Shield tunnel optical fiber intelligent segment multi-parameter automatic monitoring device and method

Abstract

The invention discloses a shield tunnel optical fiber intelligent segment multi-parameter automatic monitoring device and method, and the device comprises a water and soil pressure-internal force-deformation monitoring unit, a segment crack monitoring unit, a joint deformation-differential settlement monitoring unit, and a data collection and processing unit. The water and soil pressure-internal force-deformation monitoring unit, the segment crack monitoring unit and the joint deformation-differential settlement monitoring unit are connected with the data acquisition and processing unit. According to the invention, full-life-cycle monitoring of a shield tunnel during a construction period and an operation period can be realized, and multi-parameter integrated automatic online monitoring of external water and soil pressure of shield tunnel segments, segment reinforcement stress, bolt stress, temperature, stress, strain, cracks, joint deformation and tunnel differential settlement can be realized. The multi-parameter automatic monitoring requirements of tunnel overall stress, differential settlement, water and soil pressure outside the tunnel and the like are met, and the device has the advantages of high precision, good durability, good stability, high automation degree, convenience in construction, high insulation safety and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of tunnel monitoring, and in particular relates to a multi-parameter automatic monitoring device and method for optical fiber intelligent segments of a shield tunnel. Background Art

[0002] With the acceleration of urbanization, the demand for the construction of municipal infrastructure such as underground integrated pipe corridors and subways continues to grow. The shield method is widely used in multiple application scenarios such as urban rail transit and pipe corridor tunnels because of its advantages such as short cycle, small impact on the surrounding environment, and high construction efficiency. Due to the complex surrounding environment of the city and the delicate and cumbersome construction process, higher requirements are placed on the safety and accuracy of tunnel construction. Traditional total stations, laser rangefinders, and resistive and vibrating string sensors can no longer meet the needs of modern construction, so there is an urgent need to introduce a refined, intelligent, and automated monitoring system.

[0003] Fiber optic monitoring technology has the advantages of high measurement accuracy, strong anti-electromagnetic interference ability, and convenient wiring. It can meet the complex environmental requirements of tunnel construction and has been widely used in real-time monitoring of the health status of tunnel structures. At present, a variety of fiber optic monitoring systems have been developed at home and abroad to monitor parameters such as differential settlement, tunnel structure deformation, stress and strain during tunnel excavation. The Chinese invention patent, publication number CN116989680B, discloses the deployment of sensors to monitor tunnel joint deformation during the segment assembly stage. The Chinese invention patent, publication number CN115060298A, discloses that at least one of the following conditions of segment settlement, horizontal settlement, segment cracks and clearance convergence can be achieved by distributing optical cables on the segments in a wave-like manner along the tunnel direction. The Chinese invention patent, publication number CN113863954A, discloses the deployment of earth pressure gauges, osmometers and concrete stress gauges in the segments to monitor the health and safety of the segment structures. The Chinese invention patent, publication number CN114184137B, discloses the use of displacement monitoring modules and fiber grating strain sensors to achieve comprehensive monitoring of the structural conditions of shield tunnels, such as segment settlement, horizontal displacement, and cracks between segments.

[0004] At present, shield tunnel monitoring focuses on monitoring single parameters between tunnel joints and segments, ignoring the impact of external water and soil pressure, temperature, etc. on tunnel structural instability or even compression and shear damage, as well as hazards such as circumferential misalignment of segments, bolt breakage, and joint seepage caused by differential settlement. Monitoring of single parameters between individual segments is difficult to fully reflect the health status of the overall tunnel structure. In addition, shield tunnel monitoring is mostly concentrated in the operation period, mainly based on manual data collection, which is inconvenient to monitor and may also result in data loss. Manual data processing is required for risk identification, which delays timely intervention and control of dangerous situations, and the degree of automation is not high. Due to the high safety factor requirements and long service life of shield tunnels, high durability and accuracy requirements are placed on sensors.

[0005] Based on this, the present invention discloses a multi-parameter automatic monitoring device and method for optical fiber intelligent segments of a shield tunnel. Summary of the invention

[0006] In order to solve the technical problems existing in the prior art such as single monitoring parameters, low monitoring accuracy, low degree of automation and high construction cost, the purpose of the present invention is to provide a shield tunnel optical fiber intelligent segment multi-parameter automatic monitoring device and method.

[0007] In order to achieve the above purpose and the above technical effect, the technical solution adopted by the present invention is:

[0008] A shield tunnel optical fiber intelligent segment multi-parameter automatic monitoring device, comprising:

[0009] Water and soil pressure-internal force-deformation monitoring unit;

[0010] Segment crack monitoring unit;

[0011] Joint deformation-differential settlement monitoring unit;

[0012] Data acquisition and processing unit;

[0013] The water and soil pressure-internal force-deformation monitoring unit, the segment crack monitoring unit and the joint deformation-differential settlement monitoring unit are respectively connected to the data acquisition and processing unit to realize multi-parameter integrated automatic online monitoring of the external water and soil pressure of the shield tunnel segment and the segment steel bar stress, bolt stress, temperature, stress, strain, cracks, joint deformation and tunnel differential settlement.

[0014] Furthermore, the device also includes a lead rapid integration unit. The water and soil pressure-internal force-deformation monitoring unit, the segment crack monitoring unit and the lead rapid integration unit are installed and arranged during the prefabrication stage of the segment. The communication optical cables of the water and soil pressure-internal force-deformation monitoring unit and the segment crack monitoring unit are integrated through the lead rapid integration unit and connected to the data acquisition and processing unit. The lead optical cable of the joint deformation-differential settlement monitoring unit is directly connected to the data acquisition and processing unit. The monitoring data is processed and calculated in real time by the data acquisition and processing unit to monitor the full life cycle safety of the shield tunnel during the construction and operation periods.

[0015] Furthermore, the lead rapid integration unit includes a lead integration box, which consists of a hollow box and a cover. The bottom of the hollow box contains hollow holes, the diameter of the holes is not less than 1 cm, and the number of the hollow holes is not less than 6. The lead integration box is made of stainless steel. The lead integration box is arranged during the construction period of the pipe segment together with the water and soil pressure-internal force-deformation monitoring unit and the pipe segment crack monitoring unit. The joint deformation-differential settlement monitoring unit can be arranged on the inner wall of the pipe segment only after the pipe segment is spliced, and finally the data acquisition and processing unit is connected.

[0016] Furthermore, the water and soil pressure-internal force-deformation monitoring unit includes an earth pressure gauge, an osmometer, a steel stress gauge and a bolt pressure gauge. The earth pressure gauge and osmometer are arranged on the soil facing surface of the steel cage, the steel stress gauge is arranged on the steel cage, and the bolt stress gauge is arranged between the shield tunnel segments for connection.

[0017] Furthermore, the soil pressure gauge includes a strain optical fiber, a temperature optical fiber, a bottom membrane, an upper cover, a temperature compensation terminal and a pressure terminal. The strain optical fiber and the temperature optical fiber are the same optical fiber. The middle section of one optical fiber is the temperature optical fiber and is pasted on the temperature compensation terminal. The rest of the optical fiber is the strain optical fiber and is completely pasted on the inner surface of the bottom membrane. The strain optical fiber and the temperature optical fiber are located between the bottom membrane and the upper cover and are in direct contact with the soil.

[0018] Furthermore, the segment crack monitoring unit includes a strain sensing optical cable I and a thermometer. The strain sensing optical cable I is tied to both sides of the soil surface of the steel cage and the inner wall of the pipeline to form a U-shaped loop, and the thermometer is tied and fixed to the steel cage.

[0019] Furthermore, the strain sensing optical cable I includes a fiber core, sensing points and fixed points engraved on the fiber core, an inner sheath, a metal armor tube, a steel strand, aramid fiber and an outer sheath. The sensing point is located between two fixed points. The fiber core is tightly fitted with an inner sheath, and the inner sheath is double-protected by a metal armor tube and a steel strand. The fixed point is located between the fiber core and the metal armor tube. The spacing between the two fixed points is not less than 0.5m. The steel strand is tightly wrapped around the outside of the metal armor tube. The aramid fiber is straightly arranged on the outer ring of the steel strand. The outer sheath is wrapped around the outermost layer of the aramid fiber. It has high tensile strength, can resist large local deformation, and can resist scouring during concrete pouring. The measurement results can be directly converted into displacement.

[0020] Furthermore, the joint deformation-differential settlement monitoring unit begins to be laid out after the shield tunnel segments are assembled. The joint deformation-differential settlement monitoring unit includes a strain sensing optical cable II and a customized clip. The strain sensing optical cable II includes two sections, one section is laid straight and horizontally along the tunnel direction to sense the deformation of the joints between the segments, and the other section is laid in a W-shape to sense the differential settlement of the tunnel. The installation heights of the customized clips are divided into two groups, namely, horizontal straight fixing and W-shaped laying of strain sensing optical cable II.

[0021] Furthermore, the customized clip includes a straight line groove and a V-shaped groove, and the strain sensing optical cable II has two layout modes: horizontal and W-shaped. The straight horizontally laid strain sensing optical cable II is buckled in the straight line groove, and the W-shapedly laid strain sensing optical cable II is buckled in the V-shaped groove.

[0022] Furthermore, the strain sensing optical cable II comprises a polyimide fiber core, an inner sheath, and an elastic low-smoke halogen-free sheath which are sequentially arranged from the inside to the outside, and an over-plastic anchoring point is arranged on the elastic low-smoke halogen-free sheath.

[0023] Furthermore, the data acquisition and processing unit includes a fiber optic demodulator, a wireless router, a cloud processing system and a network cable. The network port of the fiber optic demodulator is connected to the network port of the wireless router with a network cable, and the data of the fiber optic demodulator is transmitted to the cloud processing system via the 4G / 5G wireless of the wireless router.

[0024] The present invention also discloses a multi-parameter automatic monitoring method for optical fiber intelligent segments of a shield tunnel, comprising the following steps:

[0025] 1) Install water and soil pressure-internal force-deformation monitoring unit

[0026] The soil pressure gauge and the piezometer are respectively welded vertically on the soil facing surface of the steel cage through a short steel bar I. The length of the short steel bar I is the thickness of the reinforced concrete protective layer minus the thickness of the sensor; the steel bar stress gauge is replaced by cutting off the short steel bar II of the same length on the main reinforcement of the steel cage and welding and fixing it. The diameter of the steel bar stress gauge is consistent with the original main reinforcement diameter; the bolt stress gauge is arranged between the shield tunnel segments for connection, and the size of the bolt stress gauge is consistent with the actual bolt size;

[0027] 2) Install the segment crack monitoring unit

[0028] Tie the strain sensing optical cable I to the soil surface of the steel cage and both sides of the inner wall of the pipeline to form a U-shaped loop, place the thermometer inside the steel cage, and pour concrete with the steel cage;

[0029] 3) Install the lead wire quick integration unit

[0030] Place the communication optical cable reels connected to the soil pressure gauge, osmometer, steel bar stress gauge, bolt stress gauge, strain sensor optical cable I and thermometer in the lead wire integration box;

[0031] 4) Install joint deformation-differential settlement monitoring unit

[0032] After the shield tunnel segments are assembled in the tunnel, the joint deformation-differential settlement monitoring unit is installed; the installation position of the strain sensing optical cable II is located along the tunnel waistline and marked, and the customized clips at all points are installed by gluing and pasting at fixed intervals according to the on-site environment of a certain tunnel. Then the strain sensing optical cable II is laid, the I-shaped slot fixes the strain sensing optical cable II laid horizontally in the tunnel, and the V-shaped slot buckles fix the strain sensing optical cable II laid in a W shape;

[0033] 5) Install the data acquisition and processing unit

[0034] The optical fiber demodulator is connected to the wireless router with a network cable, and the soil pressure gauge, osmometer, steel bar stress gauge, bolt stress gauge, strain sensing optical cable I, thermometer and strain sensing optical cable II are connected to the optical fiber demodulator through their respective communication optical cables. The optical fiber demodulator is used to demodulate the data, and the demodulated data is transmitted to the cloud processing system through the wireless router. The cloud processing system is used to analyze and process the data, and the water and soil pressure outside the shield tunnel segment and the segment steel bar stress, bolt stress, temperature, stress, strain, cracks, joint deformation and tunnel differential settlement are monitored in real time.

[0035] There is no particular order between step 1) and step 2).

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The present invention discloses a multi-parameter automatic monitoring device and method for optical fiber intelligent segments of a shield tunnel, which can realize full life cycle monitoring of the shield tunnel during the construction period and the operation period, and can realize multi-parameter integrated automatic online monitoring of the external water and soil pressure of the shield tunnel segments, the stress of the segment steel bars, the stress of the bolts, the temperature, the stress, the strain, the cracks, the deformation of the joints and the differential settlement of the tunnel, so as to meet the multi-parameter automatic monitoring requirements of the overall stress of the tunnel, the differential settlement and the water and soil pressure outside the tunnel, and has the advantages of multi-parameter monitoring, high precision, good durability, integration, good stability, high degree of automation, convenient construction, fast installation and integration, high insulation safety and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0039] Figure 2 It is a cross-sectional view of the installation of the soil pressure gauge and the piezometer of the present invention;

[0040] Figure 3 It is a front view of the installation of the soil pressure gauge and the piezometer of the present invention;

[0041] Figure 4 It is a structural diagram of the earth pressure gauge of the present invention;

[0042] Figure 5 It is an installation diagram of the steel bar stress meter of the present invention;

[0043] Figure 6 is a structural diagram of the strain sensing optical cable I of the present invention;

[0044] Figure 7 It is an installation diagram of the strain sensing optical cable II of the present invention;

[0045] Figure 8 It is the installation diagram of the strain sensing optical cable II and the customized clip of the present invention;

[0046] Fig. 9 This is a schematic diagram of differential settlement calculation of the present invention;

[0047] The following are marked in the figure: 1. shield tunnel segment; 2. steel cage; 3. earth pressure gauge; 31. strain optical fiber; 32 temperature optical fiber; 33. bottom membrane; 34. upper cover; 35. temperature compensation terminal; 36. pressure terminal; 4. osmometer; 5. steel stress gauge; 6. bolt stress gauge; 7. strain sensing optical cable I; 71. sensing point; 72. fixed point; 73. fiber core; 74. inner sheath; 75. metal armor tube; 76. steel strand; 77. aramid fiber; 78. outer sheath; 8. thermometer; 9. lead wire Integrated box; 91. Hollow hole; 10. Fiber optic demodulator; 101. Network port; 102. Channel interface; 11. Wireless router; 12. Cloud processing system; 13. Network cable; 14. Communication optical cable; 15. Short steel bar I; 16. Segment concrete surface; 17. Short steel bar II; 18. Strain sensing optical cable II; 181. Polyimide fiber core; 182. Elastic low-smoke halogen-free sheath; 183. Plastic anchor point; 19. Customized clip; 191. I-shaped slot; 192. V-shaped slot. DETAILED DESCRIPTION

[0048] The present invention is described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0049] A brief summary of one or more aspects is given below to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceived aspects, and is neither intended to identify the key or critical elements of all aspects nor to define the scope of any or all aspects. Its only purpose is to give some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be given later.

[0050] like Figure 1-9 As shown, the present invention discloses a shield tunnel optical fiber intelligent segment multi-parameter automatic monitoring device, which realizes multi-parameter automatic monitoring by using dense distributed optical fiber monitoring technology. The device mainly includes:

[0051] Water and soil pressure-internal force-deformation monitoring unit;

[0052] Segment crack monitoring unit;

[0053] Joint deformation-differential settlement monitoring unit;

[0054] Data acquisition and processing unit;

[0055] Among them, the communication optical cables 14 connected to the water and soil pressure-internal force-deformation monitoring unit and the segment crack monitoring unit are integrated with the data acquisition and processing unit through the lead wire rapid integration unit. The communication optical cables 14 connected to the water and soil pressure-internal force-deformation monitoring unit and the segment crack monitoring unit are integrated and protected by the lead wire rapid integration unit. The water and soil pressure-internal force-deformation monitoring unit, the segment crack monitoring unit and the lead wire rapid integration unit are installed and laid out in the prefabrication stage of the shield tunnel segment 1 and are set on the steel cage 2. The joint deformation-differential settlement monitoring unit begins to be laid out after the assembly of the shield tunnel segment 1 is completed. The lead wire cable of the joint deformation-differential settlement monitoring unit is directly connected to the data acquisition and processing unit. The monitoring data is processed and calculated in real time by the data acquisition and processing unit to monitor the full life cycle safety of the shield tunnel during the construction period and the operation period, and realize the multi-parameter integrated automatic online monitoring of the external water and soil pressure of the tunnel segment and the segment steel stress, bolt stress, temperature, stress, strain, cracks, joint deformation and tunnel differential settlement.

[0056] like Figure 1 As shown, the data acquisition and processing unit includes an optical fiber demodulator 10, a wireless router 11, a cloud processing system 12 and a network cable 13, wherein the network port 101 of the optical fiber demodulator 10 is connected to the network port 101 of the wireless router 11 by the network cable 13, and the data of the optical fiber demodulator 10 is transmitted to the cloud processing system 12 through the 4G / 5G wireless of the wireless router 11, and the cloud processing system 12 configures the parameters of the optical cable corresponding to each channel to complete the system integration. The cloud processing system 12 can process and calculate the data of each parameter in real time, and can also set the warning value, and issue a risk warning in the first time when encountering a dangerous situation.

[0057] like Figure 2-3 As shown, the water and soil pressure-internal force-deformation monitoring unit includes an earth pressure gauge 3, a piezometer 4, a steel stress gauge 5 and a bolt pressure gauge 6, wherein the earth pressure gauge 3 and the piezometer 4 are respectively vertically welded to the steel cage 2 through a short steel bar Ⅰ15, and the sensor contact surfaces of the earth pressure gauge 3 and the piezometer 4 are flush with the concrete surface 16 of the shield tunnel segment 1. The length of the short steel bar Ⅰ15 is the thickness of the reinforced concrete protective layer minus the sensor thickness. The bolt stress gauge 6 is embedded and installed when two shield tunnel segments 1 are assembled and connected, and the size of the bolt stress gauge 6 is consistent with the actual bolt size.

[0058] like Figure 4As shown, the soil pressure gauge 3 includes a strain optical fiber 31, a temperature optical fiber 32, a bottom film 33, an upper cover 34, a temperature compensation terminal 35 and a pressure terminal 36. The strain optical fiber 31 and the temperature optical fiber 32 are the same optical fiber. The middle section of one optical fiber is the temperature optical fiber 32 and is pasted on the temperature compensation terminal 36. The rest of the optical fiber is the strain optical fiber 31 and is completely pasted on the inner surface of the bottom film 33. The strain optical fiber 31 and the temperature optical fiber 32 are located between the bottom film 33 and the upper cover 34 to prevent moisture, gravel, etc. from entering the bottom film 33 to damage the optical fiber. They are in direct contact with the soil, do not require power supply, have good long-term stability, can be connected in series with multiple soil pressure gauges, have a range greater than 0.2MPa, have internal temperature compensation, and are not affected by ambient temperature changes.

[0059] like Figure 5 As shown, the steel bar stress gauge 5 is replaced by cutting off the main bar of the steel cage 2 and welding it. The connection between the steel bar stress gauge 5 and the main bar of the steel cage is overlapped with short steel bars Ⅱ17. The diameter of the steel bar stress gauge 5 is consistent with the diameter of the original main bar. The specific operation is: cut off the steel bar of the main bar of the steel cage 2 by the length of the steel bar stress gauge 5, put the steel bar stress gauge 5 at the position of the original main bar cutting section, fix the two ends on the main bar with a certain length of short steel bars Ⅱ17, overlap the short steel bars Ⅱ17 with the main bar and the steel bar stress gauge 5 for a distance, fully weld the joints between the steel bar stress gauge 5, the main bar of the steel cage and the connecting short steel bars Ⅱ17, and wrap the steel bar stress gauge 5 with a wet towel during the spot welding process to prevent overheating and damage to the steel bar stress gauge 5.

[0060] like Figure 6 As shown, the segment crack monitoring unit includes a strain sensing optical cable Ⅰ7 and a thermometer 8, wherein the strain sensing optical cable Ⅰ7 is tied to the soil-facing surface of the steel cage 2 and both sides of the inner wall of the pipeline to form a U-shaped loop, and the thermometer 8 is tied and fixed on the steel cage 2. The strain sensing optical cable Ⅰ7 includes a fiber core 73 and a sensing point 71 and a fixed point 72 engraved on the fiber core 73, and also includes an inner sheath 74, a metal armor tube 75, a steel strand 76, an aramid fiber 77 and an outer sheath 78, wherein the sensing point 71 is located between the two fixed points 72, the fiber core 73 is tightly fitted with the inner sheath 74, the inner sheath 74 uses a high-encapsulation material of sea emerald to encapsulate and encapsulate the fiber core 73, the inner sheath 74 is protected by a double layer of metal armor tube 75 and steel strand 76 outside the inner sheath 74, and the metal armor tube 75 is protected from the inner sheath by the inner sheath. The outer spiral 74 is tightly wound, the fixed point 72 is located between the fiber core 73 and the metal armor tube 75, the distance between the two fixed points 72 is not less than 0.5m, the steel strand 76 is tightly wrapped around the outside of the metal armor tube 75, the aramid fiber 77 is straightly arranged on the outer ring of the steel strand 76, and the outer sheath 78 is wrapped around the outermost layer of the aramid fiber 77. It has high tensile strength and can resist local large deformation of 20000με. The high tensile strength can resist damage during concrete pouring. Both tension and compression can be measured, and the measurement results can be directly converted into displacement.

[0061] The lead wire quick integration unit includes a lead wire integration box 9. The communication optical cables 14 connected to the water and soil pressure-internal force-deformation monitoring unit and the pipe segment crack monitoring unit are integrated into the lead wire integration box 9. The lead wire integration box 9 is made of stainless steel material and consists of a hollow box and a cover. The bottom of the hollow box contains hollow holes with a diameter of not less than 1 cm and a number of not less than 6 hollow holes.

[0062] like Figure 7 As shown, the joint deformation-differential settlement monitoring unit includes a strain sensing optical cable II 18 and a customized clip 19. The strain sensing optical cable II 18 includes a polyimide fiber core 181, an inner sheath 74, and an elastic low-smoke halogen-free sheath 182 arranged in sequence from the inside to the outside. The polyimide fiber core 181 is on the innermost side, and a polyimide coating layer is selected, which has good thermal stability and a strain responsiveness that is basically consistent with that of a bare fiber. The inner sheath 74 is encapsulated and protected by a high-encapsulation material of a sea emerald material and has good coupling. The elastic low-smoke halogen-free sheath 182 uses an elastic low-smoke halogen-free material as an outer sheath. The overall stiffness of the cable is greatly reduced, and it has good softness. It also has good strength, ductility, corrosion resistance and fatigue resistance, and can adapt to the long-term disturbance of piston wind. The elastic low-smoke halogen-free sheath 182 is provided with a plastic anchor point 183. The plastic anchor point 183 uses a plastic raised reinforced ring anchor point. The plastic material can avoid electromagnetic interference and increase the coupling with the structure. It cooperates with the matching card slot device to facilitate the adjustment of the pre-tensioning amount and the settlement measurement range; the inner diameter of the optical cable is 2mm, and the outer diameter of the anchor point is 3mm. The sensitivity, pre-tensioning and laying speed of the optical cable are significantly improved.

[0063] like Figure 8 As shown, the customized clip 19 includes a straight groove 191 and a V-shaped groove 192. The customized clip 19 is made of stainless steel with a thickness of preferably 0.5 mm. The strain sensing optical cable II 18 can be arranged horizontally and in a W shape. The straight horizontally arranged strain sensing optical cable II 18 is buckled in the straight groove 191, and the W-shapedly arranged strain sensing optical cable II 18 is buckled in the V-shaped groove 192. The angle of the V-shaped groove 192 can be customized, generally 45° to 60°.

[0064] The present invention also discloses a multi-parameter automatic monitoring method for optical fiber intelligent segments of a shield tunnel, comprising the following steps:

[0065] 1) Install water and soil pressure-internal force-deformation monitoring unit

[0066] The sensors (earth pressure gauge 3 and piezometer 4) are vertically welded to the steel cage 2 through a short steel bar Ⅰ15, and the length of the short steel bar Ⅰ15 is the thickness of the reinforced concrete protective layer minus the thickness of the sensor; the steel bar stress gauge 5 is cut off from the main bar of the steel cage 2 by the length of the steel bar stress gauge 5, and the steel bar stress gauge 5 is placed at the position of the original main bar cutting section, and the two ends are fixed to the main bar with a short steel bar Ⅱ17 of a certain length (preferably 20 cm), and the short steel bar Ⅱ17 overlaps the main bar and the steel bar stress gauge 5 for a distance (preferably 10 cm), and the joints between the steel bar stress gauge 5, the main bar of the steel cage and the connecting short steel bar Ⅱ17 are fully welded. During the spot welding process, the steel bar stress gauge 5 is wrapped with a wet towel to prevent overheating and damage to the sensor (steel bar stress gauge 5); the bolt stress gauge 6 is embedded and installed when two shield tunnel segments 1 are assembled and connected;

[0067] 2) Install the segment crack monitoring unit

[0068] The strain sensing optical cable Ⅰ7 is tied to the soil facing surface of the steel cage 2 and both sides of the inner wall of the pipeline to form a U-shaped loop. The thermometer 8 is arranged inside the steel cage 2 and poured with concrete together with the steel cage 2.

[0069] 3) Install the lead wire quick integration unit

[0070] Lead the communication optical cables 14 connected to the sensors (earth pressure gauge 3, osmometer 4, steel bar stress gauge 5, bolt stress gauge 6, strain sensor optical cable Ⅰ7 and thermometer 8) straightly and sequentially from the hollow holes 91 of the lead wire integrated box 9, and lead the communication optical cable 14 of one sensor from a small hole 91. After the installation is completed, coil the communication optical cable 14 and put it in the lead wire integrated box 9;

[0071] 4) Install joint deformation-differential settlement monitoring unit

[0072] After the shield tunnel segments 1 are assembled in the tunnel, the joint deformation-differential settlement monitoring unit is installed. The installation position of the strain sensing optical cable Ⅱ18 is located along the waistline of the tunnel and marked. According to the site environment of a certain tunnel, a fixed interval (such as 2.46m) is selected to complete the installation of the customized clips 19 at all points by brushing glue. After 24 hours of pasting, the strain sensing optical cable Ⅱ18 is laid. The straight slot 191 fixes the strain sensing optical cable Ⅱ18 laid in the horizontal direction of the tunnel, and the V-shaped slot 192 is buckled to fix the strain sensing optical cable Ⅱ18 laid in a W shape. The V-shaped angle of the V-shaped slot 192 is preferably 120°;

[0073] 5) Install the data acquisition and processing unit

[0074] The optical fiber demodulator 10 is connected to the wireless router 11 by a network cable 13, and the soil pressure gauge 3, the piezometer 4, the steel bar stress gauge 5, the bolt stress gauge 6, the strain sensing optical cable I7, the thermometer 8 and the strain sensing optical cable II18 are respectively connected to the optical fiber demodulator 10 through the communication optical cables 14 connected to them. The optical fiber demodulator 10 receives and demodulates the data uploaded by each sensor, and transmits the demodulated data to the cloud processing system 12 through the wireless router 11. The cloud processing system 12 performs data analysis and processing, and monitors the external water and soil pressure of the shield tunnel segment and the steel bar stress, bolt stress, temperature, stress, strain, crack, joint deformation and tunnel differential settlement of the segment in real time to form an intelligent segment, and further conducts multi-parameter automatic monitoring of the optical fiber intelligent segment of the shield tunnel.

[0075] There is no particular order between step 1) and step 2).

[0076] In the present invention, the soil pressure gauge 3, the piezometer 4, the steel bar stress gauge 5, and the bolt stress gauge 6 have their own temperature compensation or temperature self-compensation. In addition to sensing temperature changes, the thermometer 8 performs temperature compensation on the strain sensing optical cable I7 and the strain sensing optical cable II18. The calculation formula is:

[0077] P=K P *[(P S -P0)-K T *(P T -P T0 )]

[0078] Where P is the sensor measurement value; K P is the ratio of the measured value to the wavelength; K T is the ratio constant of wavelength to temperature; P0 is the initial wavelength value; P S is the wavelength test value; P T0 is the initial wavelength of the temperature compensation grating; P T It is the test value of temperature compensated grating.

[0079] In the present invention, the calculation principle of the joint deformation is that when the joint is opened or closed, the optical cable is stretched or retracted, and the product of the strain amount and the fixed point spacing is the joint deformation amount at that position.

[0080] In the present invention, Fig. 9 As shown, the calculation principle of differential sedimentation is:

[0081] 1) When the only displacement in the settlement is the vertical direction, the corresponding settlement amount ΔS' is calculated as follows:

[0082]

[0083] Among them, ε1 is the strain tested by the hypotenuse, S is the longitudinal height of the strain sensing optical cable Ⅱ18 laid between the two clamps, and L is the actual length of the strain sensing optical cable Ⅱ18 laid between the two clamps;

[0084] 2) When there is horizontal displacement in the actual settlement, the strain tested by the hypotenuse is ε1, and the strain of the horizontal line is:

[0085]

[0086] Among them, ε1 is the strain tested by the hypotenuse, ε2 is the displacement in the horizontal direction, S is the longitudinal height of the strain sensing optical cable Ⅱ18 laid between the two clamps, and L is the actual length of the strain sensing optical cable Ⅱ18 laid between the two clamps.

[0087] Parts or structures not specifically described in the present invention may adopt existing technologies or existing products and will not be described in detail here.

[0088] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A shield tunnel optical fiber intelligent segment multi-parameter automatic monitoring device, characterized in that: include: Water and soil pressure-internal force-deformation monitoring unit; Segment crack monitoring unit; Joint deformation-differential settlement monitoring unit; Data acquisition and processing unit; The water and soil pressure-internal force-deformation monitoring unit, the segment crack monitoring unit and the joint deformation-differential settlement monitoring unit are respectively connected to the data acquisition and processing unit to realize multi-parameter integrated automatic online monitoring of the external water and soil pressure of the shield tunnel segment and the segment steel bar stress, bolt stress, temperature, stress, strain, cracks, joint deformation and tunnel differential settlement.

2. According to claim 1, a shield tunnel optical fiber intelligent segment multi-parameter automatic monitoring device is characterized in that: It also includes a lead rapid integration unit. The water and soil pressure-internal force-deformation monitoring unit, the segment crack monitoring unit and the lead rapid integration unit are installed and arranged in the prefabrication stage of the segment. The communication optical cables of the water and soil pressure-internal force-deformation monitoring unit and the segment crack monitoring unit are integrated through the lead rapid integration unit and then connected to the data acquisition and processing unit. The lead optical cable of the joint deformation-differential settlement monitoring unit is directly connected to the data acquisition and processing unit. The monitoring data is processed and calculated in real time by the data acquisition and processing unit to monitor the full life cycle safety of the shield tunnel during the construction and operation periods.

3. The multi-parameter automatic monitoring device for optical fiber intelligent segments of a shield tunnel according to claim 1 is characterized in that: The water and soil pressure-internal force-deformation monitoring unit includes an earth pressure gauge, an osmometer, a steel stress gauge and a bolt pressure gauge. The earth pressure gauge and the osmometer are arranged on the soil facing surface of the steel cage, the steel stress gauge is arranged on the steel cage, and the bolt stress gauge is arranged between the shield tunnel segments for connection.

4. The multi-parameter automatic monitoring device for optical fiber intelligent segments of a shield tunnel according to claim 3 is characterized in that: The soil pressure gauge comprises a strain optical fiber, a temperature optical fiber, a bottom membrane, an upper cover, a temperature compensation terminal and a pressure line terminal. The strain optical fiber and the temperature optical fiber are the same optical fiber. The middle section of one optical fiber is the temperature optical fiber and is pasted on the temperature compensation terminal. The rest of the optical fiber is the strain optical fiber and is completely pasted on the inner surface of the bottom membrane. The strain optical fiber and the temperature optical fiber are located between the bottom membrane and the upper cover and are in direct contact with the soil.

5. The multi-parameter automatic monitoring device for optical fiber intelligent segments of a shield tunnel according to claim 1 is characterized in that: The segment crack monitoring unit includes a strain sensing optical cable I and a thermometer. The strain sensing optical cable I is tied to the soil surface of the steel cage and both sides of the inner wall of the pipeline to form a U-shaped loop, and the thermometer is tied and fixed on the steel cage.

6. The multi-parameter automatic monitoring device for optical fiber intelligent segments of a shield tunnel according to claim 5 is characterized in that: The strain sensing optical cable I includes a fiber core, sensing points and fixed points engraved on the fiber core, an inner sheath, a metal armor tube, a steel strand, aramid fiber and an outer sheath. The sensing point is located between two fixed points. The fiber core is tightly fitted with an inner sheath. The inner sheath is protected by a double layer of metal armor tube and steel strand. The fixed point is located between the fiber core and the metal armor tube. The distance between the two fixed points is not less than 0.5m. The steel strand is tightly wrapped on the outside of the metal armor tube. The aramid fiber is straightly arranged on the outer ring of the steel strand. The outer sheath is wrapped on the outermost layer of the aramid fiber.

7. The multi-parameter automatic monitoring device for optical fiber intelligent segments of a shield tunnel according to claim 1 is characterized in that: The joint deformation-differential settlement monitoring unit begins to be deployed after the shield tunnel segments are assembled. The joint deformation-differential settlement monitoring unit includes a strain sensing optical cable II and a customized clip. The customized clip includes a straight line groove and a V-shaped groove. The strain sensing optical cable II has two layout modes: horizontal and W-shaped. The straight horizontally laid strain sensing optical cable II is buckled in the straight line groove, and the W-shaped laid strain sensing optical cable II is buckled in the V-shaped groove.

8. The multi-parameter automatic monitoring device for optical fiber intelligent segments of a shield tunnel according to claim 7 is characterized in that: The strain sensing optical cable II comprises a polyimide fiber core, an inner sheath, and an elastic low-smoke halogen-free sheath which are arranged in sequence from the inside to the outside, and an over-plastic anchoring point is arranged on the elastic low-smoke halogen-free sheath.

9. The shield tunnel optical fiber intelligent segment multi-parameter automatic monitoring device according to claim 1 is characterized in that: The data acquisition and processing unit includes a fiber optic demodulator, a wireless router, a cloud processing system and a network cable. The network port of the fiber optic demodulator is connected to the network port of the wireless router with a network cable, and the data of the fiber optic demodulator is transmitted to the cloud processing system via the 4G / 5G wireless of the wireless router.

10. A multi-parameter automatic monitoring method for optical fiber intelligent segments of shield tunnels, characterized in that: The following steps are involved: 1) Install water and soil pressure-internal force-deformation monitoring unit The soil pressure gauge and the piezometer are respectively welded vertically on the soil facing surface of the steel cage through a short steel bar I. The length of the short steel bar I is the thickness of the reinforced concrete protective layer minus the thickness of the sensor; the steel bar stress gauge is replaced by cutting off the short steel bar II of the same length on the main reinforcement of the steel cage and welding and fixing it. The diameter of the steel bar stress gauge is consistent with the original main reinforcement diameter; the bolt stress gauge is arranged between the shield tunnel segments for connection, and the size of the bolt stress gauge is consistent with the actual bolt size; 2) Install the segment crack monitoring unit Tie the strain sensing optical cable I to the soil surface of the steel cage and both sides of the inner wall of the pipeline to form a U-shaped loop, place the thermometer inside the steel cage, and pour concrete with the steel cage; 3) Install the lead wire quick integration unit Place the communication optical cable reels connected to the soil pressure gauge, osmometer, steel bar stress gauge, bolt stress gauge, strain sensor optical cable I and thermometer in the lead wire integration box; 4) Install joint deformation-differential settlement monitoring unit After the shield tunnel segments are assembled in the tunnel, the joint deformation-differential settlement monitoring unit is installed; the installation position of the strain sensing optical cable II is located along the tunnel waistline and marked, and the customized clips at all points are installed by gluing and pasting at fixed intervals according to the on-site environment of a certain tunnel. Then the strain sensing optical cable II is laid, the I-shaped slot fixes the strain sensing optical cable II laid horizontally in the tunnel, and the V-shaped slot buckles fix the strain sensing optical cable II laid in a W shape; 5) Install the data acquisition and processing unit The optical fiber demodulator is connected to the wireless router with a network cable, and the soil pressure gauge, osmometer, steel bar stress gauge, bolt stress gauge, strain sensing optical cable I, thermometer and strain sensing optical cable II are connected to the optical fiber demodulator through their respective communication optical cables. The optical fiber demodulator is used to demodulate the data, and the demodulated data is transmitted to the cloud processing system through the wireless router. The cloud processing system is used to analyze and process the data, and the water and soil pressure outside the shield tunnel segment and the segment steel bar stress, bolt stress, temperature, stress, strain, cracks, joint deformation and tunnel differential settlement are monitored in real time. There is no particular order between step 1) and step 2).

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