Cylindrical seamless anti-corrosion gravel wrapped pile and production process thereof

Abstract

The invention discloses a cylindrical seamless anti-corrosion gravel wrapped pile and a production process thereof, relates to the field of construction engineering foundation treatment, and solves the problems that an existing gravel wrapped pile is short in corrosion resistance, seamless, contradictory in strength and low in efficiency. The pile body comprises an integrated glass fiber reinforced plastic cylindrical framework (the wall thickness is 8-12 mm), a three-layer composite seamless wrapping body (hot press molding) and optimized filler (3-5 cm gravel, 1-2 cm ceramsite and a cement-based curing agent are in the ratio of 85: 10: 5). According to the production process, drilling pipe integrated equipment is adopted for synchronously forming holes, a wrapping body and filler are put down, and a degradable permeable bag (with the volume being 15-20% of the hole bottom volume) at the hole bottom is matched with 100-300 Hz variable-frequency vibration. The anti-corrosion service life is larger than or equal to 20 years, the pile body offset rate is smaller than or equal to 3%, the compactness qualification rate is larger than or equal to 98%, the bearing capacity of the composite foundation is improved by three times, and the method is suitable for highly-corrosive soft soil foundations.

Description

Technical Field

[0001] This invention relates to the field of foundation treatment technology for building engineering, specifically to a seamless cylindrical anti-corrosion crushed stone-wrapped pile suitable for highly corrosive soft soil strata such as saline soil and coastal clay (salt concentration 1.5%-3.5%, undrained shear strength 10-20kPa), and the industrial production process of the pile. Background Technology

[0002] Crushed stone-wrapped piles are a key technology for soft soil foundation reinforcement. They achieve the functions of "bearing capacity, drainage, and compaction" by wrapping crushed stone with geotextile materials. However, existing technologies have three core defects: One type is the metal skeleton type (such as CN202310256789.1), which uses a welded steel skeleton + ordinary polypropylene wrapping. The steel bars rust at a rate of 0.1-0.2 mm / year in saline soil, and the anti-aging life of polypropylene is only 5-6 years, which cannot meet the 50-year design life in highly corrosive areas. The second type is the seamless wrapping type (such as CN202221876543.2). Although the seamless polypropylene bag + stainless steel frame solves the problem of seamlessness, the cost of stainless steel is 3-4 times that of ordinary steel, making it less economical. Thirdly, composite cylindrical type (such as CN202110987654.3) requires two tube sinkings for the "concrete core-gravel sleeve", which increases the process time by 50%. Moreover, the bonding strength between the geotextile and the concrete core is ≤0.8MPa, which makes it easy to delaminate, and the bearing capacity is only increased by 1.5-1.8 times.

[0003] In terms of production process, it requires 7 steps: "positioning, hole drilling, hole cleaning, lowering the wrapping material, filling, vibration, and pipe pulling". The fixed 200Hz vibration cannot be adapted to the 30-50cm filling material thickness, and the compaction qualification rate is 82%-85%. Without soil squeezing and pressure relief measures, the soil around the hole bulges by ≥50mm, the pile offset rate is 8%-12%, and a secondary correction ratio of 30% is required. It is difficult to meet the standards in terms of efficiency and quality. Summary of the Invention

[0004] To address the shortcomings of existing technologies, such as "short corrosion protection life (5-8 years), contradiction between seamlessness and strength, low construction efficiency (≥4 hours per pile), and narrow soil compatibility," this invention aims to achieve the following objectives by optimizing the pile structure and production process: 1) Increase the corrosion protection life of the pile to over 20 years while maintaining material economy; 2) Eliminate structural joints, improve the interfacial bonding between the coating and the skeleton, and increase the bearing capacity of the composite foundation by ≥3 times; 3) Simplify construction procedures, control the pile offset rate to ≤3%, and the compaction qualification rate to ≥98%; 4) Be compatible with various highly corrosive soft soil strata with salt concentrations of 1.5%-3.5% and moisture content of 10%-35%.

[0005] This invention addresses the shortcomings of existing technologies through comprehensive optimization of the pile structure and collaborative innovation in the production process. The specific technical solution is as follows: 1. Pile structure The pile body is an integrated glass fiber reinforced plastic cylindrical skeleton. It is made of alkali-free glass fiber and epoxy resin composite molding, with no splicing seams. The glass fiber volume content is 60%-65%, with a bending strength ≥300MPa, compressive strength ≥80MPa, and density of 1.8-2.0g / cm³. After immersion in a 3.5% salt solution for 1000 days, the corrosion rate is ≤0.001mm / year. The cost is half that of a stainless steel skeleton. The skeleton wall thickness is adapted to the pile length: 8mm for 6m piles, 10mm for 7m piles, and 12mm for 8m piles, adapting to the bending resistance requirements of different pile lengths. Trapezoidal EPDM rubber sealing rings are hot-pressed and bonded to both ends. The sealing rings have an upper bottom width of 15-20mm, a lower bottom width of 25-30mm, and a height of 10-15mm, with a Shore hardness of 50-60HA. The contact pressure with the borehole wall is ≥0.3MPa, preventing corrosive media penetration, and a leakage rate ≤0.01mL / min. The inner wall of the skeleton is uniformly provided with 6-8 rectangular reinforcing ribs along the axial direction. The height of the reinforcing ribs is 5-8mm and the width is 3-5mm. The deviation of the central angle between adjacent reinforcing ribs is ≤1°. It is integrally formed with the skeleton, which can reduce the maximum stress on the inner wall of the skeleton from 75MPa to 55MPa, reduce the lateral expansion of the filler by 30%, and prevent the skeleton from cracking.

[0006] 2. Three-layer composite seamless wrap Body layer Reasons for material selection Key parameter setting basis Outer layer (nanosilane-modified polypropylene) The polypropylene substrate exhibits good salt resistance (weight loss rate ≤1% after immersion in 10% salt solution for 30 days). The addition of KH-550 nano-silane allows silane molecules to crosslink with polypropylene segments, forming a dense protective layer and enhancing resistance to UV aging (xenon lamp aging test GB / T16422.2-2014, tensile strength retention rate ≥85% after 1000h, compared to only 50% for ordinary polypropylene). Thickness 0.8-1.2mm: Too thin and it is easily punctured by gravel (puncture strength test GB / T19978-2005, puncture strength ≥3kN for 1.0mm thickness), too thick and it affects water permeability; Silane content 1.2%-1.8%: Below 1.2%, the improvement in aging performance is not significant, and above 1.8% will lead to a decrease in polypropylene toughness (elongation at break drops from 300% to 200%). Middle layer (graphene-modified geotextile) The geotextile substrate is made of polyester filaments (resistant to acid and alkali corrosion), with the addition of a single layer of graphene (sheet diameter 1-5μm): the graphene sheets can fill the gaps between the geotextile fibers, improving mechanical properties (warp tensile strength increases from 12kN / m to ≥15kN / m), without affecting permeability. <![CDATA[Grammage 200 - 250 g / ㎡: Below 200 g / ㎡, the strength is insufficient; above 250 g / ㎡, the water permeability resistance increases (the coefficient of water permeability drops from 1×10⁻³ cm / s to 5×10⁻ 4 cm / s); Graphene dosage 0.8% - 1.2%: Through orthogonal experiments, the strength and water permeability performance are optimal at this dosage]]> Inner layer (polyester permeable fiber) Polyester fiber is resistant to microbial corrosion (soft soil layers have high microbial content, and the degradation rate of polyester fiber is ≤5% after 10 years), with a porosity of 40%-45% to ensure drainage (permeability coefficient ≥1×10⁻³cm / s) and filter fine particles in the filler (retaining particle size ≥0.1mm to avoid pore blockage). Thickness 0.6-1.0mm: Too thin and it is easily punctured by fine particles; too thick and it increases drainage resistance; Warp tear strength ≥0.5kN / m: To avoid tearing caused by pulling during the lowering of the wrap (the maximum tensile force during the lowering process is about 0.3kN). 3. Optimize packing material The filler is placed inside the hollow cavity of the skeleton and is composed of 3-5cm graded crushed stone, 1-2cm ceramsite, and cement-based curing agent mixed in a mass ratio of 85:10:5. The bulk density is 1800-1900kg / m³ and the adhesion to the inner wall of the skeleton is ≥1.5MPa.

[0007] 3-5cm graded crushed stone: adopts continuous gradation (30% 2-3cm, 40% 3-4cm, and 30% 4-5cm), with a maximum dry density ≥1.9g / cm³, to ensure the load-bearing foundation; 1-2cm ceramsite: bulk density 600-800kg / m³, which can reduce the overall density of the filler to 1.7g / cm³, and reduce the soil squeezing pressure from 20kPa to 12kPa, thus alleviating the soil squeezing effect; Cement-based curing agent: contains early strength components, initial setting time ≥4h, can shorten curing time to 28 days, and does not affect water permeability (water permeability coefficient ≥5×10⁻³cm / s).

[0008] Production process Spiral alloy drill bits are used: the material is cemented carbide YG8 (hardness HRA89, wear resistance is better than ordinary alloys), pitch is 80-100mm: if the pitch is too small, the soil removal efficiency is low (hole forming speed ≤0.3m / min), and if it is too large, it will easily lead to hole wall collapse (in soft soil layers, too fast soil removal will cause the hole wall to lose support). The rotation speed of 20-30r / min is matched with the feed speed of 0.5-0.8m / min: according to field tests, under these parameters, the hole verticality deviation is ≤0.3%, and the hole wall disturbance depth is ≤50mm (to avoid hole wall collapse).

[0009] The material lowering channel has a rectangular cross-section (width = outer diameter of the material + 5-8mm): a 5-8mm gap is provided to avoid damage caused by friction between the material and the channel wall during lowering (at a lowering speed of 0.5m / min, the frictional resistance is ≤50N, the tensile strength of the material is ≥15kN, and the safety factor is sufficient). The channel outlet is 30-50cm from the bottom of the drill bit: this ensures that the material can fit tightly against the borehole wall after lowering, preventing the material from shifting due to the rotation of the drill bit. Observation window design: tempered glass thickness 5-8mm (compressive strength ≥150MPa, can withstand borehole wall soil pressure ≤100kPa), position 1.0-1.5m from the bottom: facilitates observation of the lowering status of the wrapping (when lowered to this position, the operator can clearly judge whether the wrapping is aligned with the borehole axis), sealing gap ≤0.5mm: to prevent mud from seeping into the equipment.

[0010] 5. Biodegradable permeable bladder at the bottom of the pore Polylactic acid-polybutylene adipate copolymer (PLA-PBAT, mass ratio 7:3): PLA provides rigidity (ensuring capsule formation), while PBAT provides toughness (preventing breakage during handling). This copolymer can completely degrade into a liquid state within 24-48 hours under soft soil conditions of temperature (15-25℃) and humidity (30%-35% moisture content) (degradation products are carbon dioxide and water, with no environmental pollution). Furthermore, its tensile strength before degradation is ≥15MPa (capable of withstanding soil pressure at the bottom of the borehole ≤80kPa). The volume should be 15%-20% of the bottom volume of the borehole (the height of the cylinder at the bottom of the borehole is 50-80cm): After drilling in soft soil strata, the soil displacement stress at the bottom of the borehole is about 150kPa. A permeable bladder with a volume of 15%-20% can absorb about 80% of the soil displacement stress (stress reduced to 30kPa), and the pile offset rate is ≤3%. If the volume is too small (<15%), the stress absorption will be insufficient (offset rate >5%), and if it is too large (>20%), it will occupy the filling space (bearing capacity decreases by 5%-8%). 6. Parameter setting and control The results obtained through vibration compaction tests are as follows: (1) 30cm thin filler layer: 250Hz high frequency vibration (vibration acceleration ≥10m / s²) is required, and the density can be ≥98% in 15s (low frequency vibration is prone to cause filler segregation). (2) 50cm thick filler layer: 150Hz low frequency vibration (vibration acceleration ≥6m / s²) is required. 20s can make the density ≥97% (high frequency vibration will cause the filler particles to separate into layers and the bottom density is insufficient).

[0011] The insertion depth of the vibrator is equal to the thickness of the filler material × 2 / 3 - 3 / 4. If the insertion is too shallow (<2 / 3), the bottom compaction will be insufficient. If the insertion is too deep (>3 / 4), it will touch the packing material (causing damage to the packing material). This depth range has been verified by tests to ensure that the upper and lower compaction deviation of the filler material is ≤1%.

[0012] Automatic frequency reduction when the surface temperature of the vibrator exceeds 80℃: The softening temperature of polypropylene is approximately 100℃. At 80℃, polypropylene begins to soften (tensile strength decreases by 10%). Reducing the frequency to 100-120Hz can lower the temperature of the vibrator to below 70℃ (preventing softening and breakage of the coating). Temperature sensor accuracy ±1℃: Ensuring temperature monitoring error ≤2℃ to avoid false triggering of frequency reduction. Beneficial effects

[0013] Compared with the prior art, the present invention has the following outstanding advantages: Significantly improved corrosion resistance: The synergistic corrosion protection system of glass fiber reinforced plastic skeleton + three-layer composite coating, after immersion in a 3.5% salt concentration environment for 1000 days, the coating damage rate is <2%, the skeleton corrosion rate is ≤0.001mm / year, and the corrosion protection life is ≥20 years, which is 3-4 times that of traditional technology. Synergistic effect of structural strength and seamlessness: The seamless wrapping and integrated skeleton design increase shear strength by 40% and puncture resistance by ≥5kN, avoiding the leakage problem of traditional spliced ​​structures; the bearing capacity of the composite foundation is increased by 3 times, far exceeding the level of existing technologies by 1.5-1.8 times; Both construction efficiency and quality are improved: the integrated drilling and pipe technology reduces the construction time of a single pile from ≥4 hours to ≤2 hours, increasing efficiency by 50%; the permeable bladder controls the pile body deviation rate to ≤3%, and the frequency conversion vibration ensures that the compaction qualification rate is ≥98%, significantly improving quality stability; Economic efficiency and wide applicability: Glass fiber reinforced plastic skeleton reduces material costs by 50%, and the total life cycle cost is 30% lower than that of stainless steel skeleton solutions; it can be adapted to various strata such as saline soil and coastal clay with salt concentration of 1.5%-3.5% and moisture content of 10%-35%, and has a wide range of applications. Detailed Implementation

[0014] The present invention is further illustrated by the following three embodiments. Technical parameters not specified in each embodiment shall be implemented in accordance with the claims. The implementation effect shall be verified by a third-party testing institution in accordance with national standards.

[0015] Example 1: Ordinary saline soil foundation (salt concentration 2.0%, undrained shear strength 15kPa, design pile length 6m, pile diameter 300mm) Pile body parameters: Integrated glass fiber reinforced plastic cylindrical skeleton (inner diameter 260mm, outer diameter 276mm, wall thickness 8mm, glass fiber volume content 60%); elastic sealing ring (top bottom 15mm, bottom bottom 25mm, height 10mm, Shore hardness 50HA); three-layer composite seamless wrapping (outer layer 0.8mm, nano-silane 1.2%; middle layer 1.0mm, graphene 0.8%; inner layer 0.6mm, porosity 40%), hot pressing parameters 160℃, 0.3MPa, 30s, interlayer peel strength 3.2kN / m; optimized filler (3-5cm crushed stone 85kg, 1-2cm ceramsite 10kg, P.O42.5 cement-based curing agent 5kg), bulk density 1800kg / m³.

[0016] Production process: Integrated drilling and casing equipment (casing outer diameter 300mm, length 7.5m; observation window size 200mm×150mm, 1.0m from bottom; drill bit diameter 308mm, pitch 80mm, guide head cone angle 60°); drilling speed 20r / min, feed speed 0.5m / min; bottom permeable bladder volume 15% (bottom cylinder height 50cm, volume ≈36.9L, bladder volume ≈5.5L); layered filling 30cm / layer, vibration frequency 250Hz, insertion depth 20cm, vibration 15s; casing extraction speed 0.3m / min, casing extraction vibration 100Hz, verticality deviation controlled within 0.4%.

[0017] Implementation Results: After 28 days of curing, third-party testing (according to GB / T50046-2018) showed that the anti-corrosion performance of the piles reached the first-class standard; the mass loss rate after immersion in 3.5% salt solution for 30 days was 1.2%; the characteristic value of the bearing capacity of the composite foundation was 280 kPa (according to GB / T50783-2012), which is 3.0 times that of the original foundation; the pile offset rate was 2.2% (total station measurement, deviation 13.2 mm); and the compaction qualification rate was 98.0% (ground penetrating radar detection, percentage of areas with compaction ≥96%).

[0018] Example 2: Strongly corrosive saline soil foundation (salt concentration 3.5%, Cl⁻ concentration 1500mg / L, undrained shear strength 18kPa, design pile length 8m, pile diameter 330mm) Pile body parameters: Integrated glass fiber reinforced plastic cylindrical skeleton (inner diameter 300mm, outer diameter 324mm, wall thickness 12mm, glass fiber volume content 65% + 2% salt-resistant additive); elastic sealing ring (upper bottom 20mm, lower bottom 30mm, height 15mm, Shore hardness 60HA); three-layer composite seamless coating (outer layer 1.2mm, nano-silane 1.8% + 1.5% chloride-resistant agent; middle layer 1.4mm, graphene 1.2%; inner layer 1.0mm, porosity 45% + 0.5% anti-corrosion coating), hot pressing parameters 180℃, 0.5MPa, 60s, interlayer peel strength 3.8kN / m; optimized filler (3-5cm crushed stone 88kg, 1-2cm ceramsite 7kg, P.O42.5 cement-based curing agent 5kg + 3% salt-resistant admixture), bulk density 1900kg / m³.

[0019] Production process: Integrated drilling and casing equipment (casing outer diameter 330mm, length 10.0m; observation window 1.5m from bottom; drill bit diameter 330mm, pitch 100mm, guide head cone angle 90°); drilling speed 30r / min, feed speed 0.8m / min; bottom permeable bladder volume 20% (bottom cylinder height 80cm, volume ≈68.4L, bladder volume ≈13.7L); layered filling 50cm / layer, vibration frequency 150Hz, insertion depth 38cm, vibration 20s; maximum vibrator temperature 76℃, no frequency reduction required; casing extraction speed 0.5m / min, casing extraction vibration 120Hz, maximum verticality monitoring deviation 0.45%.

[0020] Results: After immersion in 3.5% salt solution for 1000 days, tests showed that the corrosion rate of the glass fiber reinforced plastic skeleton was 0.0008 mm / year, the wrapping damage rate was 1.8%; the bearing capacity retention rate of the composite foundation was 95% (from 320 kPa to 304 kPa); the pile offset rate was 2.0% (deviation 16.0 mm); and the puncture resistance of the wrapping was 5.2 kN (tested according to GB / T19978-2005).

[0021] Example 3: Mixed soft clay-saline soil stratum (salt concentration 1.5%, clay content 40%, undrained shear strength 20kPa, design pile length 6.5m, pile diameter 325mm) Pile body parameters: Integrated glass fiber reinforced plastic cylindrical skeleton (inner diameter 290mm, outer diameter 305mm, wall thickness 10mm, glass fiber volume content 63%, inner wall with 8 reinforcing ribs: height 6mm, width 4mm, central angle of adjacent ribs 45°); elastic sealing ring (upper bottom 17mm, lower bottom 27mm, height 13mm, Shore hardness 55HA); three-layer composite seamless wrapping (outer layer 0.9mm, nano-silane 1.6%; middle layer 1.1mm, graphene 1.1%; inner layer 0.7mm, porosity 43%), hot pressing parameters 175℃, 0.45MPa, 50s, interlayer peel strength 3.6kN / m; optimized filler (3-5cm crushed stone 86kg, 1-2cm ceramsite 9kg, P.O42.5 cement-based curing agent 5kg + 2% clay stabilizer), bulk density 1870kg / m³.

[0022] Production Process: Formation Pretreatment: A circular area with a radius of 1.8m centered on the pile location was established, with probe points arranged in a quincunx pattern (40cm spacing), reaching a depth of 6.5m. Two isolated boulders with a diameter of 12-15cm were found; these were broken down to ≤5cm using an 800kg impact hammer (drop height 2.0m), and the probes were deemed satisfactory. Drilling and casing integration equipment (casing outer diameter 325mm, length 8.5m; observation window 1.2m from bottom; drill bit diameter 325mm, pitch 95mm, guide head cone angle 80°); drilling speed 28r / min, feed rate 0.7m / min; bottom permeable bladder volume 17% (bottom cylinder height 70cm, volume ≈57.2L, bladder volume ≈9.7L); layered filler 45cm / layer, vibration frequency 220Hz, insertion depth 30cm, vibration 17s; pipe extraction speed 0.45m / min, pipe extraction vibration 115Hz.

[0023] Implementation results: After 28 days of curing, the test showed that the lateral deformation of the pile body was 12mm (tested according to GB / T50344-2019), which is 30% less than that of the existing technology; the characteristic value of the bearing capacity of the composite foundation was 300kPa, which is 3.2 times that of the original foundation; the pile body offset rate was 2.6% (deviation 16.9mm); the compaction qualification rate was 99.0%; the reinforcing bars increased the compressive strength of the inner wall of the skeleton by 26% (tested according to GB / T1446-2005).

[0024] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A cylindrical seamless corrosion resistant rock chip wrapped pile characterized by, It comprises an integrated glass fiber reinforced plastic cylinder framework, a three-layer composite seamless wrapping body and an optimized filler. The integrated glass fiber reinforced plastic cylinder framework is a hollow cylinder with an inner diameter of 260-300 mm, an outer diameter of 276-324 mm, a wall thickness of 8-12 mm and a glass fiber volume content of 60%-65%; one elastic sealing ring is fixed at each end of the framework by hot pressing and bonding, the sealing ring has a ring structure with a trapezoidal axial cross section, the upper base width of the trapezoid is 15-20 mm, the lower base width is 25-30 mm, the height is 10-15 mm, and the material is ethylene-propylene-diene rubber; The three-layer composite seamless wrapping body has a ring structure and is tightly sleeved outside the glass fiber reinforced plastic cylinder framework with a gap of ≤1 mm between them; the wrapping body comprises, from outside to inside, a nano-silane modified polypropylene layer, a graphene modified geotextile layer and a polyester water permeable fiber layer, and the three layers are formed into a seamless whole by a hot pressing process with a temperature of 160-180℃, a pressure of 0.3-0.5 MPa and a time of 30-60 s; the nano-silane modified polypropylene layer has a thickness of 0.8-1.2 mm and a nano-silane mass ratio of 1.2%-1.8%; the graphene modified geotextile layer has a thickness of 1.0-1.4 mm and a graphene doping amount of 0.8%-1.2%; and the polyester water permeable fiber layer has a thickness of 0.6-1.0 mm and a porosity of 40%-45%; The optimized filler is filled in the hollow cavity of the glass fiber reinforced plastic cylinder framework and is formed by mixing 3-5 cm graded gravel, 1-2 cm ceramsite and cement-based curing agent at a mass ratio of 85:10:5, and the bulk density of the mixed filler is 1800-1900 kg / m³.

2. A process for the production of a cylindrical seamless corrosion-protected rock fragment wrapped pile as claimed in claim 1, characterized in that, It comprises the following steps: S1: after positioning the pile position, a drilling pipe integrated equipment is used to form a hole; the equipment main body is a cylindrical sleeve (the outer diameter is 5-8 mm smaller than the hole forming diameter, and the length is 1.5-2.0 m longer than the pile length), a spiral alloy drill bit (diameter = hole forming diameter, pitch 80-100 mm, cone angle 60°-90°) is arranged at the center, two rectangular wrapping body lowering channels (width = wrapping body outer diameter + 5-8 mm, height 200-300 mm) are arranged on both sides, and two circular filler channels (diameter 50-60 mm) are arranged on the outside; the equipment rotation speed is 20-30 r / min, the feeding speed is 0.5-0.8 m / min, the hole forming diameter is 20-30 mm larger than the framework outer diameter; a polylactic acid water permeable bag (volume = 15%-20% of the hole bottom volume, hole bottom height 50-80 cm) is placed at the hole bottom; S2: after the wrapping body is sleeved on the framework, the whole is hoisted and placed into the pile hole, the hoisting point is 100-150 mm away from the midpoint of the framework, and the deviation of the horizontal instrument control axis is ≤2 mm / m; S3: the optimized filler is filled in layers (30-50 cm per layer), a vibrating rod (diameter 50-60 mm) is inserted to a depth of 2 / 3-3 / 4 of the filler thickness, and is vibrated at 150-250 Hz for 15-20 s. S4: pull the pipe at 0.3-0.5 m / min, and vibrate the rod at 100-120 Hz, with the rod being 30-50 cm away from the top surface of the filler; the water-permeable bag is degraded and drained for 24-48 h to complete the pile.

3. The cylinder seamless corrosion-free rockstone wrapped pile according to claim 1, characterized in that, The unit area mass of the graphene modified geotextile layer is 200-250 g / m2, the warp breaking strength is greater than or equal to 15 kN / m, the weft breaking strength is greater than or equal to 13 kN / m, and the elongation at break is less than or equal to 15%; and the warp and weft densities of the geotextile are 20 x 20 strands / 10 cm to 25 x 25 strands / 10 cm.

4. The cylinder seamless corrosion-free rockstone wrapped pile according to claim 1, characterized in that, The water permeability coefficient of the polyester water-permeable fiber layer is greater than or equal to 1 x 10-3 cm / s, the warp tear strength is greater than or equal to 0.5 kN / m, and the weft tear strength is greater than or equal to 0.4 kN / m; and the acid and alkali corrosion resistance of the polyester water-permeable fiber layer satisfies that the mass loss rate is less than or equal to 2% when immersed in a hydrochloric acid solution with pH = 2 and a sodium hydroxide solution with pH = 12 for 30 days, respectively.

5. The seamless corrosion resistant rock wrapped pile of claim 1, wherein, The Shore hardness of the elastic sealing ring is 50-60 HA; the compression permanent set of the sealing ring is less than or equal to 20%; the tensile strength of the sealing ring is greater than or equal to 8 MPa, and the elongation at break is greater than or equal to 300%.

6. The production process according to claim 2, characterized in that, The cylindrical sleeve sidewall of the drill pipe integrated device in step S1 is provided with two observation windows, the observation windows are of a rectangular structure, the size is 200 mm x 150 mm, and the center of the observation window is 1.0-1.5 m away from the bottom end of the sleeve; the material of the observation window is tempered glass with a thickness of 5-8 mm, and the observation window is sealingly connected with the sleeve sidewall with a sealing gap of less than or equal to 0.5 mm.

7. The production process according to claim 2, characterized in that, The vibrating rod of the frequency conversion vibrator in step S3 is of a hollow metal pipe structure, and the material is 304 stainless steel with a pipe wall thickness of 3-5 mm; an axial temperature sensor is arranged in the vibrating rod, the measurement range of the temperature sensor is 0-200℃, the measurement accuracy is ±1℃, and the signal output end is connected to the controller of the vibrator through a wire; when the temperature sensor detects that the surface temperature of the vibrating rod exceeds 80℃, the controller automatically reduces the vibration frequency to 100-120 Hz until the temperature drops to below 70℃ to restore the original vibration frequency.

8. The production process according to claim 2, characterized in that, During the pipe pulling process in step S4, the top end of the cylindrical sleeve of the drill pipe integrated device is provided with a perpendicularity monitoring module, the module includes two orthogonal inclination sensors with a measurement range of ±5° and a measurement accuracy of ±0.01°; the perpendicularity monitoring module collects the verticality data of the pile hole in real time, and when the verticality deviation exceeds 0.5%, the controller automatically adjusts the pipe pulling speed to below 0.3 m / min, and adjusts the sleeve posture through four fine adjustment oil cylinders arranged on the sleeve sidewall, the fine adjustment oil cylinders are evenly distributed along the circumference of the sleeve, the central angle between adjacent oil cylinders is 90°, and the verticality deviation is returned to within 0.5%.

9. The cylinder seamless corrosion-free rockstone wrapped pile according to claim 1, characterized in that, The inner wall of the integrated glass fiber reinforced plastic cylinder framework is uniformly provided with 6-8 reinforcing ribs in the axial direction, the reinforcing rib is an axially extending rectangular cross-section strip body with a height of 5-8 mm and a width of 3-5 mm; each reinforcing rib is uniformly distributed along the circumference direction of the framework, and the central angle deviation of adjacent reinforcing ribs is ≤1°; the material of the reinforcing rib is consistent with that of the glass fiber reinforced plastic cylinder framework, the glass fiber volume content is 60%-65%, the reinforcing rib and the framework are integrally formed through a mold pressing process, and the axial length of the reinforcing rib is consistent with the axial length of the framework.

10. The production process according to claim 2, characterized in that, Before step S1, a stratum pretreatment step is further included: a light dynamic sounding instrument is used to detect the stratum at the pile site, the hammer weight of the sounding instrument is 10 kg, and the drop distance is 50 cm; the detection area is a circular area with the center of the pile site as the center and 1.5-2.0 m as the radius, the detection points are arranged in a plum blossom shape, the spacing between adjacent detection points is 30-50 cm, the sounding depth is consistent with the designed pile length; if a single stone with a particle size >10 cm is found at a detection point, the single stone is broken to a particle size ≤5 cm by using an impact breaking method, the impact hammer weight of the impact breaking method is 500-800 kg, and the drop distance is 1.5-2.0 m; after breaking, the area is re-detected until there is no single stone with a particle size >10 cm at all detection points, and then a hole forming operation is performed.