Adjustable model box device for indoor roadbed model test

Abstract

The utility model belongs to the technical field of geotechnical engineering equipment, and particularly discloses an adjustable model box device for an indoor roadbed model test, which comprises a box body and a bottom steel plate, the bottom of the box body is connected with the bottom steel plate, a reaction frame is arranged above the box body, a loading device is arranged on the reaction frame, and the loading device is connected with the box body. The loading device acts on the interior of the box body, a settlement rod and an earth pressure box are embedded in the box body, a dial indicator is arranged on the settlement rod, and a digital image correlation method observation instrument is arranged on one side of the box body; a digital image correlation method can be used for acquiring the settlement of a soil body when the upper part of a roadbed indoor model test is loaded under different conditions, so that the settlement rule of different roadbed fillers under the action of different loads of a roadbed is analyzed; the problem that the model box is not perfectly matched due to size change caused by selecting different sections or different working conditions for scale test can be solved, the operation is convenient, and the waste of materials cannot be caused.

Description

TECHNICAL FIELD

[0001] The utility model belongs to geotechnical engineering equipment technical field, concretely relates to a kind of adjustable model box device for indoor roadbed model test. BACKGROUND

[0002] In recent years, with the rise of digital image correlation method, more and more researchers apply this method to scientific research, but most of them are used to collect deformation images when block body is broken, such as rock, concrete test block and unconfined compression test piece. Digital image correlation method is a non-contact, high-precision full-field observation technology based on digital image technology. This method has the advantages of loose experimental environment requirements, full-field measurement, strong anti-interference ability and high measurement accuracy, and has great advantages for deformation observation of roadbed model test.

[0003] Currently, it is difficult to solve the speckle making problem after compacting soil in the model box during indoor model box test of roadbed failure and slope stability. Speckle is essential for observation using digital image correlation method. This situation greatly hinders the progress of related tests and the acquisition and analysis of subsequent data. Therefore, we need to explore effective solutions to overcome the technical problem that speckle cannot be made after compacting in roadbed model test, so that digital image correlation method cannot be used for observation.

[0004] On the other hand, indoor scale model working conditions are rich, and the size requirements of model box will change under different working conditions and section designs. Larger model box will cause material waste and inconvenience when used in working conditions with smaller scale model size, and smaller model box cannot be used in working conditions with larger scale model size. UTILITY MODEL CONTENTS

[0005] The utility model aims to provide an adjustable model box device for indoor roadbed model test, to solve the technical problems that speckle cannot be made after compacting in roadbed model test, digital image correlation method cannot be used for observation, and it is difficult to meet the new working condition size model box under different working conditions.

[0006] To achieve the above purpose, the utility model adopts the following technical scheme:

[0007] An adjustable model box device for indoor roadbed model test, comprising a box body and a bottom steel plate, the bottom of the box body is connected with the bottom steel plate, a counterforce frame is arranged above the box body, a loading device is arranged on the counterforce frame, the loading device acts on the inside of the box body, a settlement rod and a earth pressure cell are embedded in the inside of the box body, a dial gauge is arranged on the settlement rod, and a digital image correlation method observer is arranged on one side of the box body.

[0008] Preferably, the box body comprises a first angle steel grid, a second angle steel grid, a third angle steel grid and an angle steel, the first angle steel grid and the second angle steel grid are vertically connected on one side, the second angle steel grid is vertically connected with the third angle steel grid on the other side, the first angle steel grid and the third angle steel grid are arranged in parallel, the first angle steel grid and the third angle steel grid are connected on the other side through the angle steel, the bottom surface of the first angle steel grid, the second angle steel grid and the third angle steel grid is connected with the bottom steel plate, and the upper surface of the first angle steel grid, the second angle steel grid and the third angle steel grid is connected through the angle steel.

[0009] Preferably, the first angle steel grid, the second angle steel grid and the third angle steel grid are composed of a plurality of corresponding angle steel grids, and the plurality of angle steel grids are fixedly connected through bolts.

[0010] Preferably, the loading device comprises a counterforce frame, a jack is arranged on the counterforce frame, a bearing plate is arranged on the extending end of the jack, and the bearing plate acts on the inside of the box body.

[0011] Preferably, a high-transparency glass plate is arranged on the first angle steel grid, a first high-density foam plate is arranged on the second angle steel grid, and a second high-density foam plate is arranged on the third angle steel grid.

[0012] The indoor roadbed model test device for digital image correlation method collection has the advantages that:

[0013] (1) The indoor roadbed model test device for digital image correlation method collection can collect the settlement of the soil body on the upper part of the roadbed indoor model test under different conditions by using the digital image correlation method, so that the settlement rules of the roadbed under different loads and different roadbed fillers are analyzed.

[0014] (2) The adjustable model box device of the indoor roadbed scale model test can solve the problem that the model box is not perfectly matched due to the size change caused by selecting different sections or different working conditions for scale test, which is convenient to operate and does not cause waste of materials. BRIEF DESCRIPTION OF DRAWINGS

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

[0016] Figure 2 It is a model box structure schematic view of the utility model;

[0017] In the figure: 1, No. 1 angle steel grid; 2, No. 2 angle steel grid; 3, No. 3 angle steel grid; 4, bottom steel plate; 5, No. 1 high-density foam board; 6, No. 2 high-density foam board; 7, high-transparency glass plate; 10, bolt rod; 11, silica gel gasket; 13, angle steel; 14, digital image correlation method observation instrument; 15, counterforce frame; 16, jack; 17, bearing plate; 18, dial indicator; 19, settlement rod. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the utility model will be described in detail and completely in combination with the drawings in the embodiments of the utility model. It can be very clearly known that the embodiments described herein are only a part of the numerous embodiments of the utility model, and are not all the embodiments. On the basis of the embodiments covered by the utility model, all the other embodiments obtained by the ordinary skilled in the art without creative labor are within the protection scope of the utility model.

[0019] As Figure 1 and 2 Adjustable model box device for indoor roadbed model test, including box and bottom steel plate 4, the bottom of the box is connected with the bottom steel plate 4, the upper portion of the box is provided with counterforce frame 15, the counterforce frame 15 is provided with loading device, the loading device includes counterforce frame 15, the counterforce frame 15 is provided with jack 16, the jack 16 is provided with bearing plate 17 on the extension end, the bearing plate 17 acts on the soil in the box. The settlement rod 19 and the earth pressure cell are embedded in the box, the dial indicator 18 is arranged on the settlement rod 19, the earth pressure cell (the model of the earth pressure cell used is BW27R) is used to detect the change of the internal pressure of the soil when the roadbed model is pressed, the settlement of the soil is detected by observing the change of the dial indicator data, the digital image correlation method observation instrument 14 is arranged on one side of the box, and the displacement of the roadbed filling soil after receiving the loading pressure is monitored by the digital image correlation method observation instrument 14 using the digital image correlation method.

[0020] The box body comprises a first angle steel grid 1, a second angle steel grid 2, a third angle steel grid 3 and an angle steel 13. The first angle steel grid 1 and the second angle steel grid 2 are vertically connected on one side, the second angle steel grid 2 is vertically connected with the third angle steel grid 3 on the other side, the first angle steel grid 1 and the third angle steel grid 3 are arranged in parallel, the first angle steel grid 1 and the third angle steel grid 3 are connected on the other side through the angle steel 13, the bottom surfaces of the first angle steel grid 1, the second angle steel grid 2 and the third angle steel grid 3 are connected with the bottom steel plate 4 through bolts, the upper surfaces of the first angle steel grid 1, the second angle steel grid 2 and the third angle steel grid 3 are connected through the angle steel 13, and the angle steel 13 is reinforced through "ribbed" processing. No shelter is arranged on the top to facilitate loading and observing the damage of the top of the roadbed and the slope. The high-transparency glass plate 7 is installed on the first angle steel grid 1 by using the bolt rod 10 and the silica gel gasket 11, which facilitates the dismounting and mounting of the high-transparency glass plate 7 for spraying black matte paint and point-painting white speckles. The high-transparency glass plate 7 is used for observation and digital image correlation method observation instrument 14 detection and shooting. The first high-density foam plate 5 is installed on the second angle steel grid 2, and the second high-density foam plate 6 is installed on the third angle steel grid 3. The high-density foam plate can eliminate stress concentration and meet the strength requirement.

[0021] The first angle steel grid 1, the second angle steel grid 2 and the third angle steel grid 3 are composed of a plurality of corresponding angle steel grids. The plurality of angle steel grids are fixedly connected through bolts. The positions of the bolts can be changed on the bottom plate according to different size requirements. Meanwhile, the grids can be spliced and widened or dismounted and narrowed, so that the size of the lateral model box can be changed. When the internal testing instrument of the roadbed scale model is large, the size of the model box can be increased to avoid size effect. When a large size is not needed, the size of the model box can be reduced to reduce the consumption of manpower and material resources. Embodiment

[0022] In this embodiment, as shown in Figure 2 The soil is filled in three layers, and a soil pressure box is buried at the bottom of each layer of soil to detect the change of the internal pressure of the soil when the roadbed model is pressed. A settlement rod is buried on the upper part of the first layer and the second layer of soil, and a dial gauge is arranged on the upper part of the settlement rod. The settlement of the soil is detected by observing the change of the data of the dial gauge.

[0023] After the soil compaction and sensor burying are completed, the bolt rod 10 at the observation edge of the first angle steel grid 1 is dismounted, the silica gel gasket 11 is removed, and the high-transparency glass 7 is removed. Black matte paint is sprayed on the surface of the soil. After the black matte paint is dried, white paint is used to point-paint speckles on the surface of the black matte paint. After the surface of the speckles is dried, the high-transparency glass plate is mounted back, the silica gel gasket is placed, and the bolt rod is inserted back.

[0024] In this embodiment, after the speckle is made, a bearing plate 17 is placed on the top of the roadbed model, and the bearing plate 17 is loaded by using the jack 16 and the counterforce frame 15. The displacement of the roadbed filler soil is collected by using the digital image correlation method through the digital image correlation method observation instrument 14.

[0025] The specific experiment includes the following steps:

[0026] S1, install the test device, fill the simulated soil layer structure, and bury the sensor;

[0027] S2, make speckles;

[0028] S3, obtain the settlement law of the roadbed of different roadbed fillers under different conditions by changing the working conditions

[0029] S4, complete the test, disassemble the test device, and record the data.

[0030] The method for installing the test device in S1 includes the following steps:

[0031] S11, assemble the model box bottom steel plate 4, connect the bolts welded on the bottom steel plate 4 through steel sheets, and anchor with nuts;

[0032] S12, connect the first angle steel grid 1, the second angle steel grid 2, and the third angle steel grid 3 with the bottom steel plate 4 through multiple bolts;

[0033] S13, place the first high-density foam plate 5 and the second high-density foam plate 6 on the two sides that do not need to be observed to eliminate the boundary effect.

[0034] The method for filling the simulated soil layer structure in S1 is: the soil layer is laid in layers and compacted by using a small electric grab. After each layer of compacted soil layer, random sampling is performed on each layer of compacted soil layer by using a cutting ring to detect the compaction degree of each compacted soil layer. The compaction degree calculation formula is:

[0035]

[0036] Among them, the wet density, the total mass of the cutting ring and the soil, the mass of the cutting ring, the volume of the cutting ring, the dry density of the sample, K is the compaction degree, and the maximum dry density of the sample.

[0037] The method for making speckles in S2 includes the following steps:

[0038] S21, after the soil in the model box cavity is compacted, the observation edge pin rod 10 is removed, the silica gel gasket 11 is removed, and the high-transparency glass plate 7 is removed;

[0039] S22, spray black matt paint on the soil plane after the high-transparency glass plate 7 is removed, and after the paint is dried, use a white paint pen to dot white speckles on it; the speckles are required to be random and occupy about half of the overall area, and the size of the speckle dots is best controlled at 3-5 pixels in the digital image correlation method acquisition instrument.

[0040] S23, after the paint surface is dry, put back the high-transparency glass plate 7, place the silica gel gasket 11, and insert the bolt rod 10.

[0041] In summary, the digital image correlation method can be used to analyze the settlement deformation of different roadbed fillers under different loads, and the settlement law of different roadbed fillers can be obtained by analyzing the observation results, which has guiding significance for actual engineering.

Claims

1. An adjustable model box apparatus for indoor roadbed model testing, characterized by: Including box and bottom steel sheet (4), the box bottom is connected with bottom steel sheet (4), the box top is equipped with counterforce frame (15), the counterforce frame (15) is equipped with loading device, the loading device acts on the box inside, the box inside is buried with settlement rod (19) and earth pressure cell, the settlement rod (19) is equipped with dial gauge (18), one side of the box is equipped with digital image correlation method observation instrument (14).

2. The adjustable model box apparatus for indoor roadbed model testing according to claim 1, wherein: The box includes a first angle steel grid (1), a second angle steel grid (2), a third angle steel grid (3) and an angle steel (13), the first angle steel grid (1) and the second angle steel grid (2) are vertically connected on one side, the second angle steel grid (2) is vertically connected on the other side corresponding to the third angle steel grid (3), the first angle steel grid (1) and the third angle steel grid (3) are arranged in parallel, the first angle steel grid (1) and the third angle steel grid (3) are connected by the angle steel (13) on the other side corresponding to them, the bottom surface of the first angle steel grid (1), the second angle steel grid (2) and the third angle steel grid (3) is connected with the bottom steel plate (4), and the upper surface of the first angle steel grid (1), the second angle steel grid (2) and the third angle steel grid (3) is connected by the angle steel (13).

3. The adjustable model box apparatus for indoor roadbed model testing according to claim 2, wherein: The first angle steel grid (1), the second angle steel grid (2) and the third angle steel grid (3) are composed of a plurality of corresponding angle steel grids, and the plurality of angle steel grids are fixedly connected by bolts.

4. The adjustable model box apparatus for indoor roadbed model testing according to claim 1, wherein: The loading device includes a counterforce frame (15), the counterforce frame (15) is equipped with a jack (16), the jack (16) is provided with a bearing plate (17) at the extending end, and the bearing plate (17) acts on the inside of the box.

5. The adjustable model box apparatus for indoor roadbed model testing according to claim 2, wherein: The first angle steel grid (1) is installed with a high-transparency glass plate (7), the second angle steel grid (2) is installed with a first high-density foam plate (5), and the third angle steel grid (3) is installed with a second high-density foam plate (6).

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