CN105738599B - One kind landslide experimental rig - Google Patents

Abstract

The invention proposes a landslide test device, which includes an airflow generator arranged above the slope of the geotechnical model, the airflow generator is a cone structure, at least one tangential air inlet is arranged below it, and an outlet is arranged above it. The air outlet, the air flow generator is connected with the model box through a first connecting rod and a second connecting rod, the top of the first connecting rod is provided with an air inlet at the top of the model box, and the second The top of the connecting rod is provided with an air outlet located at the top of the model box, the air inlet and the air outlet are trumpet-shaped structures, the air inlet is connected to the tangential air inlet through a pipe, and the outlet The tuyere is connected with the air outlet through a pipe. The device for landslide geotechnical model test proposed by the present invention can generate airflow outside the geotechnical model, thereby simulating the influence of extreme airflow conditions such as typhoons and tornadoes on landslides in centrifugal model tests.

Description

A landslide test device

technical field

The invention relates to the technical field of landslide physical models, in particular to a device for landslide geotechnical model tests.

Background technique

In the research work on the mechanism of landslides, the methods used can be mainly summarized as: field survey and test, field monitoring, theoretical analysis and numerical calculation, and physical model test and other methods. Due to the complexity of the formation mechanism of landslides, the use of physical model tests has become one of the important research methods to reproduce the occurrence of landslides.

The landslide physical model test belongs to the category of geomechanics model test, and its theory is derived from the structural model test. The landslide model test is a test technology for the specific research object of landslide in the geomechanics model test. Its development has experienced frame model test, bottom surface friction model test, on-site three-dimensional and full-scale model test, water seepage model test, and geotechnical centrifugal model. At the testing stage such as testing, most of the commonly used geomechanical model tests at home and abroad are frame model tests and centrifugal model tests.

The centrifugal model test is widely used in landslide research because it uses the centrifugal force generated by the high-speed rotation of the geotechnical centrifuge to simulate gravity. Under Ng conditions, the stress and strain of the small-scale centrifugal model can be the same or similar to the prototype. In the model test, a large number of documents have disclosed the situation of simulating earthquake and rain by shaking table and precipitation device, such as a kind of rainfall device for geotechnical centrifugal model test disclosed by Chinese patent CN204108697U, and a centrifugal model disclosed by CN104391103A. Rainfall simulation methods and their devices; however, how to simulate extreme airflow conditions such as typhoons and tornadoes in centrifugal model tests to study their impact on landslides has not yet been related.

Contents of the invention

The technical problem to be solved by the present invention is to provide a landslide test device to reduce or avoid the aforementioned problems.

In order to solve the above-mentioned technical problems, the present invention proposes a landslide test device, which is arranged on a model box for placing a geotechnical model, and includes an airflow generator arranged above the slope of the geotechnical model, and the airflow generator is a cone structure, at least one tangential air inlet is arranged below it, and an air outlet is arranged above it, and the air flow generator is connected with the model box through a first connecting rod and a second connecting rod, and the first connecting rod The top of the rod is provided with an air inlet located at the top of the model box, and the top of the second connecting rod is provided with an air outlet located at the top of the model box, the air inlet and the air outlet are horn-shaped structures, The air inlet is connected to the tangential air inlet through a pipe, and the air outlet is connected to the air outlet through a pipe.

Preferably, the air outlet is provided with a solenoid valve.

Preferably, the air inlet is provided with a solenoid valve.

Preferably, the distance between the tangential air inlet and the bottom edge of the airflow generator is not less than 1/8 of the height of the airflow generator.

Preferably, the tangential air inlet and the bottom edge of the airflow generator have an inclination angle of 3-8 degrees.

Preferably, the distance between the tangential air inlet and the tangent line parallel to the inner wall of the airflow generator is 2-5 mm.

The invention proposes a device for landslide geotechnical model test, which can generate airflow outside the geotechnical model, thereby simulating the influence of extreme airflow conditions such as typhoons and tornadoes on landslides in centrifugal model tests.

Description of drawings

The following drawings are only intended to illustrate and explain the present invention schematically, and do not limit the scope of the present invention. in,

Figure 1 shows a schematic structural view of a geotechnical centrifuge;

What Fig. 2 shows is a kind of structural principle schematic diagram of the device for landslide geotechnical model test according to a specific embodiment of the present invention;

Figure 3 shows a schematic cross-sectional view of the tangential air inlet of the airflow generator in Figure 2;

FIG. 4 shows a schematic cross-sectional structure diagram of the airflow generator in FIG. 2 .

detailed description

In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation manners of the present invention will now be described with reference to the accompanying drawings. Wherein, the same parts adopt the same reference numerals.

The structural representation of the geotechnical centrifuge shown in Fig. 1; Referring to Fig. 1, in the centrifugal model test, the centrifugal model is usually arranged in a model box, and the model box is placed in the hanging basket 1 of the geotechnical centrifuge, when said When the geotechnical centrifuge rotates at a high speed, a centrifugal acceleration of Ng will be generated in the hanging basket 1. At this time, the small-sized centrifugal model can obtain the same or similar stress and strain as the prototype, and it can also achieve the same or similar stress and strain as the original mountain body. Slope landslide research. Usually, when studying landslides, the centrifugal acceleration of the geocentrifuge will be above 30g, or even exceed 50g. Therefore, there will be high-speed airflow outside the model box, but because the model boxes used in the centrifugal model test are usually open structures, the airflow outside the centrifugal model is relatively stable in the model box, that is, the airflow outside the centrifugal model relatively static.

What Fig. 2 shows is a kind of schematic diagram of the structure principle of the device for geotechnical model test of landslide according to a specific embodiment of the present invention; What Fig. 3 shows is the cross-sectional schematic diagram of the tangential air inlet of airflow generator in Fig. 2 ; Figure 4 shows a schematic diagram of the cross-sectional structure of the airflow generator in Figure 2. Referring to shown in Fig. 2-4, in order to be able to control the airflow outside the centrifugal model, thereby can simulate extreme airflows such as typhoon, tornado in the centrifugal model test, the present invention provides a kind of device that is used for landslide geotechnical model test, and it is arranged on Place on the model box 3 of the geotechnical model 2, which includes an airflow generator 41 arranged above the slope of the geotechnical model 2, the airflow generator 41 is a cone structure, and at least one tangential air inlet 4111 is arranged below it , an air outlet 412 is arranged above, and the air flow generator 41 is connected with the mold box 3 through a first connecting rod 42 and a second connecting rod 43, and a top of the first connecting rod 42 is provided with a The air intake 44 at the top of the model box 3, the top of the second connecting rod 43 is provided with an air outlet 45 at the top of the model box 3, the air intake 44 and the air outlet 45 are horn-shaped structures, The air inlet 44 is connected to the tangential air inlet 4111 through a pipe, and the air outlet 45 is connected to the air outlet 412 through a pipe.

During the installation process, the top of the model box 3 can be provided with a crossbeam, so that the first connection 42 and the second connecting rod 43 can be fixed, and the first connecting rod 42 is located at the top of the model box 3 when it is rotating. On the windward side during rotation, the second connecting rod 43 is located on the leeward side of the mold box 3 during rotation.

When the geotechnical centrifuge rotates at a high speed, the airflow entering the tangential air inlet 411 through the air inlet 44 is reduced in cross-section, so the flow velocity increases, thus entering the airflow from the tangential air inlet 411 After the airflow generator 41, a swirling air field will be generated in the airflow generator 41, and a negative pressure will be formed outside the geotechnical model 2, thereby simulating extreme airflow conditions that can generate negative pressure such as tornadoes. The airflow generated by the swirling flow and the airflow sucked into the airflow generator 41 can be discharged from the air outlet 45 through the air outlet 412 through a pipe. Therefore, the air field environment in the model box 3 will not be affected too much.

Referring to Fig. 3, the distance d between the channel of the tangential air inlet 411 and the closest tangent line parallel to the inner wall of the airflow generator 41 can be set to 2-5 mm, so that on the one hand, it can be guaranteed from the tangential The airflow entering the air inlet 411 can conveniently generate a swirl flow, and on the other hand, it is convenient to process the tangential air inlet 411 .

Referring to Fig. 2, in order to facilitate the calculation of the pressure generated by the airflow on the geotechnical model 2, the airflow generator 41 will be arranged parallel to the slope of the geotechnical model 2, that is to say, the airflow generator 41 corresponds to The bottom of the model box 3 has an angle of inclination. In this case, in order to ensure that the swirling air field in the airflow generator 41 will converge to the top of the airflow generator 41, as shown in FIG. 4, the The distance H1 between the tangential air inlet 411 and the bottom edge of the airflow generator 41 is not less than 1/8 of the height H of the airflow generator 41, and the passage of the tangential air inlet 411 and the The bottom edge of the airflow generator 41 has an inclination angle α of 3-8 degrees.

The tangential air inlets 411 can be provided in multiples, for example, two or four can be arranged symmetrically along the center of the circle on the section where they are located. This can ensure the stability of the central position of the swirl air field generated under different intake flow rates.

Referring to Fig. 4, the air outlet 412 is only used as the outflow channel of the swirling airflow, so it can be arranged on the side wall of the airflow generator 41 close to the top edge, of course, it can also be arranged on the side wall where the airflow occurs. On the top edge of the device 41, a solenoid valve can be set at the air outlet 412, so that the air outlet 412 can be closed by closing the electromagnetic valve. When the air outlet 412 is closed, the gas outlet 411 When entering the airflow generator 41, it will overflow onto the geotechnical model 2, thereby simulating extreme airflow conditions that can generate positive pressure such as typhoons.

A solenoid valve (not shown in the figure) can be provided with the air intake port 44, so that the air intake can be adjusted during the test.

The airflow pressure generated by the device for landslide geotechnical model test provided by the present invention in the centrifuge test can be measured by setting air pressure sensors in the airflow generator 41 and the model box.

The invention proposes a device for landslide geotechnical model test, which can generate airflow outside the geotechnical model, thereby simulating the influence of extreme airflow conditions such as typhoons and tornadoes on landslides in centrifugal model tests.

Those skilled in the art should understand that although the present invention is described in terms of multiple embodiments, not each embodiment only includes an independent technical solution. The description in the description is only for the sake of clarity, and those skilled in the art should understand the description as a whole, and understand the present invention by considering the technical solutions involved in each embodiment as being able to be combined with each other to form different embodiments scope of protection.

The above descriptions are only illustrative specific implementations of the present invention, and are not intended to limit the scope of the present invention. Any equivalent changes, modifications and combinations made by those skilled in the art without departing from the concept and principle of the present invention shall fall within the protection scope of the present invention.

Claims (1)

1. A landslide test device is arranged on a model box for placing a geotechnical model and is characterized by comprising an airflow generator arranged above a slope of the geotechnical model; the airflow generator is of a cone-shaped structure, at least one tangential air inlet is arranged below the airflow generator, and an air outlet is arranged above the airflow generator; the airflow generator is connected with the model box through a first connecting rod and a second connecting rod, the top of the first connecting rod is provided with an air collecting opening which is positioned at the top of the model box, the top of the second connecting rod is provided with an air outlet which is positioned at the top of the model box, the air collecting opening is of a horn-shaped structure, the air collecting opening is connected with the tangential air inlet through a pipeline, the air outlet is connected with the air outlet through a pipeline, the air outlet is provided with an electromagnetic valve, and the air collecting opening is provided with an electromagnetic valve.