Method for constructing composite ground by using balanced extruded stone pile

Abstract

This invention relates to the field of marine complex soft soil reclamation technology, and particularly to a method for constructing a composite foundation using balanced silt-displacing crushed stone piles. The method includes: construction preparation and investigation; driving a driven pipe sludge removal well; driving a driven pipe with a tip at the pile location and displacing silt; removing the tip of the driven pipe; segmented filling and compaction of the pile body; pile body circulation construction, silt removal and pressure reduction; and pile body density and bearing capacity testing. This invention utilizes pressure-reducing silt removal wells to increase the overall crushed stone replacement rate of the silt layer, balance soil pressure, avoid ground heave caused by silt displacement during the driven pipe process, and further reduce uneven foundation settlement. The rapid drilling method shortens the overall construction period by approximately 40%, increases the crushed stone replacement rate by approximately 50%, and ensures the overall effectiveness of the foundation treatment.

Description

Technical Field

[0001] This invention relates to the field of marine complex soft foundation land reclamation technology, and in particular to a method for constructing a composite foundation by using balanced silt-squeezing crushed stone piles, which is applicable to foundation treatment construction on marine silt layers where stone backfill layers are formed. Background Technology

[0002] Artificial land reclamation projects involve directly backfilling stones onto the "marine silt layer" in the original sea area to form... Figure 1 The geological conditions depicted are characterized by a large-scale upper layer of hard stone, a middle layer of soft marine silt, and a lower layer of relatively hard clay, hereinafter referred to as "upper stone, middle silt, and lower clay." The upper hard stone layer reaches 10-20m in depth. Conventional crushed stone pile techniques, such as vibratory compaction and vibratory driven crushed stone pile methods, make it difficult to penetrate the upper hard stone layer and form piles within the silt layer. Furthermore, due to the varying thickness of the marine silt layer caused by land reclamation, conventional crushed stone pile techniques cannot directly replace the silt, resulting in discrete piles that are a mixture of silt and crushed stone. This leads to uneven settlement in the composite foundation constructed with crushed stone piles.

[0003] Squeezing-and-gravel piles refer to piles constructed using a high-energy impact method. A hollow pipe with a pointed tip is driven directly through the upper, harder stone backfill layer and the middle, weak silt layer, into the clay layer. The clay layer acts as a plug, squeezing the middle, weak silt layer to the periphery. The bottom, separate pipe tip is then removed, forming a hollow filling channel inside the pipe. Small-diameter gravel is then filled in sections to form a dense pile body.

[0004] Chinese patent CN107100182A, entitled "Bundled Layered Dewatering System for Soft Foundations without Filler and its Construction Method," describes a foundation treatment effect similar to that of vacuum preloading. Both methods utilize the principle of drainage consolidation and primarily address silty geological conditions. However, they only provide drainage consolidation and cannot support heavy equipment or filler materials to construct composite foundations. Furthermore, when the upper stone layer is too thick, it cannot penetrate the upper hard layer, hindering smooth construction. This method drains water but not silt, failing to utilize the natural flow effect of silt to balance soil pressure and unable to replace silt with filler, thus posing a certain risk of uneven settlement. Summary of the Invention

[0005] To address the impact of the hard upper layer of stone on the filler channel of the crushed stone pile under geological conditions of upper stone, middle mud, and lower clay, as well as the ground heave caused by silt squeezing during the pipe-driving process, this invention proposes a method for constructing a composite foundation using balanced silt squeezing crushed stone piles. Hollow pipes without tips are pre-drilled around the pile body to the middle silt layer. A long spiral drilling rig is used to hollow out the stone and silt inside the pipes, serving as sludge removal wells for the surrounding silt. During the construction of the surrounding silt squeezing crushed stone piles, silt is squeezed into the sludge removal wells, and the silt is continuously discharged through the sludge removal wells using the long spiral drilling rig. This eliminates the pressure-increasing effect of the crushed stone pile formation process on the surrounding silt, increases the crushed stone replacement rate of the silt layer, ensures overall foundation pressure balance, and avoids ground heave and uneven settlement problems.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for constructing a composite foundation using balanced silt-displacing crushed stone piles includes the following steps:

[0008] S1. Construction preparation and investigation;

[0009] S2. Construct a submerged tube sludge removal well;

[0010] S3. Drive a pipe-tipped pipe at the pile location and squeeze out silt;

[0011] S4. Remove the tip of the submerged tube;

[0012] S5, segmented filling material, rammed and enlarged pile body;

[0013] S6. Pile circulation construction, mud removal and pressure reduction;

[0014] S7. Testing of pile density and bearing capacity.

[0015] Step S1, construction preparation and investigation, includes:

[0016] Before construction, based on the engineering exploration data, the interface between the upper stone layer and the lower silt layer in the construction area is determined, and a mud-stone decomposition surface investigation report is formed for different pile locations. Combined with the design, the key indicators of pile location, pile diameter, and pile length are clarified, and the construction parameters of pipe diameter, pile driving machine model, and pile filling volume are determined.

[0017] Step S2, which involves drilling a submerged tube-type mud removal well, includes:

[0018] S201. Determine the construction parameters. To facilitate construction, use a pipe with the same diameter as the pile. The pipe diameter is 600-800mm. A diesel pile driver is used for the pipe driving equipment.

[0019] S202. On-site measurement and layout are used to determine the center point of the dredging well. The dredging well is located at the original design pile position. After the dredging is completed, it is driven back to the design elevation and then filled with more material to form a pile.

[0020] S203. Using a diesel pile driver, the pipe is moved to the center point of the sludge removal well, the pipe is slowly lowered, and the pipe is placed and fixed at the center point of the sludge removal well. The diesel pile driver will drive the pipe without the pile tip to the depth of the silt layer.

[0021] S204. A long spiral drilling rig is used, with the diameter of the spiral drill rod being smaller than the inner diameter of the submerged pipe. The spiral drill rod is inserted into the already submerged pipe, and the upper part of the pipe and the lower part of the silt are emptied by rotation, which can be used as a sludge removal well during the construction of surrounding pile positions.

[0022] Step S3, which involves driving a pipe-equipped pointed pipe at the pile location and silting up the silt, includes:

[0023] S301. Determine the construction parameters: the diameter of the driven pipe should be 600-800mm to ensure the diameter of the construction pile. To ensure that the driven pipe is quickly driven into the upper stone backfill layer, a separable pipe tip is installed at the bottom of the driven pipe to reduce the resistance during the driving process. The pile spacing of the crushed stone piles is 1.0-3.0m, the pile diameter is 600-800mm in the backfill layer and 1000-1200mm in the silt layer, and the pile length is 15-25m.

[0024] S302. Using the dredging well as the center, measure and mark the positions of the surrounding piles. Use a crane to place the split pipe tip at the bottom of the sinking pipe onto the pile point and fix it with the surrounding soil.

[0025] S303. Using a diesel pile driver, the pipe is moved to above the pipe tip, and the pipe is slowly lowered to combine the pipe and the pipe tip.

[0026] S304. A diesel-powered piling machine is used to drive the pipe with the pile tip to the designed pile depth. During the driving process, the pressure of the silt layer increases due to the compression of the pipe sinking and the gravity of the upper stone. Taking advantage of the incompressibility of the silt, the silt is returned through the sludge removal well. A long spiral drilling rig is used to continuously discharge the silt from the sludge removal well to achieve the purpose of pressure relief. The amount of sludge discharged is 50%-100% of the volume of the pipe. As the number of piles increases, the amount of sludge discharged increases.

[0027] Step S4, removing the tip of the immersed tube, includes:

[0028] S401. The vibratory pipe puller with a lifting hook is aligned with the installed pipe. The vibratory pipe puller connects to the pipe wall and pulls the pipe out 0.5-1.0m to reduce the tightness between the pipe and the tip.

[0029] S402. The reserved steel wire rope connecting the pipe tip is lifted by the lifting hook. The assembled pipe tip is separated from the whole circle into a semi-circle under the force. The valve pile tip is taken out inside the immersed pipe to form a hollow immersed pipe material unloading channel.

[0030] The step S5, segmented filling and rammed pile body, includes:

[0031] S501. Use a crane to lift the hopper, fill the filling at the opening of the submerged pipe, fill the submerged pipe with crushed stone, and pull the submerged pipe out 1-2m.

[0032] S502. When using the reverse insertion operation of the immersed tube, reverse insertion is performed every 1-2m when the tube is pulled out, with a reverse insertion depth of 0.2-0.5m each time. The weight of the stone material already filled in the tube is used to compact the pile body downwards, so as to achieve the purpose of pile body density. Repeat the above steps until the pile body is completed.

[0033] Step S6, pile circulation construction and sludge removal and pressure reduction, includes:

[0034] S601. Around the decompression and sludge removal well, the surrounding piles are constructed in sequence. During the sludge layer pile tamping process, according to the tamping volume, the sludge is discharged and decompression is achieved in the sludge removal well using a long spiral drilling rig. The sludge discharge volume is 50%-100% of the tamping volume. The construction is repeated until the surrounding piles are completed.

[0035] S602. After the sludge removal well is used, the sludge removal well casing will be re-driven to the design elevation of the pile body. According to the pile construction requirements, the sludge removal well will be constructed as a formal pile body.

[0036] The step S7, pile density and bearing capacity testing, includes:

[0037] S701. After construction is completed, each segment is tested according to the number of pile segments and the settlement situation. The density and diameter of the crushed stone pile are tested by dynamic penetration test and drilling test.

[0038] S702. Based on the test results, compare and calculate the theoretical pile diameter, further analyze the matching relationship between pile density, pile diameter and geological conditions, and form a test report to provide technical parameters for subsequent pile construction.

[0039] This invention uses the upper stone layer as a working platform. First, pipes without tips are driven into the silt layer around the pile location to serve as sludge removal wells. Second, pipes with tips are driven into the pile location to the design elevation using a pile hammer, and then the tips are removed, forming a channel for filling the gravel pile in the lower silt layer. Small-diameter gravel is then filled in sections to form a dense pile body. Finally, the sludge removal wells continuously remove mud and reduce pressure during the surrounding pile construction process until all surrounding piles are completed, at which point the process moves to the next construction area for cyclical construction. This method, using a pile hammer to drive pipes, greatly improves the efficiency of borehole drilling, forms a gravel filling channel, and ensures the continuity of pile construction. At the same time, the sludge-squeezing effect of the pipes with tips on the silt layer, continuously removing mud through the sludge removal wells, not only improves the gravel replacement rate in the silt layer but also avoids ground heave caused by sludge squeezing, ensuring the overall effectiveness of the foundation treatment.

[0040] This invention effectively solves the problem of the influence of the hard upper stone layer on the gravel pile filling channel under geological conditions of upper stone, middle mud, and lower clay. It utilizes a pile driver to quickly penetrate the pile location using a driven pipe, and by removing the pipe tip, a gravel pile filling channel is formed in the lower mud layer, enabling rapid pile formation. Simultaneously, the use of a pressure-reducing sludge removal well increases the overall gravel replacement rate of the mud layer, balances soil pressure, and avoids ground heave caused by sludge displacement during the driven pipe process, further reducing uneven foundation settlement. This method shortens the overall construction period by approximately 40% and increases the gravel replacement rate by approximately 50% through rapid drilling, ensuring the overall effectiveness of the foundation treatment. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of a geological formation consisting of upper rock, middle mud, and lower clay.

[0042] Figure 2 This is a diagram showing the layout of the dredging wells and pile locations.

[0043] Figure 3 This is a diagram illustrating the mud removal process at a mud-dredging well.

[0044] Figure 4 This is a diagram illustrating the construction process of the silt-dissipating crushed stone piles.

[0045] In the diagram: 1. Upper backfill stone layer, 2. Middle marine silt layer, 3. Lower clay layer, 4. Mud removal well, 5. Crushed stone pile location, 6. Submerged pipe, 7. Separate submerged pipe tip, 8. Long spiral drill rod, 9. Schematic diagram of mud removal direction. Detailed Implementation

[0046] The present invention will be further described below with reference to the accompanying drawings, but the present invention is not limited to the specific embodiments.

[0047] Example 1

[0048] like Figure 1 As shown, the construction area was directly backfilled with quarry rocks without dredging. By directly backfilling the marine silt layer in the original sea area, a special geological condition was formed, consisting of a hard upper layer of rocks, a soft middle layer of marine silt, and a relatively hard lower layer of clay. This is referred to as the special geological condition of "rocks in the upper layer, mud in the middle layer, and clay in the lower layer". The upper backfilled rock layer 1 reaches a thickness of 10-20m, and the lower clay layer 3 is between 5-15m thick.

[0049] A method for constructing a composite foundation using balanced silt-displacing crushed stone piles includes the following steps:

[0050] S1. Construction preparation and investigation;

[0051] Before construction, based on the engineering exploration data, the interface between the upper stone layer and the lower silt layer in the construction area is determined, and a mud-stone decomposition surface investigation report for different pile locations is formed. Combined with the design, key indicators such as pile location, pile diameter, and pile length are clarified, and construction parameters such as the diameter of the driven pipe, the model of the pile driver, and the amount of crushed stone filling are determined.

[0052] S2. Construct a submerged tube sludge removal well;

[0053] S201. Determine the construction parameters. To facilitate construction, a pipe with the same diameter as the pile will be used. The pipe diameter will be 800mm. A diesel pile driver will be used for the pipe driving equipment.

[0054] S202, such as Figure 2 As shown, the center point of the sludge removal well is determined by on-site measurement and layout. The sludge removal well is located at the original design pile position. After the sludge removal is completed, it is driven back to the design elevation and then filled with more material to form a pile.

[0055] S203, such as Figure 3 As shown, a diesel pile driver is used to move the submerged pipe to the center point of the sludge removal well, slowly lower the submerged pipe, place it in the center point of the sludge removal well and fix it, and the diesel pile driver will drive the submerged pipe without the pile tip to the depth of the silt layer.

[0056] S204, such as Figure 3 As shown, a long spiral drilling rig is used, with the diameter of the spiral drill rod being smaller than the inner diameter of the submerged pipe. The spiral drill rod is inserted into the already submerged pipe, and by rotating, the upper part of the pipe and the lower part of the silt are emptied, which can then be used as a sludge removal well for the construction of surrounding pile positions.

[0057] S3. Drive a pipe-tipped pipe at the pile location and squeeze out silt;

[0058] S301. Determine the construction parameters. The diameter of the driven pipe is selected to be 800mm to ensure the diameter of the construction pile. To ensure the driven pipe is quickly driven into the upper stone backfill layer, a detachable pipe tip is installed at the bottom of the driven pipe to reduce resistance during the driving process. The spacing between the crushed stone piles is 2.5m, the pile diameter is 800mm in the backfill layer and 1200mm in the silt layer, and the pile length is 25m.

[0059] S302. Using the dredging well as the center, measure and mark the positions of the surrounding piles. Use a crane to place the split pipe tip at the bottom of the sinking pipe onto the pile point and fix it with the surrounding soil.

[0060] S303. Using a diesel pile driver, the pipe is moved to above the pipe tip, and the pipe is slowly lowered to combine the pipe and the pipe tip.

[0061] S304, such as Figure 4As shown, a diesel pile driver is used to drive the pipe with the pile tip to the designed pile depth. During the driving process, the pressure of the silt layer increases due to the compression of the pipe sinking and the gravity of the upper stone. Taking advantage of the incompressibility of the silt, the silt is returned through the sludge removal well. A long spiral drilling rig is used to continuously discharge the silt from the sludge removal well to achieve the purpose of pressure relief. The amount of sludge discharged is 50%-100% of the volume of the pipe. As the number of piles increases, the amount of sludge discharged increases.

[0062] S4. Remove the tip of the submerged tube;

[0063] S401. The vibratory belt hoisting hook pipe puller is aligned with the installed submerged pipe. The vibratory pipe puller connects to the submerged pipe wall and pulls the submerged pipe out by 0.5m, reducing the tightness between the submerged pipe and the pipe tip.

[0064] S402, such as Figure 4 As shown, the reserved steel wire rope connecting the pipe tip is lifted by the lifting hook. The assembled pipe tip is separated from the whole circle into a semi-circle under force. The valve pile tip is taken out inside the immersed pipe to form a hollow immersed pipe material unloading channel.

[0065] S5, segmented filling material, rammed and enlarged pile body;

[0066] S501, such as Figure 4 As shown, a crane is used to lift the hopper, fill the filling material at the opening of the submerged pipe, the submerged pipe is filled with crushed stone, and the submerged pipe is pulled out 1-2m.

[0067] S502. The reverse insertion operation of the sinking tube is adopted. When the sinking tube is pulled out, it is reversed once every 1.5m of lifting, with a reverse insertion depth of 0.3m. The pressure of the stone material inside the tube is used to achieve the purpose of compacting the pile body. The above steps are repeated until the pile body is completed.

[0068] S6. Pile circulation construction, mud removal and pressure reduction;

[0069] S601. Construct the surrounding piles sequentially around the decompression and sludge removal well. During the ramming and expansion process of the piles in the silt layer, according to the ramming and expansion volume, use a long spiral drilling rig to discharge mud and decompress in the sludge removal well. The discharge volume is 50%-100% of the ramming and expansion volume. Continue the construction cycle until the surrounding piles are completed.

[0070] S602. After the sludge removal well is used, the sludge removal well casing will be re-driven to the design elevation of the pile body. According to the pile construction requirements, the sludge removal well will be constructed as a formal pile body.

[0071] S7. Testing of pile density and bearing capacity;

[0072] S701. After construction is completed, each segment is tested according to the number of pile segments and the settlement status. The density and diameter of the crushed stone pile are tested through dynamic penetration and drilling tests.

[0073] S702. Based on the test results, compare and calculate the theoretical pile diameter, further analyze the matching relationship between pile density, pile diameter and geological conditions, and form a test report to provide technical parameters for subsequent pile construction.

[0074] Example 2

[0075] In this embodiment, the method for constructing a composite foundation using balanced silt-displacing crushed stone piles is the same as that in Embodiment 1, except that:

[0076] 1. In step S201, the diameter of the immersed tube is selected as 600mm;

[0077] 2. In step S301, the diameter of the immersed tube is 600mm, the spacing between the crushed stone piles is 1.0m, the pile diameter is 600mm in the backfill layer and 1000mm in the silt layer, and the pile length is 15m.

[0078] 3. In step S401, the immersed tube is pulled out by 0.7m;

[0079] 4. In step 502, reverse insertion is performed once every 1 m of lifting, with a reverse insertion depth of 0.2 m.

[0080] Example 3

[0081] In this embodiment, the method for constructing a composite foundation using balanced silt-displacing crushed stone piles is the same as that in Embodiment 1, except that:

[0082] 1. In step S201, the diameter of the immersed tube is selected as 700mm;

[0083] 2. In step S301, the diameter of the immersed tube is 700mm, the spacing between the crushed stone piles is 3.0m, the pile diameter is 700mm in the backfill layer and 1100mm in the silt layer, and the pile length is 20m.

[0084] 3. In step S401, the immersed tube is pulled out by 1.0m.

[0085] 4. In step 502, reverse insertion is performed every 2 m of lifting, with a reverse insertion depth of 0.5 m.

[0086] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be included within the scope of protection of the present invention.

Claims

1. A method for constructing a composite foundation using balanced silt-displacing crushed stone piles, characterized in that, Includes the following steps: S1. Construction preparation and investigation; S2. Constructing a submerged tube sludge removal well; specifically including: S201. Determine the construction parameters. To facilitate construction, use a pipe with the same diameter as the pile. The pipe diameter is 600-800mm. A diesel pile driver is used for the pipe driving equipment. S202. On-site measurement and layout are used to determine the center point of the dredging well. The dredging well is located at the original design pile position. After the dredging is completed, it is driven back to the design elevation and then filled with more material to form a pile. S203. Using a diesel pile driver, the pipe is moved to the center point of the sludge removal well, the pipe is slowly lowered, and the pipe is placed and fixed at the center point of the sludge removal well. The diesel pile driver will drive the pipe without the pile tip to the depth of the silt layer. S204. A long spiral drilling rig is used, with the diameter of the spiral drill rod being smaller than the inner diameter of the submerged pipe. The spiral drill rod is inserted into the already submerged pipe, and the upper stone and lower silt inside the pipe are emptied by rotation, which can be used as a sludge removal well during the construction of surrounding pile positions. S3. Drive a pipe-tipped pipe at the pile location and squeeze out silt; S4. Remove the tip of the submerged tube; S5, segmented filling material, rammed and enlarged pile body; S6. Pile circulation construction, mud removal and pressure reduction; specifically including: S601. Around the decompression and sludge removal well, the surrounding piles are constructed in sequence. During the ramming and expansion process of the piles in the silt layer, according to the ramming and expansion volume, the sludge is discharged and decompression is achieved in the sludge removal well using a long spiral drilling rig. The sludge discharge volume is 50%-100% of the ramming and expansion volume. The construction is repeated until the surrounding piles are completed. S602. After the sludge removal well is used, the sludge removal well casing will be re-driven to the design elevation of the pile body. According to the pile construction requirements, the sludge removal well will be constructed as a formal pile body. S7. Testing of pile density and bearing capacity.

2. The method for constructing a composite foundation using balanced silt-displacing crushed stone piles according to claim 1, characterized in that, Step S1, construction preparation and investigation, includes: Before construction, based on the engineering exploration data, the interface between the upper stone layer and the lower silt layer in the construction area is determined, and a mud-stone decomposition surface investigation report is formed for different pile locations. Combined with the design, the key indicators of pile location, pile diameter, and pile length are clarified, and the construction parameters of pipe diameter, pile driving machine model, and pile filling volume are determined.

3. The method for constructing a composite foundation using balanced silt-displacing crushed stone piles according to claim 1, characterized in that, Step S3 involves driving a pipe-tipped pipe at the pile location and discharging silt, including: S301. Determine the construction parameters: the diameter of the immersed tube should be 600-800mm, and a detachable tube tip should be installed at the bottom of the immersed tube; the spacing of the crushed stone piles should be 1.0-3.0m, the pile diameter should be 600-800mm in the backfill layer and 1000-1200mm in the silt layer, and the pile length should be 15-25m. S302. Using the dredging well as the center, measure and mark the positions of the surrounding piles. Use a crane to place the split pipe tip at the bottom of the sinking pipe onto the pile point and fix it with the surrounding soil. S303. Using a diesel pile driver, the pipe is moved to above the pipe tip, and the pipe is slowly lowered to combine the pipe and the pipe tip. S304. A diesel-powered piling machine is used to drive the pipe with the pile tip to the designed pile depth. During the driving process, the pressure of the silt layer increases due to the compression of the pipe sinking and the gravity of the upper stone. Taking advantage of the incompressibility of the silt, the silt is returned through the sludge removal well. A long spiral drilling rig is used to continuously discharge the silt from the sludge removal well to achieve the purpose of pressure relief. The amount of sludge discharged is 50%-100% of the volume of the pipe. As the number of piles increases, the amount of sludge discharged increases.

4. The method for constructing a composite foundation using balanced silt-displacing crushed stone piles according to claim 1, characterized in that, Step S4, removing the tip of the submerged tube, includes: S401. The vibratory pipe puller with a lifting hook is aligned with the installed submerged pipe. The vibratory pipe puller connects to the wall of the submerged pipe and pulls the pipe out 0.5-1.0m. S402. The reserved steel wire rope connecting the pipe tip is lifted by the lifting hook. The assembled pipe tip is separated from the whole circle into a semi-circle under the force. The valve pile tip is taken out inside the immersed pipe to form a hollow immersed pipe material unloading channel.

5. A method for constructing a composite foundation using balanced silt-displacing crushed stone piles according to claim 1, characterized in that, Step S5, segmented filling and compacted pile body, includes: S501. Use a crane to lift the hopper, fill the filling at the opening of the submerged pipe, fill the submerged pipe with crushed stone, and pull the submerged pipe out 1-2m. S502. When using the reverse insertion operation of the immersed tube, reverse insertion is performed every 1-2m when the tube is pulled out, with a reverse insertion depth of 0.2-0.5m each time. The weight of the stone material already filled in the tube is used to compact the pile body downwards, so as to achieve the purpose of pile body density. Repeat the above steps until the pile body is completed.

6. A method for constructing a composite foundation using balanced silt-displacing crushed stone piles according to claim 1, characterized in that, Step S7, pile compaction and bearing capacity testing, includes: S701. After construction is completed, each segment is tested according to the number of pile segments and the settlement situation. The density and diameter of the crushed stone pile are tested by dynamic penetration test and drilling test. S702. Based on the test results, compare and calculate the theoretical pile diameter, further analyze the matching relationship between pile density, pile diameter and geological conditions, and form a test report to provide technical parameters for subsequent pile construction.

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