阅读说明：本技术 喀斯特地区水土地表地下流失及漏失过程实验装置及方法 (Experiment device and method for water and soil surface underground loss and leakage process in karst region ) 是由 李�瑞 袁江 王耀鑫 于 2021-08-11 设计创作，主要内容包括：本发明公开了一种喀斯特地区水土地表地下流失及漏失过程实验装置及方法,该装置包括由侧挡板构成的箱体结构,在该箱体结构顶部设有由带孔托板构成的洼地坡面填筑区；在该箱体结构内部通过带孔挡板划分为上下两个空间,上部空间是由PVC管制成的落水洞模型主体部分,以及试验过程采用土石填筑的浅层岩溶带,落水洞主体部分穿越浅层岩溶带；落水洞模型主体部分的顶部位于由带孔托板构成的洼地坡面填筑区的中心开口处,该落水洞模型主体部分向下穿过前述带孔挡板后的PVC管为落水洞模型下半部分,连接至箱体结构外部并设有落水洞出口；在落水洞模型下半部分的下方设有浅层岩溶带水沙承接器。该装置较好地实现了目前地下水沙过程观测。(The invention discloses an experimental device and method for water and soil surface underground loss and leakage process in a karst region, wherein the experimental device comprises a box body structure consisting of side baffles, and a depression slope filling area consisting of perforated supporting plates is arranged at the top of the box body structure; the interior of the box body structure is divided into an upper space and a lower space by a baffle plate with holes, the upper space is a main body part of a downpipe model made of PVC pipes, a shallow karst zone filled with earth and stones is adopted in the test process, and the main body part of the downpipe passes through the shallow karst zone; the top of the main body part of the water falling hole model is positioned at the central opening of a depression slope filling area formed by the perforated supporting plates, and the PVC pipe, which penetrates through the perforated baffle plate downwards, of the main body part of the water falling hole model is the lower half part of the water falling hole model, is connected to the outside of the box body structure and is provided with a water falling hole outlet; and a shallow karst water-sand carrying bearing device is arranged below the lower half part of the water falling tunnel model. The device realizes the observation of the current underground water and sand process better.)

1. The utility model provides a karst region soil and water surface underground loss and leakage process experimental apparatus which characterized in that: comprises a box body structure consisting of side baffles (4), wherein the top of the box body structure is provided with a depression slope filling area (1) consisting of a supporting plate (2) with holes; the interior of the box body structure is divided into an upper space and a lower space through a perforated baffle (8), the upper space is a water falling hole model main body part (3) made of a PVC pipe, a shallow karst zone filled with earth and stones is adopted in the test process, the water falling hole model main body part (3) penetrates through the shallow karst zone, the top of the water falling hole model main body part (3) is positioned at a central opening of a depression slope filling area (1) formed by perforated supporting plates (2), the part of the bottom of the water falling hole model main body part (3) penetrating through the perforated baffle (8) downwards is a lower water falling hole model half part (5), and the lower water falling hole model half part (5) is connected to the exterior of the box body structure and is provided with a water falling hole outlet (7); and a shallow karst water and sand carrying container (6) is arranged below the lower half part (5) of the overboard model.

2. The karst region water and soil surface underground loss and leakage process experimental device as claimed in claim 1, wherein: the supporting plate (2) with holes and the baffle (8) with holes are both provided with densely distributed small holes (9).

3. The karst region water and soil surface underground loss and leakage process experimental device as claimed in claim 1, wherein: concrete bulges (11) used for simulating the raised karst development structure are arranged in the main body part (3) of the water falling cave model.

4. The karst region water and soil surface underground loss and leakage process experimental device as claimed in claim 1, wherein: the shallow karst water and sand carrying container (6) is of a drawer structure, and a handle (10) is arranged in the front.

5. The karst region water and soil surface underground loss and leakage process experimental device as claimed in claim 4, wherein: the shallow karst water and sand carrying container (6) is placed in a carrying groove plate (12) below the box body structure.

6. The karst region water and soil surface underground loss and leakage process experimental device as claimed in claim 4, wherein: the outer contour of the supporting plate (2) with holes adopts a sector structure, and four supporting plates (2) with holes are spliced to form a funnel-shaped depression slope filling area (1).

7. A method for carrying out water and sand process simulation experiments by adopting the karst region water and soil surface underground loss and leakage process experiment device as claimed in any one of claims 1 to 6, which is characterized in that: the method is characterized in that an experiment device for the water and soil surface underground loss and leakage process of the karst region is manufactured on the basis of detecting the karst region underground karst structure by using a field detection technology including ground penetrating radar detection, and is used for simulating the water and sand migration process of the surface, shallow karst zones and a water and sand falling hole, so that the fast flow velocity and the water and sand yield of the water and sand passing through the depression falling hole are calculated, the flow velocity and the water and sand yield of the creeping of the shallow karst zones are calculated, and parameters including the fast flow velocity of the water falling hole in the karst region, the slow flow conductivity coefficient of the shallow karst zone, the fast/slow flow delay ratio, the soil loss amount of the sub-rainfall surface, the underground leakage amount of the sub-rainfall soil, and the soil surface/underground loss and leakage ratio are calculated.

8. The method of water sand process simulation experiment of claim 7, characterized by comprising the steps of:

1) firstly, utilizing a field artificial rainfall simulator to perform artificial rainfall and recording the rainfall starting moment, recording the initial moment of runoff when runoff is produced in a depression slope filling area (1) formed by a perforated supporting plate (2) on the top of the device, observing the moment when the runoff enters a downpipe hole formed by a PVC pipe and the moment when the runoff flows out of the downpipe, and calculating the time spent by the runoff entering the downpipe to the runoff from the downpipe;

2) meanwhile, when artificial rainfall simulation starts, observing the time when the runoff permeates into the shallow karst zone and the time when the runoff permeates out, namely observing and recording the seepage starting time and the seepage ending time of the shallow karst zone;

3) then, when the rainfall stops, recording the rainfall stopping time, and then observing the runoff producing ending moment of the surface slope, namely observing the lag time of the runoff production; collecting a water-sand mixed sample which enters the water-sand receiving device (6) from the shallow karst zone and flows into the experimental device from the water falling hole after seepage or outflow is finished, and completely collecting and measuring;

4) wherein the total amount of muddy water is measured by a measuring cylinder, and the sediment content is measured by combining a filtering and drying method and an instrument method;

5) and (4) according to the test result, measuring and calculating parameters including the fast flow velocity of the water falling tunnel, the hydraulic conductivity of the shallow karst zone slow flow, the fast/slow flow delay ratio, the soil loss amount of the sub-rainfall earth surface, the soil underground leakage amount of the sub-rainfall, and the soil earth surface/underground loss and leakage ratio.

Technical Field

The invention relates to an experimental device and method for water and soil surface underground loss and leakage process in karst regions, and belongs to the field of soil erosion related research.

Background

In the process of slope water erosion, runoff formed on the ground surface usually carries a certain amount of silt, and along with the continuous increase of runoff, the runoff containing the silt has stronger erosion capacity to soil below the runoff. On the other hand, with global climate change, the river basin underlying surface correspondingly changes, natural incoming water and sand situations and water and sand transportation boundary conditions are changed with human activities such as dam construction and the like, so that extreme events such as dam break and the like can be caused, active water and sand movement and rapid river bed deformation can be further caused, difficulty is brought to scientific cognition of a water and sand interaction mechanism in the river flushing process, and great challenge is brought to prediction of water and sand movement change. Therefore, the water and sand process is simulated through an experimental model or device, so that theoretical reference is provided for researching water and sand movement, and the method has great significance.

In the prior art, the invention with publication number CN205643100U discloses a water and sand seepage experiment system for a fractured rock mass, which comprises: the device comprises a water-sand mixing device, a broken rock mass experiment device, a rock mass loading assembly and a data acquisition device; the experimental device for the fractured rock mass comprises an inner cylinder, an outer cylinder and a base, wherein the inner cylinder is arranged in the outer cylinder, and the inner cylinder and the outer cylinder are both arranged on the base; the base is provided with a groove, the lower end surface of the groove is uniformly provided with flow guide holes, and the flow guide holes are communicated with the seepage liquid conveying pipe; the water and sand jet orifice of the water and sand mixing device is communicated with the water and sand through hole of the broken rock mass experiment device, the rock mass loading assembly adopts an axial loader, and a piston of the axial loader is arranged on the upper part of an inner cylinder of the broken rock mass experiment device. The scheme can truly reflect the water-sand mixture seepage quantity of the broken rock under the condition of water burst and sand burst.

For another example, the invention patent with publication number CN212568770U discloses a water and sand process simulation monitoring system, which comprises a raindrop generator, a soil erosion simulation tank, a data collection box, a sample collection box, an interflow collection pipe and a connecting pipeline, which are arranged in layers from top to bottom. The scheme forms an integrated system for the raindrop generator, the soil sample monitoring, the surface runoff, the production confluence, the infiltration interflow, the soil sample sampling and the related support, so that the experiment is more active, the mapping of the production condition of water erosion is visually represented under the specific condition of rainfall, and the surface landform erosion phenomenon is realized under the monitoring condition of data.

However, due to the special 'binary' hydrological structure in the southwest karst region of China, the underground water-sand process is extremely complex, the observation difficulty is extremely high, no better mode is available at present, the related research of the underground water-sand process can be accurately carried out in a laboratory, and the field in-situ observation has a lot of difficulties based on the complexity of the karst environment.

Disclosure of Invention

The invention mainly aims to solve the problems that the 'binary' water and soil flow (leakage) of a karst region in the prior art and the field measured data are difficult to obtain, and provides an experimental device and an experimental method for the water and soil surface underground loss and leakage process of the karst region.

The invention is realized by the following steps:

a karst region soil and water surface underground loss and leakage process experimental device comprises a box body structure formed by side baffles, wherein the top of the box body structure is provided with a depression slope filling area formed by perforated supporting plates; the interior of the box body structure is divided into an upper space and a lower space by a baffle plate with holes, the upper space is a main body part of a downpipe model made of PVC pipes, a shallow karst zone filled with earth and stones is adopted in the test process, and the main body part of the downpipe passes through the shallow karst zone; the top of the water falling hole model is positioned at the central opening of a depression slope filling area formed by the perforated supporting plates, the bottom of the main body part of the water falling hole model downwards penetrates through the PVC pipe behind the perforated baffle plate to form the lower half part of the water falling hole model, and the PVC pipe is connected to the outside of the box body structure and is provided with a water falling hole outlet; a shallow karst water and sand bearing device is arranged below the lower half part of the overboard model.

Wherein, the supporting plate with holes and the baffle with holes are both provided with densely distributed small holes.

Furthermore, a concrete bulge for simulating a raised karst development structure is arranged in the overboard cave model.

Furthermore, the water and sand container is of a drawer structure, and a handle is arranged at the front of the water and sand container.

Furthermore, the water and sand receiver is placed in a receiving groove plate below the box body structure.

Furthermore, the outer contour of the supporting plate with holes adopts a sector structure, and four supporting plates with holes are spliced to form a funnel-shaped depression slope filling area.

The experimental method comprises the following steps: the method comprises the steps of firstly utilizing a field artificial rainfall simulator to carry out artificial rainfall and recording the rainfall starting time, recording the initial time of the runoff yield when the runoff yield of a depression slope filling area formed by a supporting plate with holes is recorded at the top of the device, then observing the time when the runoff yield enters a downpipe hole formed by a PVC pipe and the time when the runoff yield flows out of the downpipe hole, and calculating the time consumed by the runoff yield from entering the downpipe hole to flowing out of the downpipe hole. Meanwhile, the time when the runoff permeates into the shallow karst zone and the time when the runoff permeates out are observed at the beginning of the artificial rainfall simulation, namely the seepage beginning time and the seepage ending time of the shallow karst zone are observed and recorded. And then observing the runoff finishing time of the surface slope after the rainfall stops (the rainfall stopping time is recorded), namely observing the lag time of runoff.

And after the seepage (outflow) is finished, collecting the water-sand mixed sample which enters the water-sand container from the shallow karst zone and flows into the experimental device from the water falling hole, and completely collecting and measuring. The total amount of muddy water is measured by a measuring cylinder, and the sediment content is measured by combining a filtering and drying method and an instrument method. And (4) calculating the fast flow velocity of the water falling tunnel, the hydraulic conductivity of the slow flow of the shallow karst zone, the delay ratio of the fast flow to the slow flow, the soil loss amount of the sub-rainfall surface, the underground leakage amount of the sub-rainfall soil, the soil surface/underground flow (leakage) loss ratio and the like according to the test result.

On the basis of a test in the future, related parts of the device, such as an internal structure of a water falling tunnel, a shallow karst zone fracture structure, a surface slope karst exposed structure and the like, can be deeply improved, and a water and sand simulation process in a karst area can be better developed after improvement.

Compared with the prior art, the invention has the following effects:

compared with the prior art, the device realizes the observation of the current underground water and sand process well, and has application prospect for revealing underground water and sand process characteristics, water and soil underground flow (leakage) loss principles and the like.

Drawings

FIG. 1 is an overall schematic view of the present invention;

FIG. 2 is an internal cross-sectional view of the present invention;

FIG. 3 is a schematic view of a perforated pallet of the present invention;

FIG. 4 is a schematic view of the structure of the perforated baffle of the present invention;

fig. 5 is a schematic structural view of the water and sand receiving device of the invention.

Description of reference numerals: 1-depression slope filling area, 2-perforated supporting plate, 3-drop hole model main body part, 4-side baffle, 5-drop hole model lower half part, 6-shallow karst water and sand carrying container, 7-drop hole outlet, 8-perforated baffle, 9-densely distributed small holes, 10-handle, 11-concrete bulge and 12-carrying trough plate.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention discloses an experimental device for water and soil surface underground loss and leakage process in a karst region, which is shown in figures 1-5, and comprises a box body structure consisting of side baffles 4, wherein the top of the box body structure is provided with a depression slope filling area 1 consisting of perforated supporting plates 2; the interior of the box body structure is divided into an upper space and a lower space through a perforated baffle 8, the upper space is a water falling hole model main body part 3 made of PVC pipes, a shallow karst zone filled with earth and stones is adopted in the test process, the water falling hole main body part penetrates through the shallow karst zone, the top of the water falling hole model main body part 3 is positioned at a central opening of a depression slope filling area 1 formed by perforated supporting plates 2, the PVC pipes, which penetrate through the perforated baffle 8 downwards, at the bottom of the water falling hole model 3 are a lower half part 5 of the water falling hole model, and the lower half part is connected to the exterior of the box body structure and is provided with a water falling hole outlet 7; a shallow karst water-sand carrying container 6 is arranged below the lower half part 5 of the downpipe model. Wherein, the supporting plate 2 with holes and the baffle 8 with holes are both provided with densely distributed small holes 9.

The invention is implemented as follows: the device mainly comprises 4 parts, wherein firstly, a main body part 3 of the downpipe model is simulated by adopting a PVC pipe (shown in figure 1), the PVC pipe with a preset specification is cut into 2 halves along a vertical section in the manufacturing process (the PVC pipe is subsequently tightened by adopting an iron wire), a concrete bulge 11 is adopted in the downpipe model to simulate a raised karst development structure (shown in figure 2), the roughness is manufactured, the lower half part 5 of the downpipe model also adopts the PVC pipe, a certain number of small holes are punched on the PVC pipe to simulate structures such as cracks of the downpipe, the specific size and the structure are scaled according to a certain proportion according to the detection result of the downpipe in the subsequent stage, and a downpipe outlet 7 adopts a plastic barrel and the like to receive a muddy water sample for water sand determination; the surface rock soil structure simulates the surface rock soil slope surface of a shallow karst zone according to different karst exposure rates, the shallow karst zone below the surface slope surface is connected by a baffle 8 (figure 4) with a hole, and the water sand container 6 with the shallow karst zone vertically downward is contained by a prefabricated aluminum box (figure 5) with a drawer structure. The depression and slope filling area 1 is composed of 4 perforated supporting plates 2 and is surrounded into a shape similar to a depression, the middle part of the depression and slope filling area is connected with a water falling hole model main body part 3, and a rock and soil mixture of a research area is adopted for slope filling to simulate different rock desertification exposure rates of a slope; the shallow karst zone below the slope is filled by original rock and soil excavated in the researched area as far as possible, and the filling thickness and density are determined according to the detection condition of the shallow karst zone in the subsequent stage and are scaled according to a certain proportion.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.