Positioning device and construction method for cast-in-place piles used in solar power stations in high-altitude grasslands

Abstract

This invention provides a positioning device and construction method for cast-in-place piles in a solar power station located in a high-altitude grassland. The positioning device includes a positioning upright, a positioning diagonal brace, and at least two auxiliary positioning rods. A spirit level is provided on the pressure plate of the positioning upright. Each auxiliary positioning rod is connected to the positioning upright via a leveling diagonal brace. One end of each leveling diagonal brace is hinged to the top of the positioning upright, and the other end is hinged to a second adjusting sleeve fitted on the auxiliary positioning rod. One end of the positioning diagonal brace is hinged to the top of the positioning upright, and the other end extends downwards at an angle, with a horizontal support rod, a rangefinder mounting plate, and a plumb bob hinged to its lower end. The free end of the horizontal support rod is hinged to a first adjusting sleeve. This invention utilizes three sets of positioning devices to position the cast-in-place piles of a single-row solar power station, ensuring that the pile foundation provides sufficient bearing capacity into the stable strata below the ground surface, and reducing risks such as pile misalignment, excessive length, and excessive misalignment of embedded parts.

Description

Technical Field

[0001] This invention relates to the field of power plant construction, specifically to a positioning device and construction method for a cast-in-place pile array used in a solar power station in a high-altitude grassland. Technical Background

[0002] With the deepening of new energy development, wasteland, forest land and highland grassland are being fully utilized and built into a large new energy base.

[0003] However, the construction of photovoltaic and other new energy bases on high-altitude grasslands faces challenges in pile foundation construction. Firstly, high-altitude grasslands are pastoral areas, and due to ecological protection and local customs, leveling and destruction of the grasslands are generally not permitted; only pile foundations and other basic structures are allowed at fixed locations. Secondly, the naturally undulating terrain of high-altitude grasslands, with generally gentle slopes but steep and drastically varying local slopes, poses significant difficulties for pile foundation array construction. The unique topography of high-altitude grasslands leads to uncertainties in pile length (variable depth of boreholes), precise positioning of the reinforcing cage (embedded parts), and uniform control of the pile top plane during pile foundation construction, making photovoltaic construction on high-altitude grasslands more difficult than on flat sites. Since leveling, excavation, and filling are not feasible, traditional methods for constructing equal-length pile foundation arrays are also insufficient. Therefore, how to construct pile foundation arrays on high-altitude grasslands has become another technical challenge in the field of photovoltaic new energy. Summary of the Invention

[0004] This invention addresses the problems existing in the prior art by providing a positioning device and construction method for a cast-in-place pile array for a solar power station in a high-altitude grassland. The method utilizes the positioning device to initially determine the pile length of the pile array, ensuring that the piles provide sufficient bearing capacity into the stable strata below the ground surface, and enabling real-time control of the pile length on-site. Simultaneously, based on the control of four-point measurement and straightening of the overhead lines, it reduces the risks of pile misalignment, excessive length, and excessive misalignment of embedded parts. Furthermore, the method is convenient to construct, economical, and can overcome a series of technical problems in the construction of pile arrays in high-altitude grasslands.

[0005] To achieve the above-mentioned technical objectives, the present invention provides a positioning device for a cast-in-place pile of a solar power station in a high-altitude grassland. The positioning device includes a positioning upright, a positioning diagonal brace, and at least two auxiliary positioning rods. The bottom of both the positioning upright and the auxiliary positioning rods is provided with a tapered fixing rod and a pressure foot plate. A spirit level is provided on the pressure foot plate of the positioning upright. Each auxiliary positioning rod is connected to the positioning upright via a leveling diagonal rod. One end of each leveling diagonal rod is hinged to the top of the positioning upright, and the other end is hinged to a second adjusting sleeve fitted on the auxiliary positioning rod. One end of the positioning diagonal brace is hinged to the top of the positioning upright, and the other end extends downwards at an angle, with a horizontal support rod, a rangefinder mounting plate, and a plumb bob hinged to its lower end. A first adjusting sleeve is provided on the positioning upright, and the free end of the horizontal support rod is hinged to the first adjusting sleeve. The rangefinder mounting plate is rotatably mounted on the positioning diagonal brace.

[0006] A preferred technical solution of the present invention: The horizontal support rod includes two hinged first horizontal rods and a second horizontal rod. A positioning buckle is provided at the hinged part of the two horizontal rods. The positioning buckle is hinged to the first horizontal rod and has an eagle-beak shaped latch at the other end. An L-shaped locking slot is correspondingly provided on the second horizontal rod. The latch end of the positioning buckle extends horizontally to the other horizontal rod and engages with the L-shaped locking slot for locking. The horizontal support rod is hinged to the middle part of the first adjusting sleeve. A return arm spring is also provided between the horizontal support rod and the positioning upright. One end of the return arm spring is fixedly connected to the hinged part of the two horizontal rods of the horizontal support rod, and the other end is movably connected to the connecting ear plate at the upper end of the first adjusting sleeve.

[0007] The preferred technical solution of the present invention is as follows: a positioning groove is provided at the end of the positioning diagonal brace connecting to the horizontal support rod, and the positioning sleeve is movably sleeved on the positioning diagonal brace and fixed and locked by locking bolts; a connecting ear plate is provided on the side of the positioning sleeve adjacent to the horizontal support rod, and the horizontal support rod is hinged to the connecting ear plate on the positioning sleeve; the plumb bob and the rangefinder mounting plate are both set on the positioning sleeve, and the plumb bob is vertically downward.

[0008] A preferred technical solution of the present invention: the height of the positioning rod is higher than that of the two auxiliary positioning rods, and the positioning rod is marked with scale values. The first adjusting sleeve moves up and down along the positioning rod and is fixed and locked by locking bolts. Connecting ear plates are provided at the middle and upper parts of the first adjusting sleeve. The horizontal telescopic rod is connected to the connecting ear plate at the middle part of the first adjusting sleeve. The return arm spring is provided with a movable buckle at the connection end with the first adjusting sleeve and is connected to the connecting ear plate at the upper part of the first adjusting sleeve by the movable buckle. The second adjusting sleeve moves up and down along the auxiliary positioning rod and is fixed and locked by locking bolts.

[0009] The preferred technical solution of the present invention is as follows: the rangefinder mounting plate is a slotted plate with a rangefinder slot at one end. The middle part of the rangefinder mounting plate is installed on the side of the positioning diagonal rod away from the horizontal support rod through a rotation adjustment mechanism, and the plate surface is perpendicular to the positioning diagonal rod. A reflective magnetic plate is provided at the center of the plate surface of the rangefinder mounting plate. Under the action of the rotation adjustment mechanism, the plate body of the rangefinder mounting plate is parallel to the positioning diagonal rod or perpendicular to the positioning diagonal rod.

[0010] This invention also provides a method for positioning and constructing cast-in-place piles for a solar power station in a high-altitude grassland. The method is applicable to the construction of a cast-in-place pile array for a solar power station in a high-altitude grassland. The high-altitude grassland is located in a high-altitude pastoral area with a certain slope. The solar power station uses a unidirectional light tracking system, and the pile foundation of the unidirectional light tracking system consists of at least one row of cast-in-place piles. Each row of piles is distributed from the higher part of the slope towards the lower part. During the positioning and construction process for any row of piles, three sets of the above-mentioned positioning devices for solar power stations in high-altitude grasslands are used for positioning and adjustment. The specific steps are as follows:

[0011] S1. Based on the site topographic survey information and the design requirements of the unidirectional light tracking system, determine the number and design location of each row of cast-in-place piles in the pile foundation of the unidirectional light tracking system. The number of cast-in-place piles in a single row is 5 to 9, and the spacing L between the first and last fixed support points of the light tracking system support structure is... zc The inclination angle of a single row of cast-in-place piles shall not exceed 60m, the distance between any two adjacent fixed support points shall be 6-8m, and the overall inclination angle of the single row of cast-in-place piles shall be [missing information]. The angle is less than 15°, and the height H of the pile top exposed above the ground is 0.5 to 1.8.

[0012] S2. Based on the design requirements for single-row cast-in-place piles in step S1, measure the center of gravity of the single-row cast-in-place piles on the construction slope.

[0013] The initial positions of the first pile at the highest point of the slope, the m-th pile in the middle, and the last pile at the lowest point are determined. A set of positioning devices for the cast-in-place piles used in the high-altitude grassland solar power station is installed at each pile position. Each positioning device is installed 1.8–2 meters away from the corresponding pile position, perpendicular to the single row of cast-in-place piles. The specific installation process is as follows: First, the positioning pole and the conical fixing rods at the lower ends of the two auxiliary poles are pressed into the soil, but not fixed temporarily; then, the two poles are pulled to level the inclined rods, and the position of the positioning pole's pressure plate is observed. With a level bubble set up, adjust the verticality of the positioning pole. After the positioning pole pressure plate is leveled, fix the positioning pole and the two auxiliary poles respectively, and the positioning pole and the auxiliary poles should be pressed into the soil to a depth of not less than 30cm. Adjust the first adjusting sleeve to the lowest part of the positioning pole and fix it. Then extend and fix the horizontal support rod so that the plumb bob at the end of the positioning diagonal brace is directly opposite the center of the initial pile position of the corresponding cast-in-place pile, and the tip of the plumb bob is in contact with the slope surface. At this time, the initial height of the end of the diagonal brace from the ground is H1.

[0014] S3. Stretch a long nylon line through the end of the positioning diagonal brace of the three positioning devices. When the nylon line is not on the same straight line, loosen the first adjusting sleeve on the positioning rod of the positioning device at the m pile position. Then adjust the height of the positioning diagonal brace of the m pile position to make the nylon line straight and taut, thereby adjusting the position of the m pile. After confirming that the three pile positions are on the same straight line, fix and lock the first adjusting sleeve of the positioning device at the m pile position. At this time, the position of the plumb bob on the positioning diagonal brace of the m pile position is the correction pile position m1 of the m pile position.

[0015] S4. After completing step S3, install a laser rangefinder on the positioning brace of the highest first pile position positioning device, and adjust the angle of the laser rangefinder mounting plate so that the laser rangefinder is aligned with the angle of the nylon line. The emitting end of the laser rangefinder should face the tail pile position. Adjust the angle of the laser rangefinder mounting plate on the lowest tail pile position positioning device so that it is perpendicular to the nylon line.

[0016] S5. Activate the laser rangefinder to measure the tilt distance L between the first and last piles. qx1 and tilt angle When the laser rangefinder measures the tilt distance L between the first and last piles qx1 The distance L between the first and last fixed support points of the tracking system support structure designed in step S1 zc If the heights are not equal, loosen the first adjusting sleeve of the first pile positioning device and adjust the height of the first pile positioning brace along the nylon line until the inclination distance L between the first and last piles is reached. qx1 The distance L between the first and last fixed support points of the tracking system support structure zc Equal, and angle of inclination When the angle is less than 15°, after the adjustment is in place, the first adjusting sleeve of the first pile position positioning device can be fixed and locked. At this time, the position of the plumb bob of the first pile position positioning device is the corrected first pile position.

[0017] S6. Based on the distance between any two adjacent fixed support points designed in step S1, the coordinates of the remaining pile positions can be calculated sequentially, and the determined pile positions can be marked sequentially.

[0018] S7. Measure the height difference between the nylon line and the ground at each pile location coordinate, and determine the pile location n with the minimum height difference from the ground. Define the height difference between the nylon line at pile location n and the ground as the minimum height H of the pile top exposed above the ground in step S1. min Then, the first adjusting sleeve on the positioning poles of the three positioning devices is loosened, and the height of the three positioning diagonal braces is adjusted to uniformly adjust the elevation of the nylon line, so that the height difference between the nylon line at pile position n and the ground reaches H. min After adjustment, lock the first adjusting sleeve of the three positioning devices;

[0019] S8. Using pile position n as the rotation axis, move the positioning device of pile position m to pile position n. The moving and installation requirements are in accordance with step S2. After the moving is completed, adjust the nylon line inclination angle by adjusting the elevation of the positioning diagonal bracing rods of the first and last pile positions. Measure the height difference between the nylon line of each pile position and the ground, i.e., the height H of the pile top exposed above the ground, until it meets the design range requirements in step S1. The fine-tuning principle is to minimize the fine-tuning angle.

[0020] S9. Design the length L and embedment depth of the corresponding cast-in-place pile based on the height H of the pile top exposed above the ground for each cast-in-place pile. Determine the construction parameters for each cast-in-place pile based on the pile length, fabricate the corresponding steel cage and embedded parts, mark the steel cage and embedded parts, and then make matching marks at the corresponding cast-in-place pile construction position.

[0021] S10. Retract the positioning braces of all positioning devices and construct the pile foundation below ground for each cast-in-place pile according to the markings, installing the corresponding steel cage and embedded parts; after the steel cage and embedded parts are installed, unfold the positioning braces of the three sets of positioning devices, tighten the nylon rope, adjust to make the axis of the embedded parts parallel to the nylon line, adjust the centering and direction of the steel cage and embedded parts for the first time, then retract the positioning braces of the three sets of positioning devices, and then pour the pile foundation below ground separately, and compact it in layers.

[0022] S11. After the pile foundation construction below ground is completed, the formwork above ground is installed and closed. At the same time, the positioning diagonal braces of the three sets of positioning devices are deployed and the nylon line is tightened. The axis of the embedded part is adjusted to be parallel to the nylon line. The centering and direction of the steel cage and embedded parts are checked and finely adjusted for the second time. Soil is piled up at the base of the formwork and anchor steel bars are pressed in for fixation. The steel cage and embedded parts are fixed to the formwork as a whole. Then the positioning diagonal braces of the three sets of positioning devices are retracted.

[0023] S12. Perform the second pouring of the pile foundation, pouring the part of the pile body exposed above the ground, and compacting it in layers with vibration; at the same time, deploy the positioning diagonal braces of the three sets of positioning devices and tighten the nylon line, adjust them to make the axis of the embedded part parallel to the nylon line, check and fine-tune the centering and direction of the steel cage and embedded parts for the third time, so as to eliminate the displacement of the steel cage and embedded parts caused by pouring and vibration. After the pouring is completed, perform finishing, covering with film and watering for curing, and perform a second finishing of the surface after demolding.

[0024] The preferred technical solution of the present invention is as follows: the cast-in-place pile consists of a portion buried in the underground bearing layer, a portion exposed above the ground, and a portion exceeding the maximum exposed height; the cast-in-place pile is a whole, and the diameters of the portion exposed above the ground and the portion buried underground may be different. A steel structure column is provided at the top of the cast-in-place pile, and the pile is connected to the top solar power generation unit through the steel structure column.

[0025] The preferred technical solution of the present invention is as follows: In step S9, the process of designing the length L of the corresponding cast-in-place pile based on the height H of the pile top exposed above the ground is as follows:

[0026] ① First, calculate the height H of the pile top above ground for each cast-in-place pile and the minimum height H of the pile top above ground required by the design. min The height difference between them is ΔH = HH min Then divide △H into M segments, each segment being 15–30 cm long, with M ≤ 7.

[0027] ②Then determine the length L of the cast-in-place pile according to the following formula, in meters:

[0028] In the formula, The measured height of the top of the first to Nth piles of a single row of cast-in-place piles above the ground, in meters;

[0029] The depth of the first to Nth piles in a single row of cast-in-place piles, expressed in meters (m).

[0030] M refers to the number of segments into which the elevation difference ΔH is divided, and generally M≤7;

[0031] This refers to the minimum height of the top of a cast-in-place pile above the ground, as required by design specifications. =0.5m;

[0032] This refers to the maximum height of the top of the cast-in-place pile above the ground, as required by the design specifications. =1.8m;

[0033] It is the height of nodes 1 to M within the range of △H from the ground, in meters;

[0034] Since the underground portion of the cast-in-place piles must penetrate the frozen soil layer, and there is an additional 50cm beyond the frozen soil layer, the thickness of the frozen soil layer DT can be determined from the specifications. Therefore, the underground depth of the first to Nth cast-in-place piles in the above formula is... Calculate using the following formula:

[0035] The calculation process is as follows: .

[0036] The preferred technical solution of the present invention is as follows: In step S2, GPS measurement technology is used to measure the initial positions of the first pile at the highest point of the slope, the m-th pile in the middle, and the tail pile at the lowest point; in steps S3, S5, and S7, the adjustment error limit of the positioning diagonal brace in the positioning device does not exceed 5mm.

[0037] The preferred technical solution of the present invention is as follows: the embedded part and the reinforcing cage are welded together. When adjusting, only the embedded part needs to be adjusted, and the reinforcing cage will be adjusted together. The specific process of the three fine adjustments of the centering and direction of the reinforcing cage and the embedded part in steps S10 to S12 is as follows: the embedded part is inserted into a steel plate with bolt holes reserved at the four corners of the steel plate. The symmetry axis of the long side of the steel plate has been marked. The direction of the steel plate is twisted so that the symmetry axis marked on the steel plate is consistent with the nylon line, and the adjustment can be completed. The steel plate is recycled and reused after the cast-in-place pile is poured and cured.

[0038] This invention can fully utilize prior design concepts to initially determine the pile length of the pile array, ensuring sufficient bearing capacity for the piles to penetrate into stable strata below the ground surface; it can also use reverse engineering during construction to guide the design, enabling real-time control of the pile length on-site; and it can reduce risks such as pile misalignment, excessive length, and excessive misalignment of embedded parts by using four-point measurement, laser ranging, and straightening control. Furthermore, it is convenient to construct, economical, and overcomes a series of technical problems in the construction of pile arrays in high-altitude grasslands, achieving excellent application results. Attached Figure Description

[0039] Figure 1 This is a front view of the positioning device in this invention.

[0040] Figure 2 This is a top view of the positioning device in this invention;

[0041] Figure 3 This is an enlarged schematic diagram of the horizontal support rod of the positioning device in this invention;

[0042] Figure 4 This is a side view of the rangefinder mounting plate of the positioning device in this invention;

[0043] Figure 5 This is a top view of the rangefinder mounting plate of the positioning device in this invention;

[0044] Figure 6 This is a schematic diagram of the light-tracking system array and topographic contour lines of the present invention;

[0045] Figure 7 This is a schematic diagram of the elevation measurement of the power generation unit of the tracking system of the present invention;

[0046] Figure 8 This is an elevation view of the pile foundation measurement results of the power generation unit of the tracking light system of this invention;

[0047] Figure 9 This is an elevation view of a single pile foundation surveyed by the light-tracking system of this invention.

[0048] In the diagram: 1—Positioning upright, 2—Positioning diagonal brace, 3—Auxiliary positioning rod, 4—Conical fixing rod, 5—Pressure foot plate, 6—Leveling diagonal rod, 7—Horizontal telescopic rod, 700—First horizontal rod, 701—Second horizontal rod, 702—Positioning buckle, 8—First adjusting sleeve, 9—Radarmeter mounting plate, 900—Radarmeter slot, 901—Reflective magnetic plate, 10—Second adjusting sleeve, 11—Plumb bob, 12—Return arm spring, 13—Positioning sliding sleeve;

[0049] 14—Topographic contour line of the plateau grassland where the power generation unit is located; 15—River of the plateau grassland where the power generation unit is located; 16—H-shaped steel column; 17—Light-following power generation unit; 18—Underground bearing layer; 19—Out-of-ground part; 20—Exceeding the limit of the exposure height; 21—Ground line; 22—H control line of the exposure height of the ground; 23—Tether line at the top of the cast-in-place pile. Detailed Implementation

[0050] The present invention will be further described below with reference to the accompanying drawings and embodiments. Figures 1 to 9 All accompanying drawings are simplified versions of embodiments and are intended only to clearly and concisely illustrate the embodiments of the present invention. The technical solutions shown in the drawings below are specific solutions of embodiments of the present invention and are not intended to limit the scope of the claimed invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0051] In the description of this invention, it should be understood that the terms "upper," "lower," "inner," "outer," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0052] Example 1 provides a positioning device for cast-in-place piles used in solar power stations in high-altitude grasslands, such as... Figures 1 to 5As shown, the positioning device includes a positioning upright 1, a positioning diagonal brace 2, and two auxiliary positioning rods 3. The positioning upright 1 is higher than the two auxiliary positioning rods 3. The positioning upright 1 is marked with scale values. The bottom of the positioning upright 1 and the auxiliary positioning rods 3 are provided with a tapered fixing rod 4 and a pressure foot plate 5. The pressure foot plate of the positioning upright 1 is provided with a spirit level. Each auxiliary positioning rod 3 is connected to the positioning upright 1 through an upright leveling diagonal rod 6. One end of each upright leveling diagonal rod 6 is hinged to the top of the positioning upright 1, and the other end is hinged to a second adjusting sleeve 10 fitted on the auxiliary positioning rod 3. The second adjusting sleeve 10 moves up and down along the auxiliary positioning rod 3 and is fixed and locked by a locking bolt. One end of the positioning diagonal brace 2 is hinged to the top of the positioning upright 1, and the other end extends downward at an incline. A horizontal support rod 7, a rangefinder mounting plate 9, and a plumb bob 11 are hinged to its lower end. A first adjusting sleeve 8 is provided on the positioning upright 1, and the free end of the horizontal support rod 7 is hinged to the first adjusting sleeve 8. The rangefinder mounting plate 9 is rotatably mounted on the positioning diagonal brace 2. The first adjusting sleeve 8 moves up and down along the positioning upright 1 and is fixed and locked by locking bolts. A positioning slide groove 13 is provided at the end of the positioning diagonal brace 2 connecting to the horizontal support rod 7. The positioning slide groove 13 is movably fitted onto the positioning diagonal brace 2 and fixed and locked by locking bolts. A connecting ear plate is provided on the side of the positioning slide groove 13 adjacent to the horizontal support rod 7, and the horizontal support rod 7 is hinged to the connecting ear plate on the positioning slide groove 13. The plumb bob 11 and the rangefinder mounting plate 9 are both located on the positioning slide groove 13, with the plumb bob 11 pointing vertically downward.

[0053] Example 1 provides a positioning device for a cast-in-place pile in a high-altitude grassland solar power station. Connecting lugs are provided at the middle and upper parts of the first adjusting sleeve 8. The horizontal telescopic rod 7 is connected to the connecting lug at the middle of the first adjusting sleeve 8. The return arm spring 12 has a movable buckle at its connection end with the first adjusting sleeve 8 and is connected to the connecting lug at the upper part of the first adjusting sleeve 8 via the movable buckle. The rangefinder mounting plate 9 is a slotted plate with a rangefinder slot 900 at one end. The middle part of the rangefinder mounting plate 9 is mounted on the side of the positioning inclined rod 2 away from the horizontal support rod 7 via a rotation adjustment mechanism, and the plate surface is perpendicular to the positioning inclined rod 2. A reflective magnetic plate 901 is provided at the center of the plate surface of the rangefinder mounting plate 9. Under the action of the rotation adjustment mechanism, the plate body of the rangefinder mounting plate 9 is parallel to or perpendicular to the positioning inclined rod 2.

[0054] Example 1 uses a grouting pile positioning device for a solar power station in a high-altitude grassland, such as... Figures 1 to 5As shown, the horizontal support rod 7 includes two hinged horizontal rods 700 and 701. A positioning buckle 702 is provided at the hinge point of the two horizontal rods. The positioning buckle 702 is hinged to the first horizontal rod 700 and has an eagle-beak shaped latch at the other end. An L-shaped locking slot 703 is correspondingly provided on the second horizontal rod 701. The latch end of the positioning buckle 702 extends horizontally to the other horizontal rod and engages with the L-shaped locking slot 703 for locking. The horizontal support rod 7 is hinged to the middle of the first adjusting sleeve 8. A return arm spring 12 is also provided between the horizontal support rod 7 and the positioning upright 1. One end of the return arm spring 12 is fixedly connected to the hinge point of the two horizontal rods of the horizontal support rod 7, and the other end is movably connected to the connecting ear plate at the upper end of the first adjusting sleeve 8.

[0055] The invention will be further described below with reference to specific embodiments. Embodiment 2 specifically implements a single-axis photovoltaic bracket unidirectional tracking power generation system for a plateau grassland. The project overview is as follows: The site is located in Sangke Grassland, Gannan Tibetan Autonomous Prefecture, Gansu Province. The site has an overall southwest inclination of 15°. The planned total capacity is 200MW, with a first phase of 40MW, all using a single-axis photovoltaic bracket + 545W silicon photovoltaic panels. The tracking power station adopts a unidirectional light tracking system. The photovoltaic foundation uses 400mm / 450mm diameter cast-in-place piles, with 9 piles per power generation unit. The minimum height of the pile exposed above the ground is 50cm. The upper part uses 16 3.45m H-shaped steel columns, with thin-walled steel purlins at the top. The photovoltaic panels are installed on the purlins. The plateau grassland is located in a plateau pastoral area, and large-scale destruction of the original grassland vegetation is prohibited; only a small amount of permanent pile foundation occupation is allowed. The plateau grassland has a certain slope, such as... Figure 7 As shown, its topographic contour lines 14 are relatively uniform, and its overall slope is gentle, but the local slope changes drastically, resulting in significant local elevation differences. The tracking system rotates back and forth at least 90° in at least one direction, and the tops of the cast-in-place pile array are all exposed to a certain height and are in a straight line.

[0056] The foundation of the solar tracking system consists of an array of nine cast-in-place piles, with each array of piles forming a solar tracking power generation unit. The nine piles are numbered sequentially from A1 to A9. Figure 9As shown, the system comprises an underground bearing stratum 18, an exposed surface portion 19, and an over-exposed height portion 20. The cast-in-place piles are a single unit. The diameters of the exposed surface portion 19 and the underground bearing stratum 18 may differ. An H-shaped steel column 16 is installed at the top of each cast-in-place pile, connecting it to the top-mounted solar power generation unit 17. The exposed surface height H of each cast-in-place pile is calculated individually based on the terrain. The minimum exposed surface height H for all cast-in-place piles is 50cm, located at pile positions A5 and A6 in the middle of the array. The distance between the ground line 21 and the exposed surface height H control line 22 is 50cm. The distance between the exposed surface height H control line 22 and the pile top guy line 23 represents the portion exceeding 50cm above ground. The spacing between each cast-in-place pile along the pile top guy line 23 is 7.8m. The total length of the solar power generation unit 17's battery pack is 60m.

[0057] For the positioning construction process of single-row cast-in-place piles, three sets of the cast-in-place pile positioning devices for high-altitude grassland solar power stations provided in Example 1 were used for positioning and adjustment. The specific steps are as follows:

[0058] S1. Collect design blueprints and change drawings, complete the on-site benchmark handover, and determine the number and design location of each row of cast-in-place piles for the unidirectional light tracking system based on the pile foundation array plan projection, the tracking system support, and other foundation information. The number of cast-in-place piles per row is 9. Extract the pile coordinates of the first pile (counted from north to south), the m=4th pile in the middle, and the last pile in each array of the tracking power station's power generation unit, and the distance L between any two adjacent fixed support points. zc =7.8m, overall inclination angle of single-row cast-in-place piles =12°, minimum height of pile top from ground H0=500mm, maximum height H M =1800mm and other information;

[0059] S2. Based on the design requirements for single-row cast-in-place piles in step S1, measure the initial positions of the first pile at the highest point, the fourth pile in the middle, and the last pile at the lowest point on the construction slope. Install a set of positioning devices for the high-altitude grassland solar power station at each pile location. Each positioning device is installed perpendicular to the single-row cast-in-place piles, at a distance of 1.8–2 meters from the corresponding pile location. The specific installation process is as follows: First, press the positioning pole and the conical fixing rods at the lower ends of the two auxiliary poles into the soil, but do not fix them temporarily; then pull the two poles to level the inclined rods, and observe that the positioning pole pressure plate has a spirit level bubble, and adjust accordingly. To ensure the verticality of the positioning pole, after leveling the positioning pole's pressure plate, fix the positioning pole and two auxiliary poles respectively, ensuring that the positioning pole and auxiliary poles are pressed into the soil to a depth of not less than 30cm. Adjust the first adjusting sleeve to the lowest point of the positioning pole and lock it in place. Then extend and fix the horizontal support rod, so that the plumb bob at the end of the positioning diagonal brace is aligned with the center of the initial pile position of the corresponding cast-in-place pile, and the tip of the plumb bob is in contact with the slope surface. At this time, the initial height of the end of the diagonal brace from the ground is H1=1.0m. Use GPS measurement technology to measure the initial positions of the first pile at the highest point of the slope, the m-th pile in the middle, and the last pile at the lowest point.

[0060] S3. Stretch a long nylon line through the ends of the positioning diagonal braces of the three positioning devices. When the nylon line is not on the same straight line, loosen the first adjusting sleeve on the positioning rod of the positioning device at the fourth pile position. Then adjust the height of the positioning diagonal brace of the fourth pile position to make the nylon line straight and taut, thereby adjusting the position of the fourth pile. After confirming that the three pile positions are on the same straight line, fix and lock the first adjusting sleeve of the positioning device of the fourth pile position. At this time, the position of the plumb bob on the positioning diagonal brace of the fourth pile position is the correction pile position of the fourth pile position.

[0061] S4. After completing step S3, install a laser rangefinder on the positioning brace of the highest first pile position positioning device, and adjust the angle of the laser rangefinder mounting plate so that the laser rangefinder is aligned with the angle of the nylon line. The emitting end of the laser rangefinder should face the tail pile position. Adjust the angle of the laser rangefinder mounting plate on the lowest tail pile position positioning device so that it is perpendicular to the nylon line.

[0062] S5. Activate the laser rangefinder to measure the tilt distance L between the first and last piles. qx1 and tilt angle When the laser rangefinder measures the tilt distance L between the first and last piles qx1 The distance L between the first and last fixed support points of the tracking system support structure designed in step S1 zc If the heights are not equal, loosen the first adjusting sleeve of the first pile positioning device and adjust the height of the first pile positioning brace along the nylon line until the inclination distance L between the first and last piles is reached. qx1 The distance L between the first and last fixed support points of the tracking system support structurezc Equal, and angle of inclination When the angle is less than 15°, after the adjustment is in place, the first adjusting sleeve of the first pile position positioning device can be fixed and locked. At this time, the position of the plumb bob of the first pile position positioning device is the corrected first pile position.

[0063] S6. Based on the distance between any two adjacent fixed support points designed in step S1, the coordinates of the remaining pile positions can be calculated sequentially, and the determined pile positions can be marked sequentially.

[0064] S7. Measure the height difference between the nylon line and the ground at each pile location coordinate, determine the pile location n with the minimum height difference from the ground, and set the height difference between the nylon line and the ground at pile location n as the minimum height of the pile top exposed above the ground in step S1, 0.5. Then, loosen the first adjusting sleeve on the positioning uprights of the three sets of positioning devices, and simultaneously adjust the height of the three sets of positioning diagonal braces to uniformly adjust the elevation of the nylon line, so that the height difference between the nylon line and the ground at pile location n reaches H. min After adjustment, lock the first adjusting sleeve of the three positioning devices;

[0065] S8. Using pile position n as the rotation axis, move the positioning device of pile position m to pile position n. The moving and installation requirements are in accordance with step S2. After the moving is completed, adjust the nylon line inclination angle by adjusting the elevation of the positioning diagonal bracing rods of the first and last pile positions. Measure the height difference between the nylon line of each pile position and the ground, i.e., the height H of the pile top exposed above the ground, until it meets the design range requirements in step S1. The fine-tuning principle is to minimize the fine-tuning angle.

[0066] S9. Design the length L and embedment depth of each cast-in-place pile according to the height H of the pile top exposed above the ground. Determine the construction parameters of each cast-in-place pile according to the pile length, and make the corresponding steel cage and embedded parts. Mark the steel cage and embedded parts, and then make matching marks at the corresponding construction position of the cast-in-place pile. The marks can be distinguished by different colors.

[0067] The process of designing the length L of the cast-in-place pile corresponding to the height H of the pile top protruding above the ground is as follows:

[0068] ① First, calculate the height H of the pile top above ground for each cast-in-place pile and the minimum height H of the pile top above ground required by the design. min The height difference between them is ΔH = HH min Then divide △H into M segments, each segment being 15–30 cm long, with M ≤ 7.

[0069] ②Then determine the length L of the cast-in-place pile according to the following formula, in meters:

[0070] In the formula, The measured height of the top of the first to Nth piles of a single row of cast-in-place piles above the ground, in meters;

[0071] The depth of the first to Nth piles in a single row of cast-in-place piles, expressed in meters (m).

[0072] M refers to the number of segments into which the elevation difference ΔH is divided, and generally M≤7;

[0073] This refers to the minimum height of the top of a cast-in-place pile above the ground, as required by design specifications. =0.5m;

[0074] This refers to the maximum height of the top of the cast-in-place pile above the ground, as required by the design specifications. =1.8m;

[0075] It is the height of nodes 1 to M within the range of △H from the ground, in meters;

[0076] Since the underground portion of the cast-in-place piles must penetrate the frozen soil layer, and there is an additional 50cm beyond the frozen soil layer, the thickness of the frozen soil layer DT can be determined from the specifications. Therefore, the underground depth of the first to Nth cast-in-place piles in the above formula is... Calculate using the following formula:

[0077] The calculation process is as follows: .

[0078] S10. Retract the positioning braces of all positioning devices and construct the pile foundation below ground for each cast-in-place pile according to the markings, installing the corresponding steel cage and embedded parts; after the steel cage and embedded parts are installed, unfold the positioning braces of the three sets of positioning devices, tighten the nylon rope, adjust to make the axis of the embedded parts parallel to the nylon line, adjust the centering and direction of the steel cage and embedded parts for the first time, then retract the positioning braces of the three sets of positioning devices, and then pour the pile foundation below ground separately, and compact it in layers.

[0079] S11. After the pile foundation construction below ground is completed, the formwork above ground is installed and closed. At the same time, the positioning diagonal braces of the three sets of positioning devices are deployed and the nylon line is tightened. The axis of the embedded part is adjusted to be parallel to the nylon line. The centering and direction of the steel cage and embedded parts are checked and finely adjusted for the second time. Soil is piled up at the base of the formwork and anchor steel bars are pressed in for fixation. The steel cage and embedded parts are fixed to the formwork as a whole. Then the positioning diagonal braces of the three sets of positioning devices are retracted.

[0080] S12. Perform the second pouring of the pile foundation, pouring the part of the pile body exposed above the ground, and compacting it in layers with vibration; at the same time, deploy the positioning diagonal braces of the three sets of positioning devices and tighten the nylon line, adjust them to make the axis of the embedded part parallel to the nylon line, check and fine-tune the centering and direction of the steel cage and embedded parts for the third time, so as to eliminate the displacement of the steel cage and embedded parts caused by pouring and vibration. After the pouring is completed, perform finishing, covering with film and watering for curing, and perform a second finishing of the surface after demolding.

[0081] The adjustment error limit of the positioning brace in the positioning device in steps S3, S5, and S7 described above shall not exceed 5mm. In the above steps, the embedded parts and the reinforcing cage are welded together; during adjustment, only the embedded parts need to be adjusted, and the reinforcing cage will be adjusted together. The specific process for the three fine adjustments of the centering and direction of the reinforcing cage and embedded parts in steps S10 to S12 is as follows: Insert the embedded part into a steel plate with pre-drilled bolt holes at the four corners. The symmetry axis of the long side of the steel plate is marked. Twist the direction of the steel plate so that the marked symmetry axis is consistent with the nylon line, thus completing the adjustment. The steel plate is recycled and reused after the cast-in-place pile is poured and cured.

[0082] Measurements showed that the height H of the pile top exposed above ground in the embodiment was similar to the minimum design requirement H of the pile top exposed above ground. min The height difference between them is ΔH = HH min It can be divided into 5 sections; the length L and reinforcement of the 9 cast-in-place piles are selected as follows:

[0083]

[0084] Table 1 shows the ground elevation, pile length, and reinforcement details of the nine piles in Example 2:

[0085] Table 1 Parameter Table of Pile Foundation Array

[0086]

[0087] According to the pile foundation array parameter table in Table 1, make steel cages of the corresponding type and drill holes at the corresponding depths. Mark the steel cage embedded parts with colors. When placing the steel cage, check the hole depth, check the color, and check the steel cage parameters. After confirming that there are no errors, proceed with the subsequent procedures.

[0088] To facilitate marking, five colors—red, green, cyan, yellow, and red—can be used to mark the positioning pole of the positioning device from bottom to top. The marking spacing should meet the design requirements and the recommended range is 0.15~0.3m. The starting point of the marking should be Hmin away from the pole base. At the same time, the construction of the reinforcement cage for the pile foundation array of the power generation unit, the welding connection between the embedded parts and the reinforcement cage, the identification of the type of reinforcement cage and embedded parts, and the pile foundation pilot hole work should be carried out. The reinforcement cage and embedded parts of the corresponding length should be marked with the colors "red, green, cyan, yellow, and red".

[0089] In comparison, the cost difference between the power generation unit pile foundation array using the scheme proposed in this invention and the scheme using the same type of pile foundation is calculated as follows:

[0090] (1) Using the scheme proposed in this invention, the concrete consumption of a single power generation unit is 4.1 m³, the steel reinforcement consumption is 362.9 kg, the market embedded parts price difference is calculated as M30 is 100 yuan / piece more expensive than M24 and 150 yuan / piece more expensive than M22, the drilling cost is calculated as 65 yuan / m, the concrete unit price is 430 yuan / m³, the steel reinforcement unit price is 4500 yuan / t, and the cost of a single string pile foundation can be measured to be approximately 4643.4 yuan;

[0091] (2) Using the fixed pile length scheme, the concrete consumption of a single power generation unit is 5.0 m³, the steel reinforcement consumption is 497.5 kg, the market embedded part price difference is calculated as M30 is 100 yuan / piece more expensive than M24 and 150 yuan / piece more expensive than M22, the pilot hole fee is calculated as 65 yuan / m, the concrete unit price is 430 yuan / m³, the steel reinforcement unit price is 4500 yuan / t, and the cost of a single string of pile foundations can be measured to be approximately 6418.2 yuan;

[0092] (3) By adopting the solution proposed in this invention, the cost can be reduced by RMB 1,774.8 per unit, and the cost reduction rate is (6,418.2 - 4,643.4) / 4,643.4 = 27.7%. The array in this project has a total of 4,100 power generation units. It is preliminarily estimated that the cost can be reduced by RMB 4,100 * RMB 1,774.8 per unit = RMB 7,276,512.7, or RMB 7,276,500. The economic benefits are very considerable.

[0093] In summary, this invention fully utilizes the concept of prior determination of pile length in the pile foundation array, ensuring sufficient bearing capacity for the pile foundation to penetrate into stable strata below the ground surface. It also leverages reverse engineering during construction to guide design, enabling real-time control of the array pile length on-site. Furthermore, it reduces risks such as pile misalignment, excessive length, and excessive misalignment of embedded parts through four-point surveying and straightening of overhead lines. The proposed solution links multiple key stages, significantly reducing costs compared to traditional fixed-length pile construction methods. Moreover, the proposed solution features a clear operational process, rapid construction speed, and diverse site applicability, making it highly valuable for widespread application.

[0094] The above description is merely one embodiment of the present invention, and while it is detailed and specific, it should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A positioning device for cast-in-place piles used in solar power stations in high-altitude grasslands, characterized in that: The positioning device includes a positioning upright (1), a positioning diagonal brace (2), and at least two auxiliary positioning rods (3). The bottom of the positioning upright (1) and the auxiliary positioning rods (3) are provided with a tapered fixing rod (4) and a pressure foot plate (5). A level bubble is provided on the pressure foot plate of the positioning upright (1). Each auxiliary positioning rod (3) is connected to the positioning upright (1) through an upright leveling diagonal rod (6). One end of each upright leveling diagonal rod (6) is hinged to the top of the positioning upright (1), and the other end is sleeved on the top of the positioning upright (1). The second adjusting sleeve (10) on the auxiliary positioning rod (3) is hinged; one end of the positioning diagonal brace (2) is hinged to the top of the positioning upright (1), and the other end extends downward at an inclination, and a horizontal support rod (7), a rangefinder mounting plate (9) and a plumb bob (11) are hinged at its lower end. A first adjusting sleeve (8) is provided on the positioning upright (1). The free end of the horizontal support rod (7) is hinged to the first adjusting sleeve (8). The rangefinder mounting plate (9) is rotatably mounted on the positioning diagonal brace (2). A positioning sleeve (13) is provided at the end of the positioning diagonal brace (2) that connects to the horizontal support rod (7). The positioning sleeve (13) is movably sleeved on the positioning diagonal brace (2) and fixed and locked by a locking bolt. A connecting ear plate is provided on the side of the positioning sleeve (13) adjacent to the horizontal support rod (7). The horizontal support rod (7) is hinged to the connecting ear plate on the positioning sleeve (13). The plumb bob (11) and the rangefinder mounting plate (9) are both set on the positioning sleeve (13), and the plumb bob (11) is vertically downward.

2. The grouting pile positioning device for a solar power station in a high-altitude grassland as described in claim 1, characterized in that: The horizontal support rod (7) includes two hinged first horizontal rods (700) and second horizontal rods (701). A positioning buckle (702) is provided at the hinged part of the two horizontal rods. The positioning buckle (702) is hinged to the first horizontal rod (700) and has an eagle beak-shaped buckle at the other end. An L-shaped locking mouth (703) is provided on the second horizontal rod (701). The buckle end of the positioning buckle (702) extends horizontally to the other horizontal rod and engages with the L-shaped locking mouth (703) for locking. The horizontal support rod (7) is hinged to the middle part of the first adjusting sleeve (8). A return arm spring (12) is also provided between the horizontal support rod (7) and the positioning upright (1). One end of the return arm spring (12) is fixedly connected to the hinged part of the two horizontal rods of the horizontal support rod (7), and the other end is movably connected to the connecting ear plate at the upper end of the first adjusting sleeve (8).

3. The grouting pile positioning device for a solar power station in a high-altitude grassland as described in claim 2, characterized in that: The height of the positioning rod (1) is higher than that of the two auxiliary positioning rods (3). The positioning rod (1) is marked with a scale value. The first adjusting sleeve (8) moves up and down along the positioning rod (1) and is fixed and locked by the locking bolt. The middle and upper parts of the first adjusting sleeve (8) are provided with connecting ear plates. The horizontal support rod (7) is connected to the connecting ear plate in the middle of the first adjusting sleeve (8). The return arm spring (12) is provided with a movable buckle at the connection end with the first adjusting sleeve (8) and is connected to the connecting ear plate on the upper part of the first adjusting sleeve (8) through the movable buckle. The second adjusting sleeve (10) moves up and down along the auxiliary positioning rod (3) and is fixed and locked by the locking bolt.

4. The grouting pile positioning device for a solar power station in a high-altitude grassland as described in claim 1, characterized in that: The rangefinder mounting plate (9) is a slotted plate with a rangefinder slot (900) at one end. The middle part of the rangefinder mounting plate (9) is installed on the side of the positioning diagonal brace (2) away from the horizontal support rod (7) through a rotation adjustment mechanism, and the plate surface is perpendicular to the positioning diagonal brace (2). A reflective magnetic plate (901) is provided at the center of the plate surface of the rangefinder mounting plate (9). Under the action of the rotation adjustment mechanism, the plate body of the rangefinder mounting plate (9) is parallel to the positioning diagonal brace (2) or perpendicular to the positioning diagonal brace (2).

5. A method for positioning and constructing cast-in-place piles for a solar power station in a high-altitude grassland, characterized in that: The method described herein is applicable to the construction of a cast-in-place pile array for a solar power station in a high-altitude grassland. The high-altitude grassland is located in a pastoral area with a certain slope. The solar power station employs a unidirectional light tracking system, whose pile foundation consists of at least one row of cast-in-place piles. Each row of piles is distributed from the higher part of the slope towards the lower part. During the positioning construction process for any row of piles, the positioning adjustment is performed using the cast-in-place pile positioning device described in any one of claims 1 to 4 for solar power stations in high-altitude grasslands. The specific steps are as follows: S1. Based on the site topographic survey information and the design requirements of the unidirectional light tracking system, determine the number and design location of each row of cast-in-place piles in the pile foundation of the unidirectional light tracking system. The number of cast-in-place piles in a single row is 5 to 9, and the spacing L between the first and last fixed support points of the light tracking system support structure is... zc The inclination angle of a single row of cast-in-place piles shall not exceed 60m, the distance between any two adjacent fixed support points shall be 6-8m, and the overall inclination angle of the single row of cast-in-place piles shall be [missing information]. The angle is less than 15°, and the height H of the pile top exposed above the ground is 0.5 to 1.

8. S2. Based on the design requirements for single-row cast-in-place piles in step S1, measure the center of gravity of the single-row cast-in-place piles on the construction slope. The initial positions of the first pile at the highest point of the slope, the m-th pile in the middle, and the last pile at the lowest point are determined. A set of positioning devices for the cast-in-place piles used in the high-altitude grassland solar power station is installed at each pile position. Each positioning device is installed 1.8–2 meters away from the corresponding pile position, perpendicular to the single row of cast-in-place piles. The specific installation process is as follows: First, the positioning pole and the conical fixing rods at the lower ends of the two auxiliary poles are pressed into the soil, but not fixed temporarily; then, the two poles are pulled to level the inclined rods, and the pressure plate of the positioning pole is observed. Adjust the verticality of the positioning pole by leveling the bubble level. After the positioning pole pressure plate is leveled, fix the positioning pole and the two auxiliary poles respectively, and press the positioning pole and the auxiliary poles into the soil to a depth of not less than 30cm. Adjust the first adjusting sleeve to the lowest part of the positioning pole and fix it. Then extend and fix the horizontal support rod so that the plumb bob at the end of the positioning diagonal brace is directly opposite the center of the initial pile position of the corresponding cast-in-place pile, and the tip of the plumb bob is in contact with the slope surface. At this time, the initial height of the end of the diagonal brace from the ground is H1. S3. Stretch a long nylon line through the end of the positioning diagonal brace of the three positioning devices. When the nylon line is not on the same straight line, loosen the first adjusting sleeve on the positioning rod of the positioning device at the m pile position. Then adjust the height of the positioning diagonal brace of the m pile position to make the nylon line straight and taut, thereby adjusting the position of the m pile. After confirming that the three pile positions are on the same straight line, fix and lock the first adjusting sleeve of the positioning device at the m pile position. At this time, the position of the plumb bob on the positioning diagonal brace of the m pile position is the correction pile position m1 of the m pile position. S4. After completing step S3, install a laser rangefinder on the positioning brace of the highest first pile position positioning device, and adjust the angle of the laser rangefinder mounting plate so that the laser rangefinder is aligned with the angle of the nylon line. The emitting end of the laser rangefinder should face the tail pile position. Adjust the angle of the laser rangefinder mounting plate on the lowest tail pile position positioning device so that it is perpendicular to the nylon line. S5. Activate the laser rangefinder to measure the tilt distance L between the first and last piles. qx1 and tilt angle When the laser rangefinder measures the tilt distance L between the first and last piles qx1 The distance L between the first and last fixed support points of the tracking system support structure designed in step S1 zc If the heights are not equal, loosen the first adjusting sleeve of the first pile positioning device and adjust the height of the first pile positioning brace along the nylon line until the inclination distance L between the first and last piles is reached. qx1 The distance L between the first and last fixed support points of the tracking system support structure zc Equal, and angle of inclination When the angle is less than 15°, after the adjustment is in place, the first adjusting sleeve of the first pile position positioning device can be fixed and locked. At this time, the position of the plumb bob of the first pile position positioning device is the corrected first pile position. S6. Based on the distance between any two adjacent fixed support points designed in step S1, the coordinates of the remaining pile positions can be calculated sequentially, and the determined pile positions can be marked sequentially. S7. Measure the height difference between the nylon line and the ground at each pile location coordinate, and determine the pile location n with the minimum height difference from the ground. Define the height difference between the nylon line at pile location n and the ground as the minimum height H of the pile top exposed above the ground in step S1. min Then, the first adjusting sleeve on the positioning poles of the three positioning devices is loosened, and the height of the three positioning diagonal braces is adjusted to uniformly adjust the elevation of the nylon line, so that the height difference between the nylon line at pile position n and the ground reaches H. min After adjustment, lock the first adjusting sleeve of the three positioning devices; S8. Using pile position n as the rotation axis, move the positioning device of pile position m to pile position n. The moving and installation requirements are in accordance with step S2. After the moving is completed, adjust the nylon line inclination angle by adjusting the elevation of the positioning diagonal bracing rods of the first and last pile positions. Measure the height difference between the nylon line of each pile position and the ground, i.e., the height H of the pile top exposed above the ground, until it meets the design range requirements in step S1. The fine-tuning principle is to minimize the fine-tuning angle. S9. Design the length L and embedment depth of the corresponding cast-in-place pile based on the height H of the pile top exposed above the ground for each cast-in-place pile. Determine the construction parameters for each cast-in-place pile based on the pile length, fabricate the corresponding steel cage and embedded parts, mark the steel cage and embedded parts, and then make matching marks at the corresponding cast-in-place pile construction position. S10. Retract the positioning braces of all positioning devices and construct the pile foundation below ground for each cast-in-place pile according to the markings, installing the corresponding steel cage and embedded parts; after the steel cage and embedded parts are installed, unfold the positioning braces of the three sets of positioning devices, tighten the nylon rope, adjust to make the axis of the embedded parts parallel to the nylon line, adjust the centering and direction of the steel cage and embedded parts for the first time, then retract the positioning braces of the three sets of positioning devices, and then pour the pile foundation below ground separately, and compact it in layers. S11. After the pile foundation construction below ground is completed, the formwork above ground is installed and closed. At the same time, the positioning diagonal braces of the three sets of positioning devices are deployed and the nylon line is tightened. The axis of the embedded part is adjusted to be parallel to the nylon line. The centering and direction of the steel cage and embedded parts are checked and finely adjusted for the second time. Soil is piled up at the base of the formwork and anchor steel bars are pressed in for fixation. The steel cage and embedded parts are fixed to the formwork as a whole. Then the positioning diagonal braces of the three sets of positioning devices are retracted. S12. Perform the second pouring of the pile foundation, pouring the part of the pile body exposed above the ground, and compacting it in layers with vibration; at the same time, deploy the positioning diagonal braces of the three sets of positioning devices and tighten the nylon line, adjust them to make the axis of the embedded part parallel to the nylon line, check and fine-tune the centering and direction of the steel cage and embedded parts for the third time, so as to eliminate the displacement of the steel cage and embedded parts caused by pouring and vibration. After the pouring is completed, perform finishing, covering with film and watering for curing, and perform a second finishing of the surface after demolding.

6. The method for positioning and construction of cast-in-place piles for a solar power station in a plateau grassland, as described in claim 5, is characterized in that: The cast-in-place pile consists of a portion buried in the underground bearing layer, a portion exposed above ground, and a portion exceeding the maximum exposed height. The cast-in-place pile is a single unit, and the diameters of the portion exposed above ground and the portion buried underground may be different. A steel structure column is installed at the top of the cast-in-place pile, and the pile is connected to the top solar power generation unit through the steel structure column.

7. The method for positioning and construction of cast-in-place piles for a solar power station in a plateau grassland, as described in claim 5, is characterized in that... In step S9, the process of designing the length L of the corresponding cast-in-place pile based on the height H of the pile top protruding above the ground is as follows: ① First, calculate the height H of the pile top above ground for each cast-in-place pile and the minimum height H of the pile top above ground required by the design. min The height difference between them is ΔH = HH min Then divide △H into M segments, each segment being 15–30 cm long, with M ≤ 7. ②Then determine the length L of the cast-in-place pile according to the following formula, in meters: ; In the formula, The measured height of the top of the first to Nth piles of a single row of cast-in-place piles above the ground, in meters; The depth of the first to Nth piles in a single row of cast-in-place piles, expressed in meters (m). M refers to the number of segments into which the elevation difference ΔH is divided, and generally M≤7; This refers to the minimum height of the top of a cast-in-place pile above the ground, as required by design specifications. =0.5m; This refers to the maximum height of the top of the cast-in-place pile above the ground, as required by the design specifications. =1.8m; It is the height of nodes 1 to M within the range of △H from the ground, in meters; Since the underground portion of the cast-in-place piles must penetrate the frozen soil layer, and there is an additional 50cm beyond the frozen soil layer, the thickness of the frozen soil layer DT can be determined from the specifications. Therefore, the underground depth of the first to Nth cast-in-place piles in the above formula is... Calculate using the following formula: ; The calculation process is as follows: .

8. The method for positioning and construction of cast-in-place piles for a solar power station in a plateau grassland, as described in claim 5, is characterized in that: In step S2, GPS measurement technology is used to measure the initial positions of the first pile at the highest point of the slope, the m-th pile in the middle, and the last pile at the lowest point; in steps S3, S5, and S7, the adjustment error limit of the positioning diagonal brace in the positioning device does not exceed 5mm.

9. A method for positioning and constructing cast-in-place piles for a solar power station in a high-altitude grassland, as described in claim 5, characterized in that: The embedded parts and the reinforcing cage are welded together. When adjusting, only the embedded parts need to be adjusted, and the reinforcing cage will be adjusted together. The specific process of the three fine adjustments of the centering and direction of the reinforcing cage and the embedded parts in steps S10 to S12 is as follows: Insert the embedded parts into a steel plate. Bolt holes are reserved at the four corners of the steel plate. The symmetry axis of the long side of the steel plate has been marked. Twist the direction of the steel plate so that the symmetry axis marked on the steel plate is consistent with the nylon line. The adjustment can be completed. The steel plate can be recycled and reused after the cast-in-place pile is poured and cured.

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