Strain monitoring device for PCCP pipe core concrete
By laying distributed fiber sensors on the inner and outer surfaces of PCCP die concrete, real-time monitoring of strain distribution rules, the problem of difficulty in monitoring internal cracks in PCCP die concrete in the existing technology is solved, and accurate analysis of the causes of cracking and product quality is achieved. Improvement.
Patent Information
- Application Number
- CN202421250439.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-03
- Publication Date
- 2025-02-18
- Estimated Expiration
- 2034-06-03
AI Technical Summary
The prior art is difficult to monitor the cracking conditions at all levels of the PCCP die concrete in real time, resulting in the inability to accurately analyze the causes of cracking, which poses safety hazards.
A distributed fiber sensor is used to arrange fiber sensors on the inner and outer surfaces of PCCP die concrete, and combine optical fiber strain collectors and mobile power supply to monitor the strain distribution rules of die concrete in real time.
Real-time monitoring of strains at all levels during the entire production cycle of PCCP die concrete can accurately analyze the causes and development of cracks, and improve product quality and safety.
Smart Images
Figure CN222505318U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of strain monitoring and relates to a strain monitoring device for PCCP pipe core concrete. Background Art
[0002] In the structure of prestressed concrete cylinder pipe (PCCP for short), a certain thickness of concrete layer is set on the inner and outer surfaces of the steel cylinder. During the subsequent wire wrapping, roller mortar spraying process and the static period after the completion of the production, the inner concrete surface will be affected by the structural strain and circumferential cracks will appear. The current technology requires that the width of the circumferential cracks or spiral cracks on the inner wall of the finished pipe should not be greater than 0.5mm, and the circumferential cracks within 300mm from the pipe spigot end should not be greater than 1.5mm.
[0003] However, currently, the size of the circumferential crack can only be measured manually with the help of certain tools, and there is no better direct and effective monitoring equipment to monitor the cracking of the PCCP inner concrete surface in real time. Manual measurement has a large subjective factor and cannot monitor the cracking of the PCCP inner concrete surface and accurately analyze the cause of the cracking of the PCCP inner concrete surface, which poses a safety hazard to the use of PCCP in future projects. Utility Model Content
[0004] The utility model aims to provide a strain monitoring device for PCCP pipe core concrete, which solves the problem in the prior art that it is difficult to monitor the cracking degree of each layer inside the PCCP pipe core concrete.
[0005] The technical scheme adopted by the utility model is a strain monitoring device for PCCP pipe core concrete, wherein an umbrella cap screw 1 is fixed at the top socket end of the PCCP steel tube, and an umbrella cap screw 2 is fixed at the bottom socket end of the steel tube; an internal optical fiber is stretched and tightened between the umbrella cap screw 1 and the umbrella cap screw 2, and after the pipe core concrete is poured, the internal optical fiber is buried inside the pipe core concrete; an inner layer optical fiber is arranged on the inner circular surface of the inner layer concrete of the pipe core concrete, and a surface optical fiber is arranged on the outer circular surface of the outer layer concrete of the pipe core concrete, and the pigtails of the internal optical fiber, the inner layer optical fiber, and the surface optical fiber are connected in series end to end to form an optical fiber sensor, and both ends of the optical fiber sensor are connected to an optical fiber strain collector, the optical fiber strain collector is connected to a mobile power supply, and the optical fiber strain collector is simultaneously connected to an external data processing device.
[0006] The utility model is also characterized in that the strain monitoring device for PCCP pipe core concrete is:
[0007] The optical fiber strain collector and mobile power supply are both fixed in the working platform.
[0008] The inner circular surface of the inner concrete layer is routed back and forth along the planned monitoring line using tape or 502 glue, and the inner optical fiber is glued with epoxy resin glue.
[0009] The outer circular surface of the outer layer of concrete is provided with a through groove along the axial direction, which is called a semicircular groove. The surface optical fiber is laid in the semicircular groove by fusing A and B glue.
[0010] The inner optical fiber and the inner layer optical fiber are both made of high transmission tight sheath strain sensing optical cable NZS-DSS-C07; the surface optical fiber is made of metal-based rope-shaped strain sensing optical cable NZS-DSS-C02.
[0011] The optical fiber strain collector adopts a distributed strain sensing device OSI-C.
[0012] The mobile power supply adopts 220V alternating current.
[0013] The beneficial effect of the utility model is that distributed optical fiber sensors are introduced and fixed on the inner circular surface of the pipe core concrete, the inside of the pipe core concrete and the outer surface of the pipe core concrete respectively in a certain installation method, and the data acquisition equipment, the working platform and the pipe core concrete rotate synchronously, so as to directly obtain the strain distribution law of each layer inside the PCCP pipe core concrete during the whole cycle (including the wire winding process, the roller mortar process, the stacking period, etc.), and further analyze and obtain the cause and development of cracking. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 It is a top view of the pipe core concrete structure targeted by the device of the utility model;
[0015] Figure 2 It is a front view of the pipe core concrete structure targeted by the device of the utility model;
[0016] Figure 3 It is a schematic diagram of the utility model device for determining the monitoring line on the pipe core concrete;
[0017] Figure 4 It is a schematic diagram of the inner optical fiber and collection equipment of the utility model device arranged on the inner concrete;
[0018] Figure 5 It is a schematic diagram of the buried structure of the surface optical fiber of the device of the utility model arranged on the outer layer of concrete;
[0019] Figure 6 The first embodiment of the utility model collects the measurement data of the deformation of the inner layer of concrete;
[0020] Figure 7 The measurement data of the deformation of the outer layer of concrete is collected in Embodiment 2 of the present utility model;
[0021] Figure 8 This is the measurement data of the deformation of the outer layer of concrete collected in Example 3 of the present utility model.
[0022] In the figure, 1. steel cylinder, 2. top socket end, 3. bottom socket end, 4. inner layer concrete, 5. outer layer concrete, 6. umbrella cap screw one, 7. umbrella cap screw two, 8. internal optical fiber, 9. inner layer optical fiber, 10. surface optical fiber, 11. semicircular groove, 12. working platform, 13. optical fiber strain collector, 14. mobile power supply. DETAILED DESCRIPTION
[0023] The utility model is described in detail below with reference to the accompanying drawings and specific implementation modes.
[0024] Reference Figure 1 , Figure 2 , Figure 3 The structure of the strain monitoring device of the utility model is that an umbrella cap screw 6 is fixed on the top socket end 2 of the steel tube 1 of the PCCP, and an umbrella cap screw 2 7 is fixed on the bottom socket end 3 of the steel tube 1; the umbrella cap screw 6 and the umbrella cap screw 2 7 are used to straighten and tighten the internal optical fiber 8, and after the pipe core concrete is poured, the internal optical fiber 8 is buried inside the pipe core concrete; an inner optical fiber 9 is arranged on the inner circular surface of the inner layer concrete 4 of the pipe core concrete, and a surface optical fiber 10 is arranged on the outer circular surface of the outer layer concrete 5 of the pipe core concrete, and pigtails are reserved at both ends of the internal optical fiber 8, the inner layer optical fiber 9, and the surface optical fiber 10, and the pigtails of the internal optical fiber 8, the inner layer optical fiber 9, and the surface optical fiber 10 are connected in series head to tail to form a fiber optic sensor, and the two ends of the fiber optic sensor are connected to a fiber optic strain collector 13, the fiber optic strain collector 13 is connected to a mobile power supply 14, and the fiber optic strain collector 13 is connected to an external data processing device at the same time.
[0025] During the pouring process, the optical fiber strain collector 13 and the mobile power supply 14 are fixed in the working platform 12. The optical fiber strain collector 13 adopts the high-precision distributed strain sensing device OSI-C. The mobile power supply 14 adopts 220V AC, which can meet the power supply of the optical fiber strain collector 13.
[0026] Reference Figure 4 The inner circular surface of the inner layer of concrete 4 is glued with an inner layer of optical fiber 9 along the planned monitoring line using epoxy resin glue.
[0027] Reference Figure 5 The outer surface of the outer concrete layer 5 has a through groove axially opened, called a semicircular groove 11, and the surface optical fiber 10 is laid in the semicircular groove 11 using epoxy resin glue.
[0028] The internal optical fiber 8 and the inner optical fiber 9 adopt the high transmission tight sheath strain sensing optical cable NZS-DSS-C07; the surface optical fiber 10 adopts the metal-based rope-shaped strain sensing optical cable NZS-DSS-C02.
[0029] The installation process and working process of the utility model device are:
[0030] Step 1: Lay out the internal optical fiber 8 in the tube core concrete.
[0031] 1.1) After the steel cylinder 1 is formed and inspected to be qualified, an umbrella cap screw 6 is welded to the top socket end 2 of the steel cylinder 1, and an umbrella cap screw 7 is welded to the bottom socket end 3 of the steel cylinder 1;
[0032] The inner diameter of the cap screw 1 6 and the cap screw 2 7 is 5 mm, and the radial length of all the cap screws does not exceed the thickness of the outer core concrete. Figure 3 As shown, the internal optical fiber 8 is the same as the inner optical fiber 9, and multiple measurement lines can be planned. Figure 3 Only one is shown;
[0033] 1.2) The steel strand optical cable is obtained by combining the steel strand and the distributed optical fiber, which is called the internal optical fiber 8. The two ends of the internal optical fiber 8 are passed through the umbrella cap screw 1 6 and the umbrella cap screw 2 7 to be straightened and tightened, and a 2m long pigtail is reserved at both ends to facilitate the later series connection of monitoring lines or monitoring equipment. The role of the steel strand is to prevent the optical fiber from being damaged during concrete pouring. The falling aggregate during pouring can easily damage the optical fiber. Figure 3 .
[0034] Step 2: pour the core concrete.
[0035] According to the PCCP production process, a steel cylinder 1 is placed in a mold, and the core concrete is poured. After solidification to 70% of the design strength of the core concrete, the mold is removed to obtain the core concrete. The core concrete is divided into an inner layer concrete 4 and an outer layer concrete 5 by the steel cylinder 1. Figure 1 , Figure 2 shown.
[0036] Step 3: Lay the inner optical fiber 9 on the inner circular surface of the inner concrete 4.
[0037] 3.1) Plan the monitoring area,
[0038] According to the monitoring requirements, a monitoring line is set on the surface of the inner layer of concrete 4 and marked with a marker;
[0039] 3.2) Preliminary fixation of the inner optical fiber 9,
[0040] Grind and clean the inner surface of the inner concrete 4, first route the inner optical fiber 9 back and forth along the planned monitoring line with tape or 502 glue, and then use epoxy resin glue to stick it to the surface of the inner concrete 4, and reserve 2m of lead wires for the head and tail of the inner optical fiber 9, such as Figure 3 As shown;
[0041] 3.3) Finally fix the inner optical fiber 9,
[0042] Use a glue gun to fuse glue A and glue B and apply them on the surface of the inner optical fiber 9 to form epoxy resin glue hardening protection, and complete the hardening and fixing of the inner optical fiber 9 on the inner circular surface of the inner concrete 4;
[0043] Step 4: Lay out the optical fiber 10 on the surface of the outer concrete 5.
[0044] 4.1) After selecting the layout position along the pipe axis, an axial semicircular groove 11 is excavated on the outer surface of the outer concrete 5. The groove radius of the semicircular groove 11 is 2 mm, which is convenient for burying the surface optical fiber 10 (with a diameter of 0.9 mm) therein. Figure 5 shown.
[0045] 4.2) First, preliminarily fix the surface optical fiber 10 in the semicircular groove 11, and then use A and B glue to fuse and lay the surface optical fiber 10 in the semicircular groove 11, so that the epoxy resin glue covers the surface optical fiber 10 and fills the semicircular groove 11, forming a hardened protective layer of epoxy resin glue.
[0046] Step 5: Connect monitoring equipment and power supply.
[0047] 5.1) Connect the internal optical fiber 8, inner optical fiber 9, and surface optical fiber 10 (a 2-meter-long pigtail should be reserved at both ends of each optical fiber to facilitate later connection and testing) in series to form an optical fiber sensor. Then connect the two ends of the optical fiber sensor to the optical fiber strain collector 13, and the optical fiber strain collector 13 is connected to the mobile power supply 14. Figure 3 shown.
[0048] 5.2) Fix the optical fiber strain collector 13 and mobile power supply 14 firmly on the working platform 12 to prevent the above equipment from being thrown out due to centrifugal action during the winding process and roller spraying of mortar. Figure 4 .
[0049] Step 6: Monitor the strain ε of the core concrete during production.
[0050] According to the steps of the production process, the subsequent production processes such as lifting, wire wrapping, roller spraying mortar, etc. are carried out to monitor the strain of the pipe core concrete and collect the corresponding strain data in real time.
[0051] Step 7: Analyze the strain of the core concrete.
[0052] 7.1) According to the requirements of domestic and international PCCP specifications, such as ANSI / AWWA C304-2014 and SL 702-2015, the elastic modulus E of the core concrete is c The calculation is done using the following formula:
[0053] E c =8373(f′ c ) 0.3
[0054] Among them, f′ c It is the standard value of 28-day compressive strength of core concrete;
[0055] Design value of concrete tensile strength f′ t The calculation is done using the following formula:
[0056]
[0057] 7.2) According to the relevant PCCP specifications in the industry, the relationship between the tensile stress and strain of the core concrete of the PCCP is that the strain for micro cracks to appear in the core concrete is 1.5 times the peak strain ε′ t The strain at which visible cracks appear in the core concrete is 11 times the peak strain ε′ t , the value of the peak strain ε′ t The calculation is done using the following formula:
[0058]
[0059] 7.3) If ε>1.5ε′ t , micro cracks appear in the corresponding monitoring parts; if ε>11ε′ t , visible cracks appear in the corresponding monitoring parts.
[0060] The working principle of the utility model is to introduce distributed optical fiber sensors, combine the structural characteristics and production process of PCCP, select different types of optical fiber sensors, and use a certain installation method to fix them on the inner circle surface, inside, and outer surface of the pipe core concrete. The production process of PCCP pipes is complicated. The utility model device solves the problems of batch installation of optical fiber sensors, power supply access, and monitoring of the production process. It can realize automatic monitoring of concrete strain cracking during the entire production process of PCCP pipes and avoid the subjectivity of manual observation. In addition, compared with traditional point sensors, distributed optical fiber sensors greatly improve the test accuracy.
[0061] Example 1
[0062] According to the above steps of the utility model device, a certain type of PCCP pipe is monitored. After calculation, the design value of the tensile strength of the concrete core of the pipe is f' c=55MPa, 1.5ε′ t =207.6με, 11ε′ t =1522.6με.
[0063] An umbrella cap screw 6 is fixed to the top socket end 2 of the steel tube 1 of the PCCP, and an umbrella cap screw 2 7 is fixed to the bottom socket end 3 of the steel tube 1; the umbrella cap screw 6 and the umbrella cap screw 27 are used to straighten and tighten the internal optical fiber 8, and after the core concrete is poured, the internal optical fiber 8 is buried inside the core concrete; an inner optical fiber 9 is arranged on the inner circular surface of the inner layer concrete 4 of the core concrete, and a surface optical fiber 10 is arranged on the outer circular surface of the outer layer concrete 5 of the core concrete, and pigtails are reserved at both ends of the internal optical fiber 8, the inner layer optical fiber 9, and the surface optical fiber 10, and the pigtails of the internal optical fiber 8, the inner layer optical fiber 9, and the surface optical fiber 10 are connected in series end to end to form a fiber optic sensor, and both ends of the fiber optic sensor are connected to a fiber optic strain collector 13, the fiber optic strain collector 13 is connected to a mobile power supply 14, and the fiber optic strain collector 13 is simultaneously connected to an external data processing device.
[0064] The optical fiber strain collector 13 and the mobile power supply 14 are both fixed in the working platform 12. The optical fiber strain collector 13 adopts the high-precision distributed strain sensing device OSI-C. The mobile power supply 14 adopts 220V AC, which can meet the power supply of the optical fiber strain collector 13.
[0065] The inner surface of the inner concrete 4 is glued with inner optical fiber 9 along the planned monitoring line with epoxy resin glue. The outer surface of the outer concrete 5 has a through groove axially opened, called semicircular groove 11, and the surface optical fiber 10 is laid in the semicircular groove 11 with epoxy resin glue.
[0066] During the wire wrapping process, the measured data of the inner concrete deformation is collected. Figure 6 It can be seen that according to the monitoring process of the device of the utility model, the maximum strain of the inner layer concrete of this model of PCCP does not exceed 150με, and the overall deformation is within the allowable range, which fully meets the product quality requirements.
[0067] Example 2
[0068] According to the above steps of the utility model device, a certain type of PCCP pipe is monitored. After calculation, the design value of the tensile strength of the concrete core of the pipe is f' c =55MPa, 1.5ε′ t =207.6με, 11ε′ t =1522.6με.
[0069] An umbrella cap screw 6 is fixed to the top socket end 2 of the steel tube 1 of the PCCP, and an umbrella cap screw 2 7 is fixed to the bottom socket end 3 of the steel tube 1; the umbrella cap screw 6 and the umbrella cap screw 27 are used to straighten and tighten the internal optical fiber 8, and after the core concrete is poured, the internal optical fiber 8 is buried inside the core concrete; an inner optical fiber 9 is arranged on the inner circular surface of the inner layer concrete 4 of the core concrete, and a surface optical fiber 10 is arranged on the outer circular surface of the outer layer concrete 5 of the core concrete, and pigtails are reserved at both ends of the internal optical fiber 8, the inner layer optical fiber 9, and the surface optical fiber 10, and the pigtails of the internal optical fiber 8, the inner layer optical fiber 9, and the surface optical fiber 10 are connected in series end to end to form a fiber optic sensor, and both ends of the fiber optic sensor are connected to a fiber optic strain collector 13, the fiber optic strain collector 13 is connected to a mobile power supply 14, and the fiber optic strain collector 13 is simultaneously connected to an external data processing device.
[0070] The optical fiber strain collector 13 and the mobile power supply 14 are both fixed in the working platform 12. The optical fiber strain collector 13 adopts the high-precision distributed strain sensing device OSI-C. The mobile power supply 14 adopts 220V AC, which can meet the power supply of the optical fiber strain collector 13. The inner circle surface of the inner layer of concrete 4 is glued with the inner layer of optical fiber 9 along the planned monitoring line with epoxy resin glue. The outer surface of the outer layer of concrete 5 has a through groove along the axial direction, which is called a semicircular groove 11, and the surface optical fiber 10 is laid in the semicircular groove 11 with epoxy resin glue.
[0071] During the wire wrapping process, the measured data of the outer concrete deformation is collected. Figure 7 It can be seen that according to the monitoring process of the device of the utility model, the maximum strain of the inner layer concrete of this model of PCCP does not exceed 200με, and the overall deformation is within the allowable range, which fully meets the product quality requirements.
[0072] Example 3
[0073] According to the above steps of the utility model device, a certain type of PCCP pipe is monitored. After calculation, the design value of the tensile strength of the concrete core of the pipe is f' c =55MPa, 1.5ε′ t =207.6με, 11ε′ t =1522.6με.
[0074] An umbrella cap screw 1 6 is fixed at the top socket end 2 of the steel tube 1 of the PCCP, and an umbrella cap screw 2 7 is fixed at the bottom socket end 3 of the steel tube 1; the umbrella cap screw 1 6 and the umbrella cap screw 2 7 are used to straighten and tighten the internal optical fiber 8. After the core concrete is poured, the internal optical fiber 8 is buried inside the core concrete; an inner optical fiber 9 is arranged on the inner circular surface of the inner layer concrete 4 of the core concrete, and a surface optical fiber 10 is arranged on the outer circular surface of the outer layer concrete 5 of the core concrete, and pigtails are reserved at both ends of the internal optical fiber 8, the inner optical fiber 9, and the surface optical fiber 10. The pigtails of the internal optical fiber 8, the inner optical fiber 9, and the surface optical fiber 10 are connected in series from head to tail to form an optical fiber sensor. The two ends of the optical fiber sensor are connected to an optical fiber strain collector 13, and the optical fiber strain collector 13 is connected to a mobile power supply 14. The optical fiber strain collector 13 is also connected to an external data processing device. The optical fiber strain collector 13 and the mobile power supply 14 are both fixed in the working platform 12. The optical fiber strain collector 13 adopts a high-precision distributed strain sensing device OSI-C. The mobile power supply 14 uses 220V AC, which can meet the power supply of the optical fiber strain collector 13. The inner surface of the inner concrete 4 is glued with the inner optical fiber 9 along the planned monitoring line with epoxy resin glue. The outer surface of the outer concrete 5 has a through groove along the axial direction, called a semicircular groove 11, and the surface optical fiber 10 is laid in the semicircular groove 11 with epoxy resin glue.
[0075] During the roller spraying mortar process, the measurement data of the outer layer concrete deformation is collected. Figure 8 It can be seen that according to the monitoring device of the utility model, the maximum strain of the outer layer concrete of this model of PCCP does not exceed 70με, and the overall deformation is within the allowable range, which fully meets the product quality requirements.
Claims
1. A strain monitoring device for PCCP core concrete, characterized in that: A cap screw (6) is fixed to the top socket end (2) of the steel tube (1) of the PCCP, and a cap screw (7) is fixed to the bottom socket end (3) of the steel tube (1); an internal optical fiber (8) is stretched and tightened between the cap screw (6) and the cap screw (7); after the pipe core concrete is poured, the internal optical fiber (8) is buried inside the pipe core concrete; an inner optical fiber (9) is arranged on the inner circular surface of the inner layer concrete (4) of the pipe core concrete, and a surface optical fiber (10) is arranged on the outer circular surface of the outer layer concrete (5) of the pipe core concrete; the pigtails of the internal optical fiber (8), the inner layer optical fiber (9) and the surface optical fiber (10) are connected in series to form an optical fiber sensor; both ends of the optical fiber sensor are connected to an optical fiber strain collector (13); the optical fiber strain collector (13) is connected to a mobile power supply (14); and the optical fiber strain collector (13) is simultaneously connected to an external data processing device.
2. The strain monitoring device for PCCP core concrete according to claim 1 is characterized in that: During the pouring process, the optical fiber strain collector (13) and the mobile power source (14) are both fixed in the working platform (12).
3. The strain monitoring device for PCCP core concrete according to claim 1, characterized in that: The inner circular surface of the inner layer concrete (4) is routed back and forth along the planned monitoring line using adhesive tape or 502 glue and is affixed with an inner layer optical fiber (9) using epoxy resin glue.
4. The strain monitoring device for PCCP core concrete according to claim 1, characterized in that: The outer circular surface of the outer layer concrete (5) is provided with a through groove along the axial direction, which is called a semicircular groove (11). The surface optical fiber (10) is laid in the semicircular groove (11) by fusing A and B glue.
5. The strain monitoring device for PCCP core concrete according to claim 1, characterized in that: The inner optical fiber (8) and the inner optical fiber (9) are both high transmission tight sheath strain sensing optical cable NZS-DSS-C07; The surface optical fiber (10) adopts a metal-based rope-shaped strain sensing optical cable NZS-DSS-C02.
6. The strain monitoring device for PCCP core concrete according to claim 1, characterized in that: The optical fiber strain collector (13) adopts a distributed strain sensing device OSI-C.
7. The strain monitoring device for PCCP core concrete according to claim 1, characterized in that: The mobile power source (14) adopts 220V alternating current.