阅读说明：本技术 一种基于光纤光栅测温的灌注桩完整性检测装置及方法 (Cast-in-place pile integrity detection device and method based on fiber bragg grating temperature measurement ) 是由 戴国亮 赵仲新 于 2021-09-14 设计创作，主要内容包括：本发明涉及一种基于光纤光栅测温的灌注桩完整性检测装置,包括灌注桩(1)和钢筋笼(2),毛细无缝钢管光纤光栅温度传感器(3)和主动加热光纤光栅温度传感器(8)沿着灌注桩(1)的轴向等间距地固定于钢筋笼(2)上,且二者分别与信号解调仪(4)相连,主动加热光纤光栅温度传感器(8)再与脉冲加热电源(9)连接,信号解调仪(4)与物联网网关模块(5)连接,物联网网关模块(5)再与数据可视化处理模块(7)相连,信号解调仪(4)、物联网网关模块(5)和脉冲加热电源(9)再分别通过接口电与直流电源模块(6)相连。本发明的优点是提高桩基检测的智能化和实时化,同时提高桩基检测数据的精度,简化检测过程,降低成本。(The invention relates to a bored pile integrity detection device based on fiber bragg grating temperature measurement, which comprises a bored pile (1) and a reinforcement cage (2), wherein a capillary seamless steel pipe fiber bragg grating temperature sensor (3) and an active heating fiber bragg grating temperature sensor (8) are fixed on the reinforcement cage (2) at equal intervals along the axial direction of the bored pile (1), the capillary seamless steel pipe fiber bragg grating temperature sensor and the active heating fiber bragg grating temperature sensor are respectively connected with a signal demodulator (4), the active heating fiber bragg grating temperature sensor (8) is connected with a pulse heating power supply (9), the signal demodulator (4) is connected with an internet of things gateway module (5), the internet of things gateway module (5) is connected with a data visualization processing module (7), and the signal demodulator (4), the internet of things gateway module (5) and the pulse heating power supply (9) are respectively connected with a direct current power supply module (6) through interface electricity. The invention has the advantages of improving the intellectualization and the real-time of pile foundation detection, improving the precision of pile foundation detection data, simplifying the detection process and reducing the cost.)

1. The utility model provides a bored concrete pile integrality detection device based on fiber grating temperature measurement, includes bored concrete pile (1) and is fixed in steel reinforcement cage (2) in bored concrete pile (1), its characterized in that:

the reinforcement cage (2) is connected with a capillary seamless steel pipe fiber grating temperature sensor (3) and an active heating fiber grating temperature sensor (8), the capillary seamless steel pipe fiber grating temperature sensor (3) and the active heating fiber grating temperature sensor (8) are fixed on the reinforcement cage (2) at equal intervals along the axial direction of the cast-in-place pile (1), and the two are respectively connected with a signal demodulator (4), the active heating fiber grating temperature sensor (8) is in wired connection with a pulse heating power supply (9), the signal demodulator (4) is in wired connection with the Internet of things gateway module (5), the Internet of things gateway module (5) is connected with a data visualization processing module (7) through a wireless network, and the signal demodulator (4), the Internet of things gateway module (5) and the pulse heating power supply (9) are respectively connected with a direct current power supply module (6) through interface electricity.

2. The cast-in-place pile integrity detection device based on fiber grating temperature measurement as claimed in claim 1, wherein:

the active heating fiber bragg grating temperature sensor (8) is formed by packaging a capillary seamless steel tube fiber bragg grating temperature sensor and two heat conduction resistance wires in a corundum tube.

3. The cast-in-place pile integrity detection device based on fiber grating temperature measurement according to claim 1 or 2, characterized in that:

the capillary seamless steel pipe fiber grating temperature sensor (3) is fixed on a main rib of the steel reinforcement cage (2) at equal intervals through an OPP adhesive tape, and the active heating fiber grating temperature sensor (8) is fixed on the main rib of the steel reinforcement cage (2) at equal intervals through a high temperature resistant adhesive tape.

4. The cast-in-place pile integrity detection device based on fiber grating temperature measurement according to claim 1 or 2, characterized in that:

the number of the capillary seamless steel pipe fiber grating temperature sensors (3) and the number of the active heating fiber grating temperature sensors (8) are even, and the capillary seamless steel pipe fiber grating temperature sensors and the active heating fiber grating temperature sensors are symmetrically fixed on the main ribs of the reinforcement cage (2).

5. The cast-in-place pile integrity detection device based on fiber grating temperature measurement according to claim 1 or 2, characterized in that:

the data visualization processing module (7) is a remote wireless processing terminal.

6. The method for detecting the integrity of the cast-in-place pile based on fiber grating temperature measurement by using the device as claimed in claim 1 comprises the following steps:

the method comprises the following steps: presetting a fiber bragg grating temperature sensor, selecting a layout scheme of a capillary seamless steel pipe fiber bragg grating temperature sensor (3) or an active heating fiber bragg grating temperature sensor (8) according to the specific detection working condition of the cast-in-place pile (1), and then fixing the fiber bragg grating temperature sensor on a main rib of a steel rib cage (2) in the cast-in-place pile (1);

step two: pouring pile body concrete, namely placing the reinforcement cage (2) with the temperature sensors in place, and pouring the pile body concrete according to design requirements;

step three: detecting the temperature of the pile body, namely, detecting after the pouring of the concrete of the pile body is finished, testing the temperature of the pile body by using a capillary seamless steel pipe fiber grating temperature sensor (3) after 12-72 hours, and testing the temperature of the pile body by using an active heating fiber grating temperature sensor (8) during the service period of the pile foundation;

step four: transmitting and processing the pile body temperature distribution data, processing the pile body temperature distribution data by using a signal demodulator (4) and an Internet of things gateway module (5) and transmitting the processed pile body temperature distribution data to a data visualization processing module (7);

step five: the data visualization processing and pile body integrity evaluation are realized by wirelessly obtaining pile body temperature distribution data through a data visualization processing module (7), forming a pile body temperature distribution diagram through data processing software, and further evaluating the pile body integrity through the temperature change condition in the pile body temperature distribution diagram.

7. The method for detecting the integrity of the bored pile based on fiber grating temperature measurement according to claim 6, wherein:

in the first step, the capillary seamless steel tube fiber grating temperature sensor (3) needs to be pre-tensioned during fixing.

8. The method for detecting the integrity of the bored pile based on fiber grating temperature measurement according to claim 6, wherein:

in the third step, the pulse heating power supply (9) heats the heat conduction resistance wire to cause the temperature of the pile body to change, and then the capillary seamless steel pipe fiber grating temperature sensor in the active heating fiber grating temperature sensor (8) tests the temperature distribution condition of the pile body.

9. The method for detecting the integrity of the bored pile based on fiber grating temperature measurement according to claim 6, wherein:

in the fourth step, firstly, the optical signal generated by the temperature of the pile body is returned to the signal demodulator (4) by using the capillary seamless steel pipe fiber grating temperature sensor (3) or the active heating fiber grating temperature sensor (8), then the return value is read and converted by using the signal demodulator (4), so that the temperature variation of the pile body is obtained, and then the temperature variation of the pile body obtained by processing the signal demodulator (4) is wirelessly transmitted to the data visualization processing module (7) through the internet of things gateway module (5).

10. The method for detecting the integrity of the bored pile based on fiber grating temperature measurement according to claim 6, wherein:

and fifthly, analyzing whether the concrete pouring of the pile body is uniform, whether the pile body is complete and whether the reinforcement cage is placed eccentrically according to the relative difference of the temperature along the pile body through the characteristics that the temperature is influenced by different consumption and quality of the concrete, calculating the thickness of the cement protective layer of the reinforcement cage, thereby finishing the integrity evaluation of the cast-in-place pile, and judging that the quality of the pile body concrete in the area has problems when the temperature at a certain position of the pile body is wholly or locally reduced during the integrity evaluation of the pile body of the cast-in-place pile.

Technical Field

The invention relates to the technical field of pile foundation detection, in particular to a device and a method for detecting the integrity of a cast-in-place pile based on fiber grating temperature measurement.

Background

The cast-in-situ bored pile has a long pile length, a large pile diameter and high bearing capacity, and is widely applied to the infrastructure construction of various important building facilities such as bridges, houses and the like. Meanwhile, the cast-in-place pile has certain concealment in site construction, complex construction process and more influence factors, so that the construction quality of the pile body of the cast-in-place pile plays a decisive factor for the long-term use performance of the cast-in-place pile, and further the long-term safe use of the superstructure is influenced.

The quality control during the construction of the cast-in-place pile and the integrity evaluation after pile forming are very important. At present, the commonly used method for testing the integrity of the pile body of the cast-in-place pile mainly comprises a high-strain method, a low-strain method, a sound wave transmission method, a drilling coring method and the like. However, the above-mentioned testing methods have their own advantages and have certain limitations, such as: the low strain method is simple to operate, high in detection speed and low in cost, but is difficult to identify defects existing in a long pile and a deep part; the principle of the drilling coring method and the construction process are direct, but the pile body is damaged, the operation difficulty is high, and the cost is high.

Disclosure of Invention

The invention aims to solve the defects of the existing cast-in-place pile integrity test, and provides a cast-in-place pile integrity detection device based on fiber grating temperature measurement.

In order to achieve the purpose, the invention adopts the following technical scheme:

the utility model provides a bored concrete pile integrality detection device based on fiber grating temperature measurement, including bored concrete pile and the steel reinforcement cage that is fixed in the bored concrete pile, even there are capillary seamless steel pipe fiber grating temperature sensor and initiative heating fiber grating temperature sensor on the steel reinforcement cage, capillary seamless steel pipe fiber grating temperature sensor and initiative heating fiber grating temperature sensor are fixed in on the steel reinforcement cage along the axial of bored concrete pile equidistant, and the two links to each other with the signal demodulation appearance respectively, initiative heating fiber grating temperature sensor again with pulse heating power supply wired connection, signal demodulation appearance and thing networking gateway module wired connection, thing networking gateway module links to each other with the visual processing module of data through the wireless network again, the signal demodulation appearance, thing networking gateway module and pulse heating power supply link to each other with the DC power supply module through interface electricity respectively again.

Furthermore, the active heating fiber bragg grating temperature sensor is formed by packaging a capillary seamless steel pipe fiber bragg grating temperature sensor and two heat conduction resistance wires in a corundum tube.

Furthermore, the fiber grating temperature sensor of the capillary seamless steel pipe is fixed on a main rib of the steel reinforcement cage at equal intervals through an OPP adhesive tape, and the active heating fiber grating temperature sensor is fixed on the main rib of the steel reinforcement cage at equal intervals through a high temperature resistant adhesive tape.

Furthermore, the number of the capillary seamless steel tube fiber grating temperature sensors and the number of the active heating fiber grating temperature sensors are even, and the capillary seamless steel tube fiber grating temperature sensors and the active heating fiber grating temperature sensors are symmetrically fixed on the main ribs of the reinforcement cage.

Further, the data visualization processing module is a remote wireless processing terminal.

In order to further achieve the purpose of the invention, the invention also provides a method for detecting the integrity of the cast-in-place pile based on fiber grating temperature measurement, the used device comprises a capillary seamless steel pipe fiber grating temperature sensor, an active heating fiber grating temperature sensor, a signal demodulator, a pulse heating power supply, an internet of things gateway module, a data visualization processing module and a direct current power supply module, and the method comprises the following specific steps:

(1) presetting a fiber grating temperature sensor: selecting a layout scheme of a capillary seamless steel pipe fiber grating temperature sensor or an active heating fiber grating temperature sensor according to the specific detection working condition of the cast-in-place pile, and then fixing the capillary seamless steel pipe fiber grating temperature sensor or the active heating fiber grating temperature sensor on main ribs of a reinforcement cage in the cast-in-place pile;

(2) pouring concrete of a pile body: arranging the reinforcement cage with the temperature sensor in place, and pouring pile body concrete according to design requirements;

(3) detecting the temperature of the pile body: after the pouring of the pile body concrete is finished, the detection can be started, the pile body temperature can be tested by using the capillary seamless steel pipe fiber grating temperature sensor after 12-72 hours, and the pile body temperature is tested by using the active heating fiber grating temperature sensor during the service period of the pile foundation;

(4) transmitting and processing pile body temperature distribution data: processing the pile body temperature distribution data by using a signal demodulator and an internet of things gateway module and transmitting the processed data to a data visualization processing module;

(5) data visualization processing and pile body integrity evaluation: the method comprises the steps of wirelessly obtaining pile body temperature distribution data by utilizing a data visualization processing module, forming a pile body temperature distribution diagram through data processing software, and further evaluating the integrity of the pile body through the temperature change condition in the pile body temperature distribution diagram.

Furthermore, in the step (1), the capillary seamless steel tube fiber grating temperature sensor needs to be pre-tensioned during fixing.

Further, in the step (3), the pulse heating power supply heats the heat conduction resistance wire to cause the temperature of the pile body to change, and then the capillary seamless steel pipe fiber grating temperature sensor in the active heating fiber grating temperature sensor tests the temperature distribution condition of the pile body.

Further, in the step (4), firstly, the optical signal generated by the temperature of the pile body is returned to the signal demodulator by using the fiber bragg grating temperature sensor of the capillary seamless steel tube or the actively heating fiber bragg grating temperature sensor, then, the return value is read and converted by using the signal demodulator, so that the temperature variation of the pile body is obtained, and then, the temperature variation of the pile body obtained by processing the signal demodulator is wirelessly transmitted to the data visualization processing module through the gateway module of the internet of things.

Further, in the step (5), through the characteristics that the temperature is affected by different usage amounts and different quality of concrete, whether pile body concrete pouring is uniform or not, whether the pile body is complete or not and whether the reinforcement cage is placed eccentrically or not are analyzed according to the relative difference of the temperature along the pile body, the thickness of the cement protection layer of the reinforcement cage is calculated, and therefore the integrity evaluation of the cast-in-place pile is completed.

Compared with the prior art, the technical scheme of the invention has the advantages that:

(1) the fiber bragg grating temperature testing technology and the internet of things gateway wireless transmission technology are combined and applied to the field of pile foundation detection, and the intelligent detection level is improved;

(2) the change condition of the temperature field of the pile body of the cast-in-place pile is measured in multiple points by adopting a fiber grating temperature testing technology, and the sensor has the advantages of small volume, high transmission speed, convenience in arrangement and high detection precision;

(3) the gateway module of the Internet of things is adopted for remote wireless transmission of detection data, so that real-time automatic detection of pile body quality is realized, field test and data post-processing can be processed simultaneously and differently, and the detection intelligence is improved;

(4) the device has reasonable structure and convenient operation, improves the accuracy of pile foundation detection data, simplifies the detection process and reduces the cost;

(5) the integrity of the pile body of the cast-in-place pile is comprehensively monitored in real time, and an important data basis is provided for the evaluation of the integrity of the pile body;

(6) the detection data are accumulated, reference is provided for engineering projects of the same type, and training data are provided for development of artificial intelligence industries such as machine learning and deep learning in the field of pile foundation monitoring.

Drawings

FIG. 1 is a schematic structural diagram of a device for detecting integrity of a bored concrete pile based on fiber grating temperature measurement according to the present invention;

FIG. 2 is a flowchart of a method for detecting the integrity of a bored concrete pile based on fiber grating temperature measurement according to the present invention.

Detailed Description

Example 1

In order to make the present invention more clear, the following further describes an apparatus and a method for detecting integrity of a bored concrete pile based on fiber grating temperature measurement according to the present invention with reference to the accompanying drawings, and the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

Referring to fig. 1, a bored concrete pile integrality detection device based on fiber grating temperature measurement, includes bored concrete pile 1 and is fixed in steel reinforcement cage 2 in bored concrete pile 1, its characterized in that:

even there are capillary seamless steel pipe fiber grating temperature sensor 3 and active heating fiber grating temperature sensor 8 on steel reinforcement cage 2, capillary seamless steel pipe fiber grating temperature sensor 3 and active heating fiber grating temperature sensor 8 are fixed in steel reinforcement cage 2 along bored concrete pile 1's axial equidistant ground, and the two links to each other with signal demodulation appearance 4 respectively, active heating fiber grating temperature sensor 8 is again with pulse heating power 9 wired connection, signal demodulation appearance 4 and thing networking gateway module 5 wired connection, thing networking gateway module 5 rethread wireless network links to each other with data visualization processing module 7, signal demodulation appearance 4, thing networking gateway module 5 and pulse heating power 9 rethread interface electricity link to each other with DC power supply module 6 respectively.

In this embodiment, the active heating fiber grating temperature sensor 8 is formed by packaging a capillary seamless steel tube fiber grating temperature sensor and two heat conduction resistance wires in a corundum tube, the pulse heating power supply 9 heats the heat conduction resistance wires to cause the temperature of the pile body to change, and then the capillary seamless steel tube fiber grating temperature sensor in the active heating fiber grating temperature sensor tests the temperature distribution condition of the pile body; the capillary seamless steel pipe fiber grating temperature sensor 3 is formed by packaging a multipoint fiber grating string by adopting a seamless steel pipe packaging technology, the pile body temperature generated by hydration heat release in a certain time after concrete pouring is tested, the sensor body adopts an all-metal structure, the sensor is small in size, light in weight, high in tensile strength, high in compression resistance, high-temperature resistance, corrosion resistance, waterproof and moisture resistance, and the temperature test with high sensitivity, high heat conduction speed and good accuracy can be realized.

In this embodiment, the capillary seamless steel pipe fiber grating temperature sensor 3 may be separately arranged for temperature testing only when the integrity of the pile body of the cast-in-place pile 1 is tested within a certain time after casting, and the active heating fiber grating temperature sensor 8 may be separately arranged for temperature testing during different periods of pile formation and service if the integrity of the pile body needs to be tested again during the service period of the cast-in-place pile. The number of the temperature sensors is even, and the temperature sensors are symmetrically fixed on main ribs of a reinforcement cage in the cast-in-place pile.

The arrangement position of the capillary seamless steel pipe fiber grating temperature sensor 3 or the active heating fiber grating temperature sensor 8 influences the measurement value of the pile body temperature, the temperature value measured by the temperature sensor arranged at the central axis of the cast-in-place pile 1 is higher, and the closer the arrangement position of the temperature sensor is to the edge of the cast-in-place pile, the lower the measured temperature value is.

In this embodiment, the signal demodulator 4 is mainly used for reading and converting a signal return value of the capillary seamless steel pipe fiber grating temperature sensor 3 or the active heating fiber grating temperature sensor 8, and performing wired transmission on the pile body temperature variation obtained by conversion to the internet of things gateway module 5, and the internet of things gateway module 5 is mainly used for wirelessly transmitting the pile body temperature variation to the data visualization processing module 7;

the data visualization processing module 7 is a remote wireless processing terminal and is mainly used for receiving the distribution data of the pile body temperature, forming a pile body temperature distribution map through data processing software, and further identifying and evaluating the integrity of the pile body.

In this embodiment, the temperature values at the depths of the pile body measured by the capillary seamless steel tube fiber grating temperature sensor 3 or the active heating fiber grating temperature sensor 8 are in direct proportion to the amount of concrete at the depth, the pile body temperature of the uniform and complete pile is uniformly distributed from top to bottom, but due to the influence of the air at the pile top and the soil layer at the pile bottom, the temperature measurement values of the pile body within a range of one time of the pile diameter at the pile top and the pile bottom are relatively low, and the data processing software in the data visualization processing module performs compensation processing on the temperature measurement values at the pile top and the pile bottom before the temperature distribution diagram of the pile body is visualized.

Referring to fig. 2, the method for detecting the integrity of the cast-in-place pile by using the device comprises the following specific steps:

(1) presetting a fiber grating temperature sensor: selecting a layout scheme of a capillary seamless steel pipe fiber grating temperature sensor 3 or an active heating fiber grating temperature sensor 8 according to the specific detection working condition of the cast-in-place pile 1, fixing the capillary seamless steel pipe fiber grating temperature sensor on a main rib of a reinforcement cage 2 in the cast-in-place pile 1, and pre-tensioning the capillary seamless steel pipe fiber grating temperature sensor 3 when fixing;

(2) pouring concrete of a pile body: arranging the reinforcement cage 2 with the temperature sensors in place, and pouring pile body concrete according to design requirements;

(3) detecting the temperature of the pile body: after the pouring of the concrete of the pile body is finished, the detection can be started, the temperature of the pile body can be tested by using the fiber grating temperature sensor 3 of the capillary seamless steel pipe after 12-72 hours, the temperature of the pile body can be tested by using the active heating fiber grating temperature sensor 8 during the service period of the pile foundation, the temperature of the pile body is changed by heating the heat conducting resistance wire through a pulse heating power supply, and then the temperature distribution condition of the pile body is tested by using the fiber grating temperature sensor of the capillary seamless steel pipe in the active heating fiber grating temperature sensor;

(4) transmitting and processing pile body temperature distribution data: firstly, returning an optical signal generated by the temperature of the pile body to a signal demodulator 4 by using a capillary seamless steel pipe fiber grating temperature sensor 3 or an active heating fiber grating temperature sensor 8, then reading and converting the return value by using the signal demodulator 4 to obtain the temperature variation of the pile body, and then wirelessly transmitting the temperature variation of the pile body obtained by processing by the signal demodulator 4 to a data visualization processing module 7 through an internet of things gateway module 5;

(5) data visualization processing and pile body integrity evaluation: utilize the wireless pile body temperature distribution data that obtains of data visualization processing module 7, form pile body temperature distribution diagram through data processing software, and then carry out pile body integrality evaluation through the temperature variation condition in the pile body temperature distribution diagram, quantity and the different characteristics that influence the temperature height of quality through the concrete, whether the relative difference along the pile body according to the temperature is even for the analysis pile body concrete placement, whether the pile body is complete, whether the steel reinforcement cage is placed eccentrically, calculate the cement protective layer thickness of steel reinforcement cage, thereby accomplish bored concrete pile integrality evaluation, when carrying out the pile body integrality evaluation of bored concrete pile, when the whole or local phenomenon that the temperature reduces that appears in a certain position department of pile body, then can judge that this regional pile body concrete quality exists the problem.

The detection method combines the fiber bragg grating temperature testing technology, designs the cast-in-place pile body integrity detection device which is small in size, simple and convenient to arrange, dense in measurement points, strong in corrosion resistance, strong in anti-interference capability, high in measurement precision, long in distance measurement, large in capacity, high in transmission speed and high in intelligent degree, and improves the intellectualization and the real-time performance of pile foundation detection; the accuracy of pile foundation detection data is improved, the detection process is simplified, and the cost is reduced; meanwhile, the integrity of the pile body of the cast-in-place pile is comprehensively monitored in real time, and an important data basis is provided for the evaluation of the integrity of the pile body; in addition, detection data are accumulated, reference is provided for engineering projects of the same type, and training data are provided for development of artificial intelligence industries such as machine learning and deep learning in the field of pile foundation monitoring.

In addition to the above embodiments, the present invention may have other embodiments. All technical solutions formed by adopting equivalent substitutions or equivalent transformations fall within the protection scope of the claims of the present invention.