CN104655822B - The integral type Work condition analogue device of highway culvert centrifugal model test and test method - Google Patents

Abstract

The invention discloses an integrated working condition simulation device and a test method for a highway culvert centrifugal model test. The device includes a bottom plate, a height fixing frame, a pair of telescopic plates, a foundation model, a test soil sample, a counterweight device and a culvert model The base plate is laid flat on the bottom surface of the centrifuge model box; the height positioning frame is installed above the base plate; the foundation model is placed on the base plate; the culvert model is placed above the foundation model; the telescopic plate is symmetrically installed on the base plate on both sides of the foundation model The telescopic plate is placed obliquely; the test soil sample is filled in the cavity surrounded by the centrifuge model box, the bottom plate, a pair of telescopic plates, the foundation model and the culvert model; a counterweight device is placed above the test soil sample . The test device is simple in structure, easy to operate, does not need to be frequently disassembled and assembled, can efficiently and accurately meet the requirements of the centrifugal model test of the designed highway culvert, and improves the test efficiency and accuracy.

Description

Integrated working condition simulation device and test method for centrifugal model test of highway culvert

technical field

The invention relates to a geotechnical test device, in particular to an integrated working condition simulation device and a test method for a highway culvert centrifugal model test.

Background technique

At present, the geotechnical centrifugal test of highway high-fill culverts in our country is in the rising stage, and the experience accumulation of test design is not rich enough. However, in the existing geotechnical centrifugal tests of highway culverts, it is often necessary to specially produce different sizes, different slopes and different valley bottom widths. The valley terrain model is extremely inconvenient to operate, and the cost is extremely high.

At the same time, the terrain model of high subgrade culverts often exceeds the net height of the centrifuge model box, and the test cannot be carried out due to the size limitation of the centrifuge model box. Therefore, traditional model devices can only simulate roadbed terrain with a limited height.

Finally, in the traditional test model, the soil samples are not well fixed. During the centrifuge test, the instability of the soil sample often leads to the instability of the test results.

Contents of the invention

In order to overcome the deficiencies of the prior art above, the present invention provides an integrated working condition simulation device for highway culvert centrifugal model test. The device is simple in structure, easy to operate, and can effectively simulate the centrifugal model of highway culvert through simple assembly and disassembly. In the test, the topographic models of valleys with different sizes, different slopes and different valley bottom widths can overcome the limitation of the height of the model box and simulate the culvert model with higher fill height. During the test process, the device of the invention has strong stability, low production cost, and is easy to popularize and use.

In order to achieve the above object, the present invention adopts the following technical solutions to achieve:

An integrated working condition simulator for highway culvert centrifugal model test, including a base plate, a height fixing frame, a pair of telescopic plates, a foundation model, a test soil sample, a counterweight device and a culvert model; wherein:

Described base plate is tiled on the bottom surface of centrifuge model box, and its length is less than the length of centrifuge model box, and its width is equal to the internal width of centrifuge model box; fit; the foundation model is placed on the middle part of the base plate; the culvert model is placed in the middle part above the foundation model, and the culvert model adopts a hollow cylinder with a rectangular cross section; the length direction of the culvert model is the same as the width direction of the base plate; a pair of The telescopic plate is symmetrically installed on the bottom plate on both sides of the foundation model, and the width of the telescopic plate is equal to the width of the bottom plate; The slope and height of the valley; the test soil sample is filled in the cavity enclosed between the centrifuge model box, the bottom plate, a pair of telescopic plates, the foundation model and the culvert model, and the upper surface of the test soil sample is higher than the telescopic plates The upper end of the test soil sample is placed with a counterweight device.

Further, the center line of the foundation model coincides with the center line of the bottom plate, its length is smaller than the length of the bottom plate, its width is equal to the width of the foundation model, and its thickness is 2-3cm.

Further, a plurality of positioning grooves are uniformly arranged on the upper surface of the bottom plate, and the length direction of the positioning grooves is consistent with the width direction of the bottom plate.

Further, the cross-section of the positioning grooves is triangular, rectangular or other shapes, and two adjacent positioning grooves are closely arranged without spacing.

Further, the positioning slot is an isosceles triangle with a waist length of 1 cm and a height of 1.41 cm.

Further, the height positioning frame adopts four uprights, and the four uprights are respectively installed on the four corners of the bottom plate, and a locking device is respectively arranged on the four uprights for fixing the telescopic plate; meanwhile, the uprights are arranged along the length direction. There is a chute for the counterweight device to slowly slide down and cover the test soil sample; bolt holes are left in the lower part of the locking device, and the locking device is hooped to the column through bolts; at the upper end of the telescopic plate Hinges are installed for locking with the locking device of the height positioning frame.

Further, the height positioning frame is covered with threads, and the locking device is locked to the required height of the height positioning frame through threads.

Further, the counterweight device is formed by stacking 1-10 counterweight plates, the size of the counterweight plates is consistent with that of the model box, and the weight is 1kg-5kg, and the counterweight plates are made of rigid metal plates.

Further, the counterweight device is attached to the side wall of the centrifuge model box.

Another object of the present invention is to provide a test method for an integrated working condition simulator of the above-mentioned highway culvert centrifugal model test, which specifically includes the following steps:

Step 1, spread the bottom plate on the bottom of the centrifuge model box;

Step 2, place the foundation model in the middle of the base plate so that the center line of the foundation model coincides with the center line of the base plate; place the culvert model in the middle above the foundation model;

Step 3, install a pair of telescopic plates symmetrically on the bottom plate on both sides of the foundation model, place the telescopic plates obliquely, install the lower end on the bottom plate, and fix the upper end on the height positioning frame through the locking device, adjust the telescopic plates as needed The telescopic length is adjusted to adjust the slope and height of the valley that needs to be simulated; the bottom plate and a pair of telescopic plates form a ditch; adjust the position of the locking device on the height positioning frame and fix it;

Step 4, filling the cavity surrounded by the centrifuge model box, the bottom plate, a pair of telescopic plates, the foundation model and the culvert model with the test soil sample to a specific height;

Step 5, according to the test load requirements, put a certain weight of the counterweight device into the centrifuge model box, and let it fall along the centrifuge model box to the test soil sample; at this time, the whole set of equipment is set up and the centrifuge test can be carried out.

Compared with prior art, the beneficial effect of the present invention is:

1. The structure is simple and the operation is more convenient.

2. The use of an integrated device avoids the process of assembling parts with different specifications each time, saves the process of customizing rigid metal bottom plates and rigid metal side plates of different sizes, saves test materials, simplifies test steps, and further improves test performance. efficiency.

3. The covered counterweight device can adjust the load, which further improves the extensiveness of the simulated working conditions of the test device and the extensiveness of the test.

4. The counterweight device acting on the top of the soil sample is constrained by the height positioning frame in the horizontal direction, and can be completely attached to the model box to ensure the stability of the soil sample during the centrifugation process.

5. The whole set of working condition simulation device is constrained into a whole during the test process, which has a wide range of applications and can be extended to other similar centrifuge geotechnical simulation experiments.

To sum up, the present invention has simple structure, novel and reasonable design, high working reliability, long service life, good use effect, and is convenient for popularization and use.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

Fig. 2 is a plan view of the present invention;

Fig. 3 is a schematic diagram of a rigid metal floor frame and a height positioning frame;

Fig. 4 is a detailed schematic diagram of the locking device on the height positioning frame;

Fig. 5 is a structural schematic diagram of an embodiment of the present invention;

Fig. 6 The change diagram of the vertical earth pressure on the top of the culvert when the width of the valley changes;

Fig. 7 The change diagram of the vertical earth pressure on the top of the culvert when the slope of the valley changes.

The meaning of each label in the figure: 1. Base plate, 2. Height positioning frame; 3. Locking device; 4. Telescopic plate, 5. Foundation model, 6. Test soil sample, 7. Counterweight device, 8. Culvert model, 9. Positioning slot.

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

detailed description

As shown in Fig. 1 and Fig. 2, the present invention provides a kind of integrated working condition simulation device of highway culvert centrifugal model test, comprises base plate 1, height fixing frame 2, a pair of telescopic plates 4, foundation model 5, test Soil sample 6, counterweight device 7 and culvert model 8; where:

Bottom plate 1 and telescopic plate 4 all adopt rectangular metal plate, preferably steel plate, and bottom plate 1 is tiled on the bottom surface of centrifuge model box, and its length is less than the length of centrifuge model box, and its width is equal to the internal width of centrifuge model box; Base plate 1 It is used to simulate the bottom of the valley, and also serves as a platform for installing other components (such as telescopic plate 4, foundation model 5 and culvert model 8).

The height positioning frame 2 is attached to the side wall of the centrifugal model box, and the height positioning frame 2 is not only used to adjust the inclination of the telescopic plate 4, but also used to constrain the test soil sample and the counterweight device 7 in the horizontal direction, so that the counterweight The device 7 can move freely in the vertical direction to increase the stability of the soil sample during the test and prevent the test results from being affected by the instability of the test soil sample.

The foundation model 5 is placed on the middle part of the length direction of the base plate 1, the foundation model 5 adopts a rectangular plate, its length is less than the length of the base plate 1, its width is equal to the width of the foundation model 5, and its thickness is 2～3cm. The foundation model 5 is placed in the middle of the base plate 1 , and the center line of the foundation model 5 coincides with the center line of the base plate 1 .

The culvert model 8 is placed in the middle above the foundation model 5, and the culvert model 8 adopts a hollow cylinder with a rectangular cross section; the length direction of the culvert model 8 is the same as the width direction of the bottom plate 1, and its height is customized according to the test requirements. The culvert model 8 can be made of plexiglass or other rigid materials, and processed according to the rigidity required by different tests.

A pair of telescopic plates 4 are symmetrically installed on the bottom plate 1 on both sides of the foundation model 5, and the width of the telescopic plates 4 is equal to the width of the bottom plate 1; 3 is fixed on the height positioning frame 2; the telescopic plate 4 is used to simulate the slope and height of the valley. Therefore, the telescopic length and inclination of the rigid metal base plate 1 can be determined according to the slope and height of the valley to be simulated in the test. Compared with the existing gully model, the cost is greatly reduced and the efficiency is improved. The bottom plate 1 and a pair of telescopic plates 4 form a ditch shape.

The cavity enclosed between the centrifuge model box, the bottom plate 1, a pair of telescopic plates 4, the foundation model 5 and the culvert model 8 is filled with a test soil sample 6, and the upper surface of the test soil sample 6 is higher than the telescopic plates The upper end of 4; test soil sample 6 adopts a specific type of soil sample that is consistent with the nature of the foundation soil required by the test, such as different types of sand, silt, clay, etc.

A counterweight device 7 is placed above the test soil sample 6 . The upper end of counterweight device 7 is lower than the upper end of centrifuge model case. The counterweight device 7 is used to adjust the size of the load according to the test requirements, to simulate the situation of the high-fill embankment, and to fix the test soil sample together with the bottom plate 1, the telescopic plate 4 and the centrifuge model box.

Optionally, a plurality of positioning grooves 9 are uniformly arranged on the upper surface of the base plate 1 , and the length direction of the positioning grooves 9 is consistent with the width direction of the base plate 1 . The setting of the positioning groove 9 makes the position of the lower end of the telescopic board 4 on the base plate 1 adjustable, thereby realizing the adjustment of the inclination angle of the telescopic board 4 .

Optionally, the cross section of the positioning groove 9 is triangular, rectangular or other shapes. In order to fit closely with the rigid metal side plate, an isosceles triangle with a waist length of 1 cm and a height of 1.41 cm is preferred, and two adjacent positioning grooves 9 are closely arranged without spacing.

Optionally, the height positioning frame 2 adopts four uprights, and the four uprights are installed on the four corners of the bottom plate 1 respectively, and a locking device is respectively arranged on the four uprights for fixing the telescopic plate 4; at the same time, the length of the upper edge of the uprights There is a chute in the direction, which is used to make the counterweight device 7 slowly slide down and cover the test soil sample 6; as shown in Figure 4, there are bolt holes in the lower part of the locking device, and the locking device is hooped to the column by bolts superior. The four uprights can well constrain the counterweight device 7 in the horizontal direction, so that it can slide down slowly and cover the top of the test soil sample 6, which can stabilize the soil sample before and during the test. A hinge is installed on the upper end of the telescopic plate 4 for locking with the locking device of the height positioning frame 2 .

Optionally, the height positioning frame 2 is covered with threads, and the locking device 3 is locked to the required height of the height positioning frame 2 through threads. Optionally, the height positioning frame 2 is the same as the inner net height of the centrifuge model box.

Optionally, the counterweight device 7 is formed by stacking 1 to 10 counterweight plates with a thickness of 1 cm to 2 cm, and an appropriate number of counterweight plates can be selected according to test requirements. The size of the weight plate is consistent with that of the model box, and the weight is 1kg to 5kg. Optionally, the weight plate is a rigid metal plate.

Optionally, the counterweight device 7 is attached to the side wall of the centrifuge model box to ensure the stability of the test soil sample 6 during the test and prevent the test results from being affected by the instability of the test soil sample 6 .

An embodiment of the present invention is given below. It should be noted that the purpose of providing this embodiment is to facilitate a further understanding of the present invention, and the scope of protection claimed by the claims of the present invention is not limited to this embodiment.

Example:

Referring to Fig. 5, the culvert model 8 is a circular pipe culvert; the test soil sample 6 is sandy soil; the counterweight plate of the counterweight device 7 is a steel plate, and the length and width of the steel plate are slightly smaller than the length and width of the centrifuge model box for easy installation; The density ratio to the steel plate is 1:4, the centrifuge test is carried out at an acceleration level of 50g, the similarity ratio of the model test is 1:50, and the test condition of the simulated filling height is 20m.

Since the filling height to be simulated is as high as 20m, the filling height still needs to reach 40cm under the similarity ratio of 1:50; due to the limited height of the centrifuge model box, it is impossible to fill 40cm of sand in the test. At this time, Just need counterweight device 7 to carry out counterweight to it. In the test, in order to realize the filling height of 40cm, first fill with sand to a height of 20cm, then level off the sand layer, and then cover the counterweight device 7 on the sand with a covering height of 5cm, because the counterweight device 7 The density is 4 times that of the sand, and the length and width are slightly smaller than the length and width of the model box, so the weight of the 5cm thick steel plate is equivalent to the weight of the sand with a height of 20cm. It can be seen that the sand with a height of 20cm and a thickness of 5cm After the steel plate counterweight device 7 is combined, the simulated filling height reaches 40cm.

1. Simulation of valley width

The test device is installed according to the above-mentioned test steps, wherein when carrying out step 3 of the present invention, the distance between the 4 bases of the two telescopic plates is adjusted to 1.5D, 2.0D, 3.0D, 4.0D and 5.0D respectively (D Indicates the span of the culvert model), and by adjusting the length of the expansion plate 4, the angle between the expansion plate 4 and the side of the model box is maintained at 45°, and the simulated valley width is 1.5D when the slope of the valley is 45° , 2.0D, 3.0D, 4.0D and 5.0D test conditions, as shown in Figure 6.

2. Valley slope simulation

Install the test device according to the above test steps, wherein when performing step 3, the distance between the bottom edges of the two telescopic plates 4 is adjusted to 3.0D (D represents the span of the culvert model), and by adjusting the length of the telescopic plates 4 Make the included angles between the telescopic plate 4 and the side of the model box be 0°, 30°, 45°, 60° and 90° respectively, and simulate that when the width of the valley is 3.0D, the slopes of the valley are respectively 0°, 30°, The test conditions of 45°, 60° and 90° are shown in Figure 7.

From the test results, it can be seen that the results obtained by the test using the simulation device of this working condition are in good agreement with the results of the numerical simulation, indicating that it is necessary to use the simulation device to simulate the variation of the valley width and the slope of the valley in the high fill culvert. It is relatively reasonable; it also proves that it is feasible to use the counterweight device 7 and the test soil sample 6 to cooperate with each other to equivalently simulate the high fill culvert.

As shown in Figure 3, the present invention also provides the test method of the integrated working condition simulator of the centrifugal model test of the above-mentioned highway culvert, which specifically includes the following steps:

Step 1, spread the bottom plate 1 on the bottom of the centrifuge model box;

Step 2, placing the foundation model 5 in the middle of the base plate 1 so that the centerline of the foundation model 3 coincides with the center line of the base plate 1; placing the culvert model 8 in the middle above the foundation model 5;

Step 3, install a pair of telescopic plates 4 symmetrically on the bottom plate 1 on both sides of the foundation model 5, place the telescopic plates 4 obliquely, install the lower end on the bottom plate 1, and fix the upper end on the height positioning frame 2 through the locking device 3 , adjust the telescopic length of the telescopic plate 4 as required to adjust the slope and height of the valley that needs to be simulated; the bottom plate 1 and a pair of telescopic plates 4 form a ditch; adjust the position of the locking device on the height positioning frame 2 and fix it;

Step 4, fill the cavity surrounded by the centrifuge model box, the bottom plate 1, a pair of telescopic plates 4, the foundation model 5 and the culvert model 8, and fill the test soil sample 6 to a specific high;

Step 5, according to the test load requirements, put a certain weight of the counterweight device 7 into the centrifuge model box, and make it fall along the centrifuge model box to the test soil sample 6; at this time, the whole set of equipment is set up and the centrifuge test can be carried out.

The above are only preferred embodiments of the present invention, and do not limit the present invention in any way. Any simple modifications, changes and equivalent structural transformations made to the above embodiments according to the technical essence of the present invention still belong to the technology of the present invention. within the scope of protection of the scheme.

Claims (8)

1. An integrated working condition simulator for highway culvert centrifugal model test, is characterized in that, comprises base plate, height fixed frame, a pair of telescopic plates, foundation model, test soil sample, counterweight device and culvert model; Wherein: Described base plate is tiled on the bottom surface of centrifuge model box, and its length is less than the length of centrifuge model box, and its width is equal to the internal width of centrifuge model box; fit; the foundation model is placed on the middle part of the base plate; the culvert model is placed in the middle part above the foundation model, and the culvert model adopts a hollow cylinder with a rectangular cross section; the length direction of the culvert model is the same as the width direction of the base plate; a pair of The telescopic plate is symmetrically installed on the bottom plate on both sides of the foundation model, and the width of the telescopic plate is equal to the width of the bottom plate; The slope and height of the valley; the test soil sample is filled in the cavity enclosed between the centrifuge model box, the bottom plate, a pair of telescopic plates, the foundation model and the culvert model, and the upper surface of the test soil sample is higher than the telescopic plates The upper end of the test soil sample; a counterweight device is placed above the test soil sample; A plurality of positioning grooves are evenly arranged on the upper surface of the base plate, and the length direction of the positioning grooves is consistent with the width direction of the base plate; The centerline of the foundation model coincides with the centerline of the bottom plate, its length is less than the length of the bottom plate, its width is equal to the width of the foundation model, and its thickness is 2-3cm. 2. The integrated working condition simulator of highway culvert centrifugal model test as claimed in claim 1, is characterized in that, the cross-section of described locating groove is triangular, rectangular or other shapes, and two adjacent locating grooves are closely arranged , with no spacing. 3. The integrated working condition simulator of the highway culvert centrifugal model test as claimed in claim 1, wherein the positioning groove is selected as an isosceles triangle with a waist length of 1 cm and a height of 1.41 cm. 4. The integrated working condition simulator of the centrifugal model test of highway culverts according to any one of claims 1 to 3, wherein the height positioning frame adopts four uprights, and the four uprights are respectively installed on the four corners of the base plate , a locking device is arranged on each of the four uprights to fix the telescopic plate; at the same time, a chute is provided along the length of the uprights to allow the counterweight device to slowly slide down and cover the test soil sample; the locking Bolt holes are left in the lower part of the device, and the locking device is hooped to the column through bolts; a hinge is installed on the upper end of the telescopic plate for locking with the locking device of the height positioning frame. 5. The integrated working condition simulator of the highway culvert centrifugal model test as claimed in claim 4, wherein the height positioning frame is covered with threads, and the locking device is locked to the required height of the height positioning frame by threads. 6. The integrated working condition simulator of the highway culvert centrifugal model test according to any one of claims 1 to 3, wherein the counterweight device is formed by superimposing 1 to 10 counterweight plates, and the The size of the counterweight plate is consistent with that of the model box, and the weight is 1kg to 5kg. The counterweight plate is made of rigid metal plate. 7. The integrated working condition simulator for highway culvert centrifugal model test according to any one of claims 1 to 3, characterized in that the counterweight device is attached to the side wall of the centrifuge model box. 8. the test method of the integrated working condition simulator of highway culvert centrifugal model test as claimed in claim 1, is characterized in that, specifically comprises the steps: Step 1, spread the bottom plate on the bottom of the centrifuge model box; Step 2, place the foundation model in the middle of the base plate so that the center line of the foundation model coincides with the center line of the base plate; place the culvert model in the middle above the foundation model; Step 3, install a pair of telescopic plates symmetrically on the bottom plate on both sides of the foundation model, place the telescopic plates obliquely, install the lower end on the bottom plate, and fix the upper end on the height positioning frame through the locking device, adjust the telescopic plates as needed The telescopic length is adjusted to adjust the slope and height of the valley that needs to be simulated; the bottom plate and a pair of telescopic plates form a ditch; adjust the position of the locking device on the height positioning frame and fix it; Step 4, filling the cavity surrounded by the centrifuge model box, the bottom plate, a pair of telescopic plates, the foundation model and the culvert model with the test soil sample to a specific height; Step 5, according to the test load requirements, put a certain weight of the counterweight device into the centrifuge model box, and let it fall along the centrifuge model box to the test soil sample; at this time, the whole set of equipment is set up and the centrifuge test can be carried out.