A detection simulation device and detection method for the disease of tunnel lining void

Abstract

The present invention discloses a detection simulation device and a detection method for the disease of tunnel lining voids, which relates to the technical field of tunnel quality detection. The simulation device includes a stepped model, which is composed of nine steps with gradually increasing thicknesses. In each step, a first hollow box and a second hollow box with different heights are buried, simulating the working conditions of the dense positions at nine thicknesses and two void thicknesses, with a total of 27 working conditions. The detection method mainly includes the following steps: S1. Conduct a percussion method detection simulation experiment on the above detection simulation device to obtain the schematic diagram of the time-domain signal waveform under each working condition under percussion conditions; S2. Percuss the actual tunnel lining to be detected and collect the schematic diagram of the time-domain signal waveform; S3. Compare and analyze the two schematic diagrams of the time-domain signal waveforms. The detection simulation device and the detection method for the disease of tunnel lining voids can conveniently, quickly and accurately perform non-destructive detection on the disease of voids behind the tunnel lining by using the methods of percussion and comparison.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel quality detection, and particularly to a simulation device and detection method for detecting the disease of tunnel lining voids. Background Technique

[0002] Tunnel geological conditions and structural forms are very complex. During the construction of tunnels, many disciplines and specialties are involved, which makes the construction period of tunnel projects long and the construction difficult. In the operation process, it is common to expose diseases such as lining cracks, lining voids, and structural water leakage. This not only shortens the life of the tunnel but also poses potential safety hazards to transportation.

[0003] As a support and safety reserve, the casting process of the secondary lining structure of the tunnel is affected by geological factors, construction factors, etc., and often has defects such as insufficient thickness, voids between the lining and the surrounding rock, and non-compaction. Among them, the void behind the lining accounts for the largest proportion among various tunnel diseases. The void of the secondary lining of the tunnel will make the contact between the surrounding rock and the secondary lining concrete uneven, resulting in local stress concentration in the secondary lining, changing the stress state of the lining structure, generating deformation and damage, and finally developing into the disease of secondary lining cracking. At the same time, due to the influence of tunnel groundwater, water pockets are easily formed at the voids, and the pressure of larger water pockets will also cause the secondary lining to crack and be accompanied by water seepage phenomena, forming huge safety hazards.

[0004] In the prior art, the quality detection methods in tunnel engineering mainly include two types: mechanical damage detection and non-destructive detection. Among them, mechanical damage detection usually uses core drilling to obtain quality information more intuitively, but it will damage the lining structure and even damage the tunnel waterproof system. At the same time, the detection area of core drilling is small, and the contingency of the detection results is large, which cannot comprehensively reflect the overall quality of the tunnel. Non-destructive testing technology is a non-destructive testing method for tunnels based on the principles of light, electricity, sound, magnetism, and rays. The currently commonly used non-destructive testing method is ground penetrating radar detection. It mainly uses the propagation characteristics of high-frequency pulsed electromagnetic waves in underground media to detect the tunnel according to the propagation time, amplitude, and waveform information of electromagnetic waves to judge whether there are tunnel diseases such as voids behind the lining. Although the application of ground penetrating radar in tunnel quality detection is becoming more and more extensive and the technology is gradually mature, due to the characteristics of this method itself, it has at least the following deficiencies in the detection of lining voids: First, the antenna of the ground penetrating radar has a certain energy radiation angle. As the detection depth increases, the diffusion area increases continuously, affecting the detection accuracy of the radar. Second, during the propagation of the ground penetrating radar, total reflection will occur at the metal interface and be reflected on the radar map, affecting the identification of defects behind the lining steel bars. Summary of the Invention

[0005] The object of the present invention is to overcome the deficiencies of the prior art and provide a detection simulation device and detection method for the void disease of tunnel lining. By means of knocking and comparison, the void disease behind the tunnel lining can be nondestructively detected conveniently, quickly and accurately.

[0006] The object of the present invention is achieved by the following technical solutions:

[0007] A detection simulation device for the void disease of tunnel lining includes a stepped model. The stepped model includes nine steps with equal width. The thicknesses of the nine steps increase sequentially from bottom to top, and their thicknesses are 5 cm, 10 cm, 15 cm, 20 cm, 25 cm, 30 cm, 35 cm, 40 cm, and 45 cm respectively. A first hollow box and a second hollow box with different heights are buried in each step. The bottom surfaces of the nine first hollow boxes and the bottom surfaces of the nine second hollow boxes are all arranged on the same plane.

[0008] Further, both the first hollow box and the second hollow box are made of insulating five-ply board, and the stepped model is cast with C30 concrete.

[0009] Further, the height of the first hollow box is 5 mm, and the height of the second hollow box is 20 mm.

[0010] Further, the nine first hollow boxes are arranged in a column, and the nine second hollow boxes are arranged in a column. The first hollow box and the second hollow box are symmetrically arranged on both sides of the central axis of the stepped model;

[0011] The center of the first hollow box and the center of the second hollow box are both arranged on the transverse central axis of the step where they are located.

[0012] A detection simulation device and detection method for the void disease of tunnel lining include the following steps:

[0013] S1. Conduct a knocking method detection simulation experiment on the above detection simulation device for the void disease of tunnel lining, and obtain the time-domain signal waveform schematic diagrams of the dense positions, the positions of the first hollow boxes, and the positions of the second hollow boxes in each step under the knocking condition;

[0014] S2. Conduct the same knocking as in step S1 on the lining of the tunnel to be detected, and collect the time-domain signal waveform schematic diagrams under the knocking condition in the actual tunnel;

[0015] S3. Compare and analyze the time-domain signal waveform schematic diagrams obtained in step S2 under the knocking condition in the actual tunnel with the time-domain signal waveform schematic diagrams collected based on the simulation device in step S1.

[0016] Further, the percussion method detection refers to setting excitation points and receiving points. At the excitation points, a source hammer is used to strike and emit signals, and at the receiving points, a geophone and a coupling device are set to collect signals.

[0017] The beneficial effects of the present invention are as follows:

[0018] The stepped model of the detection simulation device for tunnel lining void diseases of the present invention is cast from C30 concrete, and the hollow box is made of insulating five-ply board. It is convenient for construction, simple in process, stable in structure, and durable. The stepped model is provided with nine steps, and the thicknesses of each step are distributed in an arithmetic progression in a specific size, respectively simulating nine working conditions within the thickness range of the secondary lining that may actually be affected by voids; under each working condition, the non-void state can be simulated, and two end-value working conditions within the actually occurring void thickness range are respectively simulated by two hollow boxes with different thicknesses. Therefore, the device can realize the simulation of 27 typical working conditions in total, providing a fast and effective experimental model for data collection and comparative analysis of the percussion method detection experiment of tunnel lining void diseases.

[0019] A method for detecting tunnel lining void diseases of the present invention realizes non-destructive detection of voids inside the tunnel lining by means of percussion. First, the above-mentioned detection simulation device is used to strike and simulate the above 27 working conditions, and the time-domain signal waveform schematic diagram is collected. Then, when actually lining the tunnel, percussion is carried out, and the time-domain signal waveform schematic diagram of the actual environment is collected and compared with the time-domain signal waveform schematic diagrams under the above 27 working conditions to complete the detection of the actual tunnel. The detection process is convenient and fast. Compared with the detection method using a radar antenna, there is no problem of reflection at the metal interface of the energy radiation angle, and the detection result is more accurate. Description of the Drawings

[0020] Figure 1 It is a schematic structural diagram of a detection simulation device for tunnel lining void diseases of the present invention;

[0021] Figure 2 It is a top view schematic diagram of a detection simulation device for tunnel lining void diseases of the present invention;

[0022] Figure 3 It is a schematic diagram of the positions of the first hollow box and the second hollow box within the 30-cm-thick step of a detection simulation device for tunnel lining void diseases of the present invention;

[0023] Figure 4 It is a schematic diagram of the principle of the percussion method simulation experiment of a detection simulation device for tunnel lining void diseases of the present invention;

[0024] Figure 5 It is a schematic diagram of the time-domain signal waveform of the percussion method within the 15-cm thickness of a detection simulation device for tunnel lining void diseases of the present invention;

[0025] Figure 6 Schematic diagram of the time-domain signal waveform of the 45-cm thick percussion method in a tunnel lining void detection simulation device of the present invention;

[0026] Figure 7 Statistical analysis chart of the spectral quality center and the number of spectral peaks of the signals collected by a tunnel lining void detection simulation device of the present invention. Detailed implementation manners

[0027] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings, but the protection scope of the present invention is not limited to the following description.

[0028] As Figures 1 to 3 shown, a tunnel lining void detection simulation device includes a stepped model. The stepped model includes nine steps 1 with equal widths. The thicknesses of the nine steps 1 increase sequentially from bottom to top, and their thicknesses are 5 cm, 10 cm, 15 cm, 20 cm, 25 cm, 30 cm, 35 cm, 40 cm, and 45 cm respectively. A first hollow box 2 and a second hollow box 3 with different heights are buried in each step 1. The bottom surfaces of the nine first hollow boxes 2 and the bottom surfaces of the nine second hollow boxes 3 are all arranged on the same plane.

[0029] This tunnel lining void detection simulation device is used to simulate the void situation inside the real tunnel lining. According to the tunnel design specifications, the thickness range of the secondary lining designed for different surrounding rock grades in the composite lining is 25 - 50 cm. According to the research results of engineering cases, the thickness of the secondary lining that may be affected by voids is 5 - 45 cm. The thickness of each step 1 is designed as 5 cm, 10 cm, 15 cm, 20 cm, 25 cm, 30 cm, 35 cm, 40 cm, and 45 cm, so that the thickness range of this stepped model is comprehensive and the interval increases evenly, which can effectively simulate various working conditions under different thickness secondary linings of the actual tunnel.

[0030] Furthermore, both the above-mentioned first hollow box 2 and the second hollow box 3 are made of insulating five-ply board. The stepped model is cast with C30 concrete, which is convenient for construction, has a simple process, a stable structure, and is durable. The buried positions of the first hollow box 2 and the second hollow box 3 are used to simulate the void situation of the tunnel lining. The positions without buried hollow boxes are cast with C30 concrete, and their structures are dense, simulating the situation without voids.

[0031] Based on a large number of engineering examples, the void thickness that usually affects the quality of the secondary lining of a tunnel is 5 - 20 mm. Considering the limitation of equipment resolution and the actual needs of the project, the hollow box model is designed with two sizes, that is, the height of the first hollow box 2 is 5 mm, and the height of the second hollow box 3 is 20 mm, to simulate the void situation of the tunnel lining. In actual engineering, the void behind the tunnel lining mostly starts from the contact position between the surrounding rock and the lining. Therefore, during installation, the bottom surfaces of the first hollow box 2 and the second hollow box 3 are both set on the same plane. The part below this plane in the stepped model simulates the tunnel surrounding rock environment, and the positions of the two hollow boxes respectively simulate the situations of two different void thicknesses. The result information collected by the percussion test can be directly applied to the comparison and analysis of the percussion results in the actual tunnel environment.

[0032] According to the above, the thickness distribution of the nine steps 1 of the tunnel lining void disease detection simulation device uses an arithmetic progression distribution to simulate nine working conditions within the thickness range of the secondary lining that may actually be affected by voids; under each working condition, the non-void state can be simulated, and the two end value working conditions of the actual void thickness range are respectively simulated by the first hollow box 2 and the second hollow box 3. Therefore, this device can actually simulate 27 typical working conditions, providing a fast and effective experimental model for data collection and comparison analysis in the percussion method detection experiment of tunnel lining void diseases.

[0033] Furthermore, the nine first hollow boxes 2 are arranged in a column, the nine second hollow boxes 3 are arranged in a column, and the first hollow box 2 and the second hollow box 3 are symmetrically arranged on both sides of the central axis of the stepped model; the centers of the first hollow box 2 and the second hollow box 3 are both set on the transverse central axis of the step 1 where they are located. Specifically, when implemented, the bottom of the above stepped model is 360 cm long and 160 cm wide, then the width of each step 1 is 40 cm and the length is 160 cm. When implemented as Figure 2 shown, in the length direction of the step 1, the step 1 is divided into four equal-length regions each 40 cm long. The sizes of the first hollow box 2 and the second hollow box 3 are respectively selected as 150×150×5 mm and 150×150×20 mm, and they are respectively buried at the centers of the middle two regions of the above four equal-length regions. The bottom plane of the hollow box is 15 mm above the bottom plane of the stepped model. The two side regions of the entire stepped model are mainly used for percussion simulation experiments and data collection for the non-void state, and the central region of the stepped model is used for percussion experiments and data collection for the two void states. In this setting, the simulation test process can be made standardized and convenient. Designing the size of the hollow box and setting it in the central region of the step 1 can effectively avoid mutual influence on the test data.

[0034] A method for detecting tunnel lining void diseases uses the method of percussion to achieve non-destructive detection of voids inside the tunnel lining, and mainly includes the following steps:

[0035] S1. Conduct a percussion method detection simulation experiment on the above tunnel lining void detection simulation device to obtain the time-domain signal waveform schematic diagrams of the dense positions, the positions of the first hollow box 2, and the positions of the second hollow box 3 in each step 1 under percussion conditions. The percussion method detection refers to setting excitation points and receiving points, using a seismic source hammer to strike and emit signals at the excitation points, and setting a geophone and a coupling device at the receiving points to collect signals. Specifically, as Figure 4 shown, excitation points and receiving points are respectively set at the positions of the non-void area (without buried hollow box), 5-mm void area (buried with the first hollow box 2), and 20-mm void area (buried with the second hollow box 3) of each step 1, and percussion experiments are carried out using a seismic source hammer such as a steel cone, a steel bar, or a nylon hammer. An appropriate IEPE-type geophone and a coupling device are configured at the receiving points of the step 1 model to collect the signals returned by percussion, and the time-domain signal waveform schematic diagrams are obtained. As Figure 5 shown is the time-domain signal waveform schematic diagram collected by the receiving points under a 15-cm thick step, Figure 6 and is the time-domain signal waveform schematic diagram collected by the receiving points under a 45-cm thick step. The waveform schematic diagrams show the relationship between the signal voltages (mV) and the durations (ms) of channels 1 (CH1) and 2 (CH2). The differences in the waveforms in the two figures reflect the differences in the dispersion characteristics of different thickness strata.

[0036] S2. Percuss the actual tunnel lining to be detected with the same intensity, frequency, etc. as in step S1, and collect the time-domain signal waveform schematic diagrams under the percussion conditions in the actual tunnel.

[0037] S3. Compare and analyze the time-domain signal waveform schematic diagrams under the percussion conditions in the actual tunnel obtained in step S2 with the time-domain signal waveform schematic diagrams collected based on the simulation device in step S1, and then it can be concluded whether there is a void disease behind the actual tunnel lining, completing the non-destructive detection of the tunnel.

[0038] Furthermore, as Figure 7 shown, during implementation, a simulation percussion test can also be carried out on the stepped model, and a statistical analysis diagram of the spectral quality center and the number of spectral peaks of the collected signals is obtained. By controlling and comparing and analyzing parameters such as the time-domain response duration, the minimum frequency, the maximum frequency, the spectral quality centroid, and the number of frequency peaks of the experimental data, it can be known that there is a zoning phenomenon in the signals of the void model and the non-void model shown in the figure in the analysis diagram. Using this zoning phenomenon, the void area of the tunnel lining can be predicted when detecting the actual tunnel using the percussion method, making the percussion method detection in the actual tunnel convenient and fast.

[0039] The above are only the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein, and should not be regarded as excluding other embodiments. Instead, it can be used in various other combinations, modifications, and environments, and can be changed within the scope of the concept described herein through the above teachings or the technology or knowledge in the relevant field. As long as the changes and variations made by those skilled in the art do not depart from the spirit and scope of the present invention, they should all be within the protection scope of the appended claims of the present invention.

Claims

1. A detection simulation device for the disease of tunnel lining void, characterized in that, It includes a stepped model, and the stepped model includes nine steps (1) with equal widths. The thicknesses of the nine steps (1) increase successively from bottom to top, and their thicknesses are 5 cm, 10 cm, 15 cm, 20 cm, 25 cm, 30 cm, 35 cm, 40 cm, and 45 cm respectively. A first hollow box (2) and a second hollow box (3) with different heights are buried in each step (1). The bottom surfaces of the nine first hollow boxes (2) and the bottom surfaces of the nine second hollow boxes (3) are all arranged on the same plane. The bottom length of the stepped model is 360 cm and the width is 160 cm. The width of each step (1) is 40 cm and the length is 160 cm.

2. The tunnel lining void disease detection simulation device according to claim 1, wherein, Both the first hollow box (2) and the second hollow box (3) are made of insulating five-ply board, and the stepped model is cast with C30 concrete.

3. A tunnel lining void disease detection simulation device according to claim 2, characterized in that, The height of the first hollow box (2) is 5 mm, and the height of the second hollow box (3) is 20 mm.

4. A tunnel lining void disease detection simulation device according to claim 3, characterized in that, The nine first hollow boxes (2) are arranged in a column, and the nine second hollow boxes (3) are arranged in a column. The first hollow box (2) and the second hollow box (3) are symmetrically arranged on both sides of the central axis of the stepped model; The center of the first hollow box (2) and the center of the second hollow box (3) are both arranged on the transverse central axis of the step (1) where they are located.

5. A method for detecting the disease of tunnel lining void, characterized in that, It includes the following steps: S1. Conduct a percussion method detection simulation experiment on the tunnel lining void disease detection simulation device described in claim 1, and obtain the time-domain signal waveform schematic diagrams of the dense positions, the positions of the first hollow box (2), and the positions of the second hollow box (3) in each step (1) under the percussion condition; S2. Conduct the same percussion as in step S1 on the lining of the tunnel to be detected, and collect the time-domain signal waveform schematic diagrams under the percussion condition in the actual tunnel; S3. Compare and analyze the time-domain signal waveform schematic diagrams obtained in step S2 under the percussion condition in the actual tunnel with the time-domain signal waveform schematic diagrams collected based on the simulation device in step S1.

6. A method for detecting the disease of tunnel lining void, according to claim 5, characterized in that, The percussion method detection refers to setting an excitation point and a receiving point, using a seismic source hammer to strike at the excitation point to emit a signal, and setting a geophone and a coupling device at the receiving point to collect the signal.

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