Test device for detecting biomineralization combined sand stabilization effect

Abstract

The utility model discloses a test device for detecting a biomineralization combined sand stabilization effect, which comprises a test box body, one end of the box body is open, the tail end of the box body is sealed, a wind power system for providing test wind power is arranged at an inlet of the test box body, and the test box body is sequentially provided with a sand storage area, a sand stabilization area and a sand collection area along the wind power advancing direction; a fence is arranged between the sand storage area and the sand stabilization area, and an embankment is arranged between the sand stabilization area and the sand collection area; sand prevention plants are planted in the sand stabilization area in batches; the fences, the sand prevention plants and the embankment are used for intercepting sand and sand, and sand and dust which are not blocked are finally intercepted in the sand collection area. According to the device, the similarity principle is utilized, the sand prevention and sand fixation system of a desert expressway and a railway is shrunk, an indoor test model is manufactured, the influence of the airflow velocity in a certain range on the sand prevention and sand fixation effect of a biomineralization sand fixation system is simulated, and the real sand prevention and sand fixation condition can be speculated according to the test result; and a test basis is provided for practical design and optimization of technical parameters.

Description

Technical Field

[0001] The utility model relates to a test device for detecting the effect of biomineralization combined with sand fixation, and belongs to the technical field of sand prevention and control. Background Art

[0002] Sandstorms in arid areas have caused a large amount of arable land and grassland to be swallowed up, and a large amount of organic soil has been taken away. The originally fertile land has become increasingly poor in soluble soil. In addition, the "sand harvesting" phenomenon has destroyed crops, resulting in a large reduction in crop yields or even a total crop failure. The large amount of fine sand and dust carried by sandstorms is also very harmful when it is blown by the wind. If these fine sand and dust fall to the ground, they will bury villages, arable land, grasslands, railways, roads and water sources, bringing a devastating blow to industrial and agricultural production; and if these fine sand and dust are blown by the wind in the air to form aerosols, it will cause great harm to human health. Therefore, for infrastructure such as highways, railways and water channels in desert areas, the design of sand control and sand fixation structures and the assessment of their effects are particularly critical, directly affecting the operational safety of these infrastructure facilities.

[0003] In the design of sand prevention and fixation structures, grass grid sand barriers are the most representative and have obvious effects. Dun Yaoquan et al. wrote an article entitled "A Review of the Research on the Protection System of the Shapotou Section of the Baotou-Lanzhou Railway" ("China Desert", 2021, 41 (3): 66-74), which introduced that the Baotou-Lanzhou Railway line crosses the vast Tengger Desert, of which 27 km of the railway embankment is directly laid on thick sand dunes. It has been more than 60 years since its opening, and the Baotou-Lanzhou Railway has been unobstructed during this period. In addition to the protective forests with a width of about 7.4 km that were built with great effort on both sides of the railway, more benefits have been gained from the large-scale laying of grass grids. These grass grids successfully fixed the sand particles, delayed the migration of sand particles, and effectively protected the railway embankment. Liu Xianwan explained in "Wind Tunnel Test of Grass Grid Sand Barrier" (Ningxia People's Publishing House, 1988) that the wind and sand prevention principle of fence projects and the wind and sand prevention benefits of various fence projects were explained through experiments, providing a theoretical and experimental basis for the design and application of fence projects. However, the grass grids are prone to degradation and being buried by quicksand. Later, sand fences were used at the front of the sand control, which played an important role in sand control. However, due to the complex and changeable airflow field, the sand fences changed the local airflow field after they were set up, and formed eddy fields and continuous effects, which accumulated a lot of quicksand beside the sand fences, causing the sand fences to fail.

[0004] Therefore, early sand control and sand fixation facilities will soon encounter problems such as fences being buried, grass grids being buried, and wind and sand rushing to the road surface or track, which seriously threatens the operational safety of roads and railways. In order to delay the occurrence of the above phenomena and improve the effect of sand control and sand fixation, technicians need to conduct corresponding simulation tests in advance in the physical engineering design to optimize parameters such as the width of the sand control belt, fence height and permeability in advance. These parameters are closely related to the local natural environment (wind force and speed, etc.). Due to the limitations of the site and test equipment, it is difficult to conduct full-scale field tests through indoor simulation tests.

[0005] Biomineralization sand fixation is a new sand fixation technology developed in recent years, but there is no test device for biomineralization sand fixation effect detection. It is best to design a scaled test model with a certain similarity ratio, and through the analysis of test results and theoretical calculation comparison, obtain the relationship between regular parameters and sand control and sand fixation effects, and realize the improvement of joint sand control and sand fixation design technology. Summary of the invention

[0006] In order to overcome the shortcomings of the prior art, the purpose of the utility model is to provide a test device for the combined biomineralization and sand fixation effect, reduce the sand control and sand fixation system of desert highways and railways according to the geometric proportion (the utility model adopts the similarity ratio = 1:100), simulate the influence of air flow velocity on the sand control and sand fixation effect of the sand fixation system, and then infer the real combined sand control and sand fixation situation, and provide technical parameters for realistic design (such as: the effective service life of fence sand control, sand control and sand fixation efficiency, and the safety of embankments).

[0007] A test device for detecting the effect of biomineralization combined with sand fixation, comprising: a test box, one end of which is open and the rear end is sealed, a wind system 1 for providing test wind force is arranged at the entrance of the test box, and the test box is arranged in sequence along the direction of wind force to form a sand storage area 7, a sand fixation area 8 and a sand collection area 3;

[0008] A fence 5 is arranged between the sand storage area and the sand fixation area 8, and an embankment 6 is arranged between the sand fixation area 8 and the sand collection area 3;

[0009] Planting sand-control plants in batches in the sand-fixing area 8;

[0010] The fence 5 , plants and embankment 6 are used to intercept the wind-blown sand, and the unobstructed sand and dust are finally retained in the sand collection area 3 .

[0011] The aforementioned test device for detecting the combined effect of biomineralization and sand fixation has wind speed sensors arranged in the spatial observation sections within the sand collection area 7, the sand fixation area 8, and behind the embankment 6. Each observation section has 9 wind speed sensors, which are evenly distributed in the upper, middle, lower, left and right directions.

[0012] The aforementioned test device for detecting the combined effect of biomineralization and sand fixation has a test box made of transparent plexiglass, a rectangular cross-section of 50 cm × 50 cm, and a total length of 260 cm. In actual use, the length of the box can be extended or shortened according to needs.

[0013] The aforementioned test device for detecting the combined effect of biomineralization and sand fixation has a cone-shaped cross-section at the rear end of the box, which is arc-shaped and convenient for intercepting the sand blown to the rear of the device.

[0014] The aforementioned test device for detecting the combined effect of biomineralization and sand fixation has a wind system that is a high-power fan, the output diameter of which is equal to the inlet of the test box, and the connection between the two is kept sealed.

[0015] The aforementioned test device for detecting the effect of biomineralization combined with sand fixation, wherein the sand storage area is 30-50cm long and the sand laying thickness is 3-5cm; the sand fixation area 8 is 80-150cm long, and the sand collection area is 30-60cm long; the embankment is 2cm-3cm high, 5-10cm wide at the top, and 10-20cm wide at the bottom; the fence is 1.5cm-2.5cm higher than the sand surface in the sand storage area, and the fence permeability is 0~60%.

[0016] Beneficial Effects

[0017] The test device for detecting the combined sand-fixing effect of biomineralization described in the utility model utilizes similar principles to produce a test model suitable for use in a laboratory, simulates the outdoor environment of desert highways and railways, keeps similar parameters consistent, and reduces the scale according to geometric proportions. It can simulate the sand-preventing and sand-fixing effect of the sand-fixing system within a certain range of airflow velocity, and then, based on the test results, the actual combined sand-preventing and sand-fixing conditions can be inferred, providing technical parameters for the design of a combined sand-fixing system for highways and railways in desert areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional structural schematic diagram of a test device for detecting the biomineralization combined with sand fixation effect of the utility model.

[0019] Figure 2 It is a top view of a test device for detecting the biomineralization combined with sand fixation effect of the utility model.

[0020] Figure 3 It is a front view of the test device for detecting the biomineralization combined with sand fixation effect of the utility model.

[0021] Figure 4 This is a schematic diagram of a fan.

[0022] Explanation of reference numerals: 1- wind system, 2- test box, 3- sand collection area, 4- air flow direction, 5- fence, 6- embankment, 7- sand storage area, 8- sand fixation area, 9- wind speed sensor. DETAILED DESCRIPTION

[0023] The technical solution of the utility model will be described below in conjunction with specific embodiments:

[0024] Example 1

[0025] The technical solution of the utility model will be specifically described below in conjunction with embodiments:

[0026] A test device for detecting the combined effect of biomineralization and sand fixation comprises a test box, which is open at one end and sealed at the rear end. The box is made of transparent organic glass, has a cross-section of 50 cm×50 cm and a total length of 260 cm. In actual use, the size of the box can be extended or shortened according to needs.

[0027] A wind system 1 for providing test wind is set at the entrance of the test box. The tail section is a cone structure with an arc shape, which is convenient for intercepting the sand blown to the tail of the device. The wind system is a high-power fan with a diameter of 60-80cm. To prevent wind loss, the fan and the test box are sealed.

[0028] The test box is arranged in the direction of wind travel in sequence as a sand storage area 7, a sand fixation area 8 and a sand collection area 3; a fence 5 is arranged between the sand storage area and the sand fixation area 8, and an embankment 6 is arranged between the sand fixation area 8 and the sand collection area 3. Wind speed sensors are arranged in the space observation sections behind the sand collection area 7, the sand fixation area 8 and the embankment 6. Each observation section is equipped with 9 wind speed sensors, which are evenly arranged in the upper, middle, lower, left and right directions.

[0029] The length of the sand collection area is 30-60cm; the length of the sand fixation area 8 is 80-150cm. There are four optional sand fixation methods: no sand fixation, plant sand prevention, biomineralization sand fixation, and biomineralization sand fixation + planting plants. The concentration of biochemical liquid for biomineralization is designed to be 0.25Mol / L and 0.5Mol / L, and the biochemical liquid is sprayed for sand fixation.

[0030] The embankment is 2cm-3cm high, 5-10cm wide at the top and 10-20cm wide at the bottom.

[0031] Fences 5 , plants planted in the sand fixation area, and embankments 6 are used to intercept wind-blown sand, and the unobstructed sand and dust are eventually retained in the sand collection area 3 .

[0032] The length of the sand storage area is 30-50cm, and the thickness of the sand is 3-5cm. The wind-blown sand from the desert area is weighed and evenly laid in the sand storage area. After the test, the weight of the sand collected in the sand collection area 3 is weighed. The sand blocking efficiency of different sand fixation methods under different wind forces is analyzed through the difference in sand weight. The sand in the sand storage area can be supplemented in time according to the progress of the test.

[0033] The wind system selects the blower products sold in the market, and its technical parameters are required to be: the adjustable wind speed range is: 5.0-30.0m / s; the air volume control range is: 8000-26000 m 3 / h. The wind speed levels are controlled as follows: 10m / s, 15m / s, 20m / s, 25m / s, 30m / s, a total of 5 levels, to study and analyze the wind erosion of different levels of wind force and the sand-blocking effects of different sand-fixing methods.

[0034] The fence is 1.5cm-2.5cm higher than the sand surface in the sand storage area, and the fence permeability is 0~60%. The height and permeability of the fence are determined according to the test needs to verify the fence's ability to block sand.

[0035] Example 2

[0036] The test device for detecting the biomineralization combined sand fixation effect of the utility model is used to investigate the sand fixation effect under different sand fixation area working conditions.

[0037] 1. Working conditions in sand fixation areas: (a) no sand fixation, (b) only plant sand fixation, (c) biomineralization sand fixation, (d) biomineralization combined with plant sand fixation. Among them, (c) biomineralization sand fixation is to use only biomineralization liquid spraying and solidification, where the concentration of biomineralization liquid is 0.25Mol / L and 0.5Mol / L respectively. The selection of biomineralization liquid is mainly determined by the project team's preliminary indoor and outdoor tests. Please refer to the paper "Experiment and Application of Biomineralization Technology for Solidification of Aeolian Sand" by Miao Linchang et al. (Journal of Southeast University (Natural Science Edition). 2023, 53(01), 149-155). (d) Biomineralization combined with plant sand fixation, the situation of using biomineralization liquid spraying and solidification combined with planting plants is investigated, and drought-resistant plants that grow naturally in the desert, such as Artemisia ordosica and Ice Grass, are selected.

[0038] 2. The similarity ratio of the model is 1:100, the length of the sand storage area is 50 cm, the length of the sand fixation area is 100 cm, the length of the sand collection area is 60 cm, the fence is 1.5 cm higher than the sand surface of the sand storage area, the embankment height is 3 cm, the embankment top width is 10 cm, and the embankment bottom width is 20 cm. The test results are summarized in Tables 1 and 2.

[0039] Table 1 Sediment transport and accumulation under different working conditions (wind speed 10m / s)

[0040]

[0041] Table 2 Sediment transport and accumulation under different working conditions (wind speed 15m / s)

[0042]

[0043] Considering that the wind fan blows continuously with equal intensity during the test, while the wind in nature is intermittent, the present invention evaluates the effect of sand fixation according to the sand blocking rate and designs the size of the corresponding sand fixation area.

[0044] The order of influence of various parameters on the effect of sand control and sand fixation is as follows: (1) The ratio of the sum of accumulated sand before and after the fence to the amount of sand transported. The larger the ratio, the better the sand control effect; (2) The less sand accumulated on the top of the embankment, the better the sand control effect. (3) The failure time of the fence. The time required for the height of the accumulated sand before and after the fence to be equal to the height of the fence is defined as the failure time of the fence. The above factors comprehensively evaluate the effect of sand control and sand fixation. From the test results in Table 1 and Table 2, as the wind force increases, the amount of sand transported also increases, and the failure time of the fence also decreases slightly. In general, biomineralization combined with plant sand fixation has the best sand control effect when the permeability of the fence is 0.3, and there is no sand accumulation on the embankment. By analyzing the above test data, the technical parameters can be optimized.

[0045] The use of this biomineralization combined sand fixation test device can greatly save the relevant test costs, which is only about 1 / 10~1 / 20 of the original test costs. The test cycle is also greatly shortened, and the test repeatability is high. At the same time, it provides a technical path for technical inspection and design parameter verification for the promotion and application of the new technology of biomineralization sand fixation.

[0046] When designing the protective belt in actual engineering, you can refer to this formula for design:

[0047] Width of protection belt = length of sand fixation area in model test * similarity ratio

[0048] Fence height = Fence height during model test * Similarity ratio

[0049] In this way, technical parameters such as fences, protection belt width, biomineralization and sand fixation can be obtained, and the effectiveness of the design parameters of the protection belts of related projects is guaranteed.

Claims

1. A test device for detecting the effect of biomineralization combined with sand fixation, characterized in that: include: A test box, wherein one end of the box is open and the rear end is sealed, a wind system (1) for providing test wind force is arranged at the entrance of the test box, and the test box is arranged in sequence along the direction of wind force travel to form a sand storage area, a sand fixation area and a sand collection area; Fences are arranged between the sand storage area and the sand fixation area, and embankments are set up between the sand fixation area and the sand collection area; Planting sand-control plants in batches in sand-fixing areas; Fences, sand-control plants and embankments are used to intercept wind-blown sand, and any sand that is not blocked is eventually retained in the sand collection area.

2. A test device for detecting the effect of biomineralization combined with sand fixation according to claim 1, characterized in that: Wind speed sensors are arranged in the spatial observation sections in the sand collection area, sand fixation area and behind the embankment. Each observation section has 9 wind speed sensors, evenly distributed in the top, middle, bottom, left and right.

3. The test device for detecting the effect of biomineralization combined with sand fixation according to claim 1, characterized in that: The test box is made of transparent plexiglass, with a cross-section of 50 cm × 50 cm in a rectangle and a total length of 260 cm. In actual use, the length of the box can be extended or shortened as needed.

4. The test device for detecting the effect of biomineralization combined with sand fixation according to claim 1, characterized in that: The cross-section of the rear end of the box is a conical structure in an arc shape, which is convenient for intercepting the sand blown to the rear of the device.

5. The test device for detecting the effect of biomineralization combined with sand fixation according to claim 1, characterized in that: The wind system is a high-power fan, the output diameter is equal to the inlet of the test chamber, and the connection between the two is kept sealed.

6. The test device for detecting the effect of biomineralization combined with sand fixation according to claim 1, characterized in that: The length of the sand storage area is 30-50cm, and the thickness of the sand is 3-5cm; The length of the sand fixation area (8) is 80-150 cm, and the length of the sand collection area is 30-60 cm; The embankment is 2cm-3cm high, 5-10cm wide at the top and 10-20cm wide at the bottom; The fence is 1.5cm-2.5cm higher than the sand surface in the sand storage area, and the fence permeability is 0~60%.

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