Sediment storage device, design method, cast-in-situ bored pile reinforcement cage and construction method

Abstract

The invention relates to the technical field of building construction, and provides a sediment storage device, a design method, a cast-in-situ bored pile reinforcement cage and a construction method. The sediment storage device comprises a top plate, a bottom plate and a plurality of vertical supporting plates supported between the top plate and the bottom plate, and an opening is formed in the bottom plate. The pile bottom sediment can be effectively collected, and the pile foundation construction quality and the bearing capacity are improved.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, specifically to sediment collection devices and design methods, drilled pile reinforcement cages, and construction methods. Background Technology

[0002] With the continuous development of urban construction, bored piles, as an important form of foundation engineering, are widely used in high-rise buildings, bridges, subways, and other projects. During the construction of bored piles, the handling of sediment at the pile bottom has always been a key factor affecting the quality and bearing capacity of the pile foundation.

[0003] The construction of bored piles typically includes steps such as installing the casing, drilling, cleaning the borehole, lowering the reinforcing cage, and pouring concrete. In the construction of bored piles with mud wall support, the mud serves to protect the borehole wall, cool the drill bit, and carry away drill cuttings, effectively preventing borehole collapse. However, due to the presence of mud, even with advanced borehole cleaning equipment, it is still difficult to completely remove all sediment from the bottom of the pile after cleaning, leaving a certain thickness of sediment layer. This directly leads to a reduction in the bearing capacity of the pile tip.

[0004] To improve the bearing capacity of bored pile tips, post-grouting is employed. After the pile is formed, cement grout is injected through a pre-installed grouting pipe within the pile body and connected to grouting valves at the pile tip and sides. This reinforces the soil (including sediment and mud cake) at the pile tip and sides, thereby increasing the single pile bearing capacity and reducing settlement. However, post-grouting requires the pre-embedding of grouting pipes, pressure grouting equipment, and sophisticated cement grout preparation techniques, making quality control difficult. Furthermore, the bearing capacity only increases after grouting, impacting the construction schedule. More importantly, the grouting pipes are prone to poor grout flow or blockage, leading to unsatisfactory grouting results. Insufficient grouting pressure and limited grout diffusion range also result in suboptimal reinforcement. When rock-socketed piles encounter rock fractures or karst caves, the grouting effect may be unstable.

[0005] Therefore, how to effectively solve the problem of pile bottom sediment, improve the bearing capacity of pile ends, and at the same time simplify the construction process and reduce technical requirements has become an urgent technical problem to be solved. Summary of the Invention

[0006] To address the problem of residual sediment remaining after cleaning boreholes in slurry-walled cast-in-place piles, which reduces the bearing capacity of the pile ends and affects the quality of the project, this invention provides a sediment collection device and its design method, a reinforcing cage for bored cast-in-place piles, and a construction method.

[0007] According to a first aspect of the present invention, a sediment collection device is provided, comprising a top plate, a bottom plate, and a plurality of vertical support plates supported between the top plate and the bottom plate, wherein the bottom plate is provided with an opening.

[0008] In one possible implementation, the ends of the plurality of vertical support plates near the center do not contact each other.

[0009] In one possible implementation, the plurality of vertical support plates do not contact each other at their central ends, and the enclosed central area surrounds the opening on the base plate.

[0010] In one possible implementation, the plurality of vertical support plates are arranged in multiple directions.

[0011] In one possible implementation, the plurality of vertical support plates are arranged in a central array.

[0012] In one possible implementation, the opening is a through hole.

[0013] In one possible implementation, the opening is one or more.

[0014] In one possible implementation, the size of the base plate is not smaller than the size of the top plate.

[0015] According to a second aspect of the present invention, a reinforcing cage for a bored pile is provided, comprising a cage body and the aforementioned sediment collection device connected to the bottom of the cage body.

[0016] In one possible implementation, the cage includes longitudinal main bars and stirrups, the longitudinal main bars being connected to the top plate of the sediment collection device; the stirrups surrounding the longitudinal main bars.

[0017] In one possible implementation, the top plate of the sediment collection device is larger than the cage size but smaller than the pile hole size.

[0018] According to a third aspect of the present invention, a design method for a sediment collection device is provided, comprising: pile foundation design; Determine the bearing capacity of the pile tip; Determine the preliminary dimensions and plate specifications of the sediment collection device; Calculate the stress and deformation of the plates in the sediment collection device; Check the stress and deformation of the sheet metal; Determine whether the stress and deformation of the plate meet the stress and deformation requirements; If the stress of the plate does not meet the stress requirements or / and the deformation does not meet the deformation requirements, adjust the plate size and return to the steps for calculating the stress and deformation of the sludge collection device plates.

[0019] According to a fourth aspect of the present invention, a method for constructing bored piles is provided, comprising: drilling; Fabrication of steel reinforcement cages; Construct a sediment collection device; The sediment collection device is welded to the steel cage; Clean the hole; The reinforcing cage for the cast-in-place pile is placed into the borehole; Pour concrete.

[0020] The top plate of the sediment collection device provided by this invention is connected to the longitudinal main reinforcement of the reinforcing cage; the bottom plate is in close contact with the bearing layer of the pile end, transmitting the pile end pressure to the bearing layer and eliminating the influence of sediment on the vertical compressive bearing capacity and settlement of the single pile. Furthermore, the opening guides the sediment at the bottom of the pile hole into the collection space, preventing sediment from affecting the bearing capacity and stability of the pile foundation. Multiple vertical support plates provide structural support and form multiple compartments. Sediment enters the collection space through the gaps between adjacent vertical support plates, making the sediment distribution more uniform and preventing sediment from affecting the bearing capacity and stability of the pile foundation.

[0021] The bottom of the reinforcing cage of the bored pile described in this invention is connected to a sediment collection device, which can effectively collect the sediment left after cleaning the hole, avoiding the problems of sediment at the bottom of the pile, mud skin on the pile side, and easy disturbance of the hole wall in traditional methods, and significantly improving the stability and reliability of the pile quality.

[0022] The drilling and grouting pile construction method described in this invention can replace the post-grouting treatment of sediment at the pile end, improve the bearing capacity of the pile foundation, reduce settlement, and avoid the problems existing in the post-grouting method at the pile end, such as poor grout discharge or blockage of the grouting pipe, insufficient grouting pressure, limited grout diffusion range leading to unsatisfactory reinforcement effect, and unstable grouting effect when the rock-socketed pile encounters rock fracture or karst cave.

[0023] This invention eliminates the need for pressure grouting equipment and cement grout preparation, has low technical requirements, ensures easy quality control, and can immediately improve load-bearing capacity without affecting the construction period, thereby saving money and shortening the construction cycle. Attached Figure Description

[0024] Figure 1 This is a cross-sectional schematic diagram of an embodiment of the sediment collection device described in this invention; Figure 2 This is a top view schematic diagram of an embodiment of the sediment collection device described in this invention; Figure 3 This is a schematic diagram of an embodiment of the base plate of the sediment collection device described in this invention; Figure 4 This is a schematic diagram of one embodiment of the reinforcing cage for bored piles according to the present invention; Figure 5 This is a flowchart illustrating an embodiment of the design method for the sediment collection device of the present invention; Figure 6 This is a schematic diagram illustrating an application scenario of an embodiment of the bored pile construction method described in this invention; Figure 7This is a schematic flowchart of an embodiment of the bored pile construction method of the present invention; Among them, 10 is a sediment collection device; 1 is a top plate; 2 is a bottom plate; 21 is an opening; 3 is a vertical support plate; 20 is a longitudinal main reinforcement; 30 is a stirrup; and 100 is a drilled pile reinforcement cage. Detailed Implementation

[0025] Numerous specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0026] In existing bored pile construction methods, problems such as pile bottom sediment, pile side mud cake, and easy disturbance of the borehole wall lead to large dispersion in pile quality and unstable single pile bearing capacity, affecting the safety and reliability of the entire project.

[0027] To address the aforementioned problems, the present invention provides a sludge collection device, such as... Figures 1-3 As shown, the sediment collection device 10 is installed above the pile end bearing layer and includes a top plate 1, a bottom plate 2, and multiple vertical support plates 3 supported between the top plate 1 and the bottom plate 2. The bottom plate 2 is provided with an opening 21, and the sediment enters the sediment collection device 10 through the bottom opening 21 or the gap between the multiple vertical support plates 3 on the side.

[0028] The top plate 1 is located at the top of the entire sediment collection device 10, used to enclose the upper space of the entire collection device and provide support points for the vertical support plate 3. The top plate 1 can be made of metal material, with a certain rigidity and strength, and can withstand a certain pressure and weight, such as steel plate. The shape of the top plate 1 can be square or round, depending on the actual use requirements.

[0029] Multiple vertical support plates 3 are positioned between the top plate 1 and the bottom plate 2, providing not only structural support but also partitioning the space into multiple compartments. This ensures a more even distribution of sediment and prevents uneven sediment accumulation in certain areas. The vertical support plates 3 are strategically positioned such that their ends near the center do not touch, creating a central area that provides both support and ample space for sediment accumulation. The vertical support plates 3 can also be arranged radially, extending from the periphery towards the center but not reaching the exact center point, thus creating an open space in the central area.

[0030] In a preferred embodiment, the central region formed by the non-contact ends of the multiple vertical support plates 3 surrounds the opening 21 on the base plate 2. The correspondence between the central region and the opening 21 facilitates the entry of sludge into the sludge settling device. This special arrangement of the vertical support plates 3 allows sludge to enter the sludge settling device from the side.

[0031] This sediment collection device 10 has a simple structure and is easy to operate. The opening design of the bottom plate 2 greatly simplifies the cleaning process and improves work efficiency. At the same time, the special arrangement of the vertical support plates 3 ensures the structural stability of the device and the convenience of cleaning.

[0032] In another feasible embodiment, the sediment collection device 10 includes a top plate 1, a bottom plate 2 and a plurality of vertical support plates 3. The top plate 1 and the bottom plate 2 are arranged opposite to each other, and the bottom plate 2 is provided with through holes. The plurality of vertical support plates 3 are supported between the top plate 1 and the bottom plate 2 to form a stable support structure.

[0033] The top plate 1 of the sediment collection device 10 is made of sturdy metal material, with sufficient strength to withstand possible pressure from above. The surface of the top plate 1 is flat, and the edges are slightly curved downwards. This design enhances the structural stability of the top plate 1 while avoiding potential safety hazards caused by sharp edges.

[0034] The base plate 2 is also made of corrosion-resistant metal material, and has a through hole in the center (the through hole can be of any shape, such as round, square, or arc). This through hole is a key part of the sediment collection device 10, allowing sediment to be pressed in for collection. The size of the through hole is designed to be moderate, ensuring smooth passage of sediment without affecting the stability of the overall structure. The edges of the through hole can be specially treated to present a smooth arc shape. This design avoids obstruction of sediment during passage and improves collection efficiency.

[0035] Multiple vertical support plates 3 are evenly distributed between the top plate 1 and the bottom plate 2, and their outer ends are fixedly connected to the top plate 1 and the bottom plate 2 to form a sturdy support structure. The inner ends of each vertical support plate 3 face the center but do not contact each other. This design forms a hollow area that corresponds to the through hole in the bottom plate 2.

[0036] The surface of the vertical support plate 3 can be treated with anti-corrosion coating, enabling it to be used for a long time in humid environments without rusting.

[0037] The gaps between the vertical support plates 3 are precisely calculated to ensure structural stability while providing sufficient space for sediment to pass through. The number of support plates can be adjusted according to actual needs, typically 4-12, evenly distributed in the surrounding area between the top plate 1 and the bottom plate 2 to form a symmetrical structure, for example, arranged in an array along the center of the top plate 1 and the bottom plate 2.

[0038] The entire sediment collection device 10 has a simple and practical structure. The connections between components are made by welding or bolting, ensuring the stability and durability of the overall structure. The height and diameter of the device can be adjusted according to the actual application scenario to adapt to different usage requirements.

[0039] In one feasible embodiment, the included angle between two adjacent support plates is 60 degrees. This multi-directional structure allows the support plates to evenly distribute the pressure between the top plate 1 and the bottom plate 2, improving the structural strength and stability of the entire device. Simultaneously, the multi-directional support plate structure can also form multiple sludge storage areas, increasing the sludge storage capacity and improving storage efficiency.

[0040] The sediment collection device 10 of the present invention has a simple structure and is easy to install. It can effectively collect and isolate sediment at the pile end, prevent sediment from affecting the quality of concrete pouring, and improve the overall bearing capacity and service life of the pile foundation.

[0041] Figure 4 This is a schematic diagram of one embodiment of the bored pile reinforcement cage 100 described in this invention, as shown below. Figure 4 As shown, the drilled pile reinforcement cage includes a cage body and a sediment collection device 10 connected to the bottom of the cage body.

[0042] The cage is a cylindrical reinforced steel skeleton structure, welded together from several longitudinal main bars 20 and circumferential stirrups 30. The longitudinal main bars 20 are evenly distributed along the circumference, typically 8-16 in number, which can be adjusted according to the pile diameter and bearing capacity requirements. The longitudinal main bars 20 use HRB400 grade steel bars, generally with a diameter of 25-40mm, and their length is determined by the pile length, reaching tens of meters. The circumferential stirrups 30 use HPB300 grade steel bars, typically with a diameter of 12-16mm, and are welded at certain intervals along the length of the cage to the outside of the longitudinal main bars 20, forming a robust skeleton structure. The spacing of the circumferential stirrups 30 can be 200-300mm in the upper part of the cage, and is usually denser to 150-200mm in the lower part of the cage to enhance the cage's torsional resistance. The diameter of the cage is designed according to the pile diameter, generally 200-300mm smaller than the designed pile diameter to ensure that the concrete cover thickness meets the requirements.

[0043] The cage is also equipped with several positioning rings, made of flat steel and welded to the outside of the cage, to ensure the cage is centered in the pile hole. The number and spacing of the positioning rings are determined according to the length of the cage, usually one ring every 3-5 meters. For ease of hoisting and transportation, the cage is also equipped with lifting lugs, which are made of 8-12mm thick steel plates cut into suitable shapes and welded to the longitudinal main reinforcement 20 at the top of the cage.

[0044] The sediment collection device 10 is connected to the bottom of the cage and is used to collect sediment from the bottom of the pile to prevent the sediment from affecting the bearing capacity of the pile foundation. The sediment collection device 10 includes a top plate 1, a bottom plate 2, and a vertical support plate 3. The top plate 1 is a circular steel plate with a diameter larger than that of the cage. The bottom plate 2 has an opening 21 in the center. While the cage crushes some of the sediment along the bearing layer direction of the pile end, some of the sediment enters the sediment collection device 10 through the opening 21 at the bottom.

[0045] By combining a steel cage with a sediment collection device 10, the sediment problem in the construction of bored cast-in-place piles can be effectively solved, the quality and bearing capacity of the pile foundation can be improved, and the service life of the pile foundation can be extended.

[0046] When using the bored pile reinforcement cage 100, it is first hoisted as a whole and vertically lowered into the drilled pile hole. During the lowering process, the positioning rings on the cage ensure that the reinforcement cage is centered in the pile hole. The sediment collection device 10 is located at the bottom of the cage. After the reinforcement cage is lowered into place, the bottom plate of the sediment collection device 10 is exactly at the bottom of the pile hole. Subsequently, during concrete pouring, the sediment at the bottom of the pile is collected into the collection cavity of the sediment collection device 10, effectively preventing sediment from mixing into the concrete and affecting the quality of the pile foundation. The presence of the sediment collection device 10 significantly improves the end bearing capacity and overall bearing capacity of the pile foundation, ensuring the quality of the project.

[0047] Figure 5 This is a flowchart illustrating an embodiment of the design method for the sediment collection device described in this invention, as shown below. Figure 5 As shown, the design method includes: Step S1: Pile foundation design, including: calculating the pile diameter, pile length and pile reinforcement based on the pile foundation data and the superstructure load.

[0048] Step S2: Determine the pile end bearing capacity, including: obtaining the pile end bearing capacity based on the pile bearing capacity and the pile side friction, for example: the pile bearing capacity minus the pile side friction equals the pile end bearing capacity; Step S3: Determine the preliminary dimensions and plate specifications of the sediment collection device, including: The diameter of the sediment collection device is the same as the pile diameter; The height of the sediment collection device is 1.5 times the thickness of the sediment it can hold; The thickness of the top and bottom plates is 20mm; The opening size of the base plate is Ф100mm; The support plates are evenly arranged along the center of the base plate, with no fewer than 8 plates; Q355B is preferred for the support plate; Step S4: Calculation of stress and deformation of the sludge collection device plates, including: The first load is obtained by dividing the pile end bearing capacity by the base plate area. The second load is obtained by multiplying the pile length by the concrete unit weight, where the buoyant unit weight can be used for underwater concrete. The larger of the first and second loads is applied to the bottom and top plates for stress and deformation calculations. Step S5: Check the stress and deformation of the sheet metal; Step S6: Determine whether the stress and deformation of the plate meet the stress and deformation requirements; If the stress of the plate does not meet the stress requirement or / and the deformation does not meet the deformation requirement, proceed to step S7 to adjust the plate size, for example, by increasing the plate thickness to increase stress, or by increasing reinforcement to reduce deformation, and return to step S4.

[0049] In the above design method, the pile bearing capacity minus the pile side friction equals the pressure on the pile bottom; the self-weight of the uncured concrete is also a pressure; the larger of these two is the calculated pressure. This pressure is evenly distributed on the top and bottom slabs; the parameters of these slabs are their thickness and steel grade (Q355, Q235, etc.), with different grades indicating different steel strengths. One-sixth of the maximum spacing between the support plates is taken as the thickness of the bottom and top slabs. The calculation controls the stress and deformation of the slabs, ensuring the support plates and top slab have the same thickness.

[0050] In one feasible embodiment, in step S3, the thickness data of the pile hole residue is obtained to determine the height of the vertical support plate 3.

[0051] First, the thickness of the pile hole residue needs to be estimated based on on-site measurements or engineering design data. The height of the vertical support plate 3 is then determined based on the pile hole residue thickness. The height of the vertical support plate 3 should be within a set multiple of the pile hole residue thickness to ensure that the sediment collection device 10 has sufficient space to accommodate the pile hole residue without being too high and wasting material. In practical design, a height of 1.5-3 times the pile hole residue thickness can be selected as the height of the vertical support plate 3 based on engineering experience to provide sufficient storage space.

[0052] In one feasible embodiment, in step S3, the pile hole size and the steel cage size are obtained to determine the size of the top plate 1.

[0053] The diameter or side length of the pile hole is obtained through engineering design drawings or on-site measurements, along with the dimensions of the reinforcing cage to be placed in the pile hole. Based on these two dimensions, the dimensions of the top plate 1 are determined to be smaller than the pile hole size but larger than the cage size. This design ensures that the sediment collection device 10 can be smoothly placed into the pile hole without affecting the installation of the reinforcing cage. In a preferred embodiment, the top plate 1 can be designed to be 20-30mm larger than the cage size (e.g., 25mm) but 20-30mm smaller than the pile hole size. This ensures sufficient clearance between the device and the reinforcing cage while maintaining the stability of the device within the pile hole.

[0054] In one feasible embodiment, in step S4: Obtain the bearing capacity data at the bottom of the pile and calculate the uniformly distributed load.

[0055] Obtain the pile bottom bearing capacity data through geological survey reports or engineering design requirements. Calculate the uniformly distributed load based on the area of ​​the top plate 1, that is, divide the pile bottom bearing capacity by the area of ​​the top plate 1 to obtain the load value per unit area. This step is to ensure that the designed sediment collection device 10 can withstand the pressure transmitted from the pile bottom. In actual design, a safety factor of 1.2-1.5 can be considered to ensure the safety and reliability of the device.

[0056] Calculate the self-weight of the concrete of the pile body above the top plate 1.

[0057] Calculate the total weight of the pile concrete located above the top slab 1 based on the designed height and diameter of the pile. Considering that the density of concrete is typically 2400 kg / m³. 3 The self-weight of the pile concrete can be obtained by multiplying its volume by its density. This step is to assess another major load that the sediment collection device 10 needs to withstand.

[0058] Compare the load magnitudes to determine the plate thickness.

[0059] Compare the uniformly distributed load obtained in step S3 and the self-weight of the pile concrete obtained in step S4, and take the larger value as the design load. Based on this design load, and in conjunction with the strength characteristics of the materials and the safety factor, calculate and determine the thickness of the top plate 1, the bottom plate 2, and the support plate. When calculating the plate thickness, it is necessary to consider parameters such as the bending strength and shear strength of the materials to ensure that the designed sediment collection device 10 has sufficient strength and rigidity.

[0060] In a preferred embodiment, multiple vertical support plates 3 are arranged in multiple directions to form a radial structure, which can improve the stability and load-bearing capacity of the entire device.

[0061] In another preferred embodiment, the multiple vertical support plates 3 are arranged in an array, such as a rectangular array or a circular array, which can make the load more evenly distributed on each support plate and improve the stability of the entire structure.

[0062] When designing the base plate 2, its dimensions should not be smaller than those of the top plate 1. This provides better stability and support for the entire structure. In practical applications, the dimensions of the base plate 2 can be the same as or slightly larger than those of the top plate 1 to provide better foundation support.

[0063] The opening 21 of the bottom plate 2 can be a through hole, allowing sediment to enter the sediment collection device from the bottom plate opening and the side. The size of the through hole should be designed according to actual needs, ensuring both sufficient strength and functional requirements.

[0064] Through the above design method, a sediment collection device 10 with reasonable structure, sufficient strength, and complete functions can be obtained, which can effectively solve the sediment handling problem in pile foundation construction and improve construction quality and efficiency. During pile foundation construction, sediment enters the sediment collection device 10 through the opening 21 on the bottom plate 2 and is effectively collected by the space enclosed by the vertical support plate 3. Since the end of the vertical support plate 3 near the center does not contact the pile, a sufficiently large space is formed, allowing the sediment to enter smoothly and be effectively collected, preventing sediment from accumulating on the bearing layer of the pile end, thereby ensuring the bearing capacity and construction quality of the pile foundation. The sediment collection device 10 has a simple structure, low manufacturing cost, and convenient installation. It is suitable for sediment collection and treatment in various pile foundation projects and can effectively improve the construction quality and safety of pile foundations.

[0065] Figure 6 This is a schematic diagram of an embodiment of the bored pile construction method described in this invention. Figure 7 This is a schematic flowchart of an embodiment of the bored pile construction method of the present invention, as shown below. Figure 6 and Figure 7 As shown, the construction method for bored piles includes: Step S10: Drilling: Drilling operations are carried out using a rotary drilling rig, with the drill bit diameter selected according to the designed pile diameter. During drilling, mud is continuously injected into the hole through a mud circulation system. This serves two purposes: firstly, to stabilize the hole wall and prevent collapse; and secondly, to remove drill cuttings and keep the hole clean. The drilling speed is adjusted according to the geological conditions, generally ranging from 0.5 to 2 meters per hour. After reaching the designed depth, the first borehole acceptance test is conducted to check whether the hole depth and diameter meet the design requirements.

[0066] Step S20: Fabricate the steel reinforcement cage.

[0067] Step S30: Construct a sediment collection device.

[0068] Step S40: Weld the sediment collection device to the steel cage.

[0069] Step S50: Hole cleaning: The pile hole is cleaned using a hole cleaner to remove sediment and deposits from the bottom and walls. The cleaning process is repeated multiple times, with the thickness of the sediment measured after each cleaning until it meets the specifications (generally no more than 5 cm). Simultaneously, the drilling mud is replaced to meet the following specifications: specific gravity 1.15-1.25, viscosity 18-22 seconds, sand content no more than 4%, and pH 8-9. After cleaning, a second borehole inspection is conducted. The depth, diameter, location, and shape of the borehole directly affect the quality and straightness of the pile. Therefore, in addition to close monitoring during drilling, the depth, location, shape, and diameter should be checked after the borehole reaches the design depth. Once the final inspection confirms that the borehole fully meets the design requirements, the bottom should be cleaned immediately to prevent excessive sedimentation and borehole collapse. For friction piles, when the borehole wall is prone to collapse, the sediment thickness should not exceed 30cm before underwater concrete pouring; when the borehole wall is not prone to collapse, it should not exceed 20cm. For column piles, the sediment thickness should not exceed 5cm before water or air jetting. Borehole cleaning methods vary depending on the drilling rig used. Commonly used methods include positive circulation rotary drilling rigs, reverse circulation rotary drilling rigs, vacuum suction rigs, and slag suction cylinders. Vacuum suction rigs require minimal equipment, are easy to operate, and provide thorough cleaning, but should be used with caution in unstable soil layers. The principle is to use high-pressure air generated by a compressor to blow mud and slag out of the suction rig's pipes.

[0070] Step S60: Place the steel cage: The bored pile reinforcement cage 100, equipped with a sediment collection device 10 at its bottom, is hoisted and vertically lowered into the pile hole. The reinforcement cage includes a cage body and the sediment collection device 10 connected to the bottom of the cage body. During the lowering process, positioning rings on the cage body ensure its centered positioning within the pile hole. Once in place, the base of the sediment collection device 10 is positioned precisely at the bottom of the pile hole, collecting sediment from the pile bottom and preventing it from affecting the pile's bearing capacity.

[0071] Step S70: Pour concrete: A tremie pipe is installed, and concrete is poured using the tremie pipe method, with the tremie pipe always embedded 2-6 meters below the concrete surface. Ready-mixed concrete with a strength grade of C30-C40 and a slump of 18-22 cm is used, with the pouring rate controlled at 15-25 cubic meters per hour. During pouring, as the concrete surface rises, the tremie pipe is raised section by section, while simultaneously draining the mud from the borehole. During pouring, due to the gravity of the reinforcing cage, sediment from the pile bottom enters the sediment collection device through openings in the base plate and its sides. As the concrete on top of the sediment collection device rises higher, the pressure increases, and the base plate of the sediment collection device and the bearing layer at the pile bottom become more compact. Once the concrete reaches the design elevation, the tremie pipe is removed, and excess concrete at the pile top is chiseled away to ensure the pile top elevation meets design requirements.

[0072] In a preferred embodiment, the hole cleaning step may only involve coarse cleaning, without fine cleaning. In the coarse cleaning stage, a large-diameter hole cleaner is used to perform 2-3 cycles of cleaning to remove most of the sediment.

[0073] In another preferred embodiment, before concrete pouring, sonic logging tubes can be installed at the bottom of the reinforcing cage for later detection of pile integrity. The sonic logging tubes are made of steel pipes with an inner diameter of 50-60 mm, with 3-4 tubes evenly arranged along the circumference of the reinforcing cage, sealed at the bottom, and the top extending about 50 cm above the pile top.

[0074] By using the above-mentioned bored pile construction method, combined with a steel cage with a sediment collection device 10, the problem of incomplete sediment treatment at the bottom of the pile in traditional bored pile construction can be effectively solved, significantly improving the end bearing capacity and overall bearing capacity of the pile foundation, and ensuring project quality.

[0075] Finally, it should be noted that the above descriptions are merely preferred embodiments of this application, and this application is not limited to the above embodiments. It is understood that other improvements and variations directly derived or conceived by those skilled in the art without departing from the spirit and concept of this application should be considered to be included within the protection scope of this application.

Claims

1. A sludge collection device, characterized in that, It includes a top plate, a bottom plate, and multiple vertical support plates supported between the top plate and the bottom plate, with an opening provided on the bottom plate.

2. The sediment collection device according to claim 1, characterized in that, The ends of the multiple vertical support plates near the center do not touch.

3. The sediment collection device according to claim 2, characterized in that, The multiple vertical support plates do not touch at their central ends, and the central area they form surrounds the opening on the base plate.

4. The sediment collection device according to claim 1, characterized in that, The opening is a through hole; Or / and, the opening is one or more; Or / and, the plurality of vertical support plates are arranged in multiple directions; Or / and, the size of the bottom plate is not smaller than the size of the top plate.

5. The sediment collection device according to claim 4, characterized in that, The plurality of vertical support plates are arranged along the array of openings.

6. A reinforcing cage for a bored pile, characterized in that, The device includes a cage and a sediment collection device according to any one of claims 1-5 connected to the bottom of the cage.

7. The reinforcing cage for bored piles according to claim 6, characterized in that, The cage body includes longitudinal main bars and stirrups. The longitudinal main bars are connected to the top plate of the sediment collection device. The stirrups surround the longitudinal main bars.

8. The reinforcing cage for bored piles according to claim 6, characterized in that, The top plate of the sediment collection device is larger than the cage size but smaller than the pile hole size.

9. A design method for a sediment collection device according to any one of claims 1-5, characterized in that, include: Pile foundation design; Determine the bearing capacity of the pile tip; Determine the preliminary dimensions and plate specifications of the sediment collection device; Calculate the stress and deformation of the plates in the sediment collection device; Check the stress and deformation of the sheet metal; Determine whether the stress and deformation of the plate meet the stress and deformation requirements; If the stress of the plate does not meet the stress requirements or / and the deformation does not meet the deformation requirements, adjust the plate size and return to the steps for calculating the stress and deformation of the sludge collection device plates.

10. A method for constructing bored cast-in-place piles, characterized in that, include: drilling; Fabrication of steel reinforcement cages; Manufacture a sediment collection device according to any one of claims 1-5; The sediment collection device is welded to the steel cage; Clean the hole; The reinforcing cage for the cast-in-place pile is placed into the borehole; Pour concrete.

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