A subgrade cavity detection system

Abstract

The utility model relates to a kind of roadbed cavity detection systems, including vertical section detection device, horizontal section detection device and data acquisition device, wherein:vertical section detection device includes the steel pipe vertically buried in the detection area both sides of existing roadbed, sound wave generating unit is arranged in the steel pipe in one side, sound wave receiving unit is arranged in the steel pipe in the other side, and sound wave transmitting unit is connected with multi-source sound wave transmitter;Horizontal section detection device includes the horizontal steel pipe horizontally buried in the detection area both sides of existing roadbed, sound wave generating unit is arranged in the horizontal steel pipe in one side, sound wave receiving unit is arranged in the steel pipe in the other side.The utility model has the advantages that:the high-precision detection of silt roadbed cavity is realized, the accuracy of silt roadbed detection is ensured;Simple and reasonable structure, less influence on silt roadbed, can restore after backfilling after detection is completed;Detection is simple and convenient, and efficiency is high, and it is suitable for promotion.

Description

Technical Field

[0001] This utility model relates to the field of roadbed detection technology, and in particular to a roadbed void detection system. Background Technology

[0002] Railway and highway subgrades constructed with silty soil and sand are a common type of subgrade widely distributed in plains areas. Under dynamic loads from the superstructure, the silty sand in the subgrade is prone to liquefaction and loss, leading to cavities within the subgrade. These cavities are a significant defect in silty sand subgrades, widely distributed, especially at bridge abutments and along culvert sides. These cavities can cause sudden track collapses, posing a serious threat to train and vehicle safety. Furthermore, these cavities are hidden defects, difficult to observe directly, and challenging to detect; accurately identifying these cavities is a key focus and a major challenge in the remediation of silty sand subgrade defects.

[0003] Currently, geophysical methods are mainly used to detect cavities in soil, with common methods including ground-penetrating radar, high-density electrical resistivity tomography (EDT), transient electromagnetic methods, micromotion methods, and seismic wave methods. However, because soil cavities are often filled with water and loose soil, and their properties are not significantly different from the surrounding soil, conventional geophysical methods often fail to detect "soil cavities" in roadbeds, thus limiting their effectiveness in detecting cavities in roadbeds. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of the existing technology by providing a roadbed void detection system. This system involves installing vertical and horizontal profile detection devices on the existing roadbed and using cross-hole CT to perform high-precision vertical and horizontal detection imaging of the existing roadbed, thereby accurately detecting voids within the silty sand roadbed.

[0005] The objective of this utility model is achieved through the following technical solution:

[0006] A roadbed void detection system is used to detect voids in existing roadbeds. Its features include a vertical profile detection device, a horizontal profile detection device, and a data acquisition device, wherein:

[0007] The vertical profile detection device includes steel pipes vertically buried on both sides of the detection area of ​​the existing roadbed. A sound wave generating unit is installed in one side of the steel pipe, and a sound wave receiving unit is installed in the other side of the steel pipe. The sound wave generating unit is connected to a multi-source sound wave transmitter, and the sound wave receiving unit is connected to a multi-source sound wave receiver. The multi-source sound wave receiver is connected to the data acquisition device.

[0008] The horizontal profile detection device includes horizontal steel pipes buried on both sides of the detection area of ​​the existing roadbed. A sound wave generating unit is installed in one side of the horizontal steel pipe, and a sound wave receiving unit is installed in the other side of the steel pipe. The sound wave generating unit is connected to a multi-source sound wave transmitter, and the sound wave receiving unit is connected to a multi-source sound wave receiver. The multi-source sound wave receiver is connected to the data acquisition device.

[0009] The horizontal steel pipe is installed by horizontally trenching along the direction of the route on the slope of the existing roadbed.

[0010] Multiple pairs of horizontal steel pipes are arranged at intervals along the height direction of the slope. Two horizontal steel pipes located at the same elevation on the left and right slopes form a pair, and the horizontal steel pipes extend along the route.

[0011] The horizontal steel pipe includes a pipe body and caps at both ends. A hook is provided on one cap for connecting the detection hose of the sound wave generating unit or the sound wave receiving unit. A round hole is provided on the other cap for the detection hose to pass through. A water inlet is provided on the pipe body.

[0012] The tube cap with a round hole is sealed with rubber.

[0013] Both the steel pipe and the horizontal steel pipe are joined together using an assembly structure.

[0014] The multi-source acoustic wave transmitter is an electric spark source, the acoustic wave emitting unit is a capacitor spark excitation source, the acoustic wave receiving unit is a hydrophone, and water as an acoustic wave medium is filled into the steel pipe and the horizontal steel pipe.

[0015] The advantages of this utility model are: it enables high-precision detection of cavities in silty sand roadbeds, ensuring the accuracy of silty sand roadbed detection; the structure is simple and reasonable, with minimal impact on silty sand roadbeds, and can be restored by backfilling after detection; the detection is simple and convenient, highly efficient, and suitable for widespread application. Attached Figure Description

[0016] Figure 1 This is a layout diagram of the vertical cross-section of the trans-hole CT in this utility model;

[0017] Figure 2 This is a vertical layout diagram of the horizontal cross-section of the transom CT in this utility model;

[0018] Figure 3 This is a plan view of the horizontal cross-section of the trans-hole CT in this utility model;

[0019] Figure 4 This is a schematic diagram of the horizontal steel pipe structure in this utility model;

[0020] Figure 5This is a schematic diagram of construction step I in this utility model;

[0021] Figure 6 This is a schematic diagram of construction step III of this utility model;

[0022] Figure 7 This is a schematic diagram of construction step IV in this utility model;

[0023] Figure 8 This is a schematic diagram of construction step V in this utility model. Detailed Implementation

[0024] The features and other related features of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments, so as to facilitate the understanding of those skilled in the art:

[0025] like Figure 1-8 As shown in the figure, 1-17 represent: sound wave transmitting unit 1, multi-source sound wave transmitter 2, sound wave receiving unit 3, multi-source sound wave receiver 4, horizontal steel pipe 5, pipe cover 6, pipe cover 7, water inlet 8, detection hose 9, steel pipe 10, steel pipe 11, threaded drill bit 12, handheld rotary power head 13, electric spark excitation source 14, electric spark vibration source 15, hydrophone 16, and data acquisition device 17.

[0026] Example: Figures 1 to 8 As shown, the roadbed void detection system in this embodiment is used to detect voids in existing roadbeds. The system will be described below by describing its construction method.

[0027] Specifically, the roadbed void detection system in this embodiment includes the following application methods:

[0028] 1) such as Figure 5 As shown, a handheld rotary power head 13 is used to drill steel pipes 10 with threaded drill bits 12 at the bottom into the existing roadbed section by section on both sides of the roadbed; two rows of parallel vertical steel pipe holes are formed on both sides of the existing roadbed.

[0029] In this embodiment, as Figure 5 As shown, to meet the depth requirements of the steel pipe borehole, the steel pipes are extended using a splicing structure. The bottom of the lowest steel pipe 10 is equipped with a threaded drill bit 12 for easy drilling, while the extended steel pipe 11 above it is a regular steel pipe with splicing structures at both ends. The splicing structure between steel pipes 10 and 11 can use common threaded connections. Technicians connect a handheld rotary power head 13 to the steel pipe and then rotate the handheld rotary power head 13 to drill the steel pipe into the existing roadbed. When drilling into the existing roadbed is difficult, the handheld rotary power head 13 can be replaced with a mechanically driven rotary power head.

[0030] 2) Combining Figure 1 and Figure 6 As shown, water is filled into the vertical steel pipe holes on both sides of the road shoulder as the sound wave medium. Taking the direction shown in the figure as an illustration, a string of electric spark excitation sources 14, which serves as the sound wave emitting unit 1, is placed in the steel pipe on the left. The electric spark excitation source 14 is connected to an electric spark source 15, which serves as the multi-source sound wave generator 2. A string of hydrophones 16, which serve as the sound wave receiving unit 2, is placed in the steel pipe on the right. The hydrophones 16 are connected to the data acquisition device 17.

[0031] 3) The electric spark source 14 is excited point by point by the electric spark source, and the sound wave is transmitted from one side to the other. The hydrophone 16 collects the sound wave and it is further collected by the data acquisition device 17. According to the data collected by the data acquisition device 17, the wave velocity distribution map between the holes on both sides of the shoulder can be obtained. The wave velocity distribution map reflects the wave velocity distribution of the existing roadbed vertical profile. The distribution of cavities in the existing road shoulder vertical profile can be further analyzed through the wave velocity distribution map.

[0032] 4) Combining Figure 2 and Figure 3 As shown, a horizontal trench is dug along the direction of the road on the slope of the existing shoulder, and horizontal steel pipes 5 extending parallel to the direction of the road are buried in pairs at the same elevation on the left and right slopes.

[0033] like Figure 4 As shown, the horizontal steel pipe 5 is a three-way pipe structure with a water inlet 8 on its body. The water inlet 8 faces in a specific direction to facilitate the filling of water, the medium for sound wave propagation, into the pipe. A pipe cap 6 and a pipe cap 7 are respectively installed at both ends of the pipe. The inner surface of the pipe cap 6 has a hook, while the pipe cap 7 has a pre-drilled hole. In use, after the detection hose of the sound wave transmitting unit 1 or the sound wave receiving unit 3 passes through the pipe, one end of the detection hose is tightened using the hook on the pipe cap 6, and the other end of the detection hose passes through the hole in the pipe cap 7 for extension. The hole in the pipe cap 7 can be secured with, for example, a rubber sealing ring to prevent leakage and ensure detection accuracy.

[0034] 5) Similarly, by exciting the electric spark source point by point through the electric spark source, the sound wave is transmitted from one side to the other. The hydrophone collects the sound wave and it is further collected by the data acquisition device. Based on the data collected by the data acquisition device, the wave velocity distribution map between the holes on both sides of the shoulder can be obtained. This wave velocity distribution map reflects the wave velocity distribution of the existing roadbed horizontal profile. Through the wave velocity distribution map, the distribution of cavities in the existing road shoulder horizontal profile can be further analyzed.

[0035] Although the above embodiments have described the concept and embodiments of the present invention in detail with reference to the accompanying drawings, those skilled in the art will recognize that various improvements and modifications can still be made to the present invention without departing from the scope of the claims, and therefore will not be elaborated here.

Claims

1. A roadbed void detection system for detecting voids in existing roadbeds, characterized in that: It includes a vertical profile detection device, a horizontal profile detection device, and a data acquisition device, wherein: The vertical profile detection device includes steel pipes vertically buried on both sides of the detection area of ​​the existing roadbed. A sound wave generating unit is installed in one side of the steel pipe, and a sound wave receiving unit is installed in the other side of the steel pipe. The sound wave generating unit is connected to a multi-source sound wave transmitter, and the sound wave receiving unit is connected to a multi-source sound wave receiver. The multi-source sound wave receiver is connected to the data acquisition device. The horizontal profile detection device includes horizontal steel pipes buried on both sides of the detection area of ​​the existing roadbed. A sound wave generating unit is installed in one side of the horizontal steel pipe, and a sound wave receiving unit is installed in the other side of the steel pipe. The sound wave generating unit is connected to a multi-source sound wave transmitter, and the sound wave receiving unit is connected to a multi-source sound wave receiver. The multi-source sound wave receiver is connected to the data acquisition device.

2. The roadbed void detection system according to claim 1, characterized in that: The horizontal steel pipe is installed by horizontally trenching along the direction of the route on the slope of the existing roadbed.

3. The roadbed void detection system according to claim 2, characterized in that: Multiple pairs of horizontal steel pipes are arranged at intervals along the height direction of the slope. Two horizontal steel pipes located at the same elevation on the left and right slopes form a pair, and the horizontal steel pipes extend along the route.

4. A roadbed void detection system according to claim 1 or 2, characterized in that: The horizontal steel pipe includes a pipe body and caps at both ends. A hook is provided on one cap for connecting the detection hose of the sound wave generating unit or the sound wave receiving unit. A round hole is provided on the other cap for the detection hose to pass through. A water inlet is provided on the pipe body.

5. A roadbed void detection system according to claim 4, characterized in that: The tube cap with a round hole is sealed with rubber.

6. The roadbed void detection system according to claim 1, characterized in that: Both the steel pipe and the horizontal steel pipe are joined together using an assembly structure.

7. The roadbed void detection system according to claim 1, characterized in that: The multi-source acoustic wave transmitter is an electric spark source, the acoustic wave emitting unit is a capacitor spark excitation source, the acoustic wave receiving unit is a hydrophone, and water as an acoustic wave medium is filled into the steel pipe and the horizontal steel pipe.

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