Carrier pile construction waste resource filling environment-friendly composite pore-forming method

Abstract

The invention discloses a carrier pile construction waste resource filling environment-friendly composite pore-forming method, which relates to the technical field of construction engineering, and comprises the following steps: step 1, pile point positioning: adopting a total station or a GPS (Global Position System) to accurately set out the center of a pile position according to a control point; secondly, a pile machine is in place; 3, hammering to form a hole, tamping a soil body to form the hole preliminarily, sleeving a column hammer with a steel casing, sinking the steel casing to a designed elevation, and hammering out the bottom of the steel casing by using the column hammer; 4, filling and tamping are conducted, specifically, filling materials and hard concrete are fed in batches, and repeated tamping and compaction are conducted through a heavy hammer; and fifthly, pile forming is conducted, a dense carrier is formed at the pile end, a reinforcement cage is placed, and concrete is poured to form the pile. According to the carrier pile construction waste resource filling environment-friendly composite hole forming method, the alloy head is of a rapid assembly structure, the hammer body does not need to be overall disassembled, and the quality is easy to control; and compared with a traditional pile foundation construction method, the construction efficiency is improved, and the bearing capacity standard reaching rate is increased.

Description

Technical Field

[0001] This invention relates to the field of building engineering technology, and in particular to an environmentally friendly composite hole-forming method for using construction waste as a filler in carrier piles. Background Technology

[0002] Carrier piles are a new type of pile foundation technology consisting of a cast-in-place concrete pile body and a compacted carrier underneath. Through hammering to form the hole and then compacting the filling material to create a dense carrier, the end resistance and lateral resistance of the pile are significantly improved. While the bearing capacity of ordinary piles mainly relies on side skin friction, the bearing capacity of carrier piles originates from the carrier itself. Carrier piles are suitable for foundation treatment in adverse geological conditions such as collapsible loess, miscellaneous fill, silt, sand, and soft soil layers. However, miscellaneous fill contains a large number of boulders, making it difficult to penetrate with a conventional heavy hammer and thus challenging to form a hole. Summary of the Invention

[0003] The purpose of this invention is to provide an environmentally friendly composite drilling method for carrier pile construction waste filling, which involves welding a high-strength solid alloy head to the end of the carrier pile machine's hammer to improve the efficiency of penetrating boulders and effectively solve the drilling problem in special geological conditions.

[0004] To achieve the above objectives, this invention provides a method for environmentally friendly composite drilling using construction waste as a carrier pile, comprising the following steps: Step 1: Locate the pile points. Use a total station or GPS to accurately mark the center of the pile position according to the control points. Insert a steel rod into the center of the pile position and sprinkle white lime around it to form a square mark. Step 2: Positioning the piling machine. After the pile points pass inspection, move the piling machine to the pile position and adjust its position. Step 3: Hammering to form a hole. The soil is compacted to form a preliminary hole. The steel casing is placed on the column hammer and driven into the design elevation. Then, the bottom of the casing is hammered out with the column hammer. Step 4: Filling and compaction. Filler and dry-hard concrete are added in batches and repeatedly compacted with a heavy hammer. Step 5: Pile formation. A dense carrier is formed at the pile end. A steel reinforcement cage is placed and concrete is poured to form the pile.

[0005] Preferably, during the hammering process in step three, the casing is simultaneously pressurized with a counter-pressure of ≥50kPa, the hammer weight for drilling is 3.5t-4.5t, and the hammer weight is 4.5t for boulders with a diameter greater than 1m.

[0006] Preferably, in step three, the depth of the casing penetration into the soil is recorded once after each blow, and the verticality is checked every 5m using a total station. If any deviation is found, the machine is stopped immediately for adjustment, and the adjustment range does not exceed 0.5° per time.

[0007] Preferably, in step three, the boulder uses a Cr12MoV alloy head, which is connected to the end of the hammer body by double-sided full welding, with a weld leg height of not less than 8mm.

[0008] Preferably, in step three, the hole-forming process for the isolated rock uses a low drop height test and a high drop height penetration method. The initial drop height is 4m, and after penetrating the isolated rock, the normal drop height is restored to form the hole. The penetration time for a single isolated rock is controlled within 30 minutes.

[0009] Preferably, in step three, the drop distance for ordinary fill is 6m, and the drop distance for areas with dense boulders is 7-8m.

[0010] Preferably, the filling material in step four is crushed construction waste from the construction site, and the amount of filling material per batch is matched with the diameter of the casing. For a casing with a diameter of 800mm, the filling depth is controlled at 0.1m. 3 A 1000mm diameter casing is controlled to a depth of 0.15m. 3 .

[0011] Preferably, in step four, the compaction degree of the carrier is determined by the compaction of the fill material. During the descent stage, the fill material is initially compressed; during the leveling stage, the compaction degree is stable; and during the rising stage, the soil rebounds.

[0012] Preferably, after the carrier is initially formed in step five, it is continuously tamped three times, with the penetration decreasing with each tamping; if the standard is not met, the filling and tamping continue until the requirements are met.

[0013] Therefore, the present invention adopts the above-mentioned environmentally friendly composite hole-forming method of resource-based filling of construction waste for carrier piles. A high-strength alloy head is welded to the end of the carrier pile column hammer. The high hardness of the alloy head is used to penetrate the boulder obstacle, effectively solving the problems of hammer jamming and hole deviation of traditional heavy hammers. The alloy head adopts a quick assembly structure, which does not require the overall disassembly of the hammer body, resulting in excellent hole-forming efficiency and quality.

[0014] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0015] Figure 1 This is a flowchart of the environmentally friendly composite hole-forming method for resource-based filling of construction waste in carrier piles according to the present invention. Detailed Implementation

[0016] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0018] Example Please see Figure 1 This invention provides a method for environmentally friendly composite drilling using construction waste as a carrier pile, comprising the following steps: Step 1: Locate the pile point. Use a total station or GPS to accurately mark the center of the pile position according to the control points. Insert a steel rod into the center of the pile position and sprinkle white lime around it to form a square mark.

[0019] Three secondary control points were set up around the construction site, with a spacing of ≥50m to ensure visibility. A Φ16mm steel rod was inserted into the center of the pile location to a depth of ≥30cm, and white lime was sprinkled around the perimeter to form a 20cm×20cm square marking to prevent deviation during subsequent construction. After the pile location was marked out, it was double-verified using a total station and a steel tape measure, with the center deviation controlled within ±10mm. Construction could only proceed after the supervisor's acceptance.

[0020] Step 2: Positioning the piling machine. After the pile point passes inspection, move the piling machine to the pile position and adjust its position. Adjust the hydraulic outriggers and place a 20mm thick steel plate with an area of ​​≥1.5m×1.5m under the outriggers to prevent the equipment from sinking or tilting. Ensure that the horizontal deviation of the piling machine platform is ≤0.5%; the alignment deviation between the center of the casing and the center of the pile position is ≤10mm; and the vertical deviation of the casing is ≤1%.

[0021] Step 3: Hammering to form holes. The principle of heavy hammering and dynamic distance adjustment is adopted. The hole is formed by alternating hammering and skipping hammering. The construction interval between adjacent piles is ≥24 hours. The soil is compacted to form the initial hole. The steel casing is placed on the column hammer and sunk to the design elevation. Then the bottom of the casing is hammered out with the column hammer.

[0022] In the initial stage, the drop height is 3-4m for light compaction to prevent the casing from tilting. After the casing is inserted into the soil for ≥1m, the drop height is adjusted according to the soil characteristics. For ordinary miscellaneous fill, the drop height is kept at 6m, and for areas with dense boulders, it is raised to 7-8m.

[0023] During construction, a counter-pressure casing is applied simultaneously with a counter-pressure of ≥50kPa to prevent borehole collapse. The drilling hammer weight is selected from 3.5t to 4.5t, and a 4.5t hammer is selected when the boulder size is >1m.

[0024] Record the depth of the casing penetration after each blow, and check the verticality with a total station every 5m. If any deviation is found, stop the machine immediately for adjustment. The adjustment range should be ≤0.5° / time to ensure that the final hole depth reaches the design bearing layer elevation and the deviation is ≤50mm.

[0025] If drilling is halted due to an isolated boulder, the machine should be stopped immediately. Use a Cr12MoV alloy head for drilling. The Cr12MoV alloy head should be Φ200-300mm in size and 150-200mm in height. Connect it to the hammer body end via double-sided full welding, with a weld leg height ≥8mm. Allow it to cool naturally for ≥2 hours after welding to prevent sudden cooling and cracking. The alloy head welding must ensure it is straight with the hammer body and the weld joint is tight. Before construction, use ultrasonic testing to inspect the weld joints; the pass rate must be 100% to prevent the alloy head from falling off during pile driving.

[0026] After welding, a low-drop-height test and high-drop-height penetration process is adopted. The initial drop height is 4m. After confirming that the alloy head is aligned with the boulder, it is raised to 7-8m. After penetrating the boulder, the normal drop height is restored to form a hole. The time for passing through a single boulder is controlled to ≤30 minutes, which is more than 10 times more efficient than the traditional "manual obstacle clearing" method.

[0027] Step 4: Filling and compaction. Filler and dry-hard concrete are added in batches and repeatedly compacted with a heavy hammer.

[0028] Filler control: After the casing reaches the design elevation, filler material is added in stages through the feeding port. Crushed construction waste from the site is preferred, with a particle size of 2-5cm and a mud content ≤5%. The amount of filler added per stage is adapted to the casing diameter; for 800mm diameter casings, the filling volume is controlled at 0.1m. 3 A 1000mm diameter casing is controlled to a depth of 0.15m. 3 The standard is that the bottom of the ram is 40-60cm higher than the bottom of the casing. A heavy hammer undergoes free fall, with an impact energy ≥210kJ. A 3.5t hammer is dropped from a height of 6m. The compaction of the fill material is observed in three stages: descent: initial compression of the fill material; leveling: stable density; and rise: soil rebound. This is used to determine the degree of compaction of the material. Three-hit penetration test: Step 5: Pile formation. A dense carrier with a diameter of 2-3m and a thickness of 3-5m is formed at the pile end. A steel cage is placed and concrete is poured to form the pile.

[0029] After the initial formation of the carrier, it is compacted three times in succession. The penetration depth of each compaction should decrease by ≥10% and the cumulative value should be ≤10cm. If there are design requirements, it should be adjusted according to a safety factor of ≥1.2. If the standard is not met, the filling and compaction should continue until the requirements are met.

[0030] When pouring concrete, a 200mm diameter tremie pipe is used, with the bottom ≤2m from the concrete surface to prevent segregation. During the pouring process, the elevation of the reinforcing cage is checked every 30cm. If floating is detected, pouring is stopped immediately. Floating is controlled by pressing down the reinforcing cage and adjusting the pouring speed.

[0031] Application Project 1: Sanmenxia City Urban-Rural Integration Demonstration Zone (High-tech Zone) Smart Manufacturing Town Standardized Factory Buildings and Supporting Facilities Project (Section 1), with a total land area of ​​95,141.67㎡, a total building area of ​​63,394.25㎡, and a ground building area of ​​63,002.85㎡ (gross floor area ratio of 99,136.35㎡). The exploration depth range is collapsible loess and silt layers, with some miscellaneous fill soil, and isolated boulders and rock layers.

[0032] Application results: 1200 piles were constructed using this method, with a 100% pass rate in bearing capacity testing, a maximum settlement of ≤5mm (far below the standard requirements), and a 98% excellent rate in pile integrity testing; the method saved 460,000 yuan in costs, shortened the construction period by 20 days, and created earlier conditions for subsequent main structure construction; it received unanimous praise from the owner.

[0033] Application Project 2: Sanmenxia High-tech Zone Comprehensive Logistics Park (Plot B) Project, located on the southeast side of the old National Highway 209 in the Sanmenxia Urban-Rural Integration Demonstration Zone, with a total construction area of ​​33,783.69㎡ and a construction period of 720 days. Within the exploration depth range, the strata of the site are mainly composed of recently deposited miscellaneous fill, Quaternary Holocene alluvial-diluvial loess, pebbles, silty clay, etc., which are collapsible.

[0034] Therefore, this invention employs the aforementioned environmentally friendly composite drilling method using recycled construction waste as filler in carrier piles. A high-strength alloy head is welded to the end of the carrier pile hammer. The high hardness of the alloy head allows it to penetrate boulder obstacles, effectively solving the problems of hammer jamming and hole deviation associated with traditional heavy hammers. The alloy head features a quick-assembly structure, eliminating the need for complete hammer disassembly, resulting in superior drilling efficiency and quality. It has wide applicability, not only suitable for mixed fill foundations containing boulders and hard construction waste, but also applicable to narrow sites and environmentally sensitive areas, improving construction efficiency and bearing capacity compliance rates.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for filling and protecting a hole by using construction waste resources, characterized in that, Includes the following steps: Step 1: Locate the pile points. Use a total station or GPS to accurately mark the center of the pile position according to the control points. Insert a steel rod into the center of the pile position and sprinkle white lime around it to form a square mark. Step 2: Positioning the piling machine. After the pile points pass inspection, move the piling machine to the pile position and adjust its position. Step 3: Hammering to form a hole. The soil is compacted to form a preliminary hole. The steel casing is placed on the column hammer and driven into the design elevation. Then, the bottom of the casing is hammered out with the column hammer. Step 4: Filling and compaction. Filler and dry-hard concrete are added in batches and repeatedly compacted with a heavy hammer. Step 5: Pile formation. A dense carrier is formed at the pile end. A steel reinforcement cage is placed and concrete is poured to form the pile.

2. The method for resource-based filling and environmentally friendly composite drilling of carrier piles using construction waste according to claim 1, characterized in that: In step three, during the hammering process, the casing is simultaneously pressurized with a back pressure of not less than 50 kPa. The hammer weight for drilling is 3.5t-4.5t, and the hammer weight is 4.5t for boulders with a diameter greater than 1m.

3. The method for resource-based filling and environmentally friendly composite drilling of carrier piles using construction waste according to claim 2, characterized in that: In step three, the depth of the casing penetration into the soil is recorded once after each blow, and the verticality is checked every 5m with a total station. If any deviation is found, the machine is stopped immediately for adjustment, and the adjustment range shall not exceed 0.5°.

4. The method for resource-based filling and environmentally friendly composite drilling of carrier piles using construction waste according to claim 3, characterized in that: In step three, the boulder uses a Cr12MoV alloy head, which is connected to the end of the hammer body by double-sided full welding, with a weld leg height of not less than 8mm.

5. The method for environmentally friendly composite hole formation using resource-based filling of construction waste in carrier piles according to claim 4, characterized in that: In step three, the drilling of the boulder uses a combination of low drop height test blows and high drop height penetration. The initial drop height is 4m. After penetrating the boulder, the normal drop height is restored to drilling. The drilling time for a single boulder is controlled within 30 minutes.

6. The method for resource-based filling and environmentally friendly composite drilling of carrier piles using construction waste according to claim 5, characterized in that: In step three, the drop distance for ordinary fill is 6m, and the drop distance for areas with dense boulders is 7-8m.

7. The method for resource-based filling and environmentally friendly composite drilling of carrier piles using construction waste according to claim 1, characterized in that: The filling material in step four is construction waste crushing material, and the single filling amount is matched with the diameter of the casing. The diameter of 800 mm casing is controlled to 0.1 m 3 , and the diameter of 1000 mm casing is controlled to 0.15 m 3 .

8. The method for resource-based filling and environmentally friendly composite drilling of carrier piles using construction waste according to claim 7, characterized in that: In step four, the compaction of the carrier is judged by the compaction of the fill material. In the descent stage, the fill material is initially compressed; in the leveling stage, the compaction is stable; and in the rising stage, the soil rebounds.

9. The method for resource-based filling and environmentally friendly composite drilling of carrier piles using construction waste according to claim 1, characterized in that: After the carrier is initially formed in step five, it is tamped three times in succession, with the penetration depth decreasing with each tamping. If the standard is not met, the filling and tamping are continued until the requirements are met.

Images