Device and method for detecting internal stress of prestressed concrete pipe pile

Abstract

The invention relates to the technical field of pile body stress detection of civil engineering, and discloses a prestressed concrete pipe pile internal stress detection device and method.The prestressed concrete pipe pile internal stress detection device comprises a tubular protection mechanism; a position adjusting mechanism; the strain gauge is connected to the position adjusting mechanism; the plastic protective sleeve is coated on the outer part of the strain gauge; the heat exchange mechanism is arranged in the tubular protection mechanism, and the heat exchange mechanism is used for transmitting the heat energy transmitted to the strain gauge to the outside of the tubular pile; a tubular protection mechanism is pre-installed on a reinforcement cage of a tubular pile, a position adjusting mechanism, a plastic protection sleeve and a heat exchange mechanism are installed on the tubular protection mechanism, and a strain gauge is fixedly connected to the position adjusting mechanism and located in the plastic protection sleeve; and meanwhile, the heat energy transferred to the strain gauge by the concrete is continuously led out through the heat exchange mechanism, so that the strain gauge can be in a stable working state.

Description

Technical Field

[0001] The present invention relates to the technical field of pile body stress detection in civil engineering, and more specifically, it relates to an internal stress detection device and method for prestressed concrete pipe piles. Background Art

[0002] Prestressed pipe piles (usually referring to concrete pipe piles) are used as the foundation of civil engineering such as building structures and bridge structures, and their applications in engineering are becoming more and more extensive. However, due to the stress mechanism of piles being affected by many factors such as the technology of piles, the characteristics of soil, the material properties of piles, the geometric features of piles, and loads, even for a single pile under vertical or horizontal loads, the research on the stress transfer mechanism to the surrounding soil is still relatively difficult.

[0003] By embedding strain gauges in prestressed pipe piles, the relationship between load and strain (stress) distributed along the pile body can be obtained. Not only can the experimental data of the relationship between vertical (horizontal) load and vertical (horizontal) displacement at the pile top be obtained, but also the relationship between load and strain (stress) distributed along the pile body can be obtained, so as to determine the distribution of side friction resistance of the pile and the magnitude of end resistance of the pile, and explore the stress characteristics and stress transfer mechanism of the pile.

[0004] However, during the pouring and centrifugation of prestressed concrete pipe pile concrete, chemical reactions will occur and a large amount of heat energy will be released. The large amount of heat energy will not only affect the detection accuracy of the strain gauge, but even cause irreversible damage to the strain gauge, resulting in the failure of the embedded strain gauge, and then interrupting the stress detection process. Summary of the Invention

[0005] The purpose of the present invention is to provide an internal stress detection device and method for prestressed concrete pipe piles to solve the above problems.

[0006] The present invention provides an internal stress detection device for prestressed concrete pipe piles, including: A tubular protection mechanism detachably connected to the steel cage of the pipe pile; A position adjustment mechanism installed at one end of the tubular protection mechanism inside the steel cage of the pipe pile; A strain gauge connected to the position adjustment mechanism. The position adjustment mechanism is used to adjust the layout attitude of the strain gauge inside the steel cage. The strain gauge includes a stress detection end and a wire. The stress detection end is fixedly connected to the position adjustment mechanism, and one end of the wire sequentially passes through the position adjustment mechanism and the tubular protection mechanism and extends to the outside of the tubular protection mechanism; A plastic protection sleeve fixedly connected to the position adjustment mechanism and covering the outside of the strain gauge; A heat exchange mechanism is provided inside the tubular protection mechanism. The gap space between the plastic protection sleeve and the strain gauge is communicated with the heat exchange mechanism through a position adjustment mechanism. The heat exchange mechanism is used to transfer the heat energy transmitted to the strain gauge to the outside of the pipe pile.

[0007] As a further optimized solution of the present invention, the tubular protection mechanism includes a protection pipe, a stepped channel provided inside the protection pipe, a sealing cover detachably connected to one end of the protection pipe, an inner sealing pipe fixedly connected to the sealing cover, and a plurality of channels one provided inside the protection pipe. The plurality of channels one are all arranged along the length direction of the tubular protection mechanism. The other end of the inner sealing pipe is movably connected to the position adjustment mechanism. A sealed liquid guide chamber one is formed between the protection pipe, the sealing cover and the inner sealing pipe. The plurality of channels one are all communicated with the sealed liquid guide chamber one.

[0008] As a further optimized solution of the present invention, the position adjustment mechanism includes a circumferential rotation assembly movably connected to the protection pipe, a telescopic protection assembly detachably connected to the central position of the circumferential rotation assembly, and a limit assembly fixedly connected to the circumferential rotation assembly. The limit assembly is located on one side of the telescopic protection assembly. The plastic protection sleeve and the strain gauge are both fixedly connected to the telescopic protection assembly. The telescopic protection assembly is communicated with the heat exchange mechanism through the circumferential rotation assembly. The gap space between the plastic protection sleeve and the strain gauge is communicated with the circumferential rotation assembly through the telescopic protection assembly. The limit assembly is detachably connected to the telescopic protection assembly.

[0009] As a further optimized solution of the present invention, the circumferential rotation assembly includes an outer ring body movably connected to the other end of the protection pipe, a plurality of connecting rods connected to the inner circular surface of the outer ring body, an inner ring body coaxially arranged with the outer ring body, a screw hole one provided on the outer circular surface of the outer ring body, and a positioning screw one threadedly connected inside the screw hole one. The plurality of connecting rods are all fixedly connected to the inner ring body. The plurality of channels one are all communicated with the gap space between the outer ring body and the inner ring body. The inner sealing pipe is movably connected to the inner ring body.

[0010] As a further optimized solution of the present invention, the telescopic protection assembly includes a ring plate one fixedly connected to the outer ring body, a ring plate two coaxially arranged with the ring plate one, an inner telescopic bellows and an outer telescopic bellows connected between the ring plate one and the ring plate two, a plurality of channels two provided on the ring plate one, and a plurality of channels three provided on the ring plate two. The plastic protection sleeve and the strain gauge are both fixedly connected to the ring plate two. A sealed liquid guide chamber two is formed between the ring plate one, the inner telescopic bellows, the outer telescopic bellows and the ring plate two. The two ends of the channel two are respectively communicated with the gap space between the outer ring body and the connecting rod and the sealed liquid guide chamber two. The two ends of the channel three are respectively communicated with the sealed liquid guide chamber two and the gap space between the plastic protection sleeve and the strain gauge.

[0011] As a further optimized solution of the present invention, the limiting component includes a fixing column fixedly connected to the outer ring body, a first hinge plate fixedly connected to the fixing column, a second hinge plate arranged in parallel with the first hinge plate, a movable column fixedly connected to the second hinge plate, a movable sleeve slidably sleeved on the movable column, a third threaded hole provided on the outer cylindrical surface of the movable sleeve, a positioning screw two threadedly connected inside the third threaded hole, and a limiting bolt connected between the first hinge plate and the second hinge plate. The limiting bolt is used to adjust the included angle between the movable column and the fixing column. A threaded portion is provided on the outer cylindrical surface of the movable sleeve, and a second threaded hole matching the threaded portion is provided on the outer cylindrical surface of the second ring plate.

[0012] As a further optimized solution of the present invention, the heat exchange mechanism includes a circulating heat exchange component and a pressure limiting component, and the circulating heat exchange component is connected to the circumferential rotation component through the pressure limiting component.

[0013] As a further optimized solution of the present invention, the circulating heat exchange component includes a liquid inlet pipe and a liquid outlet pipe connected to the sealing cover, and both the liquid inlet pipe and the liquid outlet pipe are communicated with the first sealed liquid guiding chamber.

[0014] As a further optimized solution of the present invention, the pressure limiting component includes a double-pass pipe penetrating the sealing cover, a limiting chute provided on the inner wall of the protective pipe, a limiting slider slidably connected inside the limiting chute, an annular sealing plate connected to the limiting slider, a fourth hole provided inside the protective pipe, and a plurality of fifth holes provided on the annular sealing plate. The plurality of fifth holes are respectively arranged corresponding to the plurality of first holes. The double-pass pipe is communicated with the limiting chute through the fourth hole. When the fifth hole is coaxially corresponding to the corresponding first hole, the first hole is communicated with the first sealed liquid guiding chamber through the fifth hole.

[0015] A method for detecting internal stress of a prestressed concrete pipe pile, using a device for detecting internal stress of a prestressed concrete pipe pile as described above, includes the following steps: Step 100: Vertically connect the tubular protective mechanism equipped with the position adjustment mechanism, strain gauge, plastic protective sleeve and heat exchange mechanism to the steel reinforcement cage of the pipe pile; Step 200: Adjust the layout posture of the strain gauge in the steel reinforcement cage of the pipe pile through the position adjustment mechanism, and adjust the position adjustment mechanism to a fixed state after the adjustment; Step 300: Arrange the casting formwork and conduct concrete pouring. After the pouring is completed, conduct the heat energy transferred from the concrete to the strain gauge to the outside of the pipe pile through the heat exchange mechanism. After a set time, stop the heat energy conduction of the heat exchange mechanism, and start the strain gauge to obtain the data of the change of internal strain force of the pipe pile in real time.

[0016] The beneficial effects of the present invention are as follows: A tubular protection mechanism is pre-installed on the steel reinforcement cage of the pipe pile, and a position adjustment mechanism, a plastic protection sleeve, and a heat exchange mechanism are installed on the tubular protection mechanism. The strain gauge is fixedly connected to the position adjustment mechanism and is located inside the plastic protection sleeve. At the same time, the heat energy transferred from the concrete to the strain gauge is continuously exported through the heat exchange mechanism, so that the strain gauge can be in a stable working state. Brief Description of the Drawings

[0017] Figure 1 is a schematic diagram of the overall structure of the present invention; Figure 2 is a matching view of the position adjustment mechanism and the plastic protection sleeve of the present invention; Figure 3 is of the present invention Figure 2 partial cross-sectional view; Figure 4 is of the present invention Figure 2 magnified view of part A in Figure 5 is of the present invention Figure 2 magnified view of part B in Figure 6 is of the present invention Figure 3 magnified view of part C in Figure 7 is of the present invention Figure 3 magnified view of part D in Figure 8 is of the present invention Figure 3 magnified view of part E in Figure 9 is of the present invention Figure 3 magnified view of part F in

[0018] In the figure: 1, tubular protection mechanism; 101, protection tube; 102, stepped channel; 103, sealing cover; 104, channel one; 105, inner sealing tube; 2, circumferential rotation assembly; 201, outer ring body; 202, connecting rod; 203, inner ring body; 204, screw hole one; 205, positioning screw one; 3, telescopic protection assembly; 301, ring plate one; 3010, channel two; 302, inner telescopic bellows; 303, outer telescopic bellows; 304, ring plate two; 3040, channel three; 3041, screw hole two; 4, limiting assembly; 401, fixed column; 402, hinged plate one; 403, hinged plate two; 404, limiting bolt; 405, movable column; 406, movable sleeve; 407, screw hole three; 408, positioning screw two; 5, plastic protection sleeve; 6, heat exchange mechanism; 601, liquid inlet pipe; 602, liquid outlet pipe; 603, double-pass pipe; 604, limiting slider; 605, annular sealing plate; 606, channel four; 607, channel five; 7, strain gauge; 701, stress detection end; 702, wire. Detailed implementation mode

[0019] Now, the subject matter described herein will be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and thus implement the subject matter described herein. Additionally, features described relative to some examples can be combined in other examples.

[0020] As Figures 1 - 9 shown, a prestressed concrete pipe pile internal stress detection device includes: A tubular protection mechanism 1, which is detachably connected to the steel reinforcement cage of the pipe pile; A position adjustment mechanism, which is installed at one end of the tubular protection mechanism 1 located inside the steel reinforcement cage of the pipe pile; A strain gauge 7, which is connected to the position adjustment mechanism. The position adjustment mechanism is used to adjust the layout attitude of the strain gauge 7 inside the steel reinforcement cage. The strain gauge 7 includes a stress detection end 701 and a wire 702. The stress detection end 701 is fixedly connected to the position adjustment mechanism, and one end of the wire 702 passes through the position adjustment mechanism and the tubular protection mechanism 1 in sequence and extends to the outside of the tubular protection mechanism 1; A plastic protection sleeve 5, which is fixedly connected to the position adjustment mechanism, and the plastic protection sleeve 5 covers the outside of the strain gauge 7; A heat exchange mechanism 6, which is arranged inside the tubular protection mechanism 1. The gap space between the plastic protection sleeve 5 and the strain gauge 7 is communicated with the heat exchange mechanism 6 through the position adjustment mechanism. The heat exchange mechanism 6 is used to transfer the heat energy transmitted to the strain gauge 7 to the outside of the pipe pile.

[0021] It should be noted that when implementing the internal stress detection process of the pipe pile, the tubular protection mechanism 1 equipped with the position adjustment mechanism, the strain gauge 7, the plastic protective sleeve 5, and the heat exchange mechanism 6 is vertically connected to the steel reinforcement cage of the pipe pile first; The layout attitude of the strain gauge 7 in the steel reinforcement cage of the pipe pile is adjusted through the position adjustment mechanism, and after the adjustment is completed, the position adjustment mechanism is adjusted to a fixed state; The pouring formwork is arranged and concrete is poured. After the pouring is completed, the heat energy transferred from the concrete to the strain gauge 7 is conducted to the outside of the pipe pile through the heat exchange mechanism 6. After a set time, the heat energy conduction of the heat exchange mechanism 6 is stopped, and the strain gauge 7 is started to obtain the change data of the internal strain force of the pipe pile in real time. The set time is the time consumed for the internal temperature of the concrete to drop to the set area, mostly 3 - 5 days after the concrete is poured. In the corresponding time area, the change of the heat energy value conducted by the external detection heat exchange mechanism 6 can be used for auxiliary judgment.

[0022] In an alternative embodiment of the present invention, as Figure 2 and 3 , the tubular protection mechanism 1 includes a protection pipe 101, a stepped hole 102 arranged inside the protection pipe 101, a sealing cover 103 detachably connected to one end of the protection pipe 101, an inner sealing pipe 105 fixedly connected to the sealing cover 103, and a plurality of first holes 104 arranged inside the protection pipe 101. The plurality of first holes 104 are all arranged along the length direction of the tubular protection mechanism 1. The other end of the inner sealing pipe 105 is movably connected to the position adjustment mechanism. A sealed liquid guide chamber 1 is formed between the protection pipe 101, the sealing cover 103, and the inner sealing pipe 105. The plurality of first holes 104 are all communicated with the sealed liquid guide chamber 1.

[0023] It should be noted that as described above, after the position adjustment mechanism is installed on the protection pipe 101, one end of the wire 702 is passed through the inner sealing pipe 105 and then drawn out from the through hole provided on the sealing cover 103. The length of the protection pipe 101 can be set and manufactured according to the depth at which the stress detection end 701 is installed. The protection pipe 101 can also be used as a reinforcing bar of the steel reinforcement cage, thereby further improving the strength of the steel reinforcement cage. The heat exchange mechanism 6 is installed at the sealed liquid guide chamber 1, and it is communicated with the first hole 104 through the sealed liquid guide chamber 1, so that the heat exchange medium can be introduced into the sealed liquid guide chamber 1 through the heat exchange mechanism 6 and circulated, so that the heat energy transferred to the wire 702 can be effectively transferred to the outside of the pipe pile.

[0024] In an alternative embodiment of the present invention, as Figure 2 and Figure 3, the position adjusting mechanism includes a circumferential rotation assembly 2 movably connected to the protective tube 101, a telescopic protective assembly 3 detachably connected to the central position of the circumferential rotation assembly 2, and a limiting assembly 4 fixedly connected to the circumferential rotation assembly 2. The limiting assembly 4 is located on one side of the telescopic protective assembly 3. The plastic protective sleeve 5 and the strain gauge 7 are both fixedly connected to the telescopic protective assembly 3. The telescopic protective assembly 3 communicates with the heat exchange mechanism 6 through the circumferential rotation assembly 2. The gap space between the plastic protective sleeve 5 and the strain gauge 7 communicates with the circumferential rotation assembly 2 through the telescopic protective assembly 3. The limiting assembly 4 is detachably connected to the telescopic protective assembly 3.

[0025] It should be noted that, as described above, when adjusting the layout posture of the stress detection end 701, the circumferential rotation assembly 2 can be used to drive the telescopic protective assembly 3, the limiting assembly 4, and the stress detection end 701 fixedly connected to the telescopic protective assembly 3 to rotate a set angle around the central axis of the protective tube 101. After rotation, the circumferential rotation assembly 2 is re-positioned and fixed to the protective tube 101. When adjusting the angle between the stress detection end 701 and the horizontal plane, the telescopic protective assembly 3 is stretched and bent. At the same time, the corresponding limiting assembly 4 is adjusted to a matching position, and then the telescopic protective assembly 3 is connected to the limiting assembly 4, so that the limiting assembly 4 can be limited and fixed at the set position through the telescopic protective assembly 3, so that the stress detection end 701 can be adjusted in any layout posture within the set range, and thus the stress change values in different directions inside the concrete can be obtained.

[0026] In an alternative embodiment of the present invention, as Figures 2 - 4 , the circumferential rotation assembly 2 includes an outer ring body 201 movably connected to the other end of the protective tube 101, a plurality of connecting rods 202 connected to the inner circular surface of the outer ring body 201, an inner ring body 203 coaxially arranged with the outer ring body 201, a first screw hole 204 provided on the outer circular surface of the outer ring body 201, and a positioning screw 205 threadedly connected to the inside of the first screw hole 204. A plurality of connecting rods 202 are all fixedly connected to the inner ring body 203. A plurality of first channels 104 communicate with the gap space between the outer ring body 201 and the inner ring body 203. The inner sealing tube 105 is movably connected to the inner ring body 203.

[0027] It should be noted that, as described above, when the stress detection end 701 is driven by the circumferential rotation assembly 2 to rotate around the vertical central axis of the protective tube 101, specifically, the positioning screw one 205 is screwed out of the screw hole one 204 by a set length. At this time, the positioning screw one 205 no longer contacts the protective tube 101, and the outer ring body 201 is in a state of free rotation at this time. Then, after controlling the outer ring body 201 to rotate by a set angle in the set direction, the positioning screw one 205 is screwed into the screw hole one 204 again, and the positioning screw one 205 is made to contact the protective tube 101 and apply a set extrusion force. Correspondingly, the friction coefficient of the contact part between the positioning screw one 205 and the protective tube 101 can be increased, so as to improve the limiting effect of the positioning screw one 205 on the outer ring body 201.

[0028] In an alternative embodiment of the present invention, as Figure 3 , Figure 8 and Figure 9 , the telescopic protection assembly 3 includes a first ring plate 301 fixedly connected to the outer ring body 201, a second ring plate 304 coaxially arranged with the first ring plate 301, an inner telescopic bellows 302 and an outer telescopic bellows 303 connected between the first ring plate 301 and the second ring plate 304, a plurality of second holes 3010 provided on the first ring plate 301, and a plurality of third holes 3040 provided on the second ring plate 304. The plastic protection sleeve 5 and the strain gauge 7 are both fixedly connected to the second ring plate 304. A sealed liquid guide chamber two is formed between the first ring plate 301, the inner telescopic bellows 302, the outer telescopic bellows 303 and the second ring plate 304. The two ends of the second holes 3010 are respectively communicated with the gap space between the outer ring body 201 and the connecting rod 202 and the sealed liquid guide chamber two. The two ends of the third holes 3040 are respectively communicated with the sealed liquid guide chamber two and the gap space between the plastic protection sleeve 5 and the strain gauge 7.

[0029] It should be noted that, as described above, when adjusting the angle between the stress detection end 701 and the horizontal plane, the second ring plate 304 is pulled to move away from the first ring plate 301. During this process, the inner telescopic bellows 302 and the outer telescopic bellows 303 are in a stretched state. Then, the second ring plate 304 is bent towards the direction of the limiting component 4, and the inner telescopic bellows 302 and the outer telescopic bellows 303 are in the same bending state. No matter how the bending states of the inner telescopic bellows 302 and the outer telescopic bellows 303 change, the sealed liquid guiding chamber two is always in a conducting state. The circulating heat exchange medium introduced by the heat exchange mechanism 6 flows through the sealed liquid guiding chamber one, the first channel 104, the gap between the outer ring body 201 and the inner ring body 203, the second channel 3010, the sealed liquid guiding chamber two, and the third channel 3040, and then enters the gap between the plastic protective sleeve 5 and the strain gauge 7. At this time, the plastic protective sleeve 5 can slightly expand and deform outward under the hydraulic action, and the amount of deformation is small, which does not affect the concrete forming process. And after the plastic protective sleeve 5 is reset, there will actually be no gap between it and the concrete.

[0030] In an alternative embodiment of the present invention, as Figure 3 , Figure 5 and Figure 9 , the limiting component 4 includes a fixed column 401 fixedly connected to the outer ring body 201, a first hinged plate 402 fixedly connected to the fixed column 401, a second hinged plate 403 arranged parallel to the first hinged plate 402, a movable column 405 fixedly connected to the second hinged plate 403, a movable sleeve 406 slidably sleeved on the movable column 405, a third threaded hole 407 provided on the outer cylindrical surface of the movable sleeve 406, a second positioning screw 408 threadedly connected inside the third threaded hole 407, and a limiting bolt 404 connected between the first hinged plate 402 and the second hinged plate 403. The limiting bolt 404 is used to adjust the angle between the movable column 405 and the fixed column 401. A threaded portion is provided on the outer cylindrical surface of the movable sleeve 406, and a second threaded hole 3041 matching the threaded portion is provided on the outer cylindrical surface of the second ring plate 304.

[0031] It should be noted that, as described above, when the telescopic protection component 3 is limited and fixed by the limiting component 4, according to the actual stretching length and bending state of the telescopic protection component 3, the included angle between the movable column 405 and the fixed column 401 is adaptively adjusted. Specifically, first, the limit bolt 404 is loosened so that the first hinge plate 402 and the second hinge plate 403 are no longer limited, so that the second hinge plate 403 can rotate around the central axis of the limit bolt 404. After rotating a set angle, the limit bolt 404 is tightened again so that the second hinge plate 403 is limited and fixed. At this time, the movable column 405 is limited and fixed. Then, the positioning screw two 408 is screwed out from the screw hole three 407, and the movable sleeve 406 is moved towards the screw hole two 3041 on the second ring plate 304. When the movable sleeve 406 is inserted into the screw hole two 3041, it is rotated so that the movable sleeve 406 is gradually screwed into the screw hole two 3041. When the movable sleeve 406 is completely screwed into the screw hole two 3041, the positioning screw two 408 is screwed into the screw hole three 407 again, so that the movable sleeve 406 is re-limited and fixed on the movable column 405. At this time, the second ring plate 304 is limited and fixed, so that the stress detection end 701 connected to the second ring plate 304 is also limited and fixed at the set position, so as to adjust the layout attitude of the stress detection end 701.

[0032] In an alternative embodiment of the present invention, as Figure 3 , Figure 6 and Figure 7 , the heat exchange mechanism 6 includes a circulating heat exchange component and a pressure limiting component, and the circulating heat exchange component is connected to the circumferential rotation component 2 through the pressure limiting component.

[0033] The circulating heat exchange component includes a liquid inlet pipe 601 and a liquid outlet pipe 602 connected to the sealing cover 103, and both the liquid inlet pipe 601 and the liquid outlet pipe 602 are connected to the first sealed liquid guide chamber.

[0034] The pressure limiting component includes a double-pass pipe 603 penetrating the sealing cover 103, a limit sliding groove provided on the inner wall of the protection pipe 101, a limit slider 604 slidably connected inside the limit sliding groove, an annular sealing plate 605 connected to the limit slider 604, a channel four 606 provided inside the protection pipe 101, and a plurality of channels five 607 provided on the annular sealing plate 605. The plurality of channels five 607 are respectively arranged corresponding to the plurality of channels one 104. The double-pass pipe 603 is connected to the limit sliding groove through the channel four 606. When the channel five 607 is coaxially corresponding to the corresponding channel one 104, the channel one 104 is connected to the first sealed liquid guide chamber through the channel five 607.

[0035] It should be noted that, as described above, during the heat conduction process through the heat exchange mechanism 6, a heat exchange medium is input into the first sealed liquid guiding chamber through the liquid inlet pipe 601. The heat exchange medium successively flows through the first sealed liquid guiding chamber, the first channel 104, the gap between the outer ring body 201 and the inner ring body 203, the second channel 3010, the second sealed liquid guiding chamber, and the third channel 3040, and then enters the gap between the plastic protective sleeve 5 and the strain gauge 7. With the continuous input of the heat exchange medium, when the first sealed liquid guiding chamber, the first channel 104, the gap between the outer ring body 201 and the inner ring body 203, the second channel 3010, the second sealed liquid guiding chamber, the third channel 3040, and the gap between the plastic protective sleeve 5 and the strain gauge 7 are all filled with the heat exchange medium, the heat exchange medium begins to discharge towards the liquid outlet pipe 602. During this process, most of the heat energy transferred from the concrete to the stress detection end 701 and the wire 702 is conducted by the heat exchange medium to the outside of the pipe pile, thereby maximizing the reduction of the influence of heat energy on the stress detection end 701 and preventing the stress detection process from being unable to be realized due to a malfunction of the stress detection end 701; The pressure of the heat exchange medium can also be adjusted by an external input pump body. After the heat exchange is completed, in order to enable the stress detection end 701 to clearly obtain the stress change data in the concrete, the plastic protective sleeve 5 can be restored to the state of tightly covering the stress detection end 701, or a certain amount of heat exchange medium can be left between the plastic protective sleeve 5 and the stress detection end 701, so that the plastic protective sleeve 5 is in a slightly expanded state. These two states will not affect the acquisition of stress data by the stress detection end 701. And for these two states, a medium with a set pressure needs to be introduced into the fourth channel 606 through the double-pass pipe 603. Through the medium with the set pressure, the limit slider 604 is pushed to rotate a set angle around the central axis of the protective pipe 101, thereby driving the annular sealing plate 605 to rotate in the same direction and by the same angle, so that the fifth channel 607 is no longer connected to the first channel 104. At this time, the gap space between the plastic protective sleeve 5 and the stress detection end 701 and the second sealed liquid guiding chamber are both in a stable hydraulic state, so that the stress detection end 701 only obtains stress change parameters and will not be affected by other parameters.

[0036] The above describes the present embodiment, but the present embodiment is not limited to the above specific implementation manners. The above specific implementation manners are merely illustrative and not restrictive. Under the inspiration of the present embodiment, those of ordinary skill in the art can also make many forms, all of which fall within the protection scope of the present embodiment.

Claims

1. A prestressed concrete pipe pile internal stress detection device, characterized in that, Comprising: A tubular protection mechanism (1), which is detachably connected to the steel reinforcement cage of the pipe pile; A position adjustment mechanism, which is installed at one end of the tubular protection mechanism (1) inside the steel reinforcement cage of the pipe pile; A strain gauge (7), which is connected to the position adjustment mechanism. The position adjustment mechanism is used to adjust the layout attitude of the strain gauge (7) inside the steel reinforcement cage. The strain gauge (7) includes a stress detection end (701) and a wire (702). The stress detection end (701) is fixedly connected to the position adjustment mechanism, and one end of the wire (702) sequentially passes through the position adjustment mechanism and the tubular protection mechanism (1) and extends to the outside of the tubular protection mechanism (1); A plastic protective sleeve (5), which is fixedly connected to the position adjustment mechanism, and the plastic protective sleeve (5) covers the outside of the strain gauge (7); A heat exchange mechanism (6), which is arranged inside the tubular protection mechanism (1). The gap space between the plastic protective sleeve (5) and the strain gauge (7) is communicated with the heat exchange mechanism (6) through the position adjustment mechanism. The heat exchange mechanism (6) is used to transfer the heat energy transmitted to the strain gauge (7) to the outside of the pipe pile.

2. The internal stress detection device for a prestressed concrete pipe pile according to claim 1, characterized in that, The tubular protection mechanism (1) includes a protection pipe (101), a stepped hole (102) arranged inside the protection pipe (101), a sealing cover (103) detachably connected to one end of the protection pipe (101), an inner sealing pipe (105) fixedly connected to the sealing cover (103), and a plurality of first holes (104) arranged inside the protection pipe (101). The plurality of first holes (104) are all arranged along the length direction of the tubular protection mechanism (1). The other end of the inner sealing pipe (105) is movably connected to the position adjustment mechanism. A sealed liquid guide chamber one is formed between the protection pipe (101), the sealing cover (103) and the inner sealing pipe (105). The plurality of first holes (104) are all communicated with the sealed liquid guide chamber one.

3. The prestressed concrete pipe pile internal stress detection device according to claim 2, characterized in that, The position adjustment mechanism includes a circumferential rotation assembly (2) movably connected to the protection pipe (101), a telescopic protection assembly (3) detachably connected to the central position of the circumferential rotation assembly (2), and a limit assembly (4) fixedly connected to the circumferential rotation assembly (2). The limit assembly (4) is located on one side of the telescopic protection assembly (3). The plastic protective sleeve (5) and the strain gauge (7) are both fixedly connected to the telescopic protection assembly (3). The telescopic protection assembly (3) is communicated with the heat exchange mechanism (6) through the circumferential rotation assembly (2). The gap space between the plastic protective sleeve (5) and the strain gauge (7) is communicated with the circumferential rotation assembly (2) through the telescopic protection assembly (3). The limit assembly (4) is detachably connected to the telescopic protection assembly (3).

4. The prestressed concrete pipe pile internal stress detection device according to claim 3, characterized in that, The circumferential rotation assembly (2) includes an outer ring body (201) movably connected to the other end of the protective tube (101), a plurality of connecting rods (202) connected to the inner circumferential surface of the outer ring body (201), an inner ring body (203) coaxially arranged with the outer ring body (201), a first screw hole (204) provided on the outer circumferential surface of the outer ring body (201), and a first positioning screw (205) threadedly connected to the inside of the first screw hole (204). The plurality of connecting rods (202) are all fixedly connected to the inner ring body (203). The plurality of first channels (104) are all communicated with the gap space between the outer ring body (201) and the inner ring body (203). The inner sealing tube (105) is movably connected to the inner ring body (203).

5. The internal stress detection device for a prestressed concrete pipe pile according to claim 4, characterized in that, The telescopic protection assembly (3) includes a first ring plate (301) fixedly connected to the outer ring body (201), a second ring plate (304) coaxially arranged with the first ring plate (301), an inner telescopic bellows (302) and an outer telescopic bellows (303) connected between the first ring plate (301) and the second ring plate (304), a plurality of second channels (3010) provided on the first ring plate (301), and a plurality of third channels (3040) provided on the second ring plate (304). The plastic protection sleeve (5) and the strain gauge (7) are both fixedly connected to the second ring plate (304). A sealed liquid guide chamber two is formed between the first ring plate (301), the inner telescopic bellows (302), the outer telescopic bellows (303) and the second ring plate (304). The two ends of the second channel (3010) are respectively communicated with the gap space between the outer ring body (201) and the connecting rod (202) and the sealed liquid guide chamber two. The two ends of the third channel (3040) are respectively communicated with the sealed liquid guide chamber two and the gap space between the plastic protection sleeve (5) and the strain gauge (7).

6. The prestressed concrete pipe pile internal stress detection device according to claim 5, characterized in that, The limiting assembly (4) includes a fixed column (401) fixedly connected to the outer ring body (201), a first hinged plate (402) fixedly connected to the fixed column (401), a second hinged plate (403) arranged parallel to the first hinged plate (402), a movable column (405) fixedly connected to the second hinged plate (403), a movable sleeve (406) slidably sleeved on the movable column (405), a third screw hole (407) provided on the outer circumferential surface of the movable sleeve (406), a second positioning screw (408) threadedly connected to the inside of the third screw hole (407), and a limiting bolt (404) connected between the first hinged plate (402) and the second hinged plate (403). The limiting bolt (404) is used to adjust the included angle between the movable column (405) and the fixed column (401). A threaded portion is provided on the outer circumferential surface of the movable sleeve (406). A second screw hole (3041) matching the threaded portion is provided on the outer circumferential surface of the second ring plate (304).

7. An internal stress detection device for prestressed concrete pipe piles according to claim 6, characterized in that, The heat exchange mechanism (6) includes a circulating heat exchange assembly and a pressure limiting assembly. The circulating heat exchange assembly is communicated with the circumferential rotation assembly (2) through the pressure limiting assembly.

8. The internal stress detection device for prestressed concrete pipe piles according to claim 7, characterized in that, The circulating heat exchange component includes a liquid inlet pipe (601) and a liquid outlet pipe (602) connected to the sealing cover (103), and both the liquid inlet pipe (601) and the liquid outlet pipe (602) are communicated with a first sealed liquid guide chamber.

9. An internal stress detection device for prestressed concrete pipe piles according to claim 8, characterized in that, The pressure limiting component includes a double-pass pipe (603) penetrating through the sealing cover (103), a limiting sliding groove provided on the inner wall of the protective pipe (101), a limiting slider (604) slidably connected inside the limiting sliding groove, an annular sealing plate (605) connected to the limiting slider (604), a fourth hole (606) provided inside the protective pipe (101), and a plurality of fifth holes (607) provided on the annular sealing plate (605). The plurality of fifth holes (607) are respectively arranged corresponding to a plurality of first holes (104). The double-pass pipe (603) is communicated with the limiting sliding groove through the fourth hole (606). When the fifth hole (607) is coaxially corresponding to the corresponding first hole (104), the first hole (104) is communicated with the first sealed liquid guide chamber through the fifth hole (607).

10. A method for detecting internal stress of prestressed concrete pipe piles, characterized in that, Using a prestressed concrete pipe pile internal stress detection device according to any one of claims 1-9, comprising the following steps: Step 100: Vertically connect the tubular protection mechanism (1) equipped with a position adjustment mechanism, a strain gauge (7), a plastic protective sleeve (5), and a heat exchange mechanism (6) to the steel reinforcement cage of the pipe pile. Step 200: Adjust the layout posture of the strain gauge (7) in the steel reinforcement cage of the pipe pile through the position adjustment mechanism, and adjust the position adjustment mechanism to a fixed state after the adjustment. Step 300: Arrange a casting formwork and perform concrete casting. After the casting is completed, conduct the heat energy transferred from the concrete to the strain gauge (7) to the outside of the pipe pile through the heat exchange mechanism (6). After a set time, stop the heat energy conduction of the heat exchange mechanism (6), and start the strain gauge (7) to obtain the change data of the internal strain force of the pipe pile in real time.

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