CN105372140A - Device and method for evaluating anti-erosion capacity of soil - Google Patents

Abstract

The invention relates to a device and method for evaluating the anti-erosion capacity of soil. According to the device, a support is arranged on a base, a loading mechanism is arranged on the top of the support, an annular fixing plate is arranged in the middle of the support, a pressure bearing unit is arranged on the fixing plate, the pressure bearing unit is right opposite to the loading mechanism, an acquisition unit for acquiring residual particles disintegrated after erosion is arranged below the pressure bearing unit, and the bottom of the pressure bearing unit is connected with an erosion mechanism through a water pipe. A tested part is uniform in load carrying, a covering layer on the upper portion of soil in the practical situation is simulated through weight loads, the defect that existing soil anti-erosion research does not involve the influence of force action is overcome, in addition, the device is simple in structure and convenient to dismount and mount, the loading mode is easy and convenient, the experimental result is stable, the anti-erosion performance of a material can be preliminarily evaluated, and the problems of water and soil loss, land subsidence, surface collapse and the like of pavement engineering and fields can be effectively solved.

Description

A device and method for evaluating soil erosion resistance

technical field

The invention belongs to the technical field of soil anti-scouring performance testing, in particular to a device and method for evaluating soil anti-scouring performance.

Background technique

For many years, soil erosion has been one of the most important ecological and environmental problems in the Loess Plateau region, and it has been widely concerned by scholars at home and abroad in recent years. Soil anti-scourability index and soil disintegration rate are important indicators that can best reflect the regional water and soil loss process and soil erosion law. Soil anti-scourability is the performance of soil to resist mechanical damage and push down by runoff. At present, the soil anti-scourability Most of the sex researches use undisturbed soil scouring as the main method, and Jiang Dingsheng’s actual undisturbed soil scouring method is commonly used, that is, the undisturbed soil is placed in the scour tank after sampling with a strip ring knife for scour experiments. The experimental method is rough and the results are not accurate, so At present, there is an urgent need for a test method and device for evaluating soil erosion resistance performance with simple structure, reasonable design, easy operation and good test results.

Contents of the invention

One of the objectives of the present invention is to overcome the above-mentioned deficiencies in the prior art, and provide a test device for evaluating the anti-scouring performance of soil with simple structure, reasonable design, easy operation and good test effect.

The second object of the present invention is to provide a method for evaluating the anti-scourability of soil by using the above-mentioned device to realize that the top of the tested object is loaded, the bottom is scoured, and the loading and scouring are synchronized.

In order to achieve the above object, the technical scheme adopted in the present invention is:

The device is provided with a bracket on the base, a loading mechanism for applying load to the tested piece on the top of the bracket, a ring-shaped fixing plate in the middle, and a bearing for placing the tested piece and receiving pressure on the fixing plate. A pressure unit, the pressure unit is facing the loading mechanism, and a collection unit for collecting the residual particles disintegrated after washing is arranged under the pressure unit, and the bottom of the pressure unit is connected to the washing mechanism through a water pipe;

The above-mentioned loading mechanism includes a guide rod arranged on the top of the support and connected to the top of the pressure-bearing unit and a weight set on the guide rod, and the guide rod is on the same straight line as the central axis of the tested piece;

The above-mentioned pressure-bearing unit includes a mold for placing the tested piece and permeable stones arranged on the top and bottom of the tested piece in the mold, and filter paper is also arranged between the permeable stone and the tested piece; Both the center of the filter paper and the permeable stone are processed with a water hole, the longitudinal distance between the water outlet end of the water pipe and the permeable stone at the bottom of the test piece is 4~6cm, and it is directly opposite to the center of the bottom of the test piece;

The collection unit includes a fixed rod fastened to the support, a collecting hopper fixed on the support through the fixed rod, and a collecting cup arranged directly under the collecting hopper for collecting disintegrated particles; the collecting hopper is facing the bottom of the mould.

The structure of the above flushing mechanism is as follows: an air inlet is processed on the top of the airtight water tank containing water, an air pipe connected with the air pump is arranged on the air inlet, a water outlet hole is processed at the bottom of the water tank, and the water inlet end of the water pipe is connected to the water tank. The outlet holes are connected.

The water outlet end of the above-mentioned water pipe is fixed by a support rod.

A dial indicator for measuring the vertical deformation of the tested piece is also arranged on the above-mentioned guide rod.

The condition to be satisfied between the inner diameter of the water hole and the diameter of the test piece is that the ratio of the inner diameter of the water hole to the diameter of the test piece is between 1/3-2/3.

The thickness of the above-mentioned permeable stone is 5-8mm, and the longitudinal distance between the water outlet end of the water pipe and the permeable stone at the bottom of the test piece is 5cm.

A method for evaluating soil erosion resistance with the above-mentioned device, which is composed of the following steps:

(1) Place the prefabricated tested piece by the soil to be tested in the mold with permeable stone and filter paper, and lay filter paper and permeable stone successively on the top of the tested piece;

(2) Set the parameters of the flushing mechanism to ensure that the water flow rate of the water pipe is constant. The longitudinal distance between the water outlet of the water pipe and the permeable stone at the bottom of the test piece is 5cm. Select the corresponding weight according to the size of the test piece and set it in the guide On the pole, the load is evenly transmitted to the tested piece through the permeable stone and filter paper, and the scouring mechanism is turned on. The scouring time is t, and the soil particles of the tested piece disintegrate under the action of the top load and the bottom hydraulic impact;

(3) The washed and disintegrated soil particles fall into the collecting hopper, are collected by the collecting cup, and after drying at a temperature of 105-110°C, the corresponding load and water flow velocity conditions can be obtained by weighing the mass of the fallen soil particles The erosion resistance capacity of the soil can be evaluated by calculating the corresponding erosion rate v according to the erosion amount m corresponding to the soil.

The method for evaluating the anti-scouring ability of soil provided by the present invention is to transmit the load to the permeable stone through the guide rod, and then transmit the pressure to the tested piece by the permeable stone, and the pressurized weight does not directly load the tested piece. Realize that the top of the tested piece is loaded, the bottom is scoured, and the loading and scouring are carried out synchronously, and the tested piece of the present invention is evenly stressed, and the weight load is used to simulate the covering layer on the upper part of the soil in the actual situation, making up for the current soil resistance. The study of scourability does not involve the influence of force effect. In addition, the device of the present invention has simple structure, reasonable design, convenient disassembly and assembly, simple loading method, loading weight can be freely combined by weights, and data reading is also convenient. The vertical displacement can be read directly by the dial indicator, the experimental results are stable, and the anti-scour performance of the material can be evaluated initially, and the problems of soil erosion, ground subsidence, and ground subsidence in road surface engineering and field sites can be effectively solved. The invention has a wide range of applications , is applicable to most soil and other rock materials, and can effectively solve practical problems such as non-uniform test standards, inconvenient measurement of disintegration, and unreliable test results in the loess disintegration test method.

Description of drawings

Fig. 1 is the structural representation of embodiment 1.

FIG. 2 is a schematic structural diagram of the pressure-bearing unit 4 in FIG. 1 .

FIG. 3 is a schematic structural diagram of the acquisition unit 9 in FIG. 1 .

detailed description

The technical solutions of the present invention will now be further described in conjunction with the drawings and embodiments, but the present invention is not limited to the following implementation situations.

Example 1

As shown in Figure 1, the device for evaluating the anti-scourability of soil in this embodiment is composed of a base 1, a bracket 2, a fixed plate 3, a pressure-bearing unit 4, a loading mechanism 5, a collection unit 9, a water pipe 7, and a scouring mechanism 6. .

The base 1 of the present embodiment is an installation platform for fixing the entire experimental device, on which a support 2 is fixed, and a loading mechanism 5 is installed in the middle of the crossbeam at the top of the support 2, and the loading mechanism 5 includes a guide rod 5-1, a weight 5-2 and the dial indicator 5-3, wherein the guide rod 5-1 extends through the center hole of the bracket 2 crossbeam to the bottom of the crossbeam, and the weight 5-2 is fixed on the guide rod 5-1 by threads, which can be obtained according to The size of the experimental load is adjusted, and a dial gauge 5-3 is installed under the weight 5-2, through which the vertical deformation of the tested piece can be directly measured. In the middle of the bracket 2, a fixed plate 3 with a ring-shaped plate structure is fixed and installed with threaded fasteners. The inner diameter of the fixed plate 3 is 40mm, and it is mainly used to place the pressure unit 4 and provide a place for the pressure unit 4 to be installed. The platform, the pressure unit 4 of this embodiment includes a mold 4-3, an upper permeable stone 4-1, an upper layer of filter paper 4-2, a lower layer of filter paper 4-4 and a lower permeable stone 4-5, as can be seen in Figure 2, the mold 4- 3 is a cylindrical structure that is open at both ends and is used to place the test piece. An upper layer of filter paper 4-2 is placed on the top of the mold 4-3, that is, the top of the test piece, and an upper layer of filter paper 4-2 is placed on the top of the upper layer of filter paper 4-2. Permeable stone 4-1, the diameter of the upper permeable stone 4-1 is the same as the outer diameter of the test piece, the thickness is 5mm, the bottom end of the guide rod 5-1 extends to the middle of the upper permeable stone 4-1, and passes through the upper permeable stone 4 -1 can uniformly bear the load of the weight 5-2 transmitted by the guide rod 5-1, and truly simulate the covering layer on the soil surface. At the bottom of the mold 4-3, that is, the bottom of the tested piece, a lower filter paper 4-4 is placed, and a lower permeable stone 4-5 is placed at the bottom of the lower filter paper 4-4, so that the lower filter paper 4-4, the lower permeable stone 4- 5 are respectively vertically symmetrical with the upper filter paper 4-2 and the upper permeable stone 4-1, and the centers of the lower filter paper 4-4 and the lower permeable stone 4-5 are all processed with water holes to ensure the flushing water flow and the disintegration after being washed For the circulation of soil particles, the diameter of the water hole is 30 mm, and the ratio of the diameter of the test piece to the diameter of the tested piece is 1.5:3. The central axes of the stone 4-1, the upper filter paper 4-2, the mold 4-3, the lower permeable stone 4-5, and the lower filter paper 4-4 are on the same straight line. Below the fixed plate 3, a support rod 8 is installed. The support rod 8 of this embodiment is an L-shaped structure, and its longer arm is placed horizontally. The end is fixed on the support 2 with a threaded fastener, and the other arm extends to In the central hole of the fixing plate 3, the water outlet end of the water pipe 7 is fixed on the arm of the support rod 8 with a cable tie to prevent it from shaking under the action of water pressure. In order to ensure a reliable flushing structure, the water outlet end of the water outlet pipe 7 in this embodiment It should be directly opposite to the center of the bottom of the tested piece, and the longitudinal distance from the lower permeable stone 4-5 is 5cm. In order to control the stability of the water flow velocity, a flow meter is installed at the outlet end of the water pipe 7 to detect the flow of flushing water. The water inlet end of the water pipe 7 communicates with the flushing mechanism 6 . The flushing mechanism 6 of the present embodiment is that an air inlet is processed on the top of the airtight water tank containing the flushing water, and an air pipe communicating with the air pump is installed on the air inlet, and the water tank is pressurized by the air pump, thereby effectively controlling the water pressure and The water flow speed is processed with a water outlet hole at the bottom of the water tank. The water inlet end of the water pipe 7 is installed on the water outlet hole of the water tank. The water flow speed in the water pipe 7 can be controlled by controlling the air pressure in the water tank. When the air pressure is large, the corresponding water flow speed Also fast. A collection unit 9 is installed below the outlet end of the water pipe 7, referring to Fig. 3, the collection unit 9 of the present embodiment is made up of a fixed rod 9-2, a collecting hopper 9-1 and a collecting cup 9-3, the present embodiment Fixed bar 9-2 is to be used for fixing and supporting collecting hopper 9-1, and the funnel-shaped collecting hopper 9-1 can be fixed on the fixed bar 9-2 by common connectors, and the collection hopper is placed directly below collecting hopper 9-1. The material cup 9-3 collects the soil particles that are washed and disintegrated. The diameter of the opening of the collecting hopper 9-1 in this embodiment is greater than the diameter of the water hole of the lower permeable stone 4-5, so as to ensure that all the washed soil particles can pass through the collecting hopper 9- 1 is collected in the collection cup 9-3.

The method for evaluating soil erosion resistance with the above-mentioned device consists of the following steps:

(1) The cylindrical tested piece with a diameter of 60mm and a height of 100mm prefabricated by the soil to be tested is placed in the mold 4-3 with the lower permeable stone 4-5 and the lower filter paper 4-4. The upper layer of filter paper 4-2 and the upper permeable stone 4-1 are successively laid on the top;

(2) Set the parameters of the flushing mechanism 6 to ensure that the water flow rate of the water pipe 7 is constant. The longitudinal distance between the water outlet of the water pipe 7 and the permeable stone at the bottom of the test piece is 5cm, and the corresponding weight 5 is selected according to the size of the test piece -2, set on the guide rod 5-1, through the upper permeable stone 4-1, the upper filter paper 4-2, the lower filter paper 4-4 and the lower permeable stone 4-5, evenly transmit the load to the tested piece, and open the flushing mechanism 6 , under the set constant water flow rate and pressure to wash for t minutes, the soil particles of the tested piece disintegrate under the load on the top and the hydraulic impact on the bottom;

(3) The washed and disintegrated soil particles fall into the collecting hopper 9-1, are collected by the collecting cup 9-3, dried at 108°C for 24 hours, and the corresponding load can be obtained by weighing the collected soil particles According to the erosion amount m corresponding to the soil under the condition of water flow velocity, the corresponding erosion rate v is calculated according to v=m/t. At the same time, the vertical deformation of the tested piece can be directly measured with the dial indicator 5-3, which Evaluate the erosion resistance of the soil.

Example 2

In the device for evaluating the anti-scourability of soil in this embodiment, the pressure-bearing unit 4 includes a mold 4-3, an upper permeable stone 4-1, an upper layer of filter paper 4-2, a lower layer of filter paper 4-4, and a lower permeable stone 4-5. 4-3 is a cylindrical structure that is open at both ends and is used to place the tested piece. On the top of the mold 4-3, that is, the top of the tested piece is placed an upper layer of filter paper 4-2, and placed on the top of the upper layer of filter paper 4-2. There is an upper permeable stone 4-1, the diameter of the upper permeable stone 4-1 is the same as the outer diameter of the test piece, and the thickness is 7mm. The bottom end of the guide rod 5-1 extends to the middle of the upper permeable stone 4-1, and passes through the upper permeable The stone 4-1 can evenly bear the load of the weight 5-2 transmitted by the guide rod 5-1, and truly simulate the covering layer on the soil surface. At the bottom of the mold 4-3, that is, the bottom of the tested piece, a lower filter paper 4-4 is placed, and a lower permeable stone 4-5 is placed at the bottom of the lower filter paper 4-4, so that the lower filter paper 4-4, the lower permeable stone 4- 5 are respectively up and down symmetrical with the upper filter paper 4-2 and the upper permeable stone 4-1, and the centers of the lower filter paper 4-4 and the lower permeable stone 4-5 are all processed with water holes, and the aperture of the water holes is 20mm, which is the same as The ratio of the diameter of the tested piece is 1:3.

The water outlet end of the water outlet pipe 7 of this embodiment should face the bottom center of the test piece, and the longitudinal distance from the lower permeable stone 4-5 is 4cm.

Other components and their connections are the same as in Embodiment 1.

The method for evaluating soil erosion resistance with the above-mentioned device consists of the following steps:

(1) The cylindrical tested piece with a diameter of 60mm and a height of 100mm prefabricated by the soil to be tested is placed in the mold 4-3 with the lower permeable stone 4-5 and the lower filter paper 4-4. The upper layer of filter paper 4-2 and the upper permeable stone 4-1 are successively laid on the top;

(2) Set the parameters of the flushing mechanism 6 to ensure that the water flow rate of the water pipe 7 is constant. The longitudinal distance between the water outlet of the water pipe 7 and the permeable stone at the bottom of the test piece is 5cm, and the corresponding weight 5 is selected according to the size of the test piece -2, set on the guide rod 5-1, through the upper permeable stone 4-1, the upper filter paper 4-2, the lower filter paper 4-4 and the lower permeable stone 4-5, evenly transmit the load to the tested piece, and open the flushing mechanism 6 , under the set constant water flow rate and pressure to wash for t minutes, the soil particles of the tested piece disintegrate under the load on the top and the hydraulic impact on the bottom;

(3) The washed and disintegrated soil particles fall into the collecting hopper 9-1, are collected by the collecting cup 9-3, dried at 105°C for 22 hours, and the corresponding load can be obtained by weighing the collected soil particles According to the erosion amount m corresponding to the soil under the condition of water flow velocity, the corresponding erosion rate v is calculated according to v=m/t. At the same time, the vertical deformation of the tested piece can be directly measured with the dial indicator 5-3, which Evaluate the erosion resistance of the soil.

Example 3

In the device for evaluating the anti-scourability of soil in this embodiment, the pressure-bearing unit 4 includes a mold 4-3, an upper permeable stone 4-1, an upper layer of filter paper 4-2, a lower layer of filter paper 4-4, and a lower permeable stone 4-5. 4-3 is a cylindrical structure that is open at both ends and is used to place the tested piece. On the top of the mold 4-3, that is, the top of the tested piece is placed an upper layer of filter paper 4-2, and placed on the top of the upper layer of filter paper 4-2. There is an upper permeable stone 4-1, the diameter of the upper permeable stone 4-1 is the same as the outer diameter of the test piece, and the thickness is 7mm. The bottom end of the guide rod 5-1 extends to the middle of the upper permeable stone 4-1, and passes through the upper permeable The stone 4-1 can evenly bear the load of the weight 5-2 transmitted by the guide rod 5-1, and truly simulate the covering layer on the soil surface. At the bottom of the mold 4-3, that is, the bottom of the tested piece, a lower filter paper 4-4 is placed, and a lower permeable stone 4-5 is placed at the bottom of the lower filter paper 4-4, so that the lower filter paper 4-4, the lower permeable stone 4- 5 are respectively up and down symmetrical with upper layer filter paper 4-2, upper permeable stone 4-1, are all processed with water hole at the center of lower layer filter paper 4-4 and lower water stone 4-5, and the aperture of this water hole is 40mm, and The ratio of the diameter of the tested piece is 2:3.

The water outlet end of the water outlet pipe 7 of this embodiment should face the bottom center of the test piece, and the longitudinal distance from the lower permeable stone 4-5 is 6cm.

Other components and their connections are the same as in Embodiment 1.

The method for evaluating soil erosion resistance with the above-mentioned device consists of the following steps:

(1) The cylindrical tested piece with a diameter of 60mm and a height of 100mm prefabricated by the soil to be tested is placed in the mold 4-3 with the lower permeable stone 4-5 and the lower filter paper 4-4. The upper layer of filter paper 4-2 and the upper permeable stone 4-1 are successively laid on the top;

(2) Set the parameters of the flushing mechanism 6 to ensure that the water flow rate of the water pipe 7 is constant. The longitudinal distance between the water outlet of the water pipe 7 and the permeable stone at the bottom of the test piece is 5cm, and the corresponding weight 5 is selected according to the size of the test piece -2, set on the guide rod 5-1, through the upper permeable stone 4-1, the upper filter paper 4-2, the lower filter paper 4-4 and the lower permeable stone 4-5, evenly transmit the load to the tested piece, and open the flushing mechanism 6 , under the set constant water flow rate and pressure to wash for t minutes, the soil particles of the tested piece disintegrate under the load on the top and the hydraulic impact on the bottom;

(3) The washed and disintegrated soil particles fall into the collection hopper 9-1, are collected by the collection cup 9-3, dried at 110°C for 26 hours, and the corresponding load can be obtained by weighing the collected soil particles According to the erosion amount m corresponding to the soil under the condition of water flow velocity, the corresponding erosion rate v is calculated according to v=m/t. At the same time, the vertical deformation of the tested piece can be directly measured with the dial indicator 5-3, which Evaluate the erosion resistance of the soil.

The connection methods not described in detail in the above embodiments all belong to welding or screw connection in the conventional technology, and the connection method can be selected according to the actual application.

Claims (7)

1. evaluate the device of Soil Anti scouring capability for one kind, it is provided with support (2) on base (1), be provided with at the top of support (2) for the load maintainer (5) to test specimen load application, middle part is provided with ring-type fixing plate (3), fixed head (3) is provided with the pressure-bearing unit (4) for placing test specimen and undertaking pressure, pressure-bearing unit (4) is just right with load maintainer (5), it is characterized in that: be provided with the collecting unit (9) that the residual particles of washing away rear disintegration is collected in the below of pressure-bearing unit (4), the bottom of pressure-bearing unit (4) is connected with scouring mechanism (6) by water pipe (7),

Above-mentioned load maintainer (5) comprises and is arranged on support (2) top and the guide rod (5-1) be connected with pressure-bearing unit (4) top and the counterweight (5-2) be sleeved on guide rod (5-1), and the central shaft of guide rod (5-1) and test specimen is on same straight line;

Above-mentioned pressure-bearing unit (4) comprises the mould (4-3) for placing test specimen and is arranged on the permeable stone of the interior test specimen top of mould (4-3) and bottom, between permeable stone and test specimen, be also provided with filter paper; The center being arranged on filter paper bottom test specimen and permeable stone is all processed with water hole, and the fore-and-aft distance of the permeable stone bottom the water side distance test specimen of water pipe (7) is 4 ~ 6cm, and just right with the bottom centre of test specimen;

Above-mentioned collecting unit (9) is comprised the fixed bar (9-2) be anchored on support (2), is fixed on the aggregate bin (9-1) on support (2) and is arranged on immediately below aggregate bin (9-1) for collecting the cup that gathers materials (9-3) of disintegration particle by fixed bar (9-2); Aggregate bin (9-1) is just right with the bottom of mould (4-3).

2. the device of evaluation Soil Anti scouring capability according to claim 1, it is characterized in that: the structure of described scouring mechanism (6) is: be processed with air intake opening at the top of the airtight water tank holding water, air intake opening is provided with the tracheae be communicated with air pump, be processed with apopore in the bottom of water tank, the water inlet end of water pipe (7) is communicated with this water tank apopore.

3. the device of evaluation Soil Anti scouring capability according to claim 1 and 2, is characterized in that: the water side of described water pipe (7) is fixed by support bar (8).

4. the device of evaluation Soil Anti scouring capability according to claim 1, is characterized in that: described guide rod (5-1) is also provided with the dial gauge (5-3) for measuring the vertical distortion of test specimen.

5. the device of evaluation Soil Anti scouring capability according to claim 1, is characterized in that: the condition met between the internal diameter of described water hole and the diameter of test specimen is: water hole internal diameter and test specimen diameter ratio are between 1:3 ~ 2:3.

6. the device of evaluation Soil Anti scouring capability according to claim 1, is characterized in that: the thickness of described permeable stone is 5 ~ 8mm, and the fore-and-aft distance of the permeable stone bottom the water side distance test specimen of water pipe (7) is 5cm.

7. evaluate a method for Soil Anti scouring capability with said apparatus, it is made up of following steps:

(1) by be positioned over by the prefabricated test specimen completed of soil to be tested be equipped with permeable stone and filter paper mould (4-3) in, successively lay filter paper and permeable stone at the top of test specimen;

(2) parameter of scouring mechanism (6) is set, ensure that the water flow velocity of water pipe (7) is constant, bottom the water delivering orifice distance test specimen of water pipe (7), the fore-and-aft distance of permeable stone is 5cm, size according to test specimen to be measured selects corresponding counterweight (5-2), be sleeved on guide rod (5-1), evenly load is transmitted to test specimen by permeable stone and filter paper, open scouring mechanism (6), flushing time is t, test specimen soil particle disintegration under top stand under load, bottom waterpower percussive action;

(3) soil particle washing away disintegration is fallen in aggregate bin (9-1), collect through the cup that gathers materials (9-3), under 105 ~ 110 DEG C of temperature conditions after drying, weigh the quality of the soil particle that drops can obtain corresponding load and the erosion quantity m corresponding to water velocity Soil Under Conditions, what calculate correspondence washes away speed v, can evaluate the erosion resistibility of this soil.