System for measuring volume of closed half-water-filled karst cave

Abstract

The utility model provides a system for measuring the volume of a closed half-water-filled karst cave. The measuring system comprises a gas cylinder, a gas guide pipe, a water taking device and a sleeve, the sleeve extends into a non-water-filling area of the to-be-measured karst cave, a sleeve sealing cover with a threaded connector is arranged at a pipe opening of the sleeve, an inner cover of the sleeve sealing cover is provided with a telescopic pipe communicated with the threaded connector, and the water taking device is a sealed container with the maximum diameter smaller than the inner diameter of the sleeve. An air outlet and a water inlet are formed in two sides of the upper part of the telescopic pipe; the water taking device is connected to the lower end of the telescopic pipe; one end of the gas-guide tube is in sealed connection with the gas cylinder, the other end of the gas-guide tube is in sealed connection with the threaded connector on the sleeve sealing cover, and a pressure reducing valve, a flow meter and a gas concentration detector are arranged on the gas-guide tube. According to the utility model, the gas concentration detector and the liquid concentration detector are used for detecting gas and liquid concentration changes in the karst cave and calculating the volume of the karst cave, so that great convenience can be provided for engineering construction in a karst area.

Description

Technical Field

[0001] The utility model relates to the field of measuring the volume of a karst cave in a karst area, in particular to a system for measuring the volume of a closed semi-water-filled karst cave. Background Art

[0002] When carrying out geotechnical engineering construction in limestone areas, caves are often encountered, and the cave strata will bring great obstacles to construction. At this time, the construction unit must formulate a targeted construction plan and must first clarify the size of the cave. Blind construction may cause potential engineering hazards and cause immeasurable losses. At present, the measurement of cave volume is mainly to obtain the internal point cloud information of the cave by three-dimensional laser scanning to establish a three-dimensional model of the cave, and to obtain the size of the cave volume by calculating the volume of the model. However, this method is costly and the number of instruments required in China is small. This method is not completely applicable to water environments. Muddy water can cause the laser beam to be scattered, absorbed or refracted, thereby affecting the scanning effect of the laser scanner, resulting in reduced accuracy or complete failure of the obtained three-dimensional model. Therefore, inventing a convenient, efficient and low-cost cave volume measurement device can bring great convenience to engineering construction. Summary of the invention

[0003] The utility model aims to provide a system for measuring the volume of a closed semi-water-filled cave. The system can inject gas into the cave and calculate the volume of the unfilled cavity by detecting the gas concentration. It can also conveniently put solid soluble objects into the cave, then take out water samples from the cave, measure the liquid concentration, and conveniently calculate the volume of the water-filled part of the cave.

[0004] In order to achieve the above technical purpose, the utility model provides a system for measuring the volume of a closed semi-water-filled cave, which is used to measure a closed cave located in a rock layer, and the cave to be measured is semi-filled with water. The measuring system includes a gas cylinder, an air guide tube, a water intake device and a casing. The lower end of the casing sequentially passes through the soil layer and the rock layer at the top of the cave to be measured and extends into the non-water-filled area of ​​the cave to be measured, and the pipe mouth of the casing is located above the soil layer, and a casing sealing cover is provided at the pipe mouth of the casing; the top surface of the casing sealing cover is provided with a first threaded interface matching the air guide tube, and the inner cover of the casing sealing cover is provided with a first threaded interface matching the first threaded interface A telescopic tube connected to a threaded interface, and the length of the telescopic tube after being extended is greater than that of the sleeve, and a second threaded interface matched with a water intake device is provided at the lower end of the telescopic tube; the water intake device is a sealed container with a maximum diameter smaller than the inner diameter of the sleeve, a connecting port matched with the second threaded interface is provided on the upper part of the sealed container, and air outlets and water inlets are provided on both sides of the upper part of the sealed container, and the water intake device is connected to the lower end of the telescopic tube; one end of the air guide tube is sealed with the gas cylinder, and the other end is sealed with the first threaded interface, and a pressure reducing valve, a flow meter and a gas concentration detector are provided on the air guide tube.

[0005] A better technical solution of the utility model: the measuring system also includes a liquid concentration and density detection device and a measuring cup, the water sample taken out by the water taking device is placed in the measuring cup; the liquid concentration and density detection device is used to detect the concentration and density of the water sample in the measuring cup.

[0006] The preferred technical solution of the utility model is as follows: a control valve is provided at the connection portion between the gas cylinder and the air guide tube, and the pressure reducing valve, flow meter and gas concentration detector are arranged on the air guide tube in sequence from the gas cylinder end toward the sleeve end.

[0007] The better technical solution of the utility model: the water intake device is a cylindrical sealed container with a diameter smaller than the inner diameter of the sleeve, the top surface of which is provided with a connecting port matching the second threaded interface, and two air outlets and water inlets are symmetrically provided on both sides of the upper part.

[0008] The better technical solution of the utility model is as follows: an exploration hole is drilled in the soil layer and rock layer at the top of the cave to be tested, the casing is arranged in the exploration hole, and the lower end passes through the exploration hole and extends into the cave to be tested, and an expansion material filling sealing layer is provided in the gap between the casing and the wall of the exploration hole.

[0009] A more optimal technical solution of the utility model is that the gas cylinder is filled with non-toxic inert gas.

[0010] A more optimal technical solution of the utility model: sealing rubber rings are provided at both the first threaded interface and the second threaded interface.

[0011] The preferred technical solution of the utility model is as follows: the sleeve sealing cover is connected to the pipe opening of the sleeve by threads; the telescopic tube adopts a telescopic sleeve or a corrugated telescopic tube, and its upper pipe opening is fixedly connected to the inner cover of the sleeve sealing cover as a whole.

[0012] The measuring system of the utility model can first deliver a quantitative amount of solid soluble matter into the cave through the casing, then seal the casing with a cap, connect the air guide tube and the gas cylinder, first measure the initial gas concentration value c1 in the cave through the gas concentration detector, then inject inert gas into the cave through the gas cylinder, and observe the pressure reading on the dial of the air inlet of the pressure reducing valve. If the reading is close to 0, it means that the gas in the bottle has been completely released, and then measure the gas concentration value after the inert gas is injected into the cave through the gas concentration detector, and then deduce and calculate the volume V1 of the unfilled cavity of the cave according to the gas concentration calculation formula c=m / v1; after the calculation of the volume of the unfilled cavity is completed, the telescopic tube is extended to allow the water intake device to enter the water area of ​​the cave, take out the water sample through the water intake device and put it into the liquid concentration and density detector for detection, and then calculate the liquid density according to the liquid density calculation formula m 液 =ρv2, and the concentration of the dissolved matter is obtained by the mass of the soluble matter dissolved in the hole, formula c = m 固 / m 液, the volume V2 of the water-filled part of the cave can be calculated.

[0013] The utility model can be used to measure the volume of the non-water-filled area and the water-filled area of ​​the cave through a set of devices, providing fast and effective data for cave volume calculation, facilitating workers to quickly calculate the volume of the water-filled and non-water-filled parts of the cave, providing great convenience for engineering construction in karst areas, and providing an important reference for formulating targeted construction plans. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 It is a schematic diagram of the structure of the utility model;

[0016] Figure 2 It is a front view of the contact part between the casing sealing cover and the threaded joint of the utility model;

[0017] Figure 3 It is a top view of the contact part between the casing sealing cover and the threaded joint of the utility model;

[0018] Figure 4 It is a front view of the water intake device in the utility model;

[0019] Figure 5 It is a side view of the water intake device in the utility model;

[0020] Figure 6 It is a top view of the water intake device in the utility model.

[0021] In the figure: 1-gas cylinder; 2-valve; 3-pressure reducing valve; 4-flow meter; 5-gas concentration detector; 6-air guide tube; 7-telescopic tube; 700-second threaded interface; 8-casing sealing cover; 800-first threaded interface; 9-casing; 10-cavern to be tested; 11-water intake device; 12-gas outlet and water inlet; 13-liquid concentration and density detector; 14-measuring cup; 15-expansion material filling sealing layer; 16-sealing rubber ring; 17-connection port. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0023] The terms "comprises," "comprising," or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0024] The embodiment provides a system for measuring the volume of a closed semi-water-filled cave, such as Figures 1 to 3 As shown, it is used to measure a closed cave located in a rock stratum, and the karst cave 10 to be measured is half filled with water. A survey hole is drilled in the soil layer and the rock layer at the top of the karst cave 10 to be measured, and the survey hole passes through the soil layer and the rock layer at the top of the karst cave 10 to be measured in sequence and leads to the karst cave 10 to be measured. The measuring system comprises a gas cylinder 1, an air pipe 6, a water intake device 11 and a casing 9, wherein the casing 9 is arranged in an exploration hole, and the lower end thereof passes through the exploration hole and extends into a non-water-filled area in a karst cave 10 to be measured, and a sealing layer 15 filled with an expansion material is arranged in a gap between the casing 9 and the wall of the exploration hole, and the pipe mouth of the casing 9 is located above the soil layer, and a casing sealing cover 8 is arranged at the pipe mouth of the casing 9; the casing sealing cover 8 is connected to the pipe mouth of the casing 9 by threads, and a first threaded interface 800 matching the air pipe 6 is arranged on the top surface of the casing sealing cover 8, one end of the air pipe 6 is sealed and connected to the gas cylinder 1, and a control valve 2 is arranged at the connection position, and the other end of the air pipe 6 is threadedly connected to the first threaded interface 800, and a pressure reducing valve 3, a flow meter 4 and a gas concentration detector 5 are arranged on the air pipe 6 in sequence, and the pressure reducing valve 3 is arranged at one end adjacent to the gas cylinder 1.

[0025] The embodiment provides a system for measuring the volume of a closed semi-water-filled cave, such as Figures 1 to 3 As shown, the inner cover of the sleeve sealing cover 8 is provided with a telescopic tube 7 connected to the first threaded interface 800, and the length of the telescopic tube 7 after being extended is greater than the sleeve 9, and a second threaded interface 700 matching and connected to the water intake device 11 is provided at the lower end of the telescopic tube 7; Figures 4 to 6As shown, the water intake device 11 is a cylindrical sealed container with a diameter smaller than the inner diameter of the sleeve 9, and a connection port 17 matching the second threaded interface 700 is provided on the top surface thereof, and two air outlets and water inlets 12 are symmetrically provided on both sides of the upper part; the water intake device 11 is threadedly connected to the lower end of the telescopic tube 7. The telescopic tube 7 adopts a telescopic sleeve or a corrugated telescopic tube, and its upper pipe opening is fixedly connected to the inner cover of the sleeve sealing cover 8 as a whole. Sealing rubber rings 16 are provided at both the first threaded interface 800 and the second threaded interface 700.

[0026] The embodiment provides a system for measuring the volume of a closed semi-water-filled cave, such as Figure 1 As shown, the measuring system further comprises a liquid concentration and density detection device 13 and a measuring cup 14. The water sample taken out by the water taking device 11 is placed in the measuring cup 14. The liquid concentration and density detection device 13 is used to detect the concentration and density of the water sample in the measuring cup 14. The gas cylinder 1 is filled with non-toxic inert gas.

[0027] The method for measuring the volume of a closed semi-water-filled cave using a measurement system for the volume of a closed semi-water-filled cave in the embodiment specifically comprises the following steps:

[0028] Step 1: according to the top plate depth of the karst cave 10 to be tested detected by the exploration hole, a sufficiently long casing 9 is placed in the hole, the length of the casing is greater than the depth of the top rock layer and soil layer of the karst cave 10 to be tested, and it is ensured that the lower end of the casing 9 can extend into the area of ​​the karst cave 10 to be tested that is not filled with water, and the top of the casing 9 is located above the soil layer, and then the gap between the casing 9 and both sides of the hole wall is filled with expansion material;

[0029] Step 2, deliver a fixed amount of solid soluble matter into the to-be-tested cave 10 through the sleeve 9, connect the water intake device 11 to the lower end of the telescopic tube 7, then place the water intake device 11 and the telescopic tube 7 together in the sleeve 9, and tighten the sleeve sealing cover 8. At this time, the telescopic tube 7 is in a contracted state, and its length is not greater than the length of the sleeve 9. Then, the air guide tube 6 is threadedly connected to the first threaded interface 800 on the sleeve sealing cover 8, and then the other end of the air guide tube 6 is sealed and connected to the gas cylinder 1, and the gas cylinder 1 is filled with inert gas;

[0030] Step 3, close the control valve 2, open the gas concentration detector 5, wait until the concentration value of the gas A in the cave (the same as the concentration of the gas stored in the gas cylinder) is stable, record the initial value c1 of the gas concentration at this time, and close the gas concentration detector;

[0031] Step 4, open the gas cylinder control valve 2, the gas passes through the pressure reducing valve 3, the flow meter 4, the air guide tube 6 and the telescopic tube 7, and then enters the cave cavity through the gas outlet and water inlet 12 on the water intake device 11, observe the pressure reading on the dial of the pressure reducing valve 3 inlet, if the reading is close to 0, it means that the gas in the gas cylinder 1 has been completely released, close the control valve 2, turn on the gas concentration detector 5, and record the gas concentration reading after it stabilizes c2;

[0032] Step 5: According to the gas concentration calculation formula, the calculation formula for the unfilled cavity volume V1 of the cave is obtained:

[0033]

[0034] In formula (1), c1 is the initial concentration of gas A in the cave, c2 is the stable concentration of gas A after diffusion in the cave, m1 is the initial mass of gas A in the cave, m2 is the mass of gas A in the gas cylinder, and V1 is the volume of the unfilled cavity in the cave;

[0035] Step 6, unscrew the sleeve sealing cover 8, and extend the telescopic tube 7, the extended length of the telescopic tube 7 is sufficient for the water intake device at its end to extend out of the sleeve 9, and can extend downward into the cave water to take water, and then cover the sleeve sealing cover 8, and take water through the water intake device 11. During the water intake process, the water in the cave can automatically flow into the cavity of the water intake device 11 through the air outlet and water inlet 12 on the water intake device 11. After the water intake is completed, unscrew the sleeve sealing cover 8, and remove the telescopic tube 7 and the water intake device 11 together, and then pour the water sample in the water intake device 11 into the measuring cup 14 of the liquid concentration and density detector 13 for detection, and obtain the density ρ and concentration c of the liquid in the cave;

[0036] Step 7, according to the liquid concentration calculation formula, the calculation formula of the volume V2 of the water-filled part of the cave is obtained:

[0037]

[0038] In formula (2), c is the concentration of the solid soluble matter in the cave after it is fully dissolved, m 固 is the mass of the solid soluble matter, m 液 is the mass of the liquid in the cave, ρ is the density of the liquid in the cave, and V2 is the volume of the water-filled part of the cave;

[0039] Step 7, add the volume of the unfilled cavity V1 of the cave calculated in step 5 and the volume of the water-filled part V2 of the cave calculated in step 6 to calculate the volume V of the closed semi-filled cave:

[0040]

[0041] The utility model can conveniently and effectively obtain data for calculating the volume of the cave, and is convenient for calculating the volume of the water-filled and non-water-filled parts of the cave, which greatly facilitates the engineering construction in the karst area and provides an important reference for formulating targeted construction plans.

[0042] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A system for measuring the volume of a closed semi-water-filled cave, used for measuring a closed cave located in a rock formation, wherein the cave (10) to be measured is semi-filled with water, and characterized in that: The measuring system comprises a gas cylinder (1), an air guide tube (6), a water intake device (11) and a casing (9); the lower end of the casing (9) sequentially passes through the soil layer and the rock layer at the top of the karst cave (10) to be measured and extends into the non-water-filled area of ​​the karst cave (10) to be measured, and the pipe mouth of the casing (9) is located above the soil layer, and a casing sealing cover (8) is provided at the pipe mouth of the casing (9); the top surface of the casing sealing cover (8) is provided with a first threaded interface (800) matching the air guide tube (6), and the inner cover of the casing sealing cover (8) is provided with a telescopic tube (7) connected to the first threaded interface (800), and the length of the telescopic tube (7) after being extended is greater than that of the casing (9), and the telescopic tube (7) is extended when the telescopic tube (7) is extended. The lower end of the contraction tube (7) is provided with a second threaded interface (700) matched with the water intake device (11); the water intake device (11) is a sealed container with a maximum diameter smaller than the inner diameter of the sleeve (9), and a connection port matched with the second threaded interface (700) is provided on its upper part, and air outlet and water inlet (12) are provided on both sides of the upper part of the sealed container, and the water intake device (11) is connected to the lower end of the contraction tube (7); one end of the air guide pipe (6) is sealed with the gas cylinder (1), and the other end is sealed with the first threaded interface (800), and a pressure reducing valve (3), a flow meter (4) and a gas concentration detector (5) are provided on the air guide pipe (6).

2. A closed semi-water-filled cave volume measurement system according to claim 1, characterized in that: The measuring system further comprises a liquid concentration and density detection device (13) and a measuring cup (14); the water sample taken out by the water taking device (11) is placed in the measuring cup (14); the liquid concentration and density detection device (13) is used to detect the concentration and density of the water sample in the measuring cup (14).

3. A closed semi-water-filled cave volume measurement system according to claim 1 or 2, characterized in that: A control valve (2) is provided at the connection portion between the gas cylinder (1) and the gas guide tube (6), and the pressure reducing valve (3), flow meter (4) and gas concentration detector (5) are arranged on the gas guide tube (6) in sequence from the gas cylinder (1) end toward the sleeve (9) end.

4. A closed semi-water-filled cave volume measurement system according to claim 1 or 2, characterized in that: The water intake device (11) is a cylindrical sealed container with a diameter smaller than the inner diameter of the sleeve (9), and its top surface is provided with a connection port (17) matching the second threaded interface (700), and two air outlets and water inlets (12) are symmetrically provided on both sides of the upper part.

5. A closed semi-water-filled cave volume measurement system according to claim 1 or 2, characterized in that: An exploration hole is drilled in the soil layer and rock layer at the top of the karst cave (10) to be tested, the casing (9) is arranged in the exploration hole, and the lower end thereof passes through the exploration hole and extends into the karst cave (10) to be tested, and an expansion material filling sealing layer (15) is provided in the gap between the casing (9) and the wall of the karst cave.

6. A closed semi-water-filled cave volume measurement system according to claim 1 or 2, characterized in that: The gas cylinder (1) is filled with non-toxic inert gas.

7. A closed semi-water-filled cave volume measurement system according to claim 1 or 2, characterized in that: Sealing rubber rings (16) are provided at both the first threaded interface (800) and the second threaded interface (700).

8. A closed semi-water-filled cave volume measurement system according to claim 1 or 2, characterized in that: The sleeve sealing cover (8) is connected to the pipe opening of the sleeve (9) by means of threads; the telescopic tube (7) is a telescopic sleeve or a corrugated telescopic tube, and its upper pipe opening is fixedly connected to the inner cover of the sleeve sealing cover (8) as a whole.

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