbersome. The drying method damages the soil when collecting soil samples, affecting the accuracy of the test results. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the problems in the prior art that field phreatic evaporation cannot be fully simulated and the evaporation measurement is cumbersome, and to provide a phreatic evaporation test device that simulates the dynamic change of groundwater level.

[0006] In order to solve the above technical problems, the present invention is implemented by adopting the following technical solutions:

[0007] The test device for simulating submerged evaporation comprises a light-proof box, a test cylinder, an evaporation temperature and exhaust control system, a submerged evaporation monitoring system, a soil moisture and salt temperature monitoring system, a water level dynamic control system, an image acquisition system, a data acquisition and processing system and a computer;

[0008] The light-proof box is vertically installed on the test bench through the lower bottom plate therein; the test cylinder is vertically fixedly installed at the center of the lower bottom plate in the light-proof box; the evaporation temperature exhaust control system is installed on the main box in the light-proof box; the No. 1 air humidity sensor in the diving evaporation monitoring system is vertically inserted into the through hole of the sensor fixing frame outside the main box, and the No. 2 air humidity sensor is horizontally inserted into the No. 1 through hole on the water replenishment soil column in the test cylinder; 4 inserted moisture, salt and temperature sensors with the same structure in the soil moisture and salt temperature monitoring system The soil sample is inserted through No. 2 to No. 5 through holes on the water replenishment soil column; the water level dynamic control system is installed at the center of the lower bottom plate just below the water replenishment soil column in the light-proof box; the image acquisition system is installed on the test bench to the right of the shooting port at the center of the right wall of the main box; the data acquisition and processing system and the computer are installed on the test bench on the right side of the light-proof box, the data acquisition and processing system is connected to the soil water, salt and temperature monitoring system line, and the computer and the data acquisition and processing system, the image acquisition system are connected to the PLC synchronous jacking system in the water level dynamic control system;

[0009] The test cylinder comprises a permeable stone, a cylinder fixing platform and a partition;

[0010] The cylinder fixing platform is fixed on the outer wall of the water replenishment soil column by bonding, and the cylinder fixing platform is installed at 2 / 3 of the length of the cylinder body from the top of the water replenishment soil column; the partition is fixed inside the water replenishment soil column by bonding, and the partition is installed at 2 / 3 of the length of the cylinder body from the top of the water replenishment soil column, and the permeable stone is placed on the partition inside the water replenishment soil column;

[0011] The water level dynamic control system includes a lifting base, a rubber ring, a CNC hydraulic jack and a PLC synchronous lifting system;

[0012] The lifting base is inserted at the bottom of the water replenishment soil column, the inner ring wall of the rubber ring is fixed to the outer cylindrical surface of the large cylindrical structure of the lifting base by bonding, and the outer ring wall of the rubber ring is in contact with the inner cylinder wall of the water replenishment soil column; the bottom surface of the CNC hydraulic jack is fixedly connected to the center of the lower bottom plate in the light-proof box by welding, the bottom end surface of the lifting base is fixedly connected to the top surface of the piston head of the CNC hydraulic jack by welding, and the oil inlet and outlet interfaces of the CNC hydraulic jack are inserted and connected with the oil inlet and outlet of the electric hydraulic pump station of the PLC synchronous jacking system through hydraulic hoses;

[0013] The circumferential structural dimensions of the permeable stone are equal to the inner wall structural dimensions of the water replenishment soil column;

[0014] The inner ring structure size of the cylinder fixing platform is equal to the outer wall structure size of the water replenishment soil column;

[0015] The outer ring structure size of the partition is equal to the inner wall structure size of the water replenishment soil column, and the inner ring structure size of the partition is equal to the circumferential structure size of the small cylindrical structure of the lifting base;

[0016] The lifting base is welded by a large cylindrical structure and a small cylindrical structure. The rotation centerline of the small cylindrical structure is collinear with the rotation centerline of the large cylindrical structure. The circumferential structural dimension of the small cylindrical structure of the lifting base is equal to the inner ring structural dimension of the partition in the test cylinder, and the circumferential structural dimension of the large cylindrical structure of the lifting base is smaller than the inner wall structural dimension of the water replenishment soil column.

[0017] The light-proof box described in the technical solution also includes a box, No. 1 ultraviolet lamp, No. 2 ultraviolet lamp, an embedded wall panel and a heating lamp fixing plate; the box also includes an upper top plate; the lower end of the main box is installed in the groove at the top of the lower bottom plate, and the two are dynamically matched; the top of the embedded wall panel is fixed to the bottom end surface of the upper top plate by welding, the symmetry center line of the embedded wall panel is collinear with the symmetry center line of the upper top plate, and the upper top plate is installed on the top port of the main box through the embedded wall panel, the top surface of the top port of the main box is in contact and connected with the bottom end surface of the upper top plate around the embedded wall panel, and the embedded wall panel and the top port of the main box are dynamically matched; one longitudinal end of the sensor fixing frame is fixed to the upper part of the outer side of the left box wall of the main box by welding, and one end of the heating lamp fixing plate is fixed to the upper part of the inner side of the left box wall of the main box by welding, and is located above the sensor fixing frame on the outer side of the left box wall; No. 1 ultraviolet lamp and No. 2 ultraviolet lamp are installed on the lower bottom plate at two right angles on the right side of the main box.

[0018] The main box body described in the technical solution is a rectangular shell structure with open top and bottom ends, a square shooting opening is arranged at the center of the right box wall of the main box body, and the main box body is made of stainless steel plate; the upper top plate is a rectangular plate-like structure, the length and width structural dimensions of the upper top plate are larger than the length and width structural dimensions of the outer side of the top port of the main box body, a conical exhaust fan access opening is arranged in the center of the upper top plate, and the upper top plate is made of stainless steel plate; the lower bottom plate is a plate-like structure with a groove arranged at the center of the rectangle, the length and width structural dimensions of the groove are equal to the length and width structural dimensions of the outer side of the bottom port of the main box body, 4 circular threaded through holes with the same structural dimensions are evenly arranged at the center of the lower bottom plate, and the lower bottom plate is made of stainless steel plate; the embedded wall panel is a hollow rectangular annular structure with open top and bottom ends, the outer length and width structural dimensions of the embedded wall panel are equal to the inner length and width structural dimensions of the top port of the main box body, and the embedded wall panel is made of stainless steel plate.

[0019] The sensor fixing frame described in the technical solution is a rectangular structural member, and a sensor insertion opening is arranged at the longitudinal center of the sensor fixing frame, and the material of the sensor fixing frame is stainless steel; the No. 1 ultraviolet lamp and the No. 2 ultraviolet lamp are two cylindrical structural members with the same structure, and the ultraviolet lamp uses a 20W universal ultraviolet lamp on the market; the heating lamp fixing plate is a rectangular structural member, and the length and width structural dimensions of one end of the heating lamp fixing plate are equal to the dimensions of the fixing clamp clamp at the tail of the lamp connecting column, and the heating lamp fixing plate is made of stainless steel plate.

[0020] The test cylinder described in the technical solution also includes 4 screws with the same structure, 12 nuts with the same structure and a fluorescent scale; the upper ends of the 4 screws with the same structure are inserted into the 4 through holes on the cylinder fixing platform on the water replenishment soil column, and a nut is set on each screw inserted into the 4 through holes on the cylinder fixing platform and located on the upper and lower sides of the cylinder fixing platform, and a nut is set on the lower end of each screw; the fluorescent scale is vertically fixed to the outer wall of the right cylinder wall of the water replenishment soil column by gluing.

[0021] The water replenishment soil column described in the technical solution is a cylindrical shell structure. A strip opening with an open top is arranged at the top position of the left cylinder wall of the water replenishment soil column. The width dimension of the strip opening in the front-to-back direction is equal to the width dimension of the lamp connecting column in the evaporation temperature exhaust control system in the front-to-back direction. The water replenishment soil column is evenly provided with 5 radial through holes along the vertical spiral direction from 70 mm below the bottom of the strip opening to 2 / 3 of the cylinder length from the top surface of the water replenishment soil column. The radial through holes are numbered No. 1 to No. 5 from top to bottom, and the diameter of the through holes is 15 mm to 25 mm. Among them, the vertical distance between the centers of two adjacent through holes in No. 1 to No. 5 is 30 mm to 50 mm, and the horizontal distance is 50 mm. The center of No. 5 through hole is 30 mm from the cylinder fixing platform, and the center of No. 1 through hole is 70 mm from the bottom of the strip opening of the water replenishment soil column. The center lines of No. 1 through hole and No. 5 through hole are vertical in space, and the water replenishment soil column is made of organic glass.

[0022] The permeable stone described in the technical solution is a circular plate-type structural member, which is a common geotechnical permeable stone on the market and is made of corundum; the cylinder fixing platform is a circular plate-type structural member, and 4 circular screw light holes with the same size as the screw structure are evenly arranged along the outer edge of the cylinder fixing platform, and the cylinder fixing platform is made of organic glass; the partition is a circular plate-type structural member, and the partition is made of organic glass; the fluorescent scale is composed of a transparent self-adhesive scale and a luminous tape, and the transparent self-adhesive scale is a common self-adhesive scale on the market, and the luminous tape is a common luminous tape on the market; the length of the fluorescent scale is equal to the height of the water replenishment soil column, and the width of the fluorescent scale is 10 mm; the transparent self-adhesive scale is made of PVC self-adhesive, and the luminous tape is made of PET self-adhesive.

[0023] The lifting base described in the technical solution is made of stainless steel; the rubber ring is a circular ring structure with a groove-shaped equal cross-section; the CNC hydraulic jack is a cylindrical structure, and a CNC hydraulic jack of model F50 / 200 is adopted; the PLC synchronous jacking system adopts a PLC synchronous jacking system of model S50 / 160 or model S50 / 200.

[0024] The image acquisition system described in the technical solution includes a bracket and a CCD microscope camera; the CCD microscope camera adopts a CCD camera of model LM2000, and the CCD microscope camera is connected to the computer through a line with a USB interface; the bracket adopts a tripod of model MT-08; the CCD microscope camera is fixedly connected to the bracket by screws; the data acquisition and processing system adopts a dynamic signal test analyzer of model NUXI-1004 / 8; the soil moisture, salt and temperature monitoring system includes 4 plug-in moisture, salt and temperature sensors of the same structure, which are inserted into the The moisture, salt and temperature sensor adopts the moisture, salt and temperature sensor of model CR1000X or the moisture and temperature sensor of model 5TM; 4 plug-in moisture, salt and temperature sensors with the same structure adopt RS485 four-wire wiring, and the red line, white line, yellow line and green line in the four-wire wiring are respectively connected to the positive pole, negative pole, 485A and 485B of the RS485 interface of the data acquisition and processing system, and the data acquisition and processing system is connected to the computer through a line with a USB interface; the computer adopts a general-purpose desktop computer on the market, and the computer and the PLC synchronous lifting system are connected through a line with a USB interface.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The water level dynamic control system of the test device for simulating submerged evaporation described in the present invention is different from the traditional submerged evaporation device in structure. The existing domestic submerged evaporation indoor test device generally sets a water replenishment cylinder outside the soil sample and manually controls the water level in the water replenishment cylinder. The device sets a water replenishment cylinder under the soil sample, and intelligently controls the water level in the water replenishment cylinder through the PLC synchronous lifting system, which is more flexible and convenient to operate;

[0027] 2. The water level dynamic control system of the test device for simulating submerged evaporation described in the present invention is different from the traditional submerged evaporation device in terms of simulation method. The existing domestic submerged evaporation indoor test device generally simulates submerged evaporation under constant groundwater level by constant pressure water replenishment into the soil sample through a water replenishment cylinder; the present device can conduct tests based on the groundwater level fluctuation data monitored in the field, and more realistically simulate the dynamic changes of the groundwater level in the natural environment. The frequency and amplitude of the water level changes in the test are controlled by the PLC synchronous jacking system, which is consistent with natural conditions and improves the test accuracy;

[0028] 3. The submerged evaporation monitoring system of the test device for simulating submerged evaporation described in the present invention is different from the traditional submerged evaporation device in terms of operation mode. The existing domestic submerged evaporation indoor test device can generally only read data manually or collect soil samples to measure evaporation by drying method at various time points in the evaporation process, and the measurement process is complicated and cumbersome; the device can obtain data immediately after the test based on the software monitoring data of two air humidity sensors, the soil quality and water replenishment quality before and after the test, and calculate the soil evaporation data during the dynamic change of the groundwater level through manual processing, so as to obtain the submerged evaporation at any time in the evaporation process, and can realize the quantitative analysis of submerged evaporation;

[0029] 4. The water replenishment soil column of the test device for simulating submerged evaporation described in the present invention is different from the traditional submerged evaporation device in terms of the test method. The existing domestic submerged evaporation indoor test device generally cannot visualize the change of the water field during the submerged evaporation process. The water replenishment soil column of the device is made of transparent organic glass. By adding a replenishment solution mixed with fluorescent element into the water replenishment soil column, the position of the solution in the soil sample column can be observed under the irradiation of ultraviolet light during the test, so that the water migration path of submerged evaporation can be observed in real time, and the process of water migration in the soil body during submerged evaporation can be truly restored, which is of great significance for the study of water migration of submerged evaporation;

[0030] 5. The water replenishment soil column of the test device for simulating submerged evaporation described in the present invention is different from the traditional submerged evaporation device in structure. The existing domestic submerged evaporation indoor test devices all have sensor holes arranged vertically on the cylinder body, while the sensor holes of the present device are spirally arranged on the water replenishment soil column. Compared with the vertically arranged sensor holes, the spirally arranged sensor holes can arrange more sensors at the same height, shorten the distance between measuring points, and improve the accuracy of the measuring range. At the same time, the present device can reduce the influence of artificial interference in the water migration path due to the vertically arranged holes, and improve the test accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below in conjunction with the accompanying drawings:

[0032] Figure 1 It is an axonometric projection view of the structural composition of a test device for simulating submerged evaporation according to the present invention;

[0033] Figure 2 for Figure 1 Sectional view at AA in the middle;

[0034] Figure 3 It is an axonometric projection view of the box structure used in the test device for simulating submerged evaporation according to the present invention;

[0035] Figure 4 for Figure 2 Axonometric projection view of the structural components at B in the middle;

[0036] Figure 5 It is an axonometric projection view of the water replenishment soil column structure used in the experimental device for simulating submerged evaporation according to the present invention;

[0037] Figure 6 A top view of the water replenishment soil column structure used in a test device for simulating submerged evaporation according to the present invention;

[0038] Figure 7 A test flow chart of a test device for simulating submerged evaporation according to the present invention;

[0039] In the figure: 1. Main box, 2. Upper top plate, 3. Lower bottom plate, 4. Sensor fixing frame, 5. Water replenishment soil column, 6. Permeable stone, 7. Lifting base, 8. Rubber ring, 9. Nut, 10. Screw, 11. Evaporation speed control exhaust fan, 12. Evaporation temperature control heating lamp, 13. No. 1 air humidity sensor, 14. Water and salt temperature sensor, 15. CNC hydraulic jack, 16. Data acquisition and processing system, 17. Temperature controller, 18. Air volume controller, 19. Computer, 20. Bracket, 21. C CD microscope camera, 22. PLC synchronous lifting system, 23. No. 1 ultraviolet lamp, 24. No. 2 ultraviolet lamp, 25. No. 2 air humidity sensor, 26. Embedded wall panel, 27. Heating lamp fixing plate, 28. Cylinder fixing table, 29. Partition, 30. Light-proof box, 31. Test cylinder, 32. Evaporation temperature exhaust control system, 33. Diving evaporation monitoring system, 34. Soil moisture, salt and temperature monitoring system, 35. Water level dynamic control system, 36. Fluorescent scale, 37. Lamp connecting column. DETAILED DESCRIPTION

[0040] The present invention is described in detail below in conjunction with the accompanying drawings:

[0041] See also Figure 1 and Figure 2 The test device for simulating submerged evaporation described in the present invention includes a light-proof box 30, a test cylinder 31, an evaporation temperature and exhaust control system 32, a submerged evaporation monitoring system 33, a soil moisture and salt temperature monitoring system 34, a water level dynamic control system 35, an image acquisition system, a data acquisition and processing system 16, and a computer 19.

[0042] See also Figure 2 and Figure 3 The light-proof box 30 includes a box body (main box body 1, upper top plate 2, lower bottom plate 3), a sensor fixing frame 4, a No. 1 ultraviolet lamp 23, a No. 2 ultraviolet lamp 24, an embedded wall plate 26 and a heating lamp fixing plate 27;

[0043] The box body is composed of a main box body 1, an upper top plate 2 and a lower bottom plate 3;

[0044] The main box body 1 is a hollow rectangular shell structure with open top and bottom ends. The lower end of the main box body 1 is installed in the groove at the top of the lower bottom plate 3. The lower end of the main box body 1 can move freely up and down in the groove at the top of the lower bottom plate 3, that is, the bottom end of the main box body 1 and the top groove of the lower bottom plate 3 are dynamically matched. A square shooting opening is set at the center of the right box wall of the main box body 1. The main box body 1 is made of stainless steel plate;

[0045] The upper top plate 2 is a rectangular plate-like structural member, the length and width of the upper top plate 2 are larger than the length and width of the outer side of the top port of the main box 1, and a conical exhaust fan access port is arranged at the center of the upper top plate 2. The upper top plate 2 is made of a stainless steel plate;

[0046] The lower bottom plate 3 is a plate-type structural member with a groove at the center of a rectangle. The length and width of the groove are equal to the length and width of the outer side of the bottom end port of the main box body 1. Four circular threaded through holes with the same structural dimensions as the screw 10 are evenly arranged at the center of the lower bottom plate 3, i.e., the center of the groove. The lower bottom plate 3 is made of a stainless steel plate.

[0047] The embedded wall panel 26 is a hollow rectangular annular structural member with open top and bottom ends. The outer length and width structural dimensions of the embedded wall panel 26 are equal to the inner length and width structural dimensions of the top port of the main box body 1. The top of the embedded wall panel 26 is fixed to the bottom end surface of the upper top plate 2 by welding. The symmetry center line of the embedded wall panel 26 is colinear with the symmetry center line of the upper top plate 2. The embedded wall panel 26 is installed in the top port of the main box body 1. The embedded wall panel 26 and the top port of the main box body 1 are in dynamic fit. The embedded wall panel 26 is made of stainless steel plate.

[0048] The sensor fixing frame 4 is a rectangular parallelepiped structural member, and a sensor insertion opening is provided at the longitudinal center of the sensor fixing frame 4, and the sensor insertion opening is used to fix the No. 1 air humidity sensor 13. One end of the sensor fixing frame 4 is fixed to the upper part of the outer side of the left box wall of the main box body 1 by welding, and the material of the sensor fixing frame 4 is stainless steel;

[0049] The No. 1 ultraviolet lamp 23 and the No. 2 ultraviolet lamp 24 are two cylindrical structural members with the same structure. The No. 1 ultraviolet lamp 23 and the No. 2 ultraviolet lamp 24 are used to observe the moisture migration path of the test soil. They are common ultraviolet lamps on the market, such as the T8 / 20W ultraviolet lamp of the Gemeis brand and the 20W ultraviolet lamp of the Shellite brand.

[0050] The heating lamp fixing plate 27 is a rectangular parallelepiped structural member, and is used to fix the evaporative temperature control heating lamp 12. The length and width structural dimensions of one end of the heating lamp fixing plate 27 are equal to the dimensions of the fixing clamp opening at the tail of the lamp connecting column 37. The other end of the heating lamp fixing plate 27 is fixed to the upper part of the inner side of the left box wall of the main box body 1 by welding, and is located above the sensor fixing frame 4 on the outer side of the left box wall. The heating lamp fixing plate 27 is made of stainless steel.

[0051] The No. 1 ultraviolet lamp 23 and the No. 2 ultraviolet lamp 24 are vertically installed on the lower base plate 3 at two right angles on the right side of the main box body 1, the bottom end port of the main box body 1 is inserted into the groove of the lower base plate 3, the bottom end surface of the bottom end port of the main box body 1 is in contact with the bottom of the groove on the lower base plate 3, the bottom end port of the embedded wall panel 26 is inserted into the top end port of the main box body 1, and the top end surface of the top end port of the main box body 1 is in contact with the bottom end surface of the upper top plate 2 around the embedded wall panel 26.

[0052] See also Figure 2 , Figure 4 , Figure 5 and Figure 6 The test cylinder 31 includes a water replenishing soil column 5, a permeable stone 6, 4 screws 10 with the same structure, 12 nuts 9 with the same structure, a cylinder fixing platform 28, a partition 29 and a fluorescent scale 36;

[0053] The water replenishment soil column 5 is a cylindrical shell structure. A strip opening with an open top is arranged at the top of the left side wall of the water replenishment soil column 5. The width of the strip opening in the front-to-back direction is equal to the width of the lamp connecting column 37 of the evaporative temperature control heating lamp 12 in the front-to-back direction. The water replenishment soil column 5 is evenly provided with 5 radial through holes along the vertical spiral direction from 70 below the bottom of the strip opening to 2 / 3 of the length of the barrel from the top surface of the water replenishment soil column 5. The through holes are The through holes are numbered from top to bottom as No. 1 to No. 5, and the diameter of the through holes is 15 mm to 25 mm, wherein the vertical distance between the centers of two adjacent through holes in No. 1 to No. 5 is 30 mm to 50 mm, and the horizontal distance is 50 mm, the center of No. 5 through hole is 30 mm away from the cylinder fixing platform 28, the center of No. 1 through hole is 70 mm below the bottom of the strip opening of the water replenishment soil column 5, the center lines of No. 1 through hole and No. 5 through hole are vertical in space, and the water replenishment soil column 5 is made of organic glass;

[0054] The permeable stone 6 is a circular plate-type structural member, and the circumferential structural dimensions of the permeable stone 6 are equal to the inner wall structural dimensions of the water replenishment soil column 5. The permeable stone 6 is a common geotechnical permeable stone on the market, such as a geotechnical permeable stone of φ100*10mm produced by Tuoce Instrument Co., Ltd., and the permeable stone 6 is made of corundum;

[0055] The nut 9 is a common hexagonal nut in the market, such as a stainless steel hexagonal nut of model M12 of Jinchao brand, and the nut 9 is made of 304 stainless steel;

[0056] The screw rod 10 is a common threaded rod in the market, such as a stainless steel threaded rod of model M12 of Jinchao brand, and the screw rod 10 is made of 304 stainless steel;

[0057] The cylinder fixing platform 28 is a circular plate-type structural member, and the cylinder fixing platform 28 is used to fix the water replenishment soil column 5. The inner ring structure size of the cylinder fixing platform 28 is equal to the outer wall structure size of the water replenishment soil column 5. The cylinder fixing platform 28 is evenly provided with 4 circular screw light through holes with the same structure size as the screw 10 along the outer edge position, and the cylinder fixing platform 28 is made of organic glass;

[0058] The partition 29 is a circular plate-type structural member, and the partition 29 is used to place the permeable stone 6. The outer ring structural size of the partition 29 is equal to the inner wall structural size of the water replenishment soil column 5, and the inner ring structural size of the partition 29 is equal to the circumferential structural size of the small cylindrical structural member of the lifting base 7. The partition 29 is made of organic glass;

[0059] The fluorescent ruler 36 is composed of a transparent self-adhesive ruler and a luminous tape. The transparent self-adhesive ruler is a common self-adhesive ruler on the market, such as a transparent self-adhesive ruler sticker with a model of 50cm long * 1cm wide. The luminous tape is a common luminous tape on the market, such as a yellow-green luminous tape with a model of 3m long * 1cm wide of the Seven Colors Space brand. The transparent self-adhesive ruler is made of PVC self-adhesive stickers, and the luminous tape is made of PET self-adhesive stickers; the transparent self-adhesive ruler and the luminous tape are selected with the same width specifications, and the transparent self-adhesive ruler and the luminous tape are cut with scissors to the same length as the water replenishment soil column 5, and the transparent self-adhesive ruler is pasted on the luminous surface of the luminous tape. The luminous tape is fixed to the outer wall of the right wall of the water replenishment soil column 5 by pasting. The fluorescent ruler 36 can show a fluorescent effect under the irradiation of an ultraviolet lamp, and is used to observe the water migration height and the solution replenishment height in the soil sample column during the test;

[0060] The partition 29 is fixed inside the water replenishment soil column 5 by bonding. The partition 29 is placed at 2 / 3 of the length of the cylinder body from the top of the water replenishment soil column 5. The internal space of the water replenishment soil column 5 is divided into two parts, the upper part of the water replenishment soil column 5, and the lower part of the water replenishment soil column 5 is used to hold the soil to be tested, and the lower part of the water replenishment soil column 5 is used to hold the water replenishment solution mixed with fluorescein.

[0061] The permeable stone 6 is placed on the partition 29 inside the water replenishment soil column 5;

[0062] The cylinder fixing platform 28 is fixed on the outer wall of the water replenishment soil column 5 by bonding, and the cylinder fixing platform 28 is placed at 2 / 3 of the cylinder length from the top of the water replenishment soil column 5;

[0063] The water replenishment soil column 5 is fixed on the lower base plate 3 by four screws 10. The upper ends of the four screws 10 with the same structure are inserted into the four through holes of the barrel fixing platform 28 on the water replenishment soil column 5. The bottom ends of the four screws are screwed into the four threaded through holes with the same structure on the lower base plate 3. The two are fixedly connected. A nut 9 is set on each screw 10 inserted into the four through holes on the barrel fixing platform 28 and located on the upper and lower sides of the barrel fixing platform 28. A nut 9 is set on each screw 10 screwed into the lower base plate 3.

[0064] See also Figure 1 and Figure 2 , the evaporation temperature exhaust control system 32 includes an evaporation temperature control heating lamp 12, a lamp connecting column 37, an evaporation speed control exhaust fan 11, a temperature controller 17 and an air volume controller 18;

[0065] The evaporative temperature-controlled heating lamp 12 is a screw-type lamp holder, and the evaporative temperature-controlled heating lamp 12 uses a 50W ceramic heater of the Pates brand. The evaporative temperature-controlled heating lamp 12 can heat the soil to be tested inside the water-supplementing soil column 5;

[0066] The lamp connection column 37 has a screw thread at one end and a fixing clamp at the other end, with a cylindrical structure in the middle. The screw thread of the lamp connection column 37 is used to fix the evaporative temperature-controlled heating lamp 12. The clamping size of the fixing clamp of the lamp connection column 37 is equal to the length and width structural dimensions of the heating lamp fixing plate 27, and is used to fix the overall structure. The cylindrical structure in the middle of the lamp connection column 37 is used to connect the screw thread and the fixing clamp, and is a universal tough hose that can be rotated 360 degrees for final shaping. The screw thread of the lamp connection column 37 is screwed into the screw thread on the evaporative temperature-controlled heating lamp 12, and the fixing clamp of the lamp connection column 37 is clamped and connected to the heating lamp fixing plate 27. The lamp connection column 37 uses a 300W curved tube lamp clamp of the REPTILE STRUCTURE brand. The lamp connection column 37 is a matching standard product for the evaporative temperature-controlled heating lamp 12.

[0067] The temperature controller 17 of model WK-SM3 can control the heating temperature and heating time of the evaporation temperature control heating lamp 12, and the temperature control range of the temperature controller 17 is 5°C to 99°C;

[0068] The evaporation temperature control heating lamp 12 is connected by inserting the two live and neutral wires in the plug of the power line into the live and neutral wires in the two sockets on the temperature controller 17 socket, and the two live and neutral wires in the plug of the power line of the temperature controller 17 are connected by inserting the two live and neutral wires in the two sockets on the power socket;

[0069] The evaporative speed-controlled exhaust fan 11 of the Jiuyefeng brand model LH-100-32W has a cylindrical plug at the bottom and a fuselage at the top. The evaporative speed-controlled exhaust fan 11 can discharge the water evaporated from the soil in time. The air volume controller 18 of the model AC / DCADAPTER YYS-1202000 can control the air volume of the evaporative speed-controlled exhaust fan 11. The air volume control range of the air volume controller 18 is 0m 3 / h~280m 3 / h;

[0070] The evaporation speed-controlled exhaust fan 11 is connected to the two live and neutral wires in the female power cord of the air volume controller 18 through insertion and connection, and the two live and neutral wires in the plug of the power cord of the air volume controller 18 are inserted and connected to the live and neutral wires in the two sockets on the power socket;

[0071] See also Figure 1 , Figure 2 and Figure 5 , the diving evaporation monitoring system 33 includes a No. 1 air humidity sensor 13 and a No. 2 air humidity sensor 25;

[0072] The No. 1 air humidity sensor 13 and the No. 2 air humidity sensor 25 are two cylindrical structural parts with the same structure. The No. 1 air humidity sensor 13 and the No. 2 air humidity sensor 25 are common temperature and humidity sensors on the market, such as the model HENGKO The temperature and humidity sensor of RHT-H31, the temperature and humidity sensor of TH10S-B, the temperature and humidity sensor of B-TH-RS30, etc., the probe housings of the plug-in air humidity sensor No. 1 13 and the air humidity sensor No. 2 25 are made of stainless steel, the air humidity sensor No. 1 13 is vertically inserted into the through hole of the sensor fixing frame 4 outside the main box 1, and the air humidity sensor No. 2 25 is horizontally inserted into the through hole No. 1 on the water replenishment soil column 5, the air humidity sensor No. 1 13 and the air humidity sensor No. 2 25 adopt RS485 four-wire wiring, the red line, white line, yellow line, and green line of the RS485 four-wire wiring of the air humidity sensor No. 1 13 and the air humidity sensor No. 2 25 are respectively connected to the positive pole, negative pole, 485A, and 485B of the RS485 interface of the data acquisition and processing system 16, and the data acquisition and processing system 16 is connected to the computer 19 through a line with a USB interface;

[0073] See also Figure 1The soil moisture, salt and temperature monitoring system 34 includes 4 inserted moisture, salt and temperature sensors 14 with the same structure. The inserted moisture, salt and temperature sensors 14 are common moisture, salt and temperature sensors on the market, such as Campbell brand moisture, salt and temperature sensors with model CR1000X and Decagon brand moisture, salt and temperature sensors with model 5TM. The 4 inserted moisture, salt and temperature sensors 14 with the same structure are inserted into the soil sample column through No. 2 to No. 5 through holes on the water replenishment soil column 5. The 4 inserted moisture, salt and temperature sensors 14 with the same structure are used to monitor the moisture content of the soil sample column in the water replenishment soil column 5. The 4 inserted moisture, salt and temperature sensors 14 with the same structure adopt RS485 four-wire wiring. The red line, white line, yellow line and green line of the RS485 four-wire wiring are respectively connected to the positive pole, negative pole, 485A and 485B of the RS485 interface of the data acquisition and processing system 16. The data acquisition and processing system 16 is connected to the computer 19 through a line with a USB interface.

[0074] See also Figure 1 , Figure 2 and Figure 4 , the water level dynamic control system 35 includes a lifting base 7, a rubber ring 8, a CNC hydraulic jack 15 and a PLC synchronous lifting system 22;

[0075] The lifting base 7 is a cylindrical structural member, which is welded by a large cylindrical structural member and a small cylindrical structural member. The lower bottom surface of the small cylindrical structural member of the lifting base 7 is arranged at the center of the top surface of the large cylindrical structural member, that is, the rotation center line of the small cylindrical structural member is collinear with the rotation center line of the large cylindrical structural member. The circumferential structural dimension of the small cylindrical structural member of the lifting base 7 is equal to the inner ring structural dimension of the partition 29, and the circumferential structural dimension of the large cylindrical structural member of the lifting base 7 is slightly smaller than the inner wall structural dimension of the water replenishment soil column 5. The lifting base 7 is used to push the replenishment solution doped with fluorescein in the water replenishment soil column 5 into the soil to be tested, and the lifting base 7 is made of stainless steel;

[0076] The rubber ring 8 is a circular ring structure with a groove shape and a uniform cross section. The rubber ring 8 is a common rubber ring in the market. The diameter and thickness of the rubber ring 8 are the same as the diameter and thickness of the large cylindrical structure of the lifting base 7. For example, a fire-fighting joint rubber ring with a model of DN100 is selected. The rubber ring 8 plays a sealing role.

[0077] The CNC hydraulic jack 15 is a cylindrical structural member, and the CNC hydraulic jack 15 is a general-purpose CNC hydraulic jack on the market, such as a CNC hydraulic jack of model F50 / 200 produced by Zhonggong Company;

[0078] The PLC synchronous lifting system 22 is a general-purpose PLC synchronous lifting system on the market, such as the PLC synchronous lifting system of model S50 / 160 produced by Zhonggong Company and model S50 / 200 produced by Zhonggong Company, etc. The PLC synchronous lifting system is used to control the lifting, lowering and pressure maintenance of the CNC hydraulic jack 15;

[0079] The lifting base 7 is inserted into the bottom of the water replenishment soil column 5, and the inner wall of the groove of the rubber ring 8 is fixed to the outer cylindrical surface of the large cylindrical structure of the lifting base 7 by bonding, and the outer ring wall of the rubber ring 8 is in contact with the inner cylinder wall of the water replenishment soil column 5; the bottom surface of the CNC hydraulic jack 15 is fixed to the lower base plate 3 by welding, and the bottom end surface of the lifting base 7 is fixedly connected to the top surface of the piston head of the CNC hydraulic jack 15 by welding. The inlet and outlet oil interfaces of the CNC hydraulic jack 15 are connected to the oil inlet and outlet of the electric hydraulic pump station of the PLC synchronous jacking system 22 through hydraulic hoses. The PLC synchronous jacking system 22 is connected to the computer 19 through a line with a USB interface. The control of the CNC hydraulic jack 15 can be controlled on the touch screen of the PLC synchronous jacking system 22, and can also be controlled on the PLC signal processing software of the computer 19;

[0080] See also Figure 1 , the image acquisition system includes a bracket 20 and a CCD microscope camera 21;

[0081] The bracket 20 is a common camera bracket on the market, such as a tripod of model Ulanzi MT-08;

[0082] The CCD microscope camera 21 is a common microscope camera on the market, such as the LM2000 CCD camera of the Ribo brand, the iXon Ultra 897 high-sensitivity CCD camera of the AVDOR brand, etc. The CCD camera can still maintain a high image resolution in areas with insufficient light, and has a higher imaging speed. The CCD microscope camera 21 is used to monitor the water migration in the water replenishment soil column 5;

[0083] The bracket 20 is fixedly connected to the CCD microscope camera 21 by screws, and the CCD microscope camera 21 is connected to the computer 19 by a line with a USB interface. The CCD microscope camera 21 is located on the right side of the shooting port at the center of the right wall of the main box 1. The CCD microscope camera 21 can be set to take pictures at a fixed time, and this function can be controlled by the shooting software installed in the computer 19;

[0084] The data acquisition and processing system 16 is a rectangular parallelepiped structure, which is a common dynamic signal test analyzer on the market, such as the dynamic signal test analyzer model NUXI-1004 / 8 produced by Top Measurement and Control Company, etc., which contains an integrated information collection and processing unit and is a standard product on the market. The data acquisition and processing system 16 and the computer 19 are installed on the right side of the main box 1;

[0085] The computer 19 is a market standard desktop computer, such as a DELL brand model 3681 desktop computer;

[0086] The light-proof box 30 is vertically mounted on the test bench through the lower base plate 3 therein;

[0087] The test cylinder 31 is vertically installed at the center of the lower bottom plate 3 in the light-proof box 30. The test cylinder 31 is connected to the lower bottom plate 3 of the light-proof box 30 through the cylinder fixing platform 28 thereon by using 4 screws 10 with the same structure and 12 nuts 9 with the same structure. The longitudinal symmetry center line of the main box 1 in the light-proof box 30 is collinear with the longitudinal symmetry center line of the test cylinder 31.

[0088] The evaporation temperature control heating lamp 12 of the evaporation temperature exhaust control system 32 is located at the top of the water replenishment soil column 5 in the test cylinder 31, and the universal flexible hose on the side of the lamp connecting column 37 close to the screw port is inserted into the strip-shaped opening on the water replenishment soil column 5, and the fixing clip at the tail of the lamp connecting column 37 is clamped and connected with the heating lamp fixing plate 27 on the inner side of the left box wall of the main box body 1 in the light-proof box body 30;

[0089] The evaporation speed control exhaust fan 11 of the evaporation temperature exhaust control system 32 is installed at the center of the top of the main box body 1 in the light-proof box body 30, and the cylindrical socket at the bottom of the evaporation speed control exhaust fan 11 is inserted into the conical exhaust fan access port at the center of the upper top plate 2 in the main box body 1, and the temperature controller 17 and the air volume controller 18 are installed on the rear side of the main box body 1;

[0090] In the submersible evaporation monitoring system 33, the No. 1 air humidity sensor 13 is vertically inserted into the through hole of the sensor fixing frame 4 outside the main box 1, and the No. 2 air humidity sensor 25 is horizontally inserted into the No. 1 through hole on the water replenishment soil column 5;

[0091] The soil moisture, salt and temperature monitoring system 34 is located inside the test cylinder 31. Four insertion-type moisture, salt and temperature sensors 14 with the same structure in the soil moisture, salt and temperature monitoring system 34 are horizontally inserted into the soil samples in the No. 2 to No. 5 through holes of the water replenishment soil column 5.

[0092] The water level dynamic control system 35 is located directly below the water replenishment soil column 5 in the light-proof box 30. The bottom surface of the CNC hydraulic jack 15 in the water level dynamic control system 35 is fixed to the lower bottom plate 3 by welding, and the top piston head is fixed to the lower bottom surface of the lifting base 7 by welding.

[0093] See also Figure 7 The test method using the test device for simulating diving evaporation is as follows:

[0094] 1. Experimental Preparation

[0095] 1) Preliminary test

[0096] Through preliminary tests, the proportional relationship between the lifting height of the PLC synchronous lifting system 22 and the water level change height of the water replenishment soil column 5 is determined, and the proportional coefficient μ of different soil layers is recorded. i (i = sub-sand layer, sub-clay layer, medium-fine sand layer, coarse sand gravel layer, etc.); the preliminary test method is as follows:

[0097] (1) Control the numerically controlled hydraulic jack 15 to slowly rise through the PLC synchronous lifting system 22, push the fluorescent solution into the first soil layer at the bottom of the soil sample column, stop lifting, observe and record the height h1 of the fluorescent in the soil sample column;

[0098] (2) Control the numerically controlled hydraulic jack 15 through the PLC synchronous lifting system 22 to inject the fluorescein solution to 20 mm, stop lifting, and observe and record the height h2 of the fluorescein in the soil sample column;

[0099] Calculate the proportional coefficient μ1 of the first soil layer, μ1=20 / (h2-h1);

[0100] (4) If the soil sample column has multiple different soil layers, the proportional coefficient μ i =20 / (h i-2 -h i-1 ), after recording the h of the first soil layer 1-2 After that, the PLC synchronous lifting system 22 is used to control the numerically controlled hydraulic jack 15 to slowly rise, and the fluorescent solution is pushed into the second soil layer at the bottom of the soil sample column. The lifting is stopped, and the height h of the fluorescent substance in the soil sample column is observed and recorded. 2-1 , and then inject to 20mm, stop lifting, observe and record the height of the fluorescent substance in the soil sample column h 2-2 , calculate the proportional coefficient μ2 of the second soil layer, μ2=20 / (h 2-2 -h 2-1 ); the third soil layer μ3=20 / (h 3-2 -h 3-1 ) until the last layer of soil;

[0101] 2) Collection and processing of groundwater level fluctuation monitoring data

[0102] Monitoring wells are used to monitor the groundwater level dynamics in the field over a period of time, and groundwater level fluctuation monitoring data are collected. The data include monitoring time and groundwater level height. The data can also be published in existing literature. The obtained monitoring data needs to be processed as follows:

[0103] (1) The groundwater level fluctuation monitoring data is made into an EXCEL table - groundwater level fluctuation monitoring data table. In the table header, column A is the monitoring time in minutes, column B is the groundwater level height in millimeters, and column C is the soil quality of the soil layer where the groundwater level is located, including sub-sand layer, sub-clay layer, medium-fine sand layer, coarse sand gravel layer, etc. The 1st row, 2nd row, 3rd row...nth row in the table are the actual monitoring data values;

[0104] (2) Record the overall height h of the field monitoring soil layer and scale it to the size of the water replenishment soil column 5. The height of the soil sample column in the water replenishment soil column 5 is recorded as h b , calculate the proportionality coefficient e, e = h b / h;

[0105] In the groundwater level fluctuation monitoring data table, add column D as the control data of the PLC synchronous jacking system 22, and enter the formula in column D of the table: The unit is mm / min. The positive value of the result is to control the PLC synchronous lifting system 22 to rise, and the negative value is to control the PLC synchronous lifting system 22 to fall.

[0106] 3) Preparation of soil sample column

[0107] Soil samples can be selected from undisturbed soil or remolded soil in the field;

[0108] (1) Prepare soil sample columns according to the actual soil thickness of the field site according to the proportional coefficient e. The height range of the soil sample column is preferably 2 cm above the top surface of the permeable stone 6 to the No. 2 through hole of the water replenishment soil column tube 5. If it is too high, it will affect the accuracy of the top moisture, salt and temperature sensor in monitoring the surface. If it is too low, the soil layer will be cracked when the top moisture, salt and temperature sensor is inserted. Fill the mold with the same size as the water replenishment soil column tube 5. Fill in the soil layer consistent with the field site, such as sub-sand layer, sub-clay layer, medium-fine sand layer, coarse sand gravel layer, etc. in layers, or just fill in one soil layer. The specific number of soil layers to be filled depends on how many soil layers are involved in the groundwater fluctuation range, and compact it every 5 cm height.

[0109] (2) After all the soil samples are filled, push the soil sample column out of the mold and weigh the mass G1 of the soil sample column using an electronic scale;

[0110] 4) Calculate static water level

[0111] According to the field monitoring data, the variation range of the groundwater level depth can be known. In the experiment, the water level with the smallest groundwater level fluctuation during the monitoring period is taken as the static water level H. j , calculate the static water level h of the test soil sample column according to the proportional coefficient e j ,h j =H j ×e;

[0112] 2. Equipment Installation

[0113] 1) The numerically controlled hydraulic jack 15 is placed at the center of the lower base plate 3, the bottom of the water replenishment soil column 5 is mounted on the lifting base 7, and the cylinder fixing platform 28 and the lower base plate 3 are fixed with four screws 10. The thickness H3 of the small cylinder of the lifting base 7 is measured with a ruler, and a layer of vaseline is evenly applied above the partition 29 in the wall of the water replenishment soil column 5 to block moisture;

[0114] 2) Pour the replenishing solution mixed with fluorescein into the replenishing soil column 5 until the liquid level reaches the position of the partition 29, and then place the permeable stone 6 on the partition 29. At this time, manually observe the fluorescent scale 36 on the replenishing soil column 5 and record the scale H1 at the top surface of the large cylinder of the lifting base 7. This scale is used to calculate the amount of solution replenishment after the test.

[0115] 3) The prepared soil sample column is loaded into the water replenishment soil column tube 5, and the bottom of the soil sample column is in contact with the permeable stone 6;

[0116] 4) inserting four water, salt and temperature sensors 14 into the soil sample through through holes No. 2 to No. 5 in the water replenishment soil column 5, and inserting No. 2 air humidity sensor 25 into through hole No. 1 of the water replenishment soil column 5;

[0117] 5) Place the No. 1 UV lamp 23 and the No. 2 UV lamp 24 at the two corners on the right side of the lower base plate 3, and then install the main box 1 on the lower base plate 3;

[0118] 6) The evaporation temperature control heating lamp 12 is placed inside the water replenishment soil column 5, the lamp connecting column 37 passes through the strip-shaped opening on the water replenishment soil column 5, and the fixing clip at the tail of the lamp connecting column 37 clamps the heating lamp fixing plate 27;

[0119] 7) Insert the No. 1 air humidity sensor 13 into the sensor fixing bracket 4;

[0120] 8) The upper top plate 2 is buckled onto the top of the main box 1; then the bottom of the evaporation speed-controlled exhaust fan 11 is inserted into the conical opening in the center of the upper top plate 2;

[0121] 9) The CCD microscope camera 21 is placed on the right side of the shooting port on the right wall of the main box body 1;

[0122] 3. Test instrument parameter setting

[0123] 1) Groundwater level fluctuation model setting

[0124] Import the results of column D in the groundwater level fluctuation monitoring data table into the PLC signal processing software of computer 19 ( The unit is mm / min), and the PLC synchronous lifting system 22 is used to control the dynamic change of the water level. The PLC synchronous lifting system 22 can control the height of the numerical control hydraulic jack 15 to rise and fall every minute, thereby simulating the change of the actual groundwater level in the field over time;

[0125] 2) Sensor data collection interval setting

[0126] When purchasing the sensor, the manufacturer provides data acquisition and processing system software. The data acquisition and processing system software includes data acquisition, chart generation and data acquisition interval setting functions. The No. 1 air humidity sensor 13, the No. 2 air humidity sensor 25 and the water-salinity temperature sensor 14 can collect time, water content, conductivity, temperature and humidity data through the data acquisition and processing system software of the computer 19. During the data acquisition process, the above data will automatically generate a table of time, water content, conductivity, temperature and humidity and an xy axis coordinate curve in real time in the software. In the curve, the x axis is time and the y axis is water content, conductivity, temperature and humidity. The data acquisition interval can be set by entering the number of minutes in the software. The interval can be set arbitrarily, and the shortest interval is 1 minute. The interval setting is determined according to the total test time. When the test time is a few hours or a few days, the collection interval should be short. When the test time is a few weeks or a few months, the collection interval should be long.

[0127] 3) Temperature controller settings

[0128] The temperature controller 17 is set to simulate the temperature and time of the sun's irradiation on the ground surface in the wild. The temperature controller 17 can manually control the heating temperature and heating time of the evaporative temperature-controlled heating lamp 12. The control panel of the temperature controller 17 has a display screen and five buttons. The display screen can display the current temperature of the evaporative temperature-controlled heating lamp 12 and the heating time of the temperature controller 17; the five buttons are a mode switching button, a start operation (increase button, decrease button), and a stop operation (increase button, decrease button); the mode switching button can adjust the temperature and time modes; in the temperature In the temperature mode, the heating temperature can be adjusted by setting the increase button and the decrease button of the start operation. The temperature control range of the temperature controller 17 is 5°C to 99°C. In the time mode, the power on and off time can be set for a few minutes. The heating time can be adjusted by setting the increase button and the decrease button of the start operation. The interval time of stopping heating can be set by setting the increase button and the decrease button of the stop operation. The control time range of the temperature controller 17 is 1min to 99min. The setting of the heating temperature can refer to the average surface temperature of the land in each season, and the heating time can be set according to the actual daily sun exposure time.

[0129] 4) Air volume controller settings

[0130] The air volume controller 18 is set to simulate the wind speed in the wild, and at the same time, the water evaporated from the soil can be discharged in time. In the wild, the wind will blow away the water evaporated from the soil, thereby accelerating the evaporation of surface water; the air volume controller 18 can manually control the air volume of the evaporation speed control exhaust fan 11. There is a knob on the control panel of the air volume controller 18, and there is an indicator light on the knob. By rotating the knob clockwise, the air volume can be controlled from small to large. The position of the indicator light is the current air volume. The air volume control range of the air volume controller 18 is 0m 3 / h~280m 3 / h, the wind volume can be set by referring to the meteorological data of the surface wind speed in each season;

[0131] 5) CCD microscope camera shooting interval setting

[0132] The CCD microscope camera 21 can collect the images taken by the CCD microscope camera through the image acquisition software of the computer 19. The image acquisition software includes image capture and setting the shooting interval time function. The captured images can generate picture files in the computer folder in real time. The file names are named according to the day-hour-minute-second of the shooting time. The picture files are arranged in chronological order in the folder; the shooting interval time can be set by entering the number of minutes in the software. The interval time can be set arbitrarily, and the shortest time is 1 minute; the interval time setting is determined according to the total test time. When the test time is a few hours or a few days, the collection interval time should be short. When the test time is a few weeks or a few months, the collection interval time should be long.

[0133] 4. Start the experiment

[0134] 1) No. 1 ultraviolet lamp 23, No. 2 ultraviolet lamp 24, PLC synchronous lifting system 22 and computer 19 are powered on;

[0135] 2) The PLC synchronous lifting system 22 controls the numerically controlled hydraulic jack 15 to slowly rise, pushing the fluorescein solution into the soil sample column to the static water level height h j Stop lifting, and during the lifting process, control the hydraulic jack 15 to rise at a speed of 1 mm / min to 10 mm / min. The rising speed should not be too fast to avoid water flow impact causing pores and cracks in the soil sample column;

[0136] 3) The data acquisition and processing system 16, the temperature controller 17, and the air volume controller 18 are powered on, the CCD microscope camera 21 is turned on, and the test is started;

[0137] 5. Data Collection

[0138] 1) Collect moisture, salt and temperature sensor data

[0139] The data acquisition and processing system 16 reads the water content, conductivity and temperature data of the water-salt-temperature sensor 14 at different times and at different heights. The data acquisition and processing system 16 transmits the data to the data acquisition and processing system software of the computer 19. The software can generate a table and a curve about time, water content, conductivity and temperature according to the time, water content, conductivity and temperature data collected by each sensor. In the curve, the x-axis is time, and the y-axis is water content, conductivity and temperature.

[0140] 2) Collect air humidity sensor data

[0141] The data acquisition and processing system 16 reads the humidity data of the No. 1 air humidity sensor 13 and the No. 2 air humidity sensor 25 at different times, and transmits the data to the data acquisition and processing system software of the computer 19. The software can generate a table and curve about time and humidity according to the time and humidity data collected by each sensor. In the air humidity change curve, the x-axis is time and the y-axis is humidity;

[0142] 3) Collect CCD microscope image data

[0143] The CCD microscope camera 21 can take real-time photos of the water migration height and solution replenishment height of the soil sample column during the test. During the test, the numerically controlled hydraulic jack 15 will push the replenishment solution mixed with fluorescein in the replenishment soil column tube 5 into the soil sample column. Under the irradiation of the ultraviolet lamp, the fluorescein solution will show a bright fluorescent green color. The position with fluorescent green is the water migration height of the soil sample column in the upper half of the replenishment soil column tube 5 and the solution height in the lower half of the replenishment soil column tube 5. After the test, the test operator can manually read the scale of the fluorescent scale 36 on the replenishment soil column tube 5 at each moment through the image taken by the CCD microscope camera 21, and obtain the water migration height and solution replenishment height in the soil sample column during the whole test. This method solves the problem of difficulty in observing the submersible evaporation test process and realizes visualization of the whole test process.

[0144] 4) Collect total test time data

[0145] When the test is completed, the start time and end time are recorded by the data acquisition and processing system 16, and the total test time t is manually calculated;

[0146] 5) Collect soil sample column quality data

[0147] After the test, push out the soil sample column and weigh the mass G2 of the soil sample column with an electronic scale;

[0148] 6) Collecting fluorescence scale data

[0149] After the test, the fluorescent scale 36 on the water replenishment soil column 5 is manually observed to record the scale H2 at the position of the top surface of the large cylinder of the lifting base 7;

[0150] 6. Calculation of diving evaporation

[0151] Based on the data obtained in the experiment, the phreatic evaporation during the dynamic change of groundwater level can be calculated according to the following method;

[0152] 1) Based on the height data of the replenishment solution, the total mass G of the replenishment solution can be obtained w ,

[0153] G w=S·(H1-H2)·ρ-S·H3,

[0154] Where: S is the inner bottom area of ​​the water replenishment soil column 5;

[0155] H1 is the scale of the position of the top surface of the 7 large cylinders of the lifting base when the equipment is installed before the test;

[0156] H2 is the scale of the position of the top surface of the 7 large cylinders of the lifting base after the test;

[0157] H3 is the height of the small cylinder of the lifting base 7;

[0158] (H1-H2) is the total height of the replenishment solution during the entire test period;

[0159] ρ is the solution density;

[0160] 2) The total evaporation of soil water G can be obtained by the mass of the soil sample column before and after the test and the total mass of water replenishment.

[0161] G=|G2-G1|+G W ,

[0162] Where: G1 is the mass of the soil sample column before the test;

[0163] G2 is the mass of the soil sample column after the test;

[0164] 3) The soil moisture evaporation amount W at time K can be obtained by obtaining the monitoring data of air humidity sensor No. 1 13 and air humidity sensor No. 2 25 k ,

[0165]

[0166] Where: W k is the amount of soil water evaporation at time K;

[0167] G is the total evaporation of soil water;

[0168] ω is the evaporation humidity of the soil sample column measured by the No. 2 air humidity sensor 25;

[0169] ω k is the evaporation humidity of the soil sample column measured by the No. 2 air humidity sensor 25 at time K;

[0170] ω i is the evaporation humidity of the soil sample column measured by the No. 2 air humidity sensor 25 at each monitoring moment;

[0171] u is the reference humidity outside the box measured by the No. 1 air humidity sensor 13;

[0172] u kis the reference humidity outside the box measured by the No. 1 air humidity sensor 13 at time K;

[0173] u i is the reference humidity outside the box measured by the No. 1 air humidity sensor 13 at each monitoring moment;

[0174] i is the evaporation monitoring time interval;

[0175] t is the total trial time.

[0176] The above indoor test method can be used to obtain the evaporation of soil at each moment, and then analyze the evaporation of soil in the area where the soil sample is located. When designing the test, the evaporation of soil can be compared by changing the soil layer structure, temperature conditions, air volume conditions and the salinity of the replenishment solution, and the influence of different soil layer structures, temperature conditions, air volume conditions and the salinity of the replenishment solution on the evaporation of soil can be obtained.

[0177] Through this method, the phreatic evaporation under the dynamic changes of actual groundwater level in the field can be simulated more scientifically and reasonably. At the same time, the phreatic evaporation amount in the process of dynamic changes of groundwater level can be measured more accurately, and the whole process of phreatic evaporation test can be visualized.

Claims

1. A test device for simulating submerged evaporation, characterized in that The test device for simulating submerged evaporation comprises a light-proof box (30), a test cylinder (31), an evaporation temperature and exhaust control system (32), a submerged evaporation monitoring system (33), a soil moisture and salt temperature monitoring system (34), a water level dynamic control system (35), an image acquisition system, a data acquisition and processing system (16) and a computer (19); The light-proof box (30) is vertically mounted on the test bench through the lower bottom plate (3) therein; the test cylinder (31) is vertically fixedly mounted at the center of the lower bottom plate (3) in the light-proof box (30); the evaporation temperature exhaust control system (32) is mounted on the main box (1) in the light-proof box (30); the No. 1 air humidity sensor (13) in the submersible evaporation monitoring system (33) is vertically inserted into the through hole of the sensor fixing frame (4) outside the main box (1), and the No. 2 air humidity sensor (25) is horizontally inserted into the No. 1 through hole on the water replenishment soil column (5) in the test cylinder (31); the four inserted moisture and salt temperature sensors (34) of the same structure in the soil moisture and salt temperature monitoring system (34) are arranged on the same surface of the test cylinder (31); the moisture and salt temperature sensors (34) of ... 14) is inserted into the soil sample through the No. 2 to No. 5 through holes on the water replenishment soil column (5); the water level dynamic control system (35) is installed at the center of the lower bottom plate (3) directly below the water replenishment soil column (5) in the light-proof box (30); the image acquisition system is installed on the test bench to the right of the shooting port at the center of the right box wall of the main box (1); the data acquisition and processing system (16) and the computer (19) are installed on the test bench on the right side of the light-proof box (30), the data acquisition and processing system (16) is connected to the soil water, salt and temperature monitoring system (34) by wire, and the computer (19) and the data acquisition and processing system (16), the image acquisition system and the PLC synchronous lifting system (22) in the water level dynamic control system (35); The test cylinder (31) comprises a permeable stone (6), a cylinder fixing platform (28) and a partition (29); The cylinder fixing platform (28) is fixed on the outer wall of the water replenishment soil column (5) by bonding, and the cylinder fixing platform (28) is installed at a distance of 2 / 3 of the cylinder length from the top of the water replenishment soil column (5); the partition (29) is fixed inside the water replenishment soil column (5) by bonding, and the partition (29) is installed at a distance of 2 / 3 of the cylinder length from the top of the water replenishment soil column (5), and the permeable stone (6) is placed on the partition (29) inside the water replenishment soil column (5); The water level dynamic control system (35) comprises a lifting base (7), a rubber ring (8), a numerically controlled hydraulic jack (15) and a PLC synchronous lifting system (22); The lifting base (7) is inserted into the bottom of the water replenishment soil column (5), the inner ring wall of the rubber ring (8) is fixed to the outer cylindrical surface of the large cylindrical structure of the lifting base (7) by bonding, and the outer ring wall of the rubber ring (8) is in contact with the inner cylinder wall of the water replenishment soil column (5); the bottom surface of the CNC hydraulic jack (15) is fixedly connected to the center of the lower bottom plate (3) in the light-proof box (30) by welding, the bottom end surface of the lifting base (7) is fixedly connected to the top surface of the piston head of the CNC hydraulic jack (15) by welding, and the oil inlet and outlet interfaces of the CNC hydraulic jack (15) are inserted and connected with the oil inlet and outlet of the electric hydraulic pump station of the PLC synchronous jacking system (22) through a hydraulic hose; The circumferential structural dimensions of the permeable stone (6) are equal to the inner wall structural dimensions of the water replenishment soil column (5); The inner ring structure size of the cylinder fixing platform (28) is equal to the outer wall structure size of the water replenishment soil column (5); The outer ring structure size of the partition (29) is equal to the inner wall structure size of the water replenishment soil column (5), and the inner ring structure size of the partition (29) is equal to the circumferential structure size of the small cylindrical structure of the lifting base (7); The lifting base (7) is welded together by a large cylindrical structure and a small cylindrical structure. The rotation centerline of the small cylindrical structure is collinear with the rotation centerline of the large cylindrical structure. The circumferential structural dimensions of the small cylindrical structure of the lifting base (7) are equal to the inner ring structural dimensions of the partition (29) in the test cylinder (31). The circumferential structural dimensions of the large cylindrical structure of the lifting base (7) are smaller than the inner wall structural dimensions of the water replenishment soil column (5).

2. A test device for simulating submerged evaporation according to claim 1, characterized in that The light-proof box (30) further comprises a box, a No. 1 ultraviolet lamp (23), a No. 2 ultraviolet lamp (24), an embedded wall plate (26) and a heating lamp fixing plate (27); The box body also includes an upper top plate (2); The lower end of the main box (1) is installed in the groove at the top of the lower base plate (3), and the two are in dynamic fit; the top of the embedded wall plate (26) is fixed to the bottom end surface of the upper top plate (2) by welding, the symmetry center line of the embedded wall plate (26) is colinear with the symmetry center line of the upper top plate (2), the upper top plate (2) is installed on the top end port of the main box (1) through the embedded wall plate (26), and the top end surface of the top end port of the main box (1) is in contact with the bottom end surface of the upper top plate (2) around the embedded wall plate (26). The embedded wall plate (26) and the top end port of the main box body (1) are in dynamic fit; one longitudinal end of the sensor fixing frame (4) is fixed to the upper part of the outer side of the left box wall of the main box body (1) by welding; one end of the heating lamp fixing plate (27) is fixed to the upper part of the inner side of the left box wall of the main box body (1) by welding and is located above the sensor fixing frame (4) on the outer side of the left box wall; the No. 1 ultraviolet lamp (23) and the No. 2 ultraviolet lamp (24) are installed on the lower bottom plate (3) at two right angles on the right side of the main box body (1).

3. A test device for simulating submerged evaporation according to claim 2, characterized in that The main box body (1) is a rectangular shell structure with open top and bottom ends. A square shooting opening is arranged at the center of the right box wall of the main box body (1). The main box body (1) is made of a stainless steel plate. The upper top plate (2) is a rectangular plate-like structural member, the length and width structural dimensions of the upper top plate (2) are larger than the length and width structural dimensions of the outer side of the top end port of the main box body (1), a conical exhaust fan access opening is arranged at the center of the upper top plate (2), and the upper top plate (2) is made of a stainless steel plate; The lower bottom plate (3) is a rectangular plate-type structural member with a groove at the center thereof, the length and width structural dimensions of the groove being equal to the length and width structural dimensions of the outer side of the bottom end port of the main box body (1), four circular threaded through holes of the same structural dimensions are evenly arranged at the center of the lower bottom plate (3), and the lower bottom plate (3) is made of a stainless steel plate; The embedded wall panel (26) is a hollow rectangular annular structural member with open top and bottom ends. The outer length and width structural dimensions of the embedded wall panel (26) are equal to the inner length and width structural dimensions of the top port of the main box body (1). The embedded wall panel (26) is made of stainless steel plate.

4. A test device for simulating submerged evaporation according to claim 2, characterized in that The sensor fixing frame (4) is a rectangular parallelepiped structural member, and a sensor insertion opening is arranged at the longitudinal center of the sensor fixing frame (4). The material of the sensor fixing frame (4) is stainless steel; The No. 1 ultraviolet lamp (23) and the No. 2 ultraviolet lamp (24) are two cylindrical structural members with the same structure, and the ultraviolet lamps are 20W ultraviolet lamps commonly used in the market; The heating lamp fixing plate (27) is a rectangular parallelepiped structural member. The length and width structural dimensions of one end of the heating lamp fixing plate (27) are equal to the dimensions of the fixing clamp opening at the tail of the lamp connecting column (37). The heating lamp fixing plate (27) is made of stainless steel plate.

5. A test device for simulating submerged evaporation according to claim 1, characterized in that , the test cylinder (31) further comprises 4 screw rods (10) of the same structure, 12 nuts (9) of the same structure and a fluorescent scale (36); The upper ends of the four screw rods (10) with the same structure are inserted into the four through holes on the cylinder fixing platform (28) on the water replenishment soil column (5), and a nut (9) is respectively set on each screw rod (10) inserted into the four through holes on the cylinder fixing platform (28) and located on the upper and lower sides of the cylinder fixing platform (28), and a nut (9) is set on the lower end of each screw rod (10); the fluorescent scale (36) is vertically fixed to the outer side wall of the right cylinder wall of the water replenishment soil column (5) by gluing.

6. A test device for simulating submerged evaporation according to claim 1 or 5, characterized in that The water replenishment soil column (5) is a cylindrical shell structure. A strip opening with an open top is arranged at the top of the left cylinder wall of the water replenishment soil column (5). The width of the strip opening in the front-to-back direction is equal to the width of the lamp connecting column (37) in the evaporation temperature exhaust control system (32). The water replenishment soil column (5) is evenly arranged with 5 radial openings along the vertical spiral direction from 70 mm below the bottom of the strip opening to 2 / 3 of the cylinder length from the top surface of the water replenishment soil column (5). The radial through holes are numbered No. 1 to No. 5 from top to bottom, and the diameter of the through holes is 15 mm to 25 mm. The vertical distance between the centers of two adjacent through holes in No. 1 to No. 5 is 30 mm to 50 mm, and the horizontal distance is 50 mm. The center of No. 5 through hole is 30 mm away from the cylinder fixing platform (28), and the center of No. 1 through hole is 70 mm below the bottom of the strip opening of the water replenishment soil column (5). The center lines of No. 1 through hole and No. 5 through hole are vertical in space, and the water replenishment soil column (5) is made of organic glass.

7. A test device for simulating submerged evaporation according to claim 5, characterized in that The permeable stone (6) is a circular plate-type structural member, the permeable stone (6) is a common geotechnical permeable stone in the market, and the permeable stone (6) is made of corundum; The barrel fixing platform (28) is a circular plate-type structural member. Four circular screw light through holes having the same structural dimensions as the screw (10) are evenly arranged along the outer edge of the barrel fixing platform (28). The barrel fixing platform (28) is made of organic glass. The partition (29) is a circular plate-type structural member, and the partition (29) is made of organic glass; The fluorescent scale (36) is composed of a transparent self-adhesive scale and a luminous tape. The transparent self-adhesive scale is a common self-adhesive scale on the market, and the luminous tape is a common luminous tape on the market. The length of the fluorescent scale (36) is equal to the height of the water replenishment soil column (5), and the width of the fluorescent scale (36) is 10 mm. The transparent self-adhesive scale is made of PVC self-adhesive, and the luminous tape is made of PET self-adhesive.

8. A test device for simulating submerged evaporation according to claim 1, characterized in that , the lifting base (7) is made of stainless steel; The rubber ring (8) is a circular ring structure with a groove-shaped cross section; The numerically controlled hydraulic jack (15) is a cylindrical structural member, and adopts a numerically controlled hydraulic jack of model F50 / 200; The PLC synchronous lifting system (22) adopts a PLC synchronous lifting system of model S50 / 160 or model S50 / 200.

9. A test device for simulating submerged evaporation according to claim 1, characterized in that , the image acquisition system comprises a bracket (20) and a CCD microscope camera (21); The CCD microscope camera (21) is a CCD camera of model LM2000, and the CCD microscope camera (21) is connected to the computer (19) via a cable with a USB interface; The support (20) is a tripod of model MT-08; The CCD microscope camera (21) is fixedly connected to the bracket (20) by screws; The data acquisition and processing system (16) adopts a dynamic signal test analyzer of model NUXI-1004 / 8; The soil moisture, salt and temperature monitoring system (34) comprises four plug-in moisture, salt and temperature sensors (14) of the same structure, wherein the plug-in moisture, salt and temperature sensors (14) are CR1000X moisture, salt and temperature sensors or 5TM moisture, salt and temperature sensors; the four plug-in moisture, salt and temperature sensors (14) of the same structure are connected to the RS485 four-wire system, wherein the red wire, white wire, yellow wire and green wire in the four-wire system are respectively connected to the positive pole, negative pole, 485A and 485B of the RS485 interface of the data acquisition and processing system (16), and the data acquisition and processing system (16) is connected to the computer (19) via a wire with a USB interface; The computer (19) is a common desktop computer on the market, and the computer (19) is connected to the PLC synchronous lifting system (22) via a line with a USB interface.

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