CN214374788U

CN214374788U - Test device for simulating stratum loosening to cause pavement collapse

Info

Publication number: CN214374788U
Application number: CN202120416696.1U
Authority: CN
Inventors: 戴轩; 王慧颖; 田昱文
Original assignee: Civil Aviation University of China
Current assignee: Civil Aviation University of China
Priority date: 2021-02-25
Filing date: 2021-02-25
Publication date: 2021-10-08
Anticipated expiration: 2031-02-25

Abstract

A test device for simulating stratum loosening to cause pavement collapse. The device comprises a sensor support, a main test box, a bottom support, an edge migration channel, an edge movable plate, a jack, a middle migration channel, a middle movable plate, a laser displacement sensor and a loosening size control plate. The utility model discloses the effect: the movable plate moving up and down controls the stratum loosening under the pavement structure, quantitative research and repeatability tests can be carried out, the sizes of different loosening bodies can be freely controlled, the jack and the movable plate are flexibly disassembled and assembled and are easy to operate, the test device provides visual, controllable and convenient-to-operate test equipment for researching urban road collapse, the test research level of urban road collapse disasters can be improved, and theoretical basis is provided for early warning and prevention of road collapse accidents.

Description

Test device for simulating stratum loosening to cause pavement collapse

Technical Field

The utility model belongs to the technical field of road engineering test equipment, concretely relates to test device that simulation stratum is not hard up to cause the road surface to sink.

Background

With the progress of society, the development of countries and the continuous promotion of urbanization process, underground spaces are developed in large quantities, and urban underground engineering is more and more constructed and has larger scale. In the process of urban underground engineering construction, deformation of an underground structure and construction quality defects easily cause soil body loss, and stratum soil bodies can be gushed into an underground space under the action of underground water. When soil in the stratum runs off and becomes flexible, the soil is often not easy to be perceived on the earth surface, a considerable flexible area appears below the pavement structure, and when traffic load acts on the flexible area, the pavement structure is collapsed.

At present, more and more road surface collapse accidents are caused by underground engineering construction, so that the road surface is cracked and traffic is influenced if the accidents are light, and casualties are caused if the accidents are heavy. The existing research shows that before the urban road collapses, soil below the road surface structure can form a loose area or even a hollow area, and the road surface structure collapses suddenly under the action of external traffic load. However, the mechanism and disaster precursors of pavement collapse caused by soil loosening are not clear, and corresponding test equipment is also lacked for systematic research and test.

In the field of road engineering design in China, various road surface structure test devices are developed, typically, an accelerated loading test device, a rut test, a fatigue tester and the like are provided, however, the test devices do not consider the loosening and loss of soil bodies below a road surface structure, and also do not consider the working state of the road surface structure under the condition that the soil bodies below the road surface structure are loosened, so that the development process of road surface collapse cannot be disclosed.

Although accidents of pavement collapse and diseases are reported in a large number, a series of disease detection methods are also provided for pavement void, quantitative prediction for different stratum loosening sizes and different loosening degrees is lacked, and especially under the action of traffic load, pavement structure damage and collapse mechanisms caused by underground engineering construction and diseases lack corresponding test means, so that a set of test device capable of simulating the pavement collapse caused by stratum loosening is urgently required to be developed, and systematic research is carried out on the pavement collapse problem caused by stratum loosening.

Disclosure of Invention

In order to solve the problem, the utility model aims to provide a test device that the not hard up road surface of initiation of simulation stratum sinks.

In order to achieve the purpose, the test device for simulating stratum loosening to cause pavement collapse comprises a sensor support, a main test box, a bottom support, an edge migration channel, an edge movable plate, a jack, a middle migration channel, a middle movable plate, a laser displacement sensor and a loosening size control plate; the main test box is a cuboid box body with an open upper end, a sensor preformed hole is reserved on the side surface and used for arranging a pressure sensor lead, a marginal stratum loosening inducing hole and a middle stratum loosening inducing hole are arranged on the bottom surface, and a stratum soil body and a pavement structure are sequentially paved inside the main test box from bottom to top during the test; the lower end of the main test box is supported on a plurality of bottom brackets; two ends of the sensor bracket are respectively arranged at the tops of two opposite side surfaces on the main test box; the plurality of laser displacement sensors are arranged on the sensor bracket at intervals; the edge migration channel and the middle migration channel are both box bodies with the upper ends and the lower ends in an opening shape, and the upper end openings are respectively connected to the edges of the edge stratum loosening inducing hole and the middle stratum loosening inducing hole; the edge movable plate and the middle movable plate are horizontally arranged and are respectively arranged in the edge migration channel and the middle migration channel in a vertically movable mode, and different descending positions of the edge movable plate and the middle movable plate are controlled through a jack to form stratum loosening areas of different degrees; one end of the cylinder body of the jacks is arranged on the ground, and the outer end of a mandril at the upper end is connected with the middle part of the bottom surface of the edge movable plate or the middle movable plate; the loosening-size control plate selectively covers the marginal-formation-loosening-inducing hole and/or the middle-formation-loosening-inducing hole, and the middle portion is formed with a formation-loss hole.

The front of the main test box is a visual panel made of organic glass, so that experimenters can observe test phenomena or collect images conveniently.

The edge stratum loosening inducing hole is a rectangular hole, and the middle stratum loosening inducing hole is a square hole.

The sensor support is door-shaped, and the laser displacement sensor is arranged on a cross beam of the sensor support 1.

The stratum lost holes have different sizes and shapes, so that the sizes of different stratum loose sizes are controlled.

The middle parts of the bottom surfaces of the edge movable plate and the middle movable plate are provided with thread threads connected with the outer end of the top rod on the jack, so that the installation and the disassembly are convenient.

The bottom support is made of I-shaped steel which is vertically arranged.

The utility model provides an advantage and positive effect that simulation stratum becomes flexible to cause test device that the road surface sinks have are: the movable plate moving up and down controls the stratum loosening under the pavement structure, so that quantitative research and repeatability tests can be carried out; stratum loss holes with different sizes are formed in the loosening size control plate, so that the sizes of different loosening bodies can be freely controlled; the main test box is provided with a visual panel, and stratum deformation caused by marginal stratum looseness can be visually obtained through image processing; the jack is connected with the movable plate through the threaded connection, so that the operation is convenient, flexible and easy; the testing device can test the looseness of the plate edge and can test the looseness of the plate, so that visual, controllable and convenient-to-operate testing equipment is provided for researching the collapse of the urban road, the level of experimental research on collapse disasters of the urban road is promoted, and a theoretical basis is provided for early warning and prevention of road surface collapse accidents.

Drawings

FIG. 1 is a perspective view of a test device for simulating pavement collapse caused by stratum loosening provided by the utility model;

FIG. 2 is a front view of the test device for simulating the pavement collapse caused by stratum loosening provided by the utility model;

FIG. 3 is a side sectional view of the test device for simulating the pavement collapse caused by the stratum loosening provided by the utility model;

FIG. 4 is a top view of the test device for simulating the formation loosening to cause the road surface collapse provided by the utility model;

fig. 5 is the utility model provides a not hard up size control board schematic diagram among the test device that simulation stratum is not hard up to cause the road surface to sink.

Detailed Description

For further understanding of the contents, features and effects of the present invention, the following embodiments are listed and will be described in detail with reference to the accompanying drawings:

as shown in fig. 1-5, the test device for simulating stratum loosening to cause pavement collapse provided by the utility model comprises a sensor support 1, a main test box 2, a bottom support 3, an edge migration channel 7, an edge movable plate 8, a jack 9, a middle migration channel 11, a middle movable plate 12, a laser displacement sensor 13 and a loosening size control plate 14; the main test box 2 is a cuboid box body with an open upper end, a sensor preformed hole 4 is reserved on the side surface and used for laying pressure sensor leads, a marginal stratum loosening inducing hole 6 and a middle stratum loosening inducing hole 10 are arranged on the bottom surface, and a stratum soil body and pavement structure 17 is sequentially laid inside from bottom to top during the test; the lower end of the main test chamber 2 is supported on a plurality of bottom brackets 3; two ends of the sensor bracket 1 are respectively arranged on the tops of two opposite side surfaces of the main test box 2; a plurality of laser displacement sensors 13 are arranged on the sensor bracket 1 at intervals; the edge migration channel 7 and the middle migration channel 11 are both box bodies with the upper ends and the lower ends in an opening shape, and the upper end openings are respectively connected to the edges of the edge stratum loosening inducing hole 6 and the middle stratum loosening inducing hole 10; the edge movable plate 8 and the middle movable plate 12 are horizontally arranged and respectively arranged in the edge migration channel 7 and the middle migration channel 11 in a manner of moving up and down, and different descending positions of the edge movable plate 8 and the middle movable plate 12 are controlled by a jack 9 to form stratum loosening areas with different degrees; one end of the cylinder body of a plurality of jacks 9 is arranged on the ground, and the outer end of a mandril at the upper end is connected with the middle part of the bottom surface of the edge movable plate 8 or the middle movable plate 12; the loosening-size control plate 14 is selectively laid over the marginal-formation-loosening-inducing hole 6 and/or the middle-formation-loosening-inducing hole 10, with a formation-loss hole 15 formed in the middle.

The front of the main test box 2 is a visual panel 5 made of organic glass, so that experimenters can observe test phenomena or collect images conveniently.

The edge stratum loosening inducing hole 6 is a rectangular hole, and the middle stratum loosening inducing hole 10 is a square hole.

The sensor support 1 is in a door shape, and the laser displacement sensor 13 is arranged on a cross beam of the sensor support 1.

The formation loss openings 15 have different sizes and shapes to control the size of the different formation loosening dimensions.

The middle parts of the bottom surfaces of the edge movable plate 8 and the middle movable plate 12 are provided with screw threads 16 connected with the outer ends of the top rods of the jacks 9, so that the installation and the disassembly are convenient.

The bottom bracket 3 is made of vertically arranged I-shaped steel.

The bearing capacity test that sinks in the road surface that causes is not hard up in middle part stratum now to the example, explains the utility model provides a not hard up use that causes the test device that sinks in road surface in simulation stratum, the not hard up bearing capacity test that sinks in road surface that causes in marginal stratum and middle part and marginal stratum simultaneously become flexible and cause the bearing capacity test that sinks in road surface that causes the same reason, concrete implementation method as follows:

(1) cleaning the test device to ensure that no foreign matter exists in the main test box 2, lifting the jack 9 to enable the edge movable plate 8 and the middle movable plate 12 to respectively ascend along the edge migration channel 7 and the middle migration channel 11 until the edge movable plate and the middle movable plate are flush with the bottom surface of the main test box 2;

(2) placing a probe of the soil pressure sensor into the main test box 2, leading out a lead through a sensor preformed hole 4, and connecting the soil pressure sensor and the laser displacement sensor 13 to an acquisition instrument;

(3) covering the upper part of the middle stratum loosening induction hole 10 with a proper loosening size control plate 14;

(4) filling a test soil body into the main test box 2, filling and tamping in layers according to calculation to form a stratum, ensuring the soil surface to be horizontal, and simultaneously embedding soil pressure sensors in the soil body at certain intervals;

(5) calculating the appropriate thickness of the pavement structure 17 according to the similarity theory and the loading level, then constructing on the filled stratum in the main test box 2 to form the pavement structure 17, and curing the pavement structure 17 to form the strength;

(6) utilizing the laser displacement sensor 13 to emit laser downwards and collect surface deformation data of the pavement structure 17, collecting soil pressure in a stratum through the soil pressure sensor, reading initial readings of the soil pressure sensor and the laser displacement sensor 13 and checking whether the soil pressure sensor and the laser displacement sensor work normally or not;

(7) the jack 9 is used for controlling the middle movable plate 12 to slowly descend to a set position along the middle migration channel 11, and at the moment, the stratum soil in the main test box 2 enters the inside of the middle migration channel 11 through the stratum loss hole 15 and the middle stratum loosening inducing hole 10, so that the soil below the pavement structure 17 at the position of the middle stratum loosening inducing hole 10 forms a loosening area;

(8) reading readings of the soil pressure sensor and the laser displacement sensor 13, and obviously reducing the soil pressure value of the loosening area;

(9) loading the pavement structure 17 step by using weights, and reading readings of the soil pressure sensor and the laser displacement sensor 13 step by step;

(10) when the load is applied to the pavement structure 17 and the collapse occurs, the test is stopped;

(11) recording the cracking load and the collapse load of the pavement structure 17, and carrying out data analysis;

(12) the above test process is repeated by changing the positions of the loosening dimension control plate 14, the middle movable plate 12, the type and the strength of the pavement structure 17.

Claims

1. The utility model provides a test device that simulation stratum is not hard up to initiate road surface and sinks which characterized in that: the test device for simulating the stratum loosening to cause the pavement collapse comprises a sensor support (1), a main test box (2), a bottom support (3), an edge migration channel (7), an edge movable plate (8), a jack (9), a middle migration channel (11), a middle movable plate (12), a laser displacement sensor (13) and a loosening size control plate (14); the main test box (2) is a cuboid box body with an open upper end, a sensor preformed hole (4) is reserved on the side surface and used for laying pressure sensor leads, a marginal stratum loosening inducing hole (6) and a middle stratum loosening inducing hole (10) are arranged on the bottom surface, and a stratum soil body and a pavement structure (17) are sequentially laid inside from bottom to top during testing; the lower end of the main test box (2) is supported on a plurality of bottom brackets (3); two ends of the sensor bracket (1) are respectively arranged on the tops of two opposite side surfaces of the main test box (2); a plurality of laser displacement sensors (13) are arranged on the sensor bracket (1) at intervals; the edge migration channel (7) and the middle migration channel (11) are box bodies with upper and lower ends in an opening shape, and the upper end openings are respectively connected to the edges of the edge stratum loosening inducing hole (6) and the middle stratum loosening inducing hole (10); the edge movable plate (8) and the middle movable plate (12) are horizontally arranged and are respectively arranged in the edge migration channel (7) and the middle migration channel (11) in a vertically movable mode, and different descending positions of the edge movable plate (8) and the middle movable plate (12) are controlled by a jack (9) to form stratum loosening areas with different degrees; one end of the cylinder body of a plurality of jacks (9) is arranged on the ground, and the outer end of a mandril at the upper end is connected with the middle part of the bottom surface of the edge movable plate (8) or the middle movable plate (12); the loosening dimension control plate (14) is selectively covered on the edge stratum loosening-inducing hole (6) and/or the middle stratum loosening-inducing hole (10), and the middle part is formed with a stratum loss hole (15).

2. The test device for simulating stratum loosening to induce pavement collapse according to claim 1, characterized in that: the front of the main test box (2) is a visual panel (5) made of organic glass, so that experimenters can observe test phenomena or collect images conveniently.

3. The test device for simulating stratum loosening to induce pavement collapse according to claim 1, characterized in that: the edge stratum loosening inducing hole (6) is a rectangular hole, and the middle stratum loosening inducing hole (10) is a square hole.

4. The test device for simulating stratum loosening to induce pavement collapse according to claim 1, characterized in that: the sensor support (1) is in a door shape, and the laser displacement sensor (13) is arranged on a cross beam of the sensor support (1).

5. The test device for simulating stratum loosening to induce pavement collapse according to claim 1, characterized in that: the formation loss holes (15) have different sizes and shapes so as to control the sizes of different formation loosening sizes.

6. The test device for simulating stratum loosening to induce pavement collapse according to claim 1, characterized in that: the middle parts of the bottom surfaces of the edge movable plate (8) and the middle movable plate (12) are provided with screw threads (16) connected with the outer end of the top rod on the jack (9), so that the installation and the disassembly are convenient.

7. The test device for simulating stratum loosening to induce pavement collapse according to claim 1, characterized in that: the bottom bracket (3) is made of I-shaped steel which is vertically arranged.