Photovoltaic pile horizontal bearing capacity testing method and method for selecting pile diameter and pile length

Abstract

The invention provides a method for testing the horizontal bearing capacity of photovoltaic piles and a method for selecting the pile diameter and the pile length, and relates to the technical field of photovoltaic.The method for testing the horizontal bearing capacity of the photovoltaic piles comprises the steps that A1, the two photovoltaic piles are arranged, and the distance between the two photovoltaic piles adopts a design value; a2, a support is installed at the tops of the two photovoltaic piles, the two photovoltaic piles are connected through the support, and the support comprises a front stand column, a rear stand column, an oblique beam, a first inclined strut and a second inclined strut; the front stand column and the rear stand column are arranged on the tops of the two photovoltaic piles respectively. The oblique beam is connected with the top end of the front stand column and the top end of the rear stand column. The first inclined strut is arranged between the front stand column and the oblique beam, and the second inclined strut is arranged between the rear stand column and the oblique beam. A3, horizontal loads are applied to the two photovoltaic piles provided with the supports; and A4, when any photovoltaic pile generates the set displacement, loading is ended, and the horizontal bearing capacity of the photovoltaic pile is obtained. According to the pile testing method, the constraint effect of the support on the photovoltaic pile is considered, and the obtained pile testing result is closer to the actual engineering value.

Description

Technical Field

[0001] The present invention belongs to the field of photovoltaic technology and relates to horizontal bearing capacity detection of photovoltaic piles, and specifically to a method for testing the horizontal bearing capacity of photovoltaic piles and a method for selecting a pile diameter and a pile length. Background Art

[0002] Photovoltaic power generation uses the photoelectric effect of semiconductors to directly convert sunlight into electrical energy. It has the advantages of being close to terminal loads and having low negative effects on the ecological environment. The structure of photovoltaic power generation mainly includes pile foundations, photovoltaic brackets, photovoltaic panels, etc. The pile foundation is partially set underground and partially exposed on the surface. It is the cornerstone of the photovoltaic power generation structure. The photovoltaic bracket is connected to the pile foundation. The photovoltaic panel is set on the photovoltaic bracket, and the photovoltaic bracket is usually at a certain angle to the horizontal plane to better absorb sunlight.

[0003] For example, the Chinese utility model patent with announcement number CN220503942U provides a photovoltaic support concrete micro-pile foundation, which includes a pre-buried steel pipe, a plurality of steel bars extending in the up-down direction and arranged at one end of the pre-buried steel pipe at intervals along the circumference of the pre-buried steel pipe, and a stirrup including a plurality of connecting rods connected in sequence, the number of connecting rods being equal to the number of steel bars, the plurality of steel bars being inserted into the stirrups and connected to the inner circumference of the stirrups, at least one steel bar being located between two adjacent connecting rods, the matrix being cast by concrete, and the stirrups, one end of the pre-buried steel pipe and a plurality of steel bars being arranged in the matrix. The photovoltaic support concrete micro-pile foundation provided by the utility model has the advantages of simple structure and low cost.

[0004] The pile foundation needs to meet multiple technical requirements such as vertical compression resistance, pull-out resistance and horizontal bearing capacity. For example, the Chinese utility model patent with announcement number CN219957147U provides a photovoltaic power generation support pile horizontal bearing capacity detection device. By setting a servo motor, a screw and a screw sleeve, the pressure detector is connected by the screw sleeve and the screw rod. The servo motor drives the screw rod to rotate through the connecting rod. The screw sleeve moves on the rotating screw rod through the internal thread, and the pressure detector is moved to the corresponding positions above, below and in the middle of the support pile in turn to detect the support pile in the horizontal direction. Although the detection device provided by the above patent can detect the corresponding positions above, below and in the middle of the support pile, making the detection data more accurate, it is based on a single support pile for detection.

[0005] Most of the pile test methods in the prior art are single pile tests, such as loading a horizontal force on the top of a single pile, where the top of the pile is a free end without any constraints, and measuring the horizontal force when the pile is displaced by 10 mm as its horizontal bearing capacity. This method assumes that the top of the pile is free, and does not consider the constraint of the pile top bracket on the pile. Therefore, the obtained horizontal bearing capacity is smaller than the actual value. Especially when constructing photovoltaic projects in areas with soft soil such as deserts, the pile diameter is often relatively small. During the pile test, the horizontal bearing capacity obtained by the ordinary pile test method is often lower than the actual value. In order to improve the horizontal bearing capacity, it is necessary to increase the pile diameter or length, which results in an overly conservative design and waste of materials.

[0006] Therefore, it is necessary to provide a photovoltaic pile horizontal bearing capacity test method that takes into account the stiffness of the support structure. Summary of the invention

[0007] In view of the problems existing in the prior art, the present invention provides a new method for testing the horizontal bearing capacity of photovoltaic piles. The method takes into account the constraint effect of the photovoltaic bracket on the top of the foundation pile, so that the force performance of the test pile is more in line with the actual photovoltaic pile, breaking the technical prejudice of the prior art that only horizontal load is applied to a single pile to obtain the horizontal bearing capacity. Testing through the method provided by the present invention can provide more accurate pile top horizontal bearing capacity for subsequent design.

[0008] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0009] A photovoltaic pile horizontal bearing capacity testing method comprises the following steps:

[0010] A1. Arrange at least two photovoltaic piles, and the distance between the two photovoltaic piles is set according to the design value;

[0011] A2. A bracket is installed on the top of the two photovoltaic piles, and the two photovoltaic piles are connected by the bracket. The bracket includes a front column, a rear column, an inclined beam, a first inclined brace, and a second inclined brace; the front column and the rear column are respectively arranged on the top of the two photovoltaic piles, and are partially buried in the photovoltaic piles, wherein the height of the front column is less than the height of the rear column; the inclined beam is connected to the top of the front column and the top of the rear column; the first inclined brace is arranged between the front column and the inclined beam, and the second inclined brace is arranged between the rear column and the inclined beam;

[0012] A3. Apply a horizontal load to the two photovoltaic piles with brackets installed;

[0013] A4. When any one of the photovoltaic piles produces a set horizontal displacement, the loading is terminated to obtain the horizontal bearing capacity of the photovoltaic pile, and the horizontal bearing capacity of the two photovoltaic piles is the same.

[0014] Furthermore, the length of the front column and the rear column buried in the photovoltaic pile is not less than 400 mm.

[0015] Furthermore, the horizontal load is a design value of the horizontal bearing capacity or an estimated ultimate horizontal bearing capacity.

[0016] Furthermore, the specific step of applying the horizontal load in A3 is: applying twice the horizontal load in the same direction to the tops of the two photovoltaic piles respectively.

[0017] Furthermore, another specific step of applying the horizontal load in A3 is: applying four times the horizontal load to the inclined beam.

[0018] Furthermore, the distance between the two photovoltaic piles in A1 ranges from 2.6m to 3.5m.

[0019] The present invention also provides a method for selecting the diameter and length of a photovoltaic pile, comprising the following steps:

[0020] B1. First, under the set pile diameter, determine the original pile length. The set pile diameter of the two photovoltaic piles is the same as the original pile length. The horizontal bearing capacity of the original pile length is obtained by calculation and testing. The test process is the photovoltaic pile horizontal bearing capacity test method described above, and it is judged whether the horizontal bearing capacity is greater than or equal to the single pile horizontal bearing capacity design value H. If the horizontal bearing capacity is greater than or equal to H, the original pile length is the required pile length. If the horizontal bearing capacity is less than H, the length of the two photovoltaic piles is increased by 0.1m, and the horizontal bearing capacity is further determined by calculation and testing, and it is judged whether the horizontal bearing capacity is greater than or equal to H, until the horizontal bearing capacity is greater than or equal to H, and the pile length corresponding to the horizontal bearing capacity that meets the requirements is the required pile length;

[0021] B2. Calculate the concrete engineering quantity according to the set pile diameter and the required pile length;

[0022] B3, under different set pile diameters, repeat B1 to obtain the corresponding required pile lengths according to the different set pile diameters; and repeat B2 to calculate the concrete engineering quantity according to the different set pile diameters and their required pile lengths;

[0023] B4. Select the set pile diameter and the required pile length corresponding to the minimum concrete engineering quantity, and use the selected set pile diameter and the required pile length as the recommended values ​​for the test pile.

[0024] Furthermore, the original pile length is a pile length that satisfies the pile's tensile and compressive bearing capacities.

[0025] Furthermore, the specific steps for obtaining the required pile length in B1 are:

[0026] B1-1. Under the set pile diameter, calculate the theoretical horizontal bearing capacity H1 of the original pile length. Determine whether H1 is greater than or equal to H. If H1≥H, proceed to B1-2. If H1<H, increase the pile length of both photovoltaic piles by 0.1 m and then calculate H1. Determine whether H1 is greater than or equal to H until H1≥H is satisfied, and then proceed to B1-2.

[0027] B1-2. Under the set pile diameter, when H1≥H is satisfied, the corresponding pile length is L1. Conduct the test according to the set pile diameter and the pile length L1 to obtain the actual horizontal bearing capacity H2. Determine whether the actual horizontal bearing capacity H2 is greater than or equal to H. If H2≥H, the corresponding pile length is the required pile length. If H2<H, increase the pile length of both photovoltaic piles by 0.1 m and then conduct the test to obtain H2. Determine whether H2 is greater than or equal to H until H2≥H is satisfied, and then obtain the required pile length.

[0028] Furthermore, the value range of the set pile diameter is 120 mm - 250 mm.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The method for testing the horizontal bearing capacity of photovoltaic piles provided by the present invention considers the constraint effect of the bracket on the top of the photovoltaic pile. The test pile is carried out on the premise that the bracket is installed, making the test pile result closer to the actual engineering value, so as to provide a more accurate pile top horizontal bearing capacity for subsequent design.

[0031] 2. The method for selecting the pile diameter and pile length of photovoltaic piles provided by the present invention is based on the new test pile method to obtain a suitable pile length that can meet the horizontal bearing capacity. This pile length is less than or equal to the pile length obtained by using the test pile method in the prior art. Calculate the concrete engineering quantity according to this pile length, which is more cost-saving. Further conduct tests on different pile diameters to obtain multiple groups of different concrete engineering quantities, and select the pile diameter and pile length with the smallest concrete engineering quantity as the recommended test pile values, which can greatly save construction costs and shorten the construction period. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is the conventional layout diagram of photovoltaic piles in the embodiment provided by the present invention;

[0033] Figure 2 It is the schematic diagram of the method for testing the horizontal bearing capacity of photovoltaic piles in the prior art in the embodiment provided by the present invention;

[0034] Figure 3 It is the schematic assembly structure diagram of photovoltaic piles and brackets in the embodiment provided by the present invention;

[0035] Figure 4 It is the schematic diagram of the method for testing the horizontal bearing capacity of photovoltaic piles in the embodiment provided by the present invention;

[0036] Figure 5 A schematic diagram of a photovoltaic pile horizontal bearing capacity testing method according to another embodiment of the present invention.

[0037] In the figure, 1, photovoltaic pile; 2, front column; 3, rear column; 4, inclined beam; 5, first diagonal brace; 6, second diagonal brace. DETAILED DESCRIPTION

[0038] In order to support the photovoltaic panels, the photovoltaic piles 1 are usually arranged as follows Figure 1 As shown, two rows of piles are set, a bracket is connected between the front and rear rows of photovoltaic piles 1, and the photovoltaic panels are set on the bracket, but the current pile test method is as follows Figure 2 As shown, a horizontal force is loaded on the top of a single photovoltaic pile 1, and the horizontal force when it is displaced by 10 mm is measured as its horizontal bearing capacity. The constraint effect of the pile top bracket on the photovoltaic pile 1 is not considered, so the obtained horizontal bearing capacity of the photovoltaic pile 1 is smaller than the actual value.

[0039] Based on this, the present invention provides a photovoltaic pile horizontal bearing capacity test pile method, comprising the following steps:

[0040] A1. Arrange at least two photovoltaic piles 1. The distance between the two photovoltaic piles 1 is set according to the design value. If there is no design value, the distance can be set to any value between 2.6m and 3.5m.

[0041] A2. Figure 3 As shown, a bracket is installed on the top of the two photovoltaic piles 1, and the two photovoltaic piles 1 are connected by the bracket. The bracket includes a front column 2, a rear column 3, an inclined beam 4, a first diagonal brace 5, and a second diagonal brace 6. The structure contained in the bracket can be executed according to the design value. If there is no design value, the bracket material is all Q235B steel. The cross-section of the inclined beam 4 can be C80*45*15*2.0, the cross-section of the front column 2 and the rear column 3 can be 80*80*2.2, and the cross-section of the first diagonal brace 5 and the second diagonal brace 6 can be C60*35*8*2.0;

[0042] The front column 2 and the rear column 3 are respectively arranged on the top of the two photovoltaic piles 1, and are partially buried in the photovoltaic piles 1. It is preferred that the length of the front column 2 and the rear column 3 buried in the photovoltaic pile 1 is not less than 400 mm, wherein the height of the front column 2 is less than the height of the rear column 3; and the inclined beam 4 is connected to the top of the front column 2 and the top of the rear column 3, so that the inclined beam 4 forms a certain angle with the horizontal plane, which can enable the photovoltaic panel arranged on the bracket to better absorb light energy; the first inclined brace 5 is arranged between the front column 2 and the inclined beam 4, and the second inclined brace 6 is arranged between the rear column 3 and the inclined beam 4, which can improve the stability of the bracket structure. Among them, the connection between the inclined beam 4 and the top of the front column 2 and the rear column 3, the connection between the first inclined brace 5 and the front column 2 and the inclined beam 4, and the connection between the second inclined brace 6 and the rear column 3 and the inclined beam 4 are all threaded connections, and the connecting bolts can be 8.8 grade M14 bolts.

[0043] A3. Apply a horizontal load to the two photovoltaic piles 1 installed with brackets. The horizontal load refers to the horizontal bearing capacity design value provided by the design institute or the estimated ultimate horizontal bearing capacity. The specific loading method shall be implemented in accordance with the requirements of the specification.

[0044] A4. When any photovoltaic pile 1 produces a set horizontal displacement, the loading is terminated. The set horizontal displacement may be 10 mm, and the horizontal bearing capacity of the photovoltaic pile 1 is obtained.

[0045] like Figure 4 As shown, the specific steps of applying the horizontal load in A3 are: applying twice the horizontal load in the same direction to the tops of the two photovoltaic piles 1 respectively.

[0046] like Figure 5 As shown, another specific step of applying horizontal load in A3 is: applying four times the horizontal load to the inclined beam 4. The position where the load is applied to the inclined beam 4 is arbitrary, and it can preferably be applied to the position between the first diagonal brace 5, the second diagonal brace 6 and the connection point of the inclined beam 4.

[0047] In a specific embodiment, a multi-cycle loading and unloading test method is used to apply a horizontal load to the top of the photovoltaic pile 1. The horizontal load is twice the design value of the horizontal bearing capacity of the single pile or twice the estimated ultimate horizontal bearing capacity. The loading is graded, and each level of load is 1 / 10-1 / 15; and a load is applied to the top of each photovoltaic pile 1, and the load direction of the two photovoltaic piles 1 is the same direction; after each level of load is applied, the constant load is maintained for 4 minutes to measure the horizontal displacement of the two photovoltaic piles 1, and then unloaded to zero, and stopped for 2 minutes to measure the horizontal residual displacement of the two photovoltaic piles 1, so that a loading and unloading cycle is completed. This cycle is repeated 5 times to complete the test observation of the first level of load, and the test needs to be carried out continuously; until any photovoltaic pile 1 produces a set horizontal displacement, the loading is terminated. The set horizontal displacement here refers to the horizontal displacement of the photovoltaic pile 1 measured when the constant load is maintained above. The set horizontal displacement can be 10mm, and then the characteristic value of the horizontal bearing capacity of the single pile can be obtained. The method for determining the characteristic value of the horizontal bearing capacity of the single pile can be determined according to the current specification "Code for Design of Building Foundations (GB 50007)》S.0.9-S.0.11 methods are used to comprehensively determine that the characteristic value of the single pile horizontal bearing capacity is the single pile horizontal bearing capacity to be obtained by the present invention, and the horizontal bearing capacities of two photovoltaic piles 1 constrained by the same bracket are the same.

[0048] The lengths of the front column 2, the rear column 3, the inclined beam 4, the first inclined brace 5, and the second inclined brace 6 in A3 can be based on the design values. If there is no design value, the present invention provides a specific embodiment, the two photovoltaic piles 1 are both 2300mm long, and the spacing between the two photovoltaic piles 1 is set to 2600mm, wherein the spacing between the photovoltaic piles 1 refers to the distance between the central axes of the two photovoltaic piles 1, and then the two photovoltaic piles 1 are partially buried underground and partially exposed to the surface. In this embodiment, the photovoltaic piles 1 are kept 300mm above the surface; according to the actual engineering situation, a front column 2 with a length of the component ground height + 100mm and a rear column 3 with a length of the front column 2 + 1500mm can be selected. The component refers to two photovoltaic piles 1, a bracket connecting the photovoltaic piles 1, and a photovoltaic panel arranged on the bracket. Since the positions where the inclined beam 4 is connected to the front column 2 and the rear column 3 are different, such as the middle position of the inclined beam 4 and the front column 2 is connected at the top end, and the tail end is connected to the top end of the rear column 3. The middle position refers to any position between the head end and the tail end of the inclined beam 4, or the head end of the inclined beam 4 is connected to the top end of the front column 2, and the middle position of the inclined beam 4 is connected to the top end of the rear column 3, or the head end and the tail end of the inclined beam 4 are respectively connected to the top ends of the front column 2 and the rear column 3. If the front column 2 is connected to the middle position of the inclined beam 4, the distance between the lowest point of the inclined beam 4 and the ground is smaller than the distance between the top end of the front column 2 and the ground. The component height is the minimum distance between the photovoltaic panel and the ground. If the photovoltaic panel is completely covered between the inclined beams 4 and the inclined beams 4, the component height can also be understood as the distance between the lowest point of the inclined beam 4 and the ground. Therefore, a front column 2 with a length of the component height above the ground + 100mm can be selected, that is, if the component height above the ground is 1500mm, the length of the front column 2 is 1600mm, and the length of the rear column 3 is 3100mm;

[0049] The front column 2 and the rear column 3 are further arranged on the top of the photovoltaic pile 1 and partially buried in the photovoltaic pile 1, wherein the length of the front column 2 and the rear column 3 buried in the photovoltaic pile 1 can be 400 mm; in this embodiment, an inclined beam 4 with a length of 3124 mm is selected, and the two ends of the inclined beam 4 are respectively connected to the top of the front column 2 and the top of the rear column 3.

[0050] In order to support the inclined beam 4 and improve its bearing capacity, the first inclined brace 5 and the second inclined brace 6 are arranged between the front column 2 and the inclined beam 4, and between the rear column 3 and the inclined beam 4. The lengths of the first inclined brace 5 and the second inclined brace 6 can be adjusted according to on-site needs. In this embodiment, a first inclined brace 5 with a length of 1582 mm and a second inclined brace 6 with a length of 2319 mm are selected. The first end of the first inclined brace 5 is arranged on the front column 2 at a distance of 50 mm from the top surface of the photovoltaic pile 1, and the second end of the first inclined brace 5 is arranged on the inclined beam 4. In this embodiment, the head end of the inclined beam 4 is connected to the inclined beam 4 and the first inclined brace 5. The distance between the points is 1000mm, and accordingly, the first end of the second diagonal brace 6 is arranged on the rear column 3 50mm away from the top surface of the photovoltaic pile 1, and the second end of the second diagonal brace 6 is arranged on the diagonal beam 4, and the distance between the second diagonal brace 6 and the diagonal beam 4 at the connection point and the tail end of the diagonal beam 4 is 2124mm. The connection points of the first diagonal brace 5, the second diagonal brace 6 and the diagonal beam 4 are close and can be approximately regarded as one, so that the connection points of the first diagonal brace 5, the second diagonal brace 6 and the diagonal beam 4 divide the diagonal beam 4 into two sections of 1000mm and 2124mm, which can improve the strength of the middle and lower parts of the diagonal beam 4 and meet the actual force.

[0051] According to the preliminary estimate, the wind pressure is 0.6kN / m according to the conventional pile test method. 2 In the region, when the component inclination angle is 30° (the angle between the inclined beam 4 and the horizontal plane), the horizontal force of a single photovoltaic pile 1 is about 4.59kN. According to the conventional pile test method, the pile diameter is 150mm and the pile length is 3.1m. If this pile test method is adopted, the pile diameter is 150mm and the pile length is 2.4m. By comparison, each photovoltaic pile 1 can save about 0.7m of pile length. On average, for 1MW photovoltaic, the number of photovoltaic piles is about 680, which can save about 680×0.7=476m of pile length and about 476m of drilling depth. 1GW photovoltaic saves about 476,000m (a total of 476,000m of drilling, 8400m3 of concrete, and 1100 tons of steel bars), saving about 25.6 million yuan in costs.

[0052] The technical solution provided by the present invention takes into account the constraint effect of the pile top bracket on the top of the foundation pile during the pile test, so that the test pile force performance is more in line with the actual photovoltaic pile 1, thereby obtaining test pile data that is closer to the actual operation process of the photovoltaic pile 1, and can provide more accurate pile top horizontal bearing capacity for subsequent design, thereby making the design results more economical and reasonable, and saving costs.

[0053] If this pile test method can be promoted, many desert or soft soil areas will not need to take measures to enhance the horizontal bearing capacity to meet engineering needs, which can save construction costs and construction period, simplify construction steps and reduce construction difficulty.

[0054] Based on the above photovoltaic pile horizontal bearing capacity test method, the present invention also provides a method for selecting the diameter and length of a photovoltaic pile, comprising the following steps:

[0055] B1. First, under the set pile diameter, determine the original pile length. The set pile diameters and the original pile lengths of the two photovoltaic piles 1 are the same. The original pile length is the pile length that meets the pile's uplift and compressive bearing capacities. Calculate the horizontal bearing capacity of the original pile length through calculation and tests. The test process is the photovoltaic pile horizontal bearing capacity test pile method described above, and determine whether the horizontal bearing capacity is greater than or equal to the single pile horizontal bearing capacity design value H. Different soil qualities, usage requirements, etc. result in different horizontal bearing capacity design values H. If the horizontal bearing capacity is greater than or equal to H, then the original pile length is the required pile length. If the horizontal bearing capacity is less than H, increase the pile lengths of the two photovoltaic piles 1 by 0.1 m each, then further calculate and test to determine the horizontal bearing capacity, and determine whether the horizontal bearing capacity is greater than or equal to H until the horizontal bearing capacity is greater than or equal to H. The pile length corresponding to the horizontal bearing capacity that meets the requirements is the required pile length.

[0056] B2. Calculate the concrete engineering quantity according to the set pile diameter and the required pile length.

[0057] B3. Under different set pile diameters, repeat B1 to obtain the respective required pile lengths corresponding to different set pile diameters; and repeat B2 to calculate the concrete engineering quantities respectively according to different set pile diameters and their required pile lengths.

[0058] B4. Select the set pile diameter and the required pile length corresponding to the minimum concrete engineering quantity, and use the selected set pile diameter and required pile length as the recommended values for the test piles.

[0059] Further, the specific steps to obtain the required pile length in B1 are as follows:

[0060] B1-1. Under the set pile diameter, calculate the theoretical horizontal bearing capacity H1 of the original pile length, and determine whether H1 is greater than or equal to H. If H1 ≥ H, enter B1-2. If H1 < H, increase the pile lengths of the two photovoltaic piles 1 by 0.1 m each, then calculate H1 and determine whether H1 is greater than or equal to H until H1 ≥ H is satisfied, and then enter B1-2.

[0061] B1-2. Under the set pile diameter, when H1 ≥ H is satisfied, the corresponding pile length is L1. Conduct the test according to the set pile diameter and the pile length L1 to obtain the actual horizontal bearing capacity H2, and determine whether the actual horizontal bearing capacity H2 is greater than or equal to H. If H2 ≥ H, the corresponding pile length is the required pile length. If H2 < H, increase the pile lengths of the two photovoltaic piles 1 by 0.1 m each, then conduct the test to obtain H2, and determine whether H2 is greater than or equal to H until H2 ≥ H is satisfied to obtain the required pile length.

[0062] First, it is determined by calculation whether the set pile diameter and pile length H1 of the photovoltaic pile 1 meets H. After it is determined that it meets H, the actual horizontal bearing capacity H2 of the photovoltaic pile 1 is obtained through testing, which can save the cost of pile testing.

[0063] Furthermore, the value range of the set pile diameter is 120mm-250mm, for example, it can be 120mm, 150mm, 180mm, 200mm, 220mm, 250mm. According to the actual scenario, part or all of the above set pile diameters can be selected to carry out the B1 test, so as to obtain the required pile lengths corresponding to different set pile diameters.

[0064] Based on the provided photovoltaic pile horizontal bearing capacity test pile method, the present invention provides a method for selecting the photovoltaic pile diameter and pile length, firstly obtaining the theoretical horizontal bearing capacity through calculation, and then conducting tests on the premise that the theoretical horizontal bearing capacity meets the requirements to obtain the actual horizontal bearing capacity, which can save construction costs; and the concrete engineering volume under multiple groups of pile diameters is obtained through tests, from which the pile diameter and pile length with the smallest concrete engineering volume can be selected as recommended values, and large-scale construction can be carried out based on the obtained test pile recommended values, which can not only meet the engineering requirements but also save construction costs and construction periods.

[0065] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A photovoltaic pile horizontal bearing capacity test method, characterized in that: The following steps are involved: A1. Arrange at least two photovoltaic piles, and the distance between the two photovoltaic piles is set according to the design value; A2. A bracket is installed on the top of the two photovoltaic piles, and the two photovoltaic piles are connected by the bracket. The bracket includes a front column, a rear column, an inclined beam, a first inclined brace, and a second inclined brace; the front column and the rear column are respectively arranged on the top of the two photovoltaic piles, and are partially buried in the photovoltaic piles, wherein the height of the front column is less than the height of the rear column; the inclined beam is connected to the top of the front column and the top of the rear column; the first inclined brace is arranged between the front column and the inclined beam, and the second inclined brace is arranged between the rear column and the inclined beam; A3. Apply a horizontal load to the two photovoltaic piles with brackets installed; A4. When any one of the photovoltaic piles produces a set horizontal displacement, the loading is terminated to obtain the horizontal bearing capacity of the photovoltaic pile, and the horizontal bearing capacity of the two photovoltaic piles is the same.

2. The photovoltaic pile horizontal bearing capacity testing method according to claim 1, characterized in that: The length of the front column and the rear column buried in the photovoltaic pile is not less than 400 mm.

3. The photovoltaic pile horizontal bearing capacity testing method according to claim 1, characterized in that: The horizontal load is the design value of the horizontal bearing capacity or the estimated ultimate horizontal bearing capacity.

4. The photovoltaic pile horizontal bearing capacity testing method according to claim 1, characterized in that: The specific steps of applying the horizontal load in A3 are: applying twice the horizontal load in the same direction to the tops of the two photovoltaic piles respectively.

5. The photovoltaic pile horizontal bearing capacity testing method according to claim 1, characterized in that: Another specific step of applying the horizontal load in A3 is: applying four times the horizontal load to the inclined beam.

6. The photovoltaic pile horizontal bearing capacity testing method according to claim 1, characterized in that: The distance between the two photovoltaic piles in A1 ranges from 2.6m to 3.5m.

7. A method for selecting the diameter and length of a photovoltaic pile, characterized in that: B1. First, under the set pile diameter, determine the original pile length. The set pile diameter of the two photovoltaic piles is the same as the original pile length. The horizontal bearing capacity of the original pile length is obtained by calculation and testing. The test process is the photovoltaic pile horizontal bearing capacity test pile method described in any one of claims 1 to 6, and judge whether the horizontal bearing capacity is greater than or equal to the single pile horizontal bearing capacity design value H. If the horizontal bearing capacity is greater than or equal to H, the original pile length is the required pile length. If the horizontal bearing capacity is less than H, the length of the two photovoltaic piles is increased by 0.1m, and then the horizontal bearing capacity is further determined by calculation and testing, and it is judged whether the horizontal bearing capacity is greater than or equal to H, until the horizontal bearing capacity is greater than or equal to H, and the pile length corresponding to the horizontal bearing capacity that meets the requirements is the required pile length; B2. Calculate the concrete engineering quantity according to the set pile diameter and the required pile length; B3, under different set pile diameters, repeat B1 to obtain the corresponding required pile lengths according to the different set pile diameters; and repeat B2 to calculate the concrete engineering quantity according to the different set pile diameters and their required pile lengths; B4. Select the set pile diameter and the required pile length corresponding to the minimum concrete engineering quantity, and use the selected set pile diameter and the required pile length as the recommended values ​​for the test pile.

8. The method for selecting the diameter and length of a photovoltaic pile according to claim 7, characterized in that: The original pile length is the pile length that meets the pile's tensile and compressive bearing capacities.

9. The method for selecting the diameter and length of a photovoltaic pile according to claim 7, characterized in that: The specific steps to obtain the required pile length in B1 are: B1-1. Under the set pile diameter, calculate the theoretical horizontal bearing capacity H1 of the original pile length. Determine whether H1 is greater than or equal to H. If H1 ≥ H, proceed to B1-2. If H1 < H, increase the pile length of both photovoltaic piles by 0.1 m, then calculate H1 and determine whether H1 is greater than or equal to H until H1 ≥ H is satisfied, and then proceed to B1-2. B1-2. Under the set pile diameter, when H1 ≥ H is satisfied, the corresponding pile length is L1. Conduct the test according to the set pile diameter and the pile length L1 to obtain the actual horizontal bearing capacity H2. Determine whether the actual horizontal bearing capacity H2 is greater than or equal to H. If H2 ≥ H, the corresponding pile length is the required pile length. If H2 < H, increase the pile length of both photovoltaic piles by 0.1 m, then conduct the test to obtain H2 and determine whether H2 is greater than or equal to H until H2 ≥ H is satisfied, and then obtain the required pile length.

10. The method for selecting the diameter and length of a photovoltaic pile according to claim 7, characterized in that: The value range of the set pile diameter is 120 mm - 250 mm.

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