Passive tunneling unfavorable geology detection device and method

Abstract

The invention discloses a passive tunnel boring unfavorable geology detection device and method, and belongs to the technical field of geology detection in tunnel construction.The passive tunnel boring unfavorable geology detection device is characterized by comprising a plurality of detection mechanisms, and the detection mechanisms are arranged in advance drill holes of a tunnel face; the detection mechanism comprises a protection system, a signal acquisition system, a signal transmission system and an intelligent terminal system, the signal acquisition system is arranged in the protection system, the protection system is used for protecting the signal acquisition system, and the signal acquisition system is connected with the intelligent terminal system through the signal transmission system; and the collected signals are transmitted to an intelligent terminal system for processing. By adopting the passive tunneling unfavorable geology detection device and method, the problems that an existing device is complex in structure, inconvenient to use and low in detection precision can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of geological detection in tunnel construction, and in particular to a passive tunnel excavation unfavorable geological detection device and method. Background Art

[0002] Affected by various factors such as topography, geology, and climate conditions, tunnel excavation often encounters a series of stratum risk hazards, including water inrush, mud inrush, broken zones, rock bursts, freeze-thaw and frost heave, etc. If these risks cannot be warned and handled in time, they will seriously affect the safety and progress of tunnel construction. Among them, the most common risk is water inrush.

[0003] Water inrush in tunnels is often related to the geological structure and precipitation conditions around the construction site. When the tunnel is excavated to a stratum containing geological structures such as faults, fissures, and caves, a water inrush channel is easily formed. If the precipitation conditions at the construction site change dramatically, a water inrush accident may also occur. Water inrush will have many impacts on the construction process: small water inrush will deteriorate the on-site construction environment and reduce the efficiency of support work; large water inrush may flood equipment and construction personnel, delay construction progress, increase construction costs, and even cause casualties in severe cases. Water inrush may cause changes in the groundwater level and affect the surrounding ecological environment. In addition, the sediment and wastewater carried during the water inrush may pollute the surrounding water and soil. Therefore, timely and effective detection of the water body in front of the tunnel under construction is of great significance to ensure the safe and stable construction.

[0004] Advanced geological prediction can obtain information about the surrounding rock in front of the tunnel face in advance to prevent disasters. Existing earthquake detection and advanced geological prediction technologies are mostly based on the full-space seismic wave field propagation model, and an observation system is arranged on the tunnel wall to obtain information ahead. However, the actual tunnel space is disturbed by free interfaces such as the tunnel face and tunnel wall and does not fully comply with the full-space wave field propagation law. The detection method based on the full-space model is prone to false detection and missed detection. The arrangement of the observation system on the tunnel wall is time-consuming, costly, and has poor repeatability, which is not conducive to multiple detections. At present, manual methods are mostly used to achieve anomaly imaging and interpretation. When the amount of data is too large, the imaging cycle is long, the cost is high, it is greatly affected by human factors, and it has strong multi-solution.

[0005] Existing devices and methods for detecting adverse geological conditions still face problems such as cumbersome equipment installation and operation, serious attenuation and diffusion of reflected wave signals, and poor signal reception during the detection process, which affect detection efficiency and accuracy. Summary of the invention

[0006] The purpose of the present invention is to provide a passive tunnel excavation bad geological detection device and method to solve the problems of complex structure, inconvenient use and low detection accuracy of the existing device.

[0007] To achieve the above-mentioned purpose, the present invention provides a passive tunnel excavation poor geological detection device, including a plurality of detection mechanisms, which are arranged in the advance drilling hole of the tunnel face; the detection mechanism includes a protection system, a signal acquisition system, a signal transmission system and an intelligent terminal system, the signal acquisition system is arranged inside the protection system, the protection system is used to protect the signal acquisition system, the signal acquisition system is connected to the intelligent terminal system through the signal transmission system, and the collected signals are transmitted to the intelligent terminal system for processing.

[0008] Preferably, the protection system includes a plurality of detection sleeves connected end to end and a magnetic sleeve for sending the detection sleeve into the advance drilling hole, the detection sleeve is provided with a plurality of mounting holes for allowing the signal acquisition system to pass through the detection sleeve, the mounting holes are provided with covers for sealing the mounting holes, and the interior of the detection sleeve is provided with a power element for driving the cover to open or close the mounting hole, and the power element is connected to the intelligent terminal system.

[0009] Preferably, a buckle is provided at the head end of the detection sleeve, and a slot adapted to the buckle is provided at the tail end of the detection sleeve, and adjacent detection sleeves are connected via the buckle and the slot.

[0010] Preferably, a connector is provided at one end of the magnetic sleeve, the magnetic sleeve is connected to the detection sleeve via the connector, and a switch structure for controlling the connection or disconnection of the connector and the detection sleeve is provided on the magnetic sleeve.

[0011] Preferably, the switch structure includes a coil, which is wound on the outer surface of a magnetic sleeve. A handle is provided at the other end of the magnetic sleeve, a battery connected to the coil is provided in the handle, and a switch for controlling the connection or disconnection of the battery and the coil is provided on the handle; the connector and the detection sleeve are both made of ferromagnetic materials, and the handle is made of insulating material.

[0012] Preferably, the signal acquisition system includes a detector, a base for mounting the detector is provided inside the detection sleeve, the base corresponds to the mounting hole one by one, the detector is electrically connected to the base, a lifting element for driving the base to rise and fall is provided inside the detection sleeve, the lifting element is connected to the intelligent terminal system, a battery pack is provided inside the detection sleeve, the battery pack is connected to the base through a wire, and the battery pack is connected to the intelligent terminal system; the detector is connected to the signal transmission system.

[0013] Preferably, the detector includes a probe, an insulating protective shell is provided on the outside of the probe, a metal interface connected to the probe is provided on the protective shell, the probe is connected to a conductive mounting groove on the base through the metal interface, and the mounting groove is connected to the wire.

[0014] Preferably, a rubber convex ring is provided on the outer surface of the protective shell, a groove matched with the convex ring is provided in the installation groove, and the detector is clamped with the base through the convex ring and the groove.

[0015] Preferably, the signal transmission system includes a storage unit and an antenna, the storage unit is connected to the probe via a signal transmission line, the storage unit is connected to the antenna via a signal transmission line, the antenna is connected to the signal transmission line via a quick-connect connector, and the signal transmission line is located inside the detection sleeve.

[0016] The detection method based on the above passive tunneling bad geological detection device includes the following steps:

[0017] S1. Determine the detection requirements according to the tunnel size and safety level, and determine the total length of the detection sleeve;

[0018] S2. Assemble the detection sleeve, install the detector in the detection sleeve, check the detector to ensure that it works normally, and insert the detection sleeve into the advance borehole;

[0019] S3. Insert the connector of the magnetic sleeve into the tail end of the terminal detection sleeve, turn on the switch, and the connector generates magnetic force after the coil is energized. The connector is fixed to the magnetic sleeve, and the detection sleeve is sent to a specific position in front of the face through the magnetic sleeve; turn off the switch and take the magnetic sleeve out of the advance drilling hole;

[0020] S4, controlling the extension of the lifting element through the intelligent terminal system, the lifting element extends the probe of the detector from the installation hole through the base, and the probe contacts the hole wall of the advance drilling hole;

[0021] S5. Hammer the tunnel face to calibrate the wave velocity of the geophone;

[0022] S6, tunnel blasting, the detector receives the incident wave signal and the reflected wave signal, the detector stores the incident wave signal and the reflected wave signal in the storage unit through the signal transmission line and sends the signal to the intelligent terminal system through the antenna;

[0023] S7, the intelligent terminal system pre-processes the received signal, determines the rock mass quality, and predicts the coordinates and size of the bad geology ahead;

[0024] S8. After completing a tunnel inspection, the intelligent terminal system controls the lifting element to descend and the probe is retracted into the inspection sleeve; the inspection sleeve is taken out from the advance drilling hole through the magnetic suction sleeve; the inspection sleeve and the detector are removed to prepare for the inspection of the next construction face.

[0025] The advantages and positive effects of the passive tunneling bad geological detection device and method described in the present invention are:

[0026] 1. The present invention utilizes the existing advance boreholes left by advance drilling for deployment, without adding additional drilling workload on site, thereby improving detection efficiency and reducing labor.

[0027] 2. The detection sleeve of the present invention can be spliced ​​to meet the detection needs of different lengths and is easy to transport and carry.

[0028] 3. The present invention can adjust the number of installed detectors and the installation spacing according to the tunnel size and construction safety level to achieve different detection accuracies, and there are no redundant parts or wires exposed outside, and the appearance is clean and tidy.

[0029] 4. The device described in the present invention has a simple structure and is easy to use. It is arranged in front of the tunnel face, and the distance between it and the unfavorable geological body is closer, the reflected wave propagation path is shorter, the effective signal loss is less, and the recognition accuracy and precision of the unfavorable geological body are high.

[0030] 5. The present invention can simultaneously realize the two functions of rock mass quality identification and poor geological body prediction. The present invention uses the seismic waves generated by drilling and blasting to identify rock mass quality and predict poor geological bodies, without the need for additional seismic sources, thus saving detection costs.

[0031] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the structure of the passive tunnel boring bad geological detection device of the present invention in application state;

[0033] Figure 2 It is a schematic diagram of the structure of the protection system of the present invention;

[0034] Figure 3 This is a schematic diagram of the structure of the detection sleeve end of the present invention;

[0035] Figure 4 It is a schematic diagram of a partial cross-sectional structure of a detection sleeve of the present invention;

[0036] Figure 5 This is a schematic diagram of the structure of the magnetic suction sleeve of the present invention;

[0037] Figure 6 It is a flow chart of the detection method of the present invention;

[0038] Figure 7 Schematic diagram of the HSP method;

[0039] Figure 8 This is the XOY slice diagram of the reflection wave analysis result;

[0040] Fig. 9 Schematic diagram for rock mass quality identification.

[0041] Reference numerals

[0042] 1. Tunnel; 2. Detection device; 3. Reflection wave signal; 4. Face; 5. Advance drilling; 6. Seismic wave signal; 7. Unfavorable geology; 21. Protection system; 211. Detection sleeve; 212. Mounting hole; 213. Cover; 214. Buckle; 215. Slot; 216. Magnetic sleeve; 217. Handle; 218. Switch; 219. Connector; 2110. Coil; 22. Signal acquisition system; 221. Probe; 222. Protective shell; 223. Convex ring; 224. Groove; 225. Base; 226. Mounting slot; 227. Battery pack; 228. Lifting element; 229. Wire; 23. Signal transmission system; 231. Signal transmission line; 232. Quick connector. DETAILED DESCRIPTION

[0043] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the invented product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "setting", "installation", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] In this application, unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the technical field of this application. In case of any inconsistency, the meaning described in this specification or the meaning derived from the contents recorded in this specification shall prevail. In addition, the terms used herein are only for the purpose of describing the embodiments of the present application and are not intended to limit the present application.

[0045] In order to accurately describe the technical content of this application and to accurately understand the present invention, the following explanations or definitions are given for the terms used in this specification before describing the specific implementation methods:

[0046] Drilling and blasting method: Drilling and blasting method refers to the method of excavating rocks by drilling, charging and blasting. Drilling and blasting method has always been the main construction method for rock excavation in underground buildings.

[0047] Water gushing: also known as water bursting, is the phenomenon of sudden large-scale water gushing that occurs during the construction of underground caves and tunnels when passing through areas with developed caves, especially when encountering underground river systems, thick layers of water-containing gravel and gravel, and large fault zones connected to surface water.

[0048] Detector: A detector is a device that detects some useful information in a wave signal. It is a device used to identify the existence or change of waves, oscillations or signals.

[0049] Tunnel face: The tunnel face refers to the top rock surface exposed during tunnel excavation. It is a professional term in tunnel engineering.

[0050] Seismic waves: Seismic waves are the wave phenomenon in which energy generated when underground rocks break or vibrate propagates within the earth. This wave can transfer energy and cause vibration.

[0051] The embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0052] like Figure 1 As shown. A passive tunnel excavation bad geological detection device includes several detection mechanisms, which are arranged in the advance borehole 5 of the tunnel face 4. The detection mechanism is arranged using the existing advance borehole 5 left by the advance drilling, without increasing the additional drilling workload on site, improving the detection efficiency and reducing the labor. The detection mechanism includes a protection system 21, a signal acquisition system 22, a signal transmission system 23 and an intelligent terminal system. The signal acquisition system 22 is arranged inside the protection system 21, and the protection system 21 is used to protect the signal acquisition system 22 to ensure that the signal acquisition system 22 can collect information at a specified position in front of the tunnel face 4. The signal acquisition system 22 forms a three-dimensional detection array on the tunnel face 4 for collecting seismic wave signals 6. The signal acquisition system 22 is connected to the intelligent terminal system through the signal transmission system 23, and the collected signals are transmitted to the intelligent terminal system for processing. The intelligent terminal system is composed of existing parallel computing units, efficient storage units, professional software and other equipment to achieve noise reduction and display of seismic wave signals 6.

[0053] like Figure 2As shown. The protection system 21 includes a plurality of detection sleeves 211 connected end to end and a magnetic sleeve 216 for sending the detection sleeve 211 into the advance drilling hole 5. The detection sleeve 211 is provided with a plurality of mounting holes 212 for allowing the signal acquisition system 22 to pass through the detection sleeve 211, and a cover 213 for blocking the mounting hole 212 is provided at the mounting hole 212. A power element for driving the cover 213 to open or close the mounting hole 212 is provided inside the detection sleeve 211, and the power element is connected to the intelligent terminal system. The power element can adopt an existing micro-electric cylinder as needed, and the micro-electric cylinder drives the cover 213 to slide in the detection sleeve 211, thereby blocking the mounting hole 212 and reducing the damage or influence of the external environment on the detector.

[0054] The head end of the detection sleeve 211 is provided with a buckle 214, and the tail end of the detection sleeve 211 is provided with a slot 215 adapted to the buckle 214, and adjacent detection sleeves 211 are connected by the buckle 214 and the slot 215. The buckle 214 and the slot 215 facilitate the assembly of the detection sleeve 211, and the number of detection sleeves 211 is assembled according to the required length to meet the detection needs of different depths.

[0055] like Figure 5 As shown. A connector 219 is provided at one end of the magnetic sleeve 216, and the magnetic sleeve 216 is connected to the detection sleeve 211 through the connector 219. A switch 218 structure for controlling the connection or disconnection of the connector 219 and the detection sleeve 211 is provided on the magnetic sleeve 216. The switch 218 structure includes a coil 2110, and the coil 2110 is wound on the outer surface of the magnetic sleeve 216. A handle 217 is provided at the other end of the magnetic sleeve 216, and a battery connected to the coil 2110 is provided in the handle 217, and a switch 218 for controlling the connection or disconnection of the battery and the coil 2110 is provided on the handle 217. The connector 219 and the detection sleeve 211 are both made of ferromagnetic materials, and the handle 217 is made of insulating material.

[0056] After the coil 2110 is energized, the connector 219 generates magnetic force, and the connector 219 attracts the detection sleeve 211 together by magnetic force, thereby sending the detection sleeve 211 to the required depth of the advance drilling hole 5 through the magnetic suction sleeve 216, or taking the detection sleeve 211 out of the advance drilling hole 5.

[0057] like Figure 4As shown. The signal acquisition system 22 includes a detector. A base 225 for mounting the detector is provided inside the detection sleeve 211, and the base 225 corresponds to the mounting hole 212 one by one. The detector is electrically connected to the base 225, and the detector is provided with power through the base 225. A lifting element 228 for driving the base 225 to rise and fall is provided inside the detection sleeve 211, and the lifting element 228 is connected to the intelligent terminal system to control the lifting of the lifting element 228. The lifting element 228 can adopt the existing micro-electric cylinder and micro-retractor, and the lifting element 228 drives the detector to extend from the detection sleeve 211 and contact the hole wall of the advance drilling hole 5, thereby receiving the seismic wave signal 6. A battery pack 227 is provided inside the detection sleeve 211, and the battery pack 227 is connected to the base 225 through a wire 229. The battery pack 227 is connected to the intelligent terminal system to control the switch 218 of the battery pack 227. The detector is connected to the signal transmission system 23.

[0058] According to different construction scales of the tunnel 1 and geological detection requirements, different numbers and spacings of detectors may be arranged in the detection sleeve 211 to achieve the best detection result.

[0059] The detector includes a probe 221, and an insulating protective shell 222 is provided outside the probe 221. The protective shell 222 is provided with a metal interface connected to the probe 221, and the probe 221 is connected to a conductive mounting groove 226 on the base 225 through the metal interface. The mounting groove 226 is connected to the wire 229. The mounting groove 226 is a copper groove, which is used to transmit the seismic wave signal 6 collected by the probe 221 to the signal transmission system 23.

[0060] A rubber convex ring 223 is provided on the outer surface of the protective shell 222, and a groove 224 matching the convex ring 223 is provided in the mounting groove 226. The detector is clamped with the base 225 through the convex ring 223 and the groove 224. By pressing the detector, the convex ring 223 is inserted into the groove 224, and the detector is installed on the base 225. The detector is easy to install and remove.

[0061] Probe 221 is an existing geophysical probe 221, which is mainly composed of a shell, a mass block (magnet), a coil 2110, a spring and a damper. Among them, the shell protects the internal components and is usually made of solid metal or plastic to prevent the influence of the external environment. The mass block is a high-quality magnet suspended on a spring and moves relative to the coil 2110 when the seismic wave passes. The coil 2110 is wound around the magnet, and when the magnet moves, an induced current is generated in the coil 2110. The spring is used to suspend and stabilize the magnet so that it can move freely and quickly return to a balanced position. The specifications of probe 221 are set to a frequency response range of 1Hz to 1000Hz and a sensitivity between 20V / m / s and 100V / m / s.

[0062] like Figure 3 The signal transmission system 23 includes a storage unit and an antenna. The storage unit is connected to the probe 221 through a signal transmission line 231. The storage unit is connected to the antenna through a signal transmission line 231. The antenna is connected to the signal transmission line 231 through a quick connector 232. The signal transmission line 231 is located inside the detection sleeve 211.

[0063] The intelligent terminal system is composed of computer system equipment such as the existing efficient central processor, storage unit, and professional platform. The intelligent terminal system uses the existing technology to share the platform with handheld tablets and mobile phones, and can remotely operate the device, view the operating status information of the detector in real time, and receive the packaged file of the sampled seismic waves. The intelligent terminal system uses the existing technology to generate the adaptive shooting frequency and resolution of each detection part in the tunnel 1 according to the first refined sampling information of the tunnel 1, taking into account the storage and collection of effective data. The intelligent terminal system uses the existing deep learning technology to efficiently and accurately identify the graphics after the visualization of the seismic waves, and judge the type, distance and risk level of the unfavorable geological 7 that may exist in front of the face 4. The intelligent terminal system uses the existing technology based on the three-dimensional visualization platform to integrate the information collected from a single or multiple boreholes to form a three-dimensional image of the disease, and updates and improves the three-dimensional database as the tunnel 1 moves forward, forming a three-dimensional geological information library for the area, providing a reference for subsequent engineering construction in similar areas.

[0064] like Figure 6 The detection method based on the above passive tunneling bad geological detection device includes the following steps:

[0065] S1. Determine the detection requirements according to the size and safety level of the tunnel 1 and determine the total length of the detection sleeve 211.

[0066] S2, assembling the detection sleeve 211, installing a detector in the detection sleeve 211, checking the detector to ensure that the detector works normally, and inserting the detection sleeve 211 into the advanced drilling hole 5.

[0067] S3. Insert the connector 219 of the magnetic sleeve 216 into the tail end of the terminal detection sleeve 211, turn on the switch 218, and after the coil 2110 is energized, the connector 219 generates magnetic force, the connector 219 is fixed to the magnetic sleeve 216, and the detection sleeve 211 is sent to a specific position in front of the tunnel face 4 through the magnetic sleeve 216; turn off the switch 218, and take the magnetic sleeve 216 out of the advance drilling hole 5.

[0068] S4. The lifting element 228 is controlled to extend through the intelligent terminal system. The lifting element 228 extends the probe 221 of the detector from the mounting hole 212 through the base 225 , and the probe 221 contacts the hole wall of the advanced drilling hole 5 .

[0069] S5. Hammer the tunnel face 4 to calibrate the wave velocity of the detector.

[0070] S6, tunnel 1 is blasted, the detector receives the incident wave signal and the reflected wave signal 3, the detector stores the incident wave signal and the reflected wave signal 3 in the storage unit through the signal transmission line 231 and sends the signal to the intelligent terminal system through the antenna.

[0071] S7. The intelligent terminal system pre-processes the received signal, determines the rock quality, and predicts the coordinates and size of the unfavorable geological conditions ahead.

[0072] S8. After completing a tunnel 1 inspection, the intelligent terminal system controls the lifting element 228 to descend, and the probe 221 is retracted into the inspection sleeve 211; the inspection sleeve 211 is taken out from the advance drilling hole 5 through the magnetic suction sleeve 216; the inspection sleeve 211 and the detector are removed to prepare for the inspection of the next construction face 4.

[0073] The device described in the present invention can realize two functions: prediction of unfavorable geology and identification of rock quality.

[0074] Adverse geological prediction:

[0075] The seismic wave reflection method is the HSP method. Figure 7 As shown. This method is based on the theory of elastic waves, and the propagation process follows the Huygens-Fresnel principle and the Fermat principle. The prerequisite for implementing this method is that there is a difference in wave impedance in the medium. The wave field propagation velocity, particle vibration amplitude, etc. are closely related to the composition, density, structural characteristics, etc. of the medium. The characteristics of geological bodies such as fault fracture zones, karst, groundwater, etc. that have obvious differences in wave impedance characteristics with the background strata are utilized to achieve the prediction of unfavorable geological bodies 7. During the implementation of HSP, according to the characteristics of tunnel 1 construction, the seismic wave signal 6 generated by the blasting during the construction of tunnel 1 is used as the prediction excitation signal of the HSP method, and the data is received by spatially arranged detectors to realize data acquisition, and inversion analysis is performed through the deep domain diffraction scanning offset stacking imaging technology. The prediction theoretical formula of the method is as follows:

[0076]

[0077] Where: R 12 Represents the reflection coefficient; ρ1, ρ2 represent the medium density, the unit is kg / m 3 ,υ1,υ2 represent the longitudinal wave velocity in the medium, the unit is m / s.

[0078] Before blasting, the position of each detector is first determined according to the position of the detection sleeve 211. After the position is determined, the wave velocity calibration is performed to obtain the propagation velocity of the seismic wave in the normal stratum. After the drilling and blasting method is detonated, the seismic incident wave generated by the blasting propagates to the front of the tunnel 1. When encountering a geological body such as a water body or a cavity whose wave impedance is significantly different from that of the normal stratum, it is reflected to generate a reflected wave, which is successively received by multiple detectors in a three-dimensional space field. The received waveform data is processed through spectrum analysis, correlation interference analysis, inversion imaging and other operations, the time difference between the incident wave and the reflected wave arriving at each detector is calculated, and the azimuth coordinates and size of the 7 bad geological bodies in front are calculated using the triangulation principle to complete the geological forecast work and guide the construction of the tunnel 1.

[0079] The schematic formula of positioning principle is as follows:

[0080]

[0081] In the formula, S represents the earthquake source location, T represents the location of the bad geological body, G i represents the detector position, v represents the wave velocity, t i Indicates the propagation time.

[0082] For each detector G i , given S and G i The coordinates of v and v are determined by the t of each detector. i The inversion algorithm is used to calculate the position of the reflection source. The inversion model will iteratively adjust the position of the bad geological body until the error between the calculated propagation time and the arrival time actually recorded by the detector is minimized, and the position T of the bad geological body can be solved.

[0083] The reflection wave analysis results are as follows: Figure 8 shown.

[0084] Rock mass quality identification:

[0085] As for the rock mass quality identification function, since the detection device 2 is placed in front of the tunnel face 4, the quality of the rock mass within a certain distance in front of the tunnel face 4 can be identified by calculating the time difference between the seismic waves generated by the earthquake source and reaching each detector. The prediction theoretical formula of this method is as follows:

[0086]

[0087] Where: V P represents the propagation velocity of longitudinal waves; K represents the bulk modulus of the material, G represents the shear modulus of the material, and ρ represents the density of the material.

[0088] like Fig. 9As shown. Broken rock is composed of multiple irregular blocks. The contact between particles is not as tight as that of intact rock. There are more gaps and contact interfaces inside. Compared with intact rock, the bulk modulus K is lower. Therefore, the propagation speed of seismic waves in the broken rock area is lower than that in the intact rock area. This is reflected in the different time differences in detecting seismic waves by equally spaced detectors in signal collection. When there is a broken rock area between two detectors, the time it takes for the latter detector to detect seismic waves is longer than when there is intact rock between the two detectors. In principle, the more broken the rock, the longer it takes for the latter detector to detect seismic waves.

[0089] Therefore, the passive tunnel excavation unfavorable geological detection device and method described in the present invention can solve the problems of complex structure, inconvenient use and low detection accuracy of existing devices.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A passive tunneling unfavorable geological detection device, characterized in that: It includes several detection mechanisms, which are arranged in the advance drilling hole of the tunnel face; the detection mechanism includes a protection system, a signal acquisition system, a signal transmission system and an intelligent terminal system. The signal acquisition system is arranged inside the protection system, and the protection system is used to protect the signal acquisition system. The signal acquisition system is connected with the intelligent terminal system through the signal transmission system, and the collected signals are transmitted to the intelligent terminal system for processing.

2. A passive tunneling unfavorable geological detection device according to claim 1, characterized in that: The protection system includes a plurality of detection sleeves connected end to end and a magnetic sleeve for sending the detection sleeve into the advanced drilling hole. The detection sleeve is provided with a plurality of mounting holes for allowing the signal acquisition system to pass through the detection sleeve. The mounting holes are provided with covers for sealing the mounting holes. A power element for driving the cover to open or close the mounting hole is provided inside the detection sleeve, and the power element is connected to the intelligent terminal system.

3. A passive tunneling unfavorable geological detection device according to claim 2, characterized in that: The head end of the detection sleeve is provided with a buckle, and the tail end of the detection sleeve is provided with a slot matched with the buckle, and adjacent detection sleeves are connected by the buckle and the slot.

4. A passive tunneling unfavorable geological detection device according to claim 2, characterized in that: A connector is provided at one end of the magnetic sleeve, and the magnetic sleeve is connected to the detection sleeve via the connector. A switch structure for controlling the connection or disconnection between the connector and the detection sleeve is provided on the magnetic sleeve.

5. A passive tunneling unfavorable geological detection device according to claim 4, characterized in that: The switch structure includes a coil, which is wound on the outer surface of a magnetic sleeve. A handle is provided at the other end of the magnetic sleeve. A battery connected to the coil is provided in the handle. A switch for controlling the connection or disconnection of the battery and the coil is provided on the handle. The connector and the detection sleeve are both made of ferromagnetic materials, and the handle is made of insulating material.

6. A passive tunneling unfavorable geological detection device according to claim 2, characterized in that: The signal acquisition system includes a detector. A base for mounting the detector is arranged inside the detection sleeve. The base corresponds to the mounting hole one by one. The detector is electrically connected to the base. A lifting element for driving the base to rise and fall is arranged inside the detection sleeve. The lifting element is connected to the intelligent terminal system. A battery pack is arranged inside the detection sleeve. The battery pack is connected to the base through a wire, and the battery pack is connected to the intelligent terminal system. The detector is connected to the signal transmission system.

7. A passive tunneling unfavorable geological detection device according to claim 6, characterized in that: The detector comprises a probe, an insulating protective shell is arranged outside the probe, a metal interface connected to the probe is arranged on the protective shell, the probe is connected to a conductive mounting groove on the base through the metal interface, and the mounting groove is connected to the wire.

8. A passive tunneling unfavorable geological detection device according to claim 7, characterized in that: A rubber convex ring is arranged on the outer surface of the protective shell, a groove matched with the convex ring is arranged in the installation groove, and the detector is clamped with the base through the convex ring and the groove.

9. A passive tunneling unfavorable geological detection device according to claim 2, characterized in that: The signal transmission system includes a storage unit and an antenna. The storage unit is connected to the probe through a signal transmission line. The storage unit is connected to the antenna through a signal transmission line. The antenna is connected to the signal transmission line through a quick-connect connector. The signal transmission line is located inside the detection sleeve.

10. A detection method based on a passive tunneling unfavorable geological detection device according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Determine the detection requirements according to the tunnel size and safety level, and determine the total length of the detection sleeve; S2. Assemble the detection sleeve, install the detector in the detection sleeve, check the detector to ensure that it works normally, and insert the detection sleeve into the advance borehole; S3. Insert the connector of the magnetic sleeve into the tail end of the terminal detection sleeve, turn on the switch, and the connector generates magnetic force after the coil is energized. The connector is fixed to the magnetic sleeve, and the detection sleeve is sent to a specific position in front of the face through the magnetic sleeve; turn off the switch and take the magnetic sleeve out of the advance drilling hole; S4, controlling the extension of the lifting element through the intelligent terminal system, the lifting element extends the probe of the detector from the installation hole through the base, and the probe contacts the hole wall of the advance drilling hole; S5. Hammer the tunnel face to calibrate the wave velocity of the geophone; S6, tunnel blasting, the detector receives the incident wave signal and the reflected wave signal, the detector stores the incident wave signal and the reflected wave signal in the storage unit through the signal transmission line and sends the signal to the intelligent terminal system through the antenna; S7, the intelligent terminal system pre-processes the received signal, determines the rock mass quality, and predicts the coordinates and size of the bad geology ahead; S8. After completing a tunnel inspection, the intelligent terminal system controls the lifting element to descend and the probe is retracted into the inspection sleeve; the inspection sleeve is taken out from the advance drilling hole through the magnetic suction sleeve; the inspection sleeve and the detector are removed to prepare for the inspection of the next construction face.

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