Construction method for replacing backfilling of construction waste with solidification of spoil in rotary digging pile empty pile section

Abstract

This invention relates to the technical field of rotary drilling pile empty pile section construction, and discloses a construction method for solidifying the excavated soil in the empty pile section of rotary drilling piles to replace construction waste backfilling. The method includes the following steps: A pile hole is formed by rotary drilling at the construction site; the excavated soil is sequentially soaked and screened to form a screened slurry, which is then placed in a slurry pool; an empty pile section is formed at the top of the pile hole, containing empty pile slurry; the empty pile slurry in the upper part of the empty pile section is extracted and placed in the slurry pool, where it is mixed with the screened slurry to form a solidified slurry; the empty pile slurry in the lower part of the empty pile section forms a sedimented slurry; a solidifying agent is added to the slurry pool and stirred to form a solidified slurry; the solidified slurry is filled into the empty pile section, and the solidified slurry is stirred and mixed with the sedimented slurry to form solidified soil; after solidification, the solidified soil forms a solidified pile filling the empty pile section. In this way, the empty pile section is backfilled, achieving energy conservation, environmental protection, and cost and material savings through waste-to-resource conversion.

Description

Technical Field

[0001] This invention patent relates to the technical field of rotary drilling pile empty pile section construction, specifically, to a construction method that uses solidified slag soil in the empty pile section of rotary drilling pile to replace backfilling with construction waste. Background Technology

[0002] Currently, most pile foundation projects use a combination of mud slurry wall protection and rotary drilling rigs to construct 200mm piles. In recent years, due to the construction of high-rise buildings, pile foundations require large-diameter, long-depth piles. The elevation difference between the pile top and the existing ground level is related to the number of basement levels in the building. If a high-rise building has multiple basement levels, the elevation difference will increase. Therefore, during the construction of 200mm piles, most of the work is done on existing ground that has not yet been excavated. Consequently, during the construction of 200mm piles, some pile sections are not poured during the pile casting process; these are referred to as empty pile sections 100mm.

[0003] Rotary drilling piles are constructed by using a rotary drilling rig to drill pile holes. Mud slurry is used to protect the pile walls during the drilling process. After the pile body is poured, the empty pile section needs to be backfilled in a timely manner to prevent the hole from collapsing or causing safety problems for on-site construction personnel.

[0004] Reference Figure 1 As shown, the empty pile segment 100 is located in the soil layer 10, and the engineering pile 200 is located below the empty pile segment 100. The bottom of the engineering pile 200 is embedded in the rock layer 20.

[0005] In existing technologies, the mud slurry in the empty pile section 100 is generally extracted using a mud pump, and then backfilled with crushed stone or brick rubble. However, this method is difficult to implement because the mud slurry at the bottom of the empty pile section 100 is quite viscous, and it is also difficult to extract and drain the mud slurry. As a result, some mud slurry remains at the bottom, leading to a weak underlying layer at the bottom of the backfilled empty pile section 100. At the same time, using excavators to transport crushed stone or brick rubble to backfill the empty pile section 100 is time-consuming, labor-intensive, costly, has a long construction period, and is not environmentally friendly. Summary of the Invention

[0006] The purpose of this invention is to provide a construction method for solidifying the slag in the empty pile section of rotary drilling piles to replace backfilling with construction waste, aiming to solve the problems of complex, time-consuming, labor-intensive, costly, and long construction period in the existing technology of backfilling empty pile sections.

[0007] This invention is implemented as follows: a construction method for replacing construction waste backfilling with solidified excavated soil from the empty pile section of a rotary drilling pile, comprising the following construction steps:

[0008] 1) Using a rotary drilling rig, the pile holes are formed by rotary drilling at the construction site. The soil excavated from the pile holes is then soaked in slurry and screened to form screened mud. The screened mud is then placed in a mud pool.

[0009] 2) An engineering pile is formed at the lower part of the pile hole, and an empty pile segment is formed at the upper part of the pile hole. The empty pile segment is located above the engineering pile and contains empty pile mud.

[0010] 3) The empty pile mud in the upper part of the empty pile section is extracted and placed in the mud pool. The empty pile mud is mixed with the screened mud to form solidified mud; the empty pile mud in the lower part of the empty pile section forms sedimented mud.

[0011] 4) Add a curing agent to the mud tank, and mix the curing agent with the curing mud to form a curing slurry;

[0012] 5) The solidified slurry is filled into the empty pile section, and the solidified slurry is mixed with the sedimented mud to form solidified soil. After the solidified soil solidifies, a solidified pile is formed that fills the empty pile section.

[0013] Optionally, in construction step 1), the excavated soil is soaked in the water in the soaking tank for a set time, the excavated soil and water are mixed to form a slurry, the slurry is sifted to remove lumps, and the slurry is then screened to remove sand, forming the screened mud.

[0014] Optionally, an inclined and rotating drum screen is provided above the mud pit, and an inclined vibrating screen is provided below the drum screen, with the vibrating screen located between the drum screen and the mud pit; the drum screen has multiple drum screen holes distributed throughout its sidewall, the upper end of the drum screen forms the feed end, and the lower end of the drum screen forms the discharge end; the vibrating screen has multiple vibrating screen holes distributed throughout its sidewall, and the lower end of the vibrating screen forms the sand discharge end;

[0015] In construction step 1), the slurry enters the drum screen from the feed end. The drum screen rotates, and the lumps in the slurry are discharged from the discharge end. The mortar falls onto the vibrating screen through the drum screen holes. The vibrating screen is tilted and vibrates, and the sand in the mortar slides along the vibrating screen and is discharged from the sand discharge end of the vibrating screen. The screened mud falls into the mud pool through the vibrating screen holes.

[0016] Optionally, in construction step 3), the grouting pipe is used to extract the grout from the upper part of the empty pile section; the grouting pipe is straight, and multiple flexible hose segments are formed at the bottom of the grouting pipe. The inner ends of the multiple flexible hose segments converge and communicate with the bottom of the grouting pipe. The outer ends of the flexible hose segments are closed. Multiple suction holes are provided on the flexible hose segments. The multiple suction holes are arranged at intervals along the circumference and axial direction of the flexible hose segments.

[0017] In construction step 3), the bottom of the grouting pipe is inserted into the upper end of the empty pile section until the bottom of the grouting pipe is inserted into the sedimented mud to a set depth from top to bottom. Multiple hose sections abut against the sedimented mud, and the hose sections extract the empty pile mud from the upper part of the empty pile section from bottom to top, and extract part of the sedimented mud.

[0018] Optionally, in construction step 3), during the process of extracting mud from empty piles, the slurry extraction pipe drives multiple hose segments to rotate horizontally. During the rotation of the multiple hose segments, the upper part of the sedimented mud is stirred, some of the sedimented mud is broken up, and then sucked out through the hose segments.

[0019] Optionally, by weight, the curing agent comprises 50%-80% mineral powder, 10%-50% fly ash, 10%-50% carbide slag, 5%-20% desulfurized gypsum, and 2%-3% water-reducing agent;

[0020] In construction step 4), mineral powder, fly ash, carbide slag, desulfurized gypsum and water-reducing agent are added to the mud tank in sequence. During the process of adding the curing agent to the mud tank, the curing mud in the mud tank is stirred by a stirring shaft so that the curing mud and the curing agent are mixed.

[0021] Optionally, in construction step 5), the solidified slurry is filled into the empty pile section using a grouting pipe; the bottom of the grouting pipe has a grouting port, the top of the grouting pipe is connected to a grout delivery pipe, the grout delivery pipe is connected to the solidified mud in the mud pit, and a grouting pump is installed in the grout delivery pipe;

[0022] In construction step 5), the grouting pipe is inserted into the empty pile section, and the grouting pump injects the solidified mud in the mud tank into the empty pile section through the grouting pipe and the grouting pipe in sequence, until the solidified mud fills the empty pile section.

[0023] During the process of injecting solidifying grout into the empty pile section through the grouting port, an air supply pipe is inserted into the empty pile section. The air supply pipe is connected to an air compressor. The air compressor injects high-pressure gas into the empty pile section from top to bottom through the air supply pipe. The high-pressure gas blows the sedimented mud in the empty pile section into a floating state, and mixes it with the solidifying grout in the empty pile section to form the solidified soil.

[0024] Optionally, the lower part of the gas supply pipe has an arc-shaped insertion part, and the bottom of the insertion part forms an arc-shaped bottom gas supply port; in the construction step 5), multiple gas supply pipes are inserted into the empty pile section, the multiple gas supply pipes are arranged at intervals along the circumference of the empty pile section, and the multiple insertion parts are inserted into the sedimented mud against the inner side wall of the empty pile section.

[0025] In construction step 5), during the process of injecting solidifying slurry into the empty pile section through the grouting port, multiple bottom air inlets inject high-pressure gas from top to bottom. The high-pressure gas blows the sedimented mud into a floating state from bottom to top, and mixes the floating sedimented mud with the solidifying slurry.

[0026] Optionally, the side of the insertion part is formed with a horizontally extending side tube, and the side tube is provided with a side air inlet that connects to the air supply pipe; in the construction step 5), after the insertion part is inserted into the sedimentation mud along the inner wall of the empty pile section, the side tube is separated from the inner wall of the empty pile section and is horizontally embedded in the sedimentation mud.

[0027] In construction step 5), during the process of injecting solidified grout into the empty pile section through the grouting port, high-pressure gas is horizontally injected into the sedimented mud through the side air outlet.

[0028] Optionally, the bottom of the grouting pipe extends outward to form multiple branch pipes, and the multiple branch pipes are arranged at intervals along the circumference of the grouting pipe. In the direction from top to bottom of the grouting pipe, the branch pipes are arranged at an outward angle away from the grouting pipe.

[0029] The upper end of the bifurcation pipe is connected to the grouting pipe, and the lower end of the bifurcation pipe forms the grouting port; in construction step 5), the grouting pipe is inserted into the empty pile section from top to bottom, and multiple bifurcation pipes are inserted into the sedimented mud.

[0030] Compared with existing technologies, the construction method of solidifying the empty pile section of rotary drilling rigs to replace construction waste backfilling provided by this invention involves extracting the low-density, high-moisture, and easily extractable empty pile slurry from the upper part of the empty pile section. This empty pile slurry is then mixed with sieved slurry formed from the excavated soil through soaking and screening. Under the solidification of a solidifying agent, a high-strength solidified slurry is formed. This solidified slurry is then mixed with the remaining high-density, sedimented, low-moisture, and difficult-to-extract empty pile slurry in the empty pile section to form a high-strength solidified soil. After the solidified soil solidifies, a solidified pile is formed. In this way, the solidified pile is formed by using the soil generated after excavating the pile hole and the empty pile slurry to be treated in the empty pile section, thus backfilling the empty pile section and ensuring the normal operation of construction equipment. By treating waste with waste, the method achieves energy conservation, environmental protection, and cost and material savings. Attached Figure Description

[0031] Figure 1 This is a front view schematic diagram of a rotary drilling pile in the prior art provided by the present invention;

[0032] Figure 2 This is a schematic diagram of the process for solidifying the slag and soil in the empty pile section of a rotary drilling pile to replace backfilling with construction waste, as provided by the present invention.

[0033] Figure 3This is a construction schematic diagram of solidifying the slag and soil in the empty pile section of a rotary drilling pile to replace backfilling with construction waste, as provided by the present invention.

[0034] Figure 4 This is a construction schematic diagram of earthwork screening provided by the present invention;

[0035] Figure 5 This is a partial schematic diagram of the bottom of the slurry extraction pipe provided by the present invention;

[0036] Figure 6 This is a partial schematic diagram of the bottom of the gas pipeline provided by the present invention;

[0037] Figure 7 This is a partial schematic diagram of the bottom of the grouting pipe provided by the present invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0039] The implementation of the present invention will be described in detail below with reference to specific embodiments.

[0040] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this invention, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the accompanying drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0041] Reference Figure 2-7 The image shown is a preferred embodiment of the present invention.

[0042] The construction method for solidifying the slag in the empty pile section of rotary drilling piles to replace backfilling with construction waste, provided by this invention, includes the following construction steps:

[0043] 1) Using a rotary drilling rig, the pile holes are formed by rotary drilling at the construction site. The soil excavated from the pile holes is soaked in slurry and screened in sequence to form screened mud. The screened mud is placed in a mud pool of 500.

[0044] 2) An engineering pile 200 is formed at the lower part of the pile hole, and an empty pile section 100 is formed at the upper part of the pile hole. The empty pile section 100 is located above the engineering pile 200 and contains empty pile mud.

[0045] 3) Extract the empty pile mud from the upper part of the empty pile section 100 and place it in the mud tank 500. Mix the empty pile mud with the screened mud to form solidified mud; the empty pile mud in the lower part of the empty pile section 100 forms sedimented mud.

[0046] 4) Add a curing agent to the mud tank 500, and mix the curing agent with the curing mud to form a curing slurry;

[0047] 5) Fill the empty pile section 100 with the curing grout and mix the curing grout with the sedimented mud to form solidified soil. After the solidified soil solidifies, a solidified pile is formed in the empty pile section 100.

[0048] The aforementioned construction method for solidifying the empty pile section of rotary drilling piles to replace construction waste backfilling involves extracting the lower-density upper part of the empty pile slurry from the empty pile section 100. This empty pile slurry is then mixed with sieved slurry formed from the excavated soil through soaking and screening. Under the curing action of a curing agent, a high-strength solidified slurry is formed. This solidified slurry is then mixed with the remaining high-density empty pile slurry in the empty pile section 100 to form a high-strength solidified soil. After the solidified soil solidifies, a solidified pile is formed. In this way, the solidified pile formed by using the soil generated after excavating the pile hole and the empty pile slurry to be treated in the empty pile section 100 allows the empty pile section 100 to be backfilled, ensuring the normal movement of construction equipment. By using waste to treat waste, the method achieves energy conservation, environmental protection, and cost and material savings.

[0049] In construction step 1), the excavated soil is soaked in the water in the soaking tank for a set time. The soil and water mix to form a slurry. After removing lumps from the slurry, mortar is formed. The mortar is then screened to remove sand, forming screened mud. In this way, the lumps are large pieces and unusable slag, and the screened sand is sold to a mixing plant for concrete processing.

[0050] Above the mud pit 500 is an inclined and rotating drum screen 300, and below the drum screen 300 is an inclined vibrating screen 400, located between the drum screen 300 and the mud pit 500. The side wall of the drum screen 300 is covered with multiple drum screen holes 301, the upper end of the drum screen 300 forms the feed end, and the lower end of the drum screen 300 forms the discharge end. The vibrating screen 400 is covered with multiple vibrating screen holes 400, and the lower end of the vibrating screen 400 forms the sand discharge end.

[0051] In construction step 1), the slurry enters the drum screen 300 through the feed end. The drum screen 300 rotates, and the lumps in the slurry are discharged from the discharge end. The mortar falls onto the vibrating screen 400 through the drum screen hole 301. The vibrating screen 400 is tilted and vibrates. The sand in the mortar slides along the vibrating screen 400 and is discharged from the sand discharge end of the vibrating screen 400. The screened mud falls into the mud pool 500 through the hole of the vibrating screen 400.

[0052] Specifically, large pieces and unusable slag are removed by a 300mm drum screen and a 400mm vibrating screen. Then, the sand is washed by a 400mm vibrating screen to form a screening slurry. The screened sand is sold to a mixing plant for concrete processing. The screening slurry is then poured into a slurry pool 500 for later use.

[0053] In construction step 3), the grouting pipe 140 is used to extract the grout from the upper part of the empty pile section 100. The grouting pipe 140 is straight and has multiple flexible hose sections 141 at its bottom. The inner ends of the multiple flexible hose sections 141 converge and communicate with the bottom of the grouting pipe 140. The outer ends of the flexible hose sections 141 are closed. Multiple suction holes 142 are provided on the flexible hose sections 141. The multiple suction holes 142 are arranged at intervals along the circumference and axial direction of the flexible hose sections 141.

[0054] In construction step 3), the bottom of the grouting pipe 140 is inserted into the upper end of the empty pile section 100 until the bottom of the grouting pipe 140 is inserted into the sedimented mud to a set depth from top to bottom. Multiple hose sections 141 are in contact with the sedimented mud. The hose sections 141 extract the empty pile mud from the upper part of the empty pile section 100 from bottom to top, and extract part of the sedimented mud.

[0055] Because the hose segment 141 is elastic, after the hose segment 141 is brought into contact with the sedimented mud, the hose segment 141 bends, effectively spreading out multiple hose segments 141 and effectively increasing the suction area.

[0056] In construction step 3), during the process of extracting mud from empty piles, the grouting pipe 140 drives multiple hose sections 141 to rotate horizontally. During the rotation, the multiple hose sections 141 stir the upper part of the sedimented mud, break up some of the sedimented mud, and suck it out through the hose sections 141.

[0057] Under the resistance of the stirring liquid or the action of external force, the pumping pipe 140 rotates, which in turn drives the hose section 141 to rotate, thereby breaking up some of the sediment and extracting as much empty pile mud as possible, further reducing the water content of the remaining sediment mud, so that the final solidified pile has higher strength.

[0058] Specifically, by weight, the curing agent includes 50%-80% mineral powder, 10%-50% fly ash, 10%-50% carbide slag, 5%-20% desulfurized gypsum, and 2%-3% water-reducing agent;

[0059] In construction step 4), mineral powder, fly ash, carbide slag, desulfurized gypsum and water-reducing agent are added to mud tank 500 in sequence. During the process of adding curing agent to mud tank 500, the curing mud in mud tank 500 is stirred by a stirring shaft so that the curing mud and curing agent are mixed.

[0060] Curing principle:

[0061] A "skeleton" is constructed within the slag, and then the material is filled into it. The mineral powder in the solidifying agent mainly consists of elements such as calcium, silicon, aluminum, magnesium, and iron. During the addition process, the mineral powder undergoes a hydration reaction, generating partially crystalline calcium silicate hydrate, crystalline calcium aluminate hydrate, and monosulfide-type calcium sulfoaluminate. While mineral powder materials possess potential hydraulic properties and fly ash materials exhibit pozzolanic activity, under normal circumstances, the hydration reaction of mineral powder and fly ash is barely activated when the pH of their aqueous solution is neutral; only a weak hydration reaction occurs on the material surface.

[0062] The incorporation of calcium carbide slag provides a strongly alkaline environment for the initial hydration reaction of the system, stimulating the activity of mineral powder and fly ash, and promoting the activation, decomposition, and depolymerization of the glassy particles of mineral powder and fly ash. Free calcium ions, sulfate ions, and aluminate ions polymerize to varying degrees to produce CSH (hydrated calcium silicate), CAH (hydrated calcium aluminate), and CASH (hydrated calcium aluminosilicate).

[0063] The active silica and alumina in the mineral powder react with the fly ash after being added. However, this reaction is more complete under alkaline conditions. Therefore, the addition of carbide slag provides a sufficiently alkaline environment to facilitate a more complete reaction and promote the construction of the framework system. Subsequent addition of slag and soil for uniform mixing fills the gaps in the framework, making the structure more complete.

[0064] Water-reducing agents are mainly lignin sulfonate and naphthalene sulfonate formaldehyde polymers. The main function of water-reducing agents is to increase fluidity, prevent solidification during transportation, and ensure their fluidity.

[0065] Advantages of curing agents:

[0066] In the existing technology, the research on curing agents mainly focuses on silicate cement systems, which are improved by adding other admixtures. However, the large-scale application of cement often generates a large amount of carbon dioxide, which has a negative impact on national carbon emissions and carbon peaking. Therefore, the research and development of traditional curing agents for cement cannot meet the needs of the new era.

[0067] In construction step 5), the solidified grout is filled into the empty pile section 100 using the grouting pipe 110; the bottom of the grouting pipe 110 has a grouting port 112, the top of the grouting pipe 110 is connected to the grout delivery pipe 120, the grout delivery pipe 120 is connected to the solidified mud in the mud tank 500, and the grout delivery pipe 120 is equipped with a grouting pump 121.

[0068] In construction step 5), the grouting pipe 110 is inserted into the empty pile section 100, and the grouting pump 121 injects the solidified mud in the mud tank 500 into the empty pile section 100 through the grouting pipe 120 and the grouting pipe 110 in sequence, until the solidified mud fills the empty pile section 100.

[0069] During the process of injecting solidifying grout into the empty pile section 100 through the grouting port 112, an air supply pipe 130 is inserted into the empty pile section 100. The air supply pipe 130 is connected to an air compressor. The air compressor injects high-pressure gas into the empty pile section 100 from top to bottom through the air supply pipe 130. The high-pressure gas blows the sedimented mud in the empty pile section 100 into a floating state, and mixes it with the solidifying grout in the empty pile section 100 to form solidified soil.

[0070] High-pressure gas is delivered synchronously to ensure that the sedimented mud and solidified slurry in the empty pile section 100 are fully mixed evenly.

[0071] The lower part of the gas pipe 130 has an arc-shaped insertion part, and the bottom of the insertion part forms an arc-shaped bottom gas outlet 131; in construction step 5), multiple gas pipes 130 are inserted into the empty pile section 100, and the multiple gas pipes 130 are arranged at intervals along the circumference of the empty pile section 100, and the multiple insertion parts are inserted into the sedimented mud along the inner side wall of the empty pile section 100.

[0072] In construction step 5), during the process of injecting curing slurry into the empty pile section 100 through the grouting port 112, multiple bottom air outlets 131 inject high-pressure gas from top to bottom. The high-pressure gas blows the sedimented mud into a floating state from bottom to top, and mixes the floating sedimented mud with the curing slurry.

[0073] Thus, as shown in the figure, two of the gas supply pipes 130 are arranged. Since the bottom of the insertion part has an arc-shaped bottom gas supply port 131, it effectively avoids the sedimented mud from clogging the bottom gas supply port 131, ensuring that high-pressure gas can be injected from top to bottom through the bottom gas supply port 131.

[0074] Specifically, the side of the insertion part has a horizontally extending side tube 132, and the side tube 132 is provided with a side air outlet 133 that connects to the air supply pipe 130; in construction step 5), after the insertion part is inserted into the sedimentation mud along the inner wall of the empty pile section 100, the side tube 132 is away from the inner wall of the empty pile section 100 and is horizontally embedded in the sedimentation mud.

[0075] In construction step 5), during the process of injecting solidifying grout into the empty pile section 100 through grouting port 112, high-pressure gas is horizontally injected into the sedimented mud through side air outlet 133. Through the design of side pipe 132, high-pressure gas can be horizontally ejected outward through side air outlet 133, promoting uniform mixing of solidifying grout and sedimented mud.

[0076] The bottom of the grouting pipe 110 extends outward to form multiple branch pipes 111. The multiple branch pipes 111 are arranged at intervals along the circumference of the grouting pipe 110, and along the top-to-bottom direction of the grouting pipe 110, the branch pipes 111 are arranged outward from the grouting pipe 110.

[0077] The upper end of the branch pipe 111 is connected to the grouting pipe 110, and the lower end of the branch pipe 111 forms a grouting port 112. In construction step 5), the grouting pipe 110 is inserted into the empty pile section 100 from top to bottom, and multiple branch pipes 111 are inserted into the sedimented mud. In this way, through the action of the branch pipes 111, the solidified grout that is sprayed from the bottom of the grouting pipe 110 is sprayed out from multiple grouting ports 112, which promotes the uniform mixing of the solidified grout in the sedimented mud.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A construction method for using solidified soil in the empty pile section of rotary drilling piles to replace backfilling with construction waste, characterized in that... The construction steps include the following: 1) Using a rotary drilling rig, the pile holes are formed by rotary drilling at the construction site. The soil excavated from the pile holes is then soaked in slurry and screened to form screened mud. The screened mud is then placed in a mud pool. 2) An engineering pile is formed at the lower part of the pile hole, and an empty pile segment is formed at the upper part of the pile hole. The empty pile segment is located above the engineering pile and contains empty pile mud. 3) The empty pile mud in the upper part of the empty pile section is extracted and placed in the mud pool. The empty pile mud is mixed with the screened mud to form solidified mud; the empty pile mud in the lower part of the empty pile section forms sedimented mud. 4) Add a curing agent to the mud tank, and mix the curing agent with the curing mud to form a curing slurry; 5) The solidified slurry is filled into the empty pile section, and the solidified slurry is mixed with the sedimented mud to form solidified soil. After the solidified soil solidifies, a solidified pile is formed that fills the empty pile section. In construction step 1), the excavated soil is soaked in the water in the soaking tank for a set time. The excavated soil and water are mixed to form a slurry. After removing the lumps from the slurry, mortar is formed. The mortar is screened to remove sand and form the screened mud. In construction step 3), the grouting pipe is used to extract the grout from the upper part of the empty pile section; the grouting pipe is straight, and multiple flexible hose sections are formed at the bottom of the grouting pipe. The inner ends of the multiple flexible hose sections converge and communicate with the bottom of the grouting pipe. The outer ends of the flexible hose sections are closed. Multiple suction holes are provided on the flexible hose sections. The multiple suction holes are arranged at intervals along the circumference and axial direction of the flexible hose sections. In construction step 3), the bottom of the grouting pipe is inserted into the upper end of the empty pile section until the bottom of the grouting pipe is inserted into the sedimented mud to a set depth from top to bottom. Multiple hose sections abut against the sedimented mud, and the hose sections extract the empty pile mud from the upper part of the empty pile section from bottom to top, and extract part of the sedimented mud. In construction step 3), during the process of extracting mud from empty piles, the slurry extraction pipe drives multiple hose segments to rotate horizontally. During the rotation of the multiple hose segments, the upper part of the sedimented mud is stirred, some of the sedimented mud is broken up, and then sucked out through the hose segments. In construction step 5), the solidified grout is filled into the empty pile section using a grouting pipe; the bottom of the grouting pipe has a grouting port, the top of the grouting pipe is connected to a grout delivery pipe, the grout delivery pipe is connected to the solidified mud in the mud pit, and a grouting pump is installed in the grout delivery pipe; In construction step 5), the grouting pipe is inserted into the empty pile section, and the grouting pump injects the solidified mud in the mud tank into the empty pile section through the grouting pipe and the grouting pipe in sequence, until the solidified mud fills the empty pile section. During the process of injecting solidifying slurry into the empty pile section through the grouting port, an air supply pipe is inserted into the empty pile section. The air supply pipe is connected to an air compressor. The air compressor injects high-pressure gas into the empty pile section from top to bottom through the air supply pipe. The high-pressure gas blows the sedimented mud in the empty pile section into a floating state, and mixes it with the solidifying slurry in the empty pile section to form the solidified soil. The bottom of the grouting pipe extends outward to form multiple branch pipes. The multiple branch pipes are arranged at intervals along the circumference of the grouting pipe, and along the top-to-bottom direction of the grouting pipe, the branch pipes are arranged at an outward inclination away from the grouting pipe. The upper end of the bifurcation pipe is connected to the grouting pipe, and the lower end of the bifurcation pipe forms the grouting port; in construction step 5), the grouting pipe is inserted into the empty pile section from top to bottom, and multiple bifurcation pipes are inserted into the sedimented mud.

2. The construction method for using solidified soil in the empty pile section of rotary drilling piles as described in claim 1 to replace backfilling with construction waste, characterized in that, An inclined, rotating drum screen is installed above the mud pit, and an inclined vibrating screen is installed below the drum screen, with the vibrating screen located between the drum screen and the mud pit; the drum screen has multiple drum screen holes distributed throughout its sidewalls, with the upper end of the drum screen forming the feed end and the lower end forming the discharge end; the vibrating screen has multiple vibrating screen holes distributed throughout its sidewalls, with the lower end forming the sand discharge end; In construction step 1), the slurry enters the drum screen from the feed end. The drum screen rotates, and the lumps in the slurry are discharged from the discharge end. The mortar falls onto the vibrating screen through the drum screen holes. The vibrating screen is tilted and vibrates, and the sand in the mortar slides along the vibrating screen and is discharged from the sand discharge end of the vibrating screen. The screened mud falls into the mud pool through the vibrating screen holes.

3. The construction method for using solidified soil from the hollow section of rotary drilling piles as described in claim 1 to replace backfilling with construction waste, characterized in that... By weight, the curing agent comprises 50%-80% mineral powder, 10%-50% fly ash, 10%-50% carbide slag, 5%-20% desulfurized gypsum, and 2%-3% water-reducing agent; In construction step 4), mineral powder, fly ash, carbide slag, desulfurized gypsum and water-reducing agent are added to the mud tank in sequence. During the process of adding the curing agent to the mud tank, the curing mud in the mud tank is stirred by a stirring shaft so that the curing mud and the curing agent are mixed.

4. The construction method for using solidified soil in the empty pile section of rotary drilling piles as described in any one of claims 1-3 to replace backfilling with construction waste, characterized in that, The lower part of the gas transmission pipe has an arc-shaped insertion part, and the bottom of the insertion part forms an arc-shaped bottom gas transmission port; in the construction step 5), multiple gas transmission pipes are inserted into the empty pile section, the multiple gas transmission pipes are arranged at intervals along the circumference of the empty pile section, and the multiple insertion parts are inserted into the sedimented mud against the inner side wall of the empty pile section. In construction step 5), during the process of injecting solidifying slurry into the empty pile section through the grouting port, multiple bottom air inlets inject high-pressure gas from top to bottom. The high-pressure gas blows the sedimented mud into a floating state from bottom to top, and mixes the floating sedimented mud with the solidifying slurry.

5. The construction method for using solidified soil in the empty pile section of rotary drilling piles as described in claim 4 to replace backfilling with construction waste, characterized in that, The side of the insertion part is formed with a horizontally extending side tube, and the side tube is provided with a side air inlet that connects to the air supply pipe; in the construction step 5), after the insertion part is inserted into the sedimentation mud along the inner wall of the empty pile section, the side tube is separated from the inner wall of the empty pile section and is horizontally embedded in the sedimentation mud. In construction step 5), during the process of injecting solidified grout into the empty pile section through the grouting port, high-pressure gas is horizontally injected into the sedimented mud through the side air outlet.

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