Intelligent detection method for concrete damage of photovoltaic PHC pipe pile

Abstract

The invention discloses a photovoltaic PHC pipe pile concrete damage intelligent detection method which comprises the steps that two adjacent photovoltaic PHC pipe piles are selected, one of the photovoltaic PHC pipe piles serves as a standard pile, the other photovoltaic PHC pipe pile serves as a test pile, an intelligent test vehicle is arranged between the standard pile and the test pile, and the intelligent test vehicle comprises a moving mechanism, a stable frame and a data center. The stable frame is used for guaranteeing stress transmission between pile bodies, the data center is used for detecting and processing data, the stable frame comprises fixed supporting legs, a telescopic rod, a transverse jack, an excitation device and a wave pickup, the excitation device can be hidden in the telescopic rod, when a test needs to be carried out, the excitation device extends out of the telescopic rod to facilitate excitation action, and the wave pickup is used for detecting and processing data. Excitation plates and strain boxes are arranged on the standard pile and the test pile and are used for detecting the horizontal shearing resistance of concrete and the integrity of a pile body; through arrangement of the comparison pile body, nondestructive pipe pile testing is completed, and later pile body maintenance and use are facilitated.

Description

Technical Field

[0001] The invention relates to the field of pipe pile detection, and in particular to an intelligent detection method for concrete damage of a photovoltaic PHC pipe pile. Background Art

[0002] Ground photovoltaic power stations are mostly built in open areas such as hillsides, fields, wastelands, and fish ponds. The photovoltaic support foundation is mainly subjected to wind loads. In the downwind state, the support foundation is mainly subjected to vertical downward pressure and horizontal thrust; in the headwind state, the support foundation is mainly subjected to vertical upward pull and horizontal thrust. Since the photovoltaic components supported by the photovoltaic support are light and the weight of the support is small, the vertical compressive bearing capacity of the support foundation can usually meet the requirements, so the horizontal load and upward pull load are the control loads. When the photovoltaic power station uses PHC pipe piles as the support foundation, the length is short, the depth of burial is shallow, and the top of the pile is exposed to a long height above the ground. The support is generally not equipped with a pedestal. In most cases, the pile-column integration form is directly adopted. The load application point is located near the top of the pile, and the pipe pile plays a dual role of foundation and structure. This type of photovoltaic PHC pipe pile is defined as a short pile, that is, a pile foundation with a pile diameter less than or equal to 300mm and a pile length less than or equal to 5m. The stress mode and bearing mechanism of this type of short piles are quite different from those of conventional piles. The theoretical support is not yet clear. Under the action of large wind loads, if the bearing capacity of the short pile foundation is not properly controlled, the photovoltaic bracket may be deformed, dislocated, or even pushed down or pulled up, which may cause the photovoltaic power station to fail to operate normally.

[0003] The pile body is affected by the environmental conditions of the construction site, such as soil quality, groundwater level, surrounding buildings, etc., which may affect the detection results of the pipe pile. In addition, the verticality of the pile body, the thickness of the sediment at the bottom of the pile, and the sand dune landform are a common natural terrain, and its soil characteristics are significantly different from those of ordinary landforms. The soil in the sand dune area is usually loose and unstable, which brings great challenges to the pile foundation construction. In particular, the adaptability of the pile foundation in the sand dune landform is of great significance to ensure the stability of the pile foundation and improve the construction efficiency. Summary of the invention

[0004] The purpose of the present invention is to provide an intelligent detection method for concrete damage of PHC piles for photovoltaic use, so as to solve the existing problems raised in the above background technology.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: an intelligent detection method for concrete damage of photovoltaic PHC pipe piles, comprising selecting two adjacent photovoltaic PHC pipe piles, one of which is used as a standard pile and the other as a test pile, and an intelligent test vehicle is arranged between the standard pile and the test pile, and the intelligent test vehicle comprises a mobile mechanism, a stable frame and a data center, the stable frame is used to ensure the force transmission between the pile bodies, and the data center is used to detect and process data, the stable frame comprises fixed legs, a telescopic rod, a transverse jack, an excitation device and a pickup, the excitation device can be hidden in the telescopic rod, and when a test is required, it is extended from the telescopic rod to facilitate the excitation action, and an excitation plate and a strain box are arranged on the standard pile and the test pile to detect the horizontal shear resistance and pile body integrity of the concrete; the specific detection method comprises:

[0006] Step 1: Waveform and horizontal force verification. First, calibrate the buried depth and size of the standard pile to ensure that its parameters are consistent with the test pile. Use the intelligent test car to excite the standard pile. The excitation device hits the test pile after excitation, and obtains the strain waveform through the pickup, which is stored and processed through the data center. After multiple tests, the standard waveform is determined; the horizontal force verification step is to support the standard pile with the telescopic rod through the extension and contraction of the transverse jack, and insert the fixed legs of the stable frame into the soil layer for fixation. The standard pile is further horizontally pressurized by the transverse jack again, and the values ​​of the horizontal pressure from small to large f1, f2, f3, f4 and f5 are recorded in turn, and the average value f0 is taken. The strain box detects the strains of the standard piles e1, e2, e3, e4 and e5 respectively corresponding to the horizontal pressure, and the average value e0 of the strain is taken. The size of e0 meets the allowable range that the standard pile is not damaged. The relationship between the horizontal force and the strain of the standard pile is obtained, f0=ne0, and the n value is used as the reference coefficient;

[0007] Step 2: Pile body detection. First, move the intelligent test vehicle between the standard pile and the test pile. The excitation device is pressed against the outer wall of the test pile. At the same time, the pickup is inserted into the soil. The pickup and the data center are connected electrically. The excitation device generates strain waves by impacting the excitation plate on the test pile. At the same time, the strain wave diagram is obtained through the pickup and stored and processed by the data center.

[0008] Step 3: Waveform analysis: by comparing the difference between the strain wave diagram of the test pile and the standard waveform diagram, if the difference ratio is greater than 5%, the test pile is judged as a presumed damaged pile, and a horizontal shear test is performed at the same time;

[0009] Step 4: Horizontal shear force test, hide the excitation device in the telescopic rod, and support the telescopic rod to contact the test pile through the extension and contraction of the lateral jack of the stable frame, and insert the fixed leg of the stable frame into the soil layer to fix it. The test pile is further horizontally pressurized by the lateral jack and tested multiple times, and the values ​​of horizontal pressure from small to large F1, F2, F3, F4 and F5 are recorded in sequence, and the average value F0 is taken. Among them, the strain box detects the strain of the standard pile E1, E2, E3, E4 and E5, and the average value of the strain is E0; after multiple tests, the average value is determined, and by comparing the relationship between horizontal pressure and strain n1=F0 / E0, where the n1 value is less than 0.85n, it can be judged that the test pile is a damaged pile, and the damaged pile is replaced or repaired according to the construction requirements.

[0010] The intelligent test vehicle includes an automatic driving module and a visual module. The visual module is used to observe the displacement of the standard pile and the test pile, and move them into place through the automatic driving module.

[0011] The excitation device includes an excitation ball, a reel and a contraction spring. The reel is connected to a reel rope through an electrically controlled shaft sleeve. The reel rope is connected to the excitation ball. Before excitation, the excitation ball is retracted inside the telescopic rod by controlling the reel rope. At this time, the inner cavity of the telescopic rod serves as the movement track of the excitation ball.

[0012] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0013] (1) The present invention completes non-destructive pipe pile testing by setting up a comparison pile body, which is beneficial to the later maintenance and use of the pile body.

[0014] (2) The device of the present invention is conducive to the self-control of the intelligent test vehicle and can ensure the safety of construction workers through remote control.

[0015] (3) The present application realizes the detection of stress waves through an excitation device, so as to obtain the damage condition of the pipe pile by comparing with the stress wave diagram of the pile body. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0017] Figure 1 It is a test schematic diagram of the intelligent test vehicle of the present invention;

[0018] Figure 2 is a flow chart of the present invention;

[0019] Figure 3 It is a schematic diagram of the excitation device of the present invention.

[0020] In the figure: 1. Standard pile; 2. Test pile; 3. Intelligent test vehicle; 31. Mobile mechanism; 32. Stabilizing frame; 33. Data center; 34. Autonomous driving module; 35. Vision module; 321. Fixed legs; 322. Telescopic rod; 323. Transverse jack; 324. Excitation device; 325. Pickup; 4. Excitation plate; 5. Strain box; 3241. Excitation ball; 3242. Reel; 3243. Contraction spring. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] A method for intelligently detecting concrete damage of a photovoltaic PHC pipe pile, comprising selecting two adjacent photovoltaic PHC pipe piles, one of which is used as a standard pile 1, and the other as a test pile 2, wherein an intelligent test vehicle 3 is arranged between the standard pile and the test pile, wherein the intelligent test vehicle comprises a moving mechanism 31, a stabilizing frame 32, and a data center 33, wherein the stabilizing frame is used to ensure force transmission between pile bodies, and the data center is used to detect and process data, wherein the stabilizing frame comprises a fixed leg 321, a telescopic rod 322, a transverse jack 323, an excitation device 324, and a pickup 325, wherein the excitation device 324 can be hidden in the telescopic rod 322, and when a test is required, it is extended from the telescopic rod to facilitate the excitation action, and an excitation plate 4 and a strain box 5 are arranged on the standard pile and the test pile to detect the horizontal shear resistance and pile body integrity of the concrete;

[0023] The specific detection method includes: step 1: waveform and horizontal force verification, first calibrate the buried depth and size of the standard pile to ensure that its parameters are consistent with the test pile, use the intelligent test car to excite the standard pile, the excitation device hits the test pile after excitation, and obtains the strain waveform through the pickup, and stores and processes it through the data center, and determines the standard waveform after multiple tests; the horizontal force verification step is to support the standard pile with the telescopic rod through the extension and contraction of the transverse jack, and insert the fixed legs of the stable frame into the soil layer for fixing, and further horizontally pressurize the standard pile through the transverse jack again, and record the values ​​of the horizontal pressure from small to large f1, f2, f3, f4 and f5 in turn, and take the average value f0, wherein the strain box detects the strains of the standard piles e1, e2, e3, e4 and e5 respectively corresponding to the horizontal pressure, and takes the average value e0 of the strain, the size of e0 meets the allowable range that the standard pile is not damaged, and obtains the relationship between the horizontal force and the strain of the standard pile f0=ne0, and the n value is used as the reference coefficient;

[0024] Step 2: Pile body detection. First, move the intelligent test vehicle between the standard pile and the test pile. The excitation device is pressed against the outer wall of the test pile. At the same time, the pickup is inserted into the soil. The pickup and the data center are connected electrically. The excitation device generates strain waves by impacting the excitation plate on the test pile. At the same time, the strain wave diagram is obtained through the pickup and stored and processed by the data center.

[0025] Step 3: Waveform analysis: by comparing the difference between the strain wave diagram of the test pile and the standard waveform diagram, if the difference ratio is greater than 5%, the test pile is judged as a presumed damaged pile, and a horizontal shear test is performed at the same time;

[0026] Step 4: Horizontal shear force test, hide the excitation device in the telescopic rod, and support the telescopic rod to contact the test pile through the extension and contraction of the lateral jack of the stable frame, and insert the fixed leg of the stable frame into the soil layer to fix it. The test pile is further horizontally pressurized by the lateral jack and tested multiple times, and the values ​​of horizontal pressure from small to large F1, F2, F3, F4 and F5 are recorded in sequence, and the average value F0 is taken. Among them, the strain box detects the strain of the standard pile E1, E2, E3, E4 and E5, and the average value of the strain is E0; after multiple tests, the average value is determined, and by comparing the relationship between horizontal pressure and strain n1=F0 / E0, where the n1 value is less than 0.85n, it can be judged that the test pile is a damaged pile, and the damaged pile is replaced or repaired according to the construction requirements.

[0027] The intelligent test vehicle comprises an automatic driving module 34 and a visual module 35. The visual module is used to observe the displacement of the standard pile and the test pile, and move them into position through the automatic driving module.

[0028] The excitation device 324 includes an excitation ball 3241, a reel 3242 and a retraction spring 3243. The reel is connected to a reel rope through an electrically controlled shaft sleeve. The retraction rope is connected to the excitation ball. Before excitation, the excitation ball is retracted inside the telescopic rod by controlling the retraction rope. At this time, the inner cavity of the telescopic rod serves as the movement track of the excitation ball.

[0029] In addition, it is necessary to determine whether the strain measurement value is a valid value when testing multiple test piles. Under ideal conditions, when the pile body is subjected to horizontal pressure, not only the pile body itself will be strained, but the soil will also undergo a small displacement. However, under a certain depth, the influence of the soil can be considered small. Under the action of horizontal loads, the pile body will bend, and the differential equation for pile body deflection is expressed as: Where EI is the bending stiffness of the pile, y is the horizontal displacement of the pile, and p(z,y) is the horizontal soil resistance acting on the unit area of ​​the pile foundation at depth z;

[0030] p(z,y)=myb, b is the calculated width of the pile, and m is the horizontal resistance coefficient.

[0031] By comparing the strain measurement value E0 of the test pile with the calculated horizontal displacement y value of the pile body, if the strain measurement value E0 is greater than the calculated horizontal displacement y value of the pile body, the strain measurement value E0 is judged to be a valid value.

[0032] m is the proportional coefficient of the horizontal resistance coefficient of the soil on the pile side, which can be determined by a single pile horizontal static load test, or can be obtained according to the table in the Technical Specifications for Building Pile Foundations JGJ94-2008. For different soil types and pile types (such as precast piles, steel piles, cast-in-place piles, etc.), the recommended value of δ can be found in Table 5.7.5 of the specification.

[0033] Table 5.7.5

[0034]

[0035]

[0036] In actual engineering, when determining the value of m, it is also necessary to consider factors such as the horizontal displacement limit of the pile top, the pile burial depth, and the nature of the soil layer. By comprehensively considering these parameters, the force and displacement of the pile under horizontal load can be more accurately evaluated.

[0037] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0038] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An intelligent detection method for concrete damage of a photovoltaic PHC pipe pile, comprising selecting two adjacent photovoltaic PHC pipe piles, one of which is used as a standard pile (1) and the other as a test pile (2), and arranging an intelligent test vehicle (3) between the standard pile and the test pile, wherein the intelligent test vehicle comprises a moving mechanism (31), a stabilizing frame (32) and a data center (33), wherein the stabilizing frame is used to ensure force transmission between pile bodies, and the data center is used to detect and process data, wherein the stabilizing frame comprises fixed legs (321), a telescopic rod (322), a transverse jack (323), an excitation device (324) and a pickup (325), wherein the excitation device (324) can be hidden in the telescopic rod (322) and can be extended from the telescopic rod when testing is required to facilitate excitation action, wherein an excitation plate (4) and a strain box (5) are arranged on the standard pile and the test pile to detect the horizontal shear resistance and pile body integrity of the concrete; and the specific detection method comprises: Step 1: Waveform and horizontal force verification. First, calibrate the buried depth and size of the standard pile to ensure that its parameters are consistent with the test pile. Use the intelligent test car to excite the standard pile. The excitation device hits the test pile after excitation, and obtains the strain waveform through the pickup, which is stored and processed through the data center. After multiple tests, the standard waveform is determined; the horizontal force verification step is to support the standard pile with the telescopic rod through the extension and contraction of the transverse jack, and insert the fixed legs of the stable frame into the soil layer for fixation. The standard pile is further horizontally pressurized by the transverse jack again, and the values ​​of the horizontal pressure from small to large f1, f2, f3, f4 and f5 are recorded in turn, and the average value f0 is taken. The strain box detects the strains of the standard piles e1, e2, e3, e4 and e5 respectively corresponding to the horizontal pressure, and the average value e0 of the strain is taken. The size of e0 meets the allowable range that the standard pile is not damaged. The relationship between the horizontal force and the strain of the standard pile is obtained, f0=ne0, and the n value is used as the reference coefficient; Step 2: Pile body detection. First, move the intelligent test vehicle between the standard pile and the test pile. The excitation device is pressed against the outer wall of the test pile. At the same time, the pickup is inserted into the soil. The pickup and the data center are connected electrically. The excitation device generates strain waves by impacting the excitation plate on the test pile. At the same time, the strain wave diagram is obtained through the pickup and stored and processed by the data center. Step 3: Waveform analysis: by comparing the difference between the strain wave diagram of the test pile and the standard waveform diagram, if the difference ratio is greater than 5%, the test pile is judged as a presumed damaged pile, and a horizontal shear test is performed at the same time; Step 4: Horizontal shear force test, hide the excitation device in the telescopic rod, and support the telescopic rod to contact the test pile through the extension and contraction of the lateral jack of the stable frame, and insert the fixed leg of the stable frame into the soil layer to fix it. The test pile is further horizontally pressurized by the lateral jack and tested multiple times, and the values ​​of horizontal pressure from small to large F1, F2, F3, F4 and F5 are recorded in sequence, and the average value F0 is taken. Among them, the strain box detects the strain of the standard pile E1, E2, E3, E4 and E5, and the average value of the strain is E0; after multiple tests, the average value is determined, and by comparing the relationship between horizontal pressure and strain n1=F0 / E0, where the n1 value is less than 0.85n, it can be judged that the test pile is a damaged pile, and the damaged pile is replaced or repaired according to the construction requirements.

2. According to claim 1, the method for intelligent detection of concrete damage of a photovoltaic PHC pile is characterized by: The intelligent test vehicle comprises an automatic driving module (34) and a visual module (35), wherein the visual module is used to observe the displacement of the standard pile and the test pile, and to move them into position through the automatic driving module.

3. The intelligent detection method for concrete damage of a photovoltaic PHC pile according to claim 1 is characterized in that: The excitation device (324) comprises an excitation ball (3241), a reel (3242) and a retraction spring (3243), wherein the reel is connected to a retraction rope via an electrically controlled shaft sleeve, and the retraction rope is connected to the excitation ball. Before excitation, the excitation ball is retracted inside the telescopic rod by controlling the retraction rope, and the inner cavity of the telescopic rod serves as a movement track for the excitation ball.

4. The intelligent detection method for concrete damage of a photovoltaic PHC pile according to claim 1 is characterized in that: Including judging whether the strain measurement value E0 is valid. Under the action of horizontal load, the pile body will bend. The differential equation of pile body deflection is expressed as: Where EI is the bending stiffness of the pile body, y is the horizontal displacement of the pile body, p(z,y) is the horizontal soil resistance acting on the unit area of ​​the pile foundation at depth z; p(z,y)=myb, b is the calculated width of the pile, and m is the horizontal resistance coefficient; by comparing the strain measurement value E0 of the test pile and the calculated horizontal displacement y value of the pile body, when the strain measurement value E0 is greater than the calculated horizontal displacement y value of the pile body, the strain measurement value E0 is judged to be a valid value.

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