Installation method of steel wire absolute stress monitoring sensor in pccp pipe winding process

Abstract

The application discloses a kind of PCCP pipe wire winding process in steel wire absolute stress monitoring sensor installation method, first in sensor connecting line place pre-installed special protective sleeve, flange structure is welded to dry powder cylinder;Pre-embed sensor into prestressed steel beam, start wire winding process, when steel wire is wound to sensor pre-buried hole, sensor is sent out by rotating flange structure;Sensor moves with steel wire, just with the embedding of steel wire winding in reserved hole, complete the installation of this sensor.Repeat the above steps to complete the remaining sensor installation work.The PCCP pipe wire winding process in steel wire absolute stress monitoring sensor installation method provided by the application overcomes the shortcomings in the prior art installation technology, has little effect on the original PCCP pipe quality, avoids the inconvenience caused by sensor connecting line to PCCP pipe production and construction, and realizes the convenient, orderly and efficient installation of electromagnetic elastic absolute stress sensor in PCCP pipe winding process.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of prestressed concrete cylinder pipe production, and particularly relates to a method for installing a steel wire absolute stress monitoring sensor in a PCCP pipe wire winding process. BACKGROUND

[0002] A prestressed concrete cylinder pipe (PCCP) refers to a pipe made of a pipe core with a steel cylinder, on which high-strength steel wires are uniformly wound in a spiral, and a mortar protective layer is covered, and has the advantages of long service life, good shock resistance, and anti-leakage, and is widely used in water supply and drainage engineering. The strength of the PCCP pipe depends on the high-strength steel wires, which generate uniform prestress on the pipe core, and can offset the tensile stress generated by internal pressure and external load; however, in the production, construction and operation process, various reasons may cause damage or corrosion of the steel wires, and then cause the steel wires to break, resulting in a decrease in the strength of the pipe, and with the increase in the number of local broken wires, the PCCP pipe wall yields, and eventually causes accidents such as leakage and pipe explosion.

[0003] At present, the health status of PCCP pipes is generally evaluated periodically or in real time in water conservancy projects at home and abroad, including the knocking echo detection method (Luo Jianjun, Yao Xuande, Zhang Dongsheng, et al. Field test study on spectral response of large-diameter PCCP pipe broken wires [J]. Journal of Civil Engineering, 2016, 49(9): 110-116), far-field eddy current electromagnetic detection method (patent publication number CN210088480U), optical fiber sensor monitoring method (patent publication number CN222718007U), hydrophone monitoring method (patent publication number CN104504380A), ultrasonic and X-ray detection method (patent publication number CN109854861A), etc. However, the existing PCCP pipe detection methods have some key problems, such as although these methods can judge the broken wire condition, they cannot accurately measure the stress of the prestressed steel strand, so they cannot predict or intervene in the broken wire condition in advance; secondly, the existing detection methods need to be measured in the pipe, and may be affected by the performance of the sensor. The electromagnetic elastic stress sensor is installed in the prestressed steel wire in the PCCP pipe winding process, does not contact the liquid in the pipe, ensures the performance of the sensor, and can obtain the stress of the steel wire at each measurement point, and accurately prevents the broken wire condition through real-time data.

[0004] In the PCCP pipe winding process, there are problems such as how to accurately and orderly install the electromagnetic elastic stress sensor, and how to ensure the performance of the sensor in the subsequent spraying process. Therefore, there is an urgent need for a convenient and feasible method for installing the electromagnetic elastic stress sensor for monitoring the absolute stress of the steel wire, so as to solve the key bottleneck problem of the technology in engineering application. SUMMARY

[0005] In order to solve the deficiency in the existing PCCP pipe steel wire absolute stress monitoring sensor installation technology, the application provides a PCCP pipe wire winding process steel wire absolute stress monitoring sensor installation method, which can quickly and simply install the electromagnetic elastic stress sensor in the PCCP pipe wire winding process.

[0006] A PCCP pipe wire winding process steel wire absolute stress monitoring sensor installation method, comprising the following steps:

[0007] (1) A sensor pre-buried hole is arranged at a selected position on the PCCP pipe wall;

[0008] (2) A rotatable flange is welded and fixed below the axis of the steel wire dry powder cylinder beam hole through a connecting rod;

[0009] (3) A proper number of electromagnetic elastic stress sensors are sequentially sleeved on the prestressed steel wire, one end of the steel wire is led out from the dry powder cylinder beam hole, passes through the transmission hole on the flange, is embedded into the anchor head reserved hole at the core first end of the PCCP pipe, and the anchor head is installed and fixed;

[0010] (4) Start winding the steel wire on the PCCP pipe, when the steel wire is wound to the sensor pre-buried hole, rotate the flange counterclockwise by 180 degrees, so that one electromagnetic elastic stress sensor passes out from the other transmission hole on the flange, and then rotate the flange clockwise by 180 degrees;

[0011] (5) Adjust the contact position of the steel wire and the PCCP pipe wall through the forward rotation or reverse rotation of the winding machine, and install the electromagnetic elastic stress sensor into the sensor pre-buried hole;

[0012] (6) Continue the wire winding work, and install the remaining electromagnetic elastic stress sensors according to steps (4) and (5);

[0013] (7) When the steel wire is wound to the end of the PCCP pipe, embed the steel wire into the anchor head reserved hole at the end of the PCCP pipe core, cut off the steel wire and install the anchor head, and complete the wire winding work.

[0014] Further, before the wire winding process, the connecting line at one end of the electromagnetic elastic stress sensor is reserved for 10-15 cm, a special protective sleeve is installed at the connecting line, the main body of the protective sleeve is a spiral structure and one end is a hexagonal seal, so that it forms a closed state for protecting the sensor connecting line from being contaminated by the coating in the subsequent spraying process.

[0015] Further, when the electromagnetic elastic stress sensor is sleeved on the prestressed steel wire, the protective sleeve at the connecting line naturally droops; when the electromagnetic elastic stress sensor is installed in the sensor pre-buried hole, the protective sleeve at the connecting line is perpendicular to the PCCP pipe wall.

[0016] Further, the center of the flange plate is provided with a rotating shaft, the transmission hole for the steel wire is located above the rotating shaft, and the transmission hole for the sensor is located below the rotating shaft, and the two transmission holes are communicated through a semicircular gap.

[0017] Further, the rotating shaft adopts a damping rotating shaft, the damping rotating shaft generates damping through the friction force of the locking between the gasket and the nut, one end of the connecting rod is connected with the flange plate through the damping rotating shaft, and the other end is fixedly connected with the dry powder cylinder.

[0018] Further, the electromagnetic elastic stress sensor comprises a cylindrical framework and a magnetic field generating element and an intelligent sensing element fixedly installed on the cylindrical framework, the magnetic field generating element is controlled by a remote control end, and is used for generating a magnetic field at the measured cross section of the steel wire, so as to magnetize the steel wire; the intelligent sensing element generates a magnetic characteristic signal representing the magnetic induction intensity of the steel wire at the measured cross section through electromagnetic induction.

[0019] Further, the magnetic field generating element adopts an excitation coil, the cylindrical framework has a through hole for the steel wire to pass through, and there are two annular cavities outside the through hole, the intelligent sensing element is located in the inner layer cavity, and the excitation coil is arranged in the outer layer cavity, and the excitation coil generates a magnetic field under the excitation of the excitation signal of the remote control end.

[0020] Preferably, in order to ensure the accuracy of the measurement result, a plurality of electromagnetic elastic stress sensors are installed on the measured cross section of the steel wire, and the sensors are uniformly spaced by a certain degree.

[0021] Based on the above technical scheme, the present application has the following beneficial technical effects:

[0022] 1. The problem of inconvenient installation of the electromagnetic elastic stress sensor is solved. The present application only needs to control the installation of the sensor through the flange plate device, and integrates it into the PCCP pipe wire winding process, effectively solving the installation problem of the electromagnetic elastic stress sensor.

[0023] 2. The installation time is short, and the construction is simple. The installation and construction technology of the present application is simple, and only one worker is needed to operate the whole process. Therefore, the installation of the sensor can be completed more conveniently.

[0024] 3. The influence on the original PCCP pipe quality is small. The present application only needs to reserve a 3cm pre-buried hole at the specified position of the PCCP pipe core, and has little influence on the quality of the PCCP pipe. After the sensor is installed, the spraying process can be carried out normally.

[0025] 4. The structure is simple, and the cost is saved. The flange plate and the sensor connecting line protection sleeve in the present application are simple and practical, and the protection sleeve and the flange plate can be reused, saving the cost.

[0026] 5. The application solves the problem of inconvenience caused by sensor connecting wires to PCCP pipe production and construction. The application reserves 10-15 cm connecting wires at the sensor, protects the connecting wires from damage by the wire winding and spraying process through the connecting wire protection sleeve, and connects by the staff at the construction site, without affecting the entire process from production to construction. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a structural diagram of the electromagnetic elastic stress sensor connecting wire protection sleeve in the application.

[0028] Figure 2 It is a structure and threading diagram of the rotatable flange in the application.

[0029] Figure 3 It is a mounting structure diagram of the electromagnetic elastic stress sensor in the application.

[0030] Figure 4 It is a PCCP pipe wire winding diagram after the sensor is installed in the application.

[0031] In the figure: 1 - protection sleeve, 2 - sensor connecting wire, 3 - electromagnetic elastic stress sensor, 4 - dry powder cylinder, 5 - flange, 6 - steel wire transmission hole, 7 - sensor transmission hole, 8 - rotating shaft, 9 - steel wire, 10 - connecting rod, 11 - sensor pre-buried hole, F represents stress. DETAILED DESCRIPTION

[0032] In order to more specifically describe the application, the technical solutions of the application will be described in detail below in combination with the drawings and specific embodiments.

[0033] The steel wire absolute stress monitoring sensor installation method in the PCCP pipe wire winding process of the application specifically includes the following steps:

[0034] (1) Before the wire winding process, set the sensor pre-buried hole 11 at the selected position on the PCCP pipe wall, as shown in Figure 4 .

[0035] (2) Reserve 10-15 cm of the sensor connecting wire 2 at one end of the electromagnetic elastic stress sensor 3, install a special protection sleeve 1 at the connecting wire, as shown in Figure 1 ; the main body of the protection sleeve 1 in this embodiment is a spiral structure and one end is a hexagonal seal, so that it forms an enclosed state, which is used to protect the sensor connecting wire 2 from being covered by the coating in the subsequent spraying process.

[0036] (3) Use the welding method to fix the flange 5 to the steel wire dry powder cylinder 4 beam hole axis below 12.5 cm through the connecting rod 10, as shown in Figure 2As shown; in this embodiment, a rotating shaft 8 is provided at the center of the flange 5. The wire transmission hole 6 through which the wire passes is located above the rotating shaft 8, and the sensor transmission hole 7 through which the sensor passes is located below the rotating shaft 8. The wire transmission hole 6 and the sensor transmission hole 7 are connected by a semi-circular opening. The rotating shaft 8 is a damping shaft. The damping shaft generates damping through the friction force of the gasket and the nut being locked. One end of the connecting rod 10 is connected to the flange 5 through the damping shaft, and the other end is fixedly connected to the dry powder cylinder 4.

[0037] (4) Place an appropriate number of electromagnetic spring-type stress sensors 3 onto the prestressed steel wire 9 in sequence, with the protective sleeve 1 of the sensor connection line 2 hanging down naturally, such as Figure 2 As shown.

[0038] (5) Lead one end of the steel wire 9 out from the outlet hole of the dry powder cylinder 4 and pass it through the steel wire transmission hole 6 on the flange 5, as shown. Figure 2 As shown, it is then inserted into the pre-drilled hole at the beginning of the PCCP core and the anchor head is installed for fixation.

[0039] (6) Start winding the wire on the PCCP pipe. When the steel wire 9 is wound to the sensor pre-embedded hole 11, rotate the flange 5 counterclockwise by 180 degrees so that an electromagnetic spring stress sensor 3 and its connecting wire 2 can pass through the sensor transmission hole 7. After passing through, rotate the flange 5 clockwise by 180 degrees to prevent other sensors from passing through.

[0040] (7) Adjust the contact position between the steel wire 9 and the PCCP pipe wall by rotating the wire winding machine forward or backward, and install the electromagnetic spring-type stress sensor 3 in the sensor pre-embedded hole 11, such as Figure 4 As shown, the protective sleeve 1 of the sensor connection line 2 is perpendicular to the pipe wall and faces outward.

[0041] (8) Continue the winding of the steel wire 9 and install the remaining electromagnetic spring stress sensor 3 according to the above steps (6) and (7).

[0042] (9) When the steel wire 9 is wound to the end of the PCCP pipe, insert the steel wire 9 into the anchor head reserved hole at the end of the PCCP pipe core, cut the steel wire and install the anchor head to fix it, and complete the wire winding work.

[0043] The electromagnetic spring-type stress sensor 3 in this embodiment includes a cylindrical frame and a magnetic field generating element and an intelligent sensing element mounted and fixed on the cylindrical frame. The magnetic field generating element is controlled by a remote control terminal and is used to generate a magnetic field at the steel wire in the tested cross-section area, thereby magnetizing the steel wire 9. The intelligent sensing element generates a magnetic characteristic signal that characterizes the magnetic field strength at the steel wire in the tested cross-section through electromagnetic induction.

[0044] like Figure 3As shown, in the present embodiment, the magnetic field generating element adopts an excitation coil, the cylindrical framework has a through hole for the force receiving member (pre-stressed steel wire 9) to pass through, and there are two annular cavities outside the through hole, wherein the intelligent sensing element is placed in the inner layer cavity and the excitation coil is placed in the outer layer cavity. The excitation coil generates a magnetic field under the excitation of the excitation signal from the remote control end.

[0045] In the present embodiment, in order to ensure the accuracy of the measurement results, four electromagnetic elastic stress sensors 3 are installed on the steel wire 9 of the measured section, and the sensors are spaced 90 degrees apart.

[0046] In the PCCP pipe wire breakage monitoring application scenario, the present embodiment pre-calibrates the sensor in the laboratory using the steel wire used for the pipe to be measured, obtains the relationship curve and coefficient between the magnetic characteristic signal and the stress, and then uses the electromagnetic elastic stress sensor as the main detection tool, installs it on the pre-stressed steel wire of the PCCP pipe, sends an excitation signal to the sensor through the remote control end, and under the magnetic elastic effect, the steel wire generates a corresponding magnetic induction intensity under the action of an external force. The sensor senses the magnetic induction intensity, calculates the magnetic characteristic signal and transmits the signal to the magneto-elastic instrument; the magneto-elastic instrument processes the received monitoring signal according to the calibration results in the laboratory in advance to convert it into stress data of the pre-stressed steel wire, and then stores the stress data on the memory of the magneto-elastic instrument; the user can control the operation of the entire device through the remote control end, and can observe the current stress data and historical data of the PCCP pipe. According to this data, the PCCP pipe wire breakage (time, position and number of wire breakage) can be monitored in real time, and the safety operation of the PCCP pipe can be evaluated, and the early warning function of the PCCP pipe burst disaster can be realized.

[0047] In the present embodiment, the working principle of the electromagnetic elastic stress sensor is as follows: the pre-stressed steel wire is subjected to an external excitation magnetic field under the action of an external force, and when its stress changes, its magnetic properties change, causing the distribution of the magnetic field in the adjacent area to change. This change is closely related to the magnetic properties of the steel wire material; the intelligent sensing element in the electromagnetic elastic strain sensor measures the magnetic field response and outputs a magnetic characteristic signal, and after signal processing, the magnetic characteristic quantity of the pre-stressed steel wire is obtained. There is a one-to-one correspondence between the magnetic characteristic quantity and the stress of the steel wire, that is, the absolute stress value of the pre-stressed steel wire can be obtained.

[0048] The embodiment can solve the problem of inconvenient installation of the electromagnetic elastic stress sensor, only needs to control the installation of the sensor through the flange device, and integrates the sensor into the wire winding process of the PCCP pipe, effectively solves the installation problem of the electromagnetic elastic stress sensor, and has the advantages that the installation time is short, the construction is simple, only one worker is needed to operate the whole process, the installation of the sensor is only needed to be adjusted through the wire winding machine, so the installation of the sensor can be conveniently completed, the influence on the original PCCP pipe quality is small, only 3cm of the pre-buried hole is reserved at the specified position of the PCCP pipe core, the influence on the quality of the PCCP pipe is small, the spraying process can be normally carried out after the sensor is installed, the structure is simple, the cost is saved, the flange and the sensor connecting line protection sleeve are simple and practical, the protection sleeve and the flange can be repeatedly used, and the cost is saved, in addition, the embodiment can also solve the problem that the sensor connecting line causes inconvenience to the production and construction of the PCCP pipe, 10-15cm of the connecting line is reserved at the sensor, the connecting line is protected by the connecting line protection sleeve and is not damaged by the wire winding and spraying process, the worker connects in the construction site, and the whole process from production to construction is not affected.

[0049] The above description of the embodiments is for the purpose of enabling a person of ordinary skill in the art to understand and apply the present application, and those skilled in the art can easily make various modifications to the above embodiments, and apply the general principles described herein to other embodiments without inventive labor. Therefore, the present application is not limited to the above embodiments, and the improvements and modifications of the present application made by those skilled in the art according to the disclosure of the present application should be within the scope of protection of the present application.

Claims

1. A method for installing a sensor for monitoring the absolute stress of steel wire in the process of winding steel wire on a PCCP pipe, comprising the following steps: (1) setting a sensor pre-buried hole at a selected position on the wall of the PCCP pipe; (2) welding and fixing a rotatable flange below the axial line of the beam hole of the steel wire dry powder cylinder through a connecting rod; the center of the flange is provided with a rotating shaft, the transmission hole for the steel wire is located above the rotating shaft, the transmission hole for the sensor is located below the rotating shaft, and the two transmission holes are connected through a semicircular slit; the rotating shaft is a damping shaft, and the damping shaft generates damping through the friction force of the locking between the gasket and the nut; one end of the connecting rod is connected with the flange through the damping shaft, and the other end is fixedly connected with the dry powder cylinder; (3) sequentially sleeving a proper number of electromagnetic elastic stress sensors on the prestressed steel wire, leading out one end of the steel wire from the beam hole of the dry powder cylinder, passing through the transmission hole on the flange, embedding the steel wire into the anchor head reserved hole at the first end of the PCCP pipe core, and installing the anchor head fixing; before the winding process, the connecting line at one end of the electromagnetic elastic stress sensor is reserved for 10-15 cm, a special protective sleeve is installed at the connecting line, the main body of the protective sleeve is a spiral structure and one end is a hexagonal seal, so that it forms a closed state for protecting the sensor connecting line from being contaminated by the coating in the subsequent spraying process; when the electromagnetic elastic stress sensor is sleeved on the prestressed steel wire, the protective sleeve at the connecting line naturally droops; when the electromagnetic elastic stress sensor is installed in the sensor pre-buried hole, the protective sleeve at the connecting line is perpendicular to the PCCP pipe wall and outward; (4) starting to wind the steel wire on the PCCP pipe, rotating the flange counterclockwise by 180 degrees when the steel wire is wound to the sensor pre-buried hole, so that one electromagnetic elastic stress sensor passes out from the other transmission hole on the flange, and then the flange is rotated clockwise by 180 degrees; (5) adjusting the contact position of the steel wire and the PCCP pipe wall through the forward rotation or reverse rotation of the wire winding machine, and installing the electromagnetic elastic stress sensor into the sensor pre-buried hole; (6) continuing the winding work, and installing the remaining electromagnetic elastic stress sensors according to steps (4) and (5); (7) when the steel wire is wound to the end of the PCCP pipe, embedding the steel wire into the anchor head reserved hole at the end of the PCCP pipe core, cutting the steel wire and installing the anchor head fixing, and completing the winding work.

2. The method for installing the wire absolute stress monitoring sensor in the PCCP pipe wire winding process according to claim 1, characterized in that: The electromagnetic elastic stress sensor comprises a cylindrical framework, a magnetic field generating element and an intelligent sensing element which are fixed on the cylindrical framework, the magnetic field generating element is controlled by a remote control end, and is used for generating a magnetic field at the measured section of the steel wire, so as to magnetize the steel wire; the intelligent sensing element generates a magnetic characteristic signal representing the magnetic induction intensity of the steel wire at the measured section through electromagnetic induction.

3. The method for installing the wire absolute stress monitoring sensor in the PCCP pipe wire winding process according to claim 2, characterized in that: The magnetic field generating element adopts an excitation coil, the cylindrical framework has a through hole for the steel wire to pass through, and there are two annular cavities around the through hole; the intelligent sensing element is located in the inner layer cavity, and the excitation coil is wound in the outer layer cavity; the excitation coil generates a magnetic field under the excitation of the excitation signal of the remote control end.

4. The method for installing the wire absolute stress monitoring sensor in the PCCP pipe wire winding process according to claim 2, characterized in that: A plurality of electromagnetic elastic stress sensors are installed on the measured section of the steel wire, and the sensors are uniformly spaced by a certain degree.

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