Method for filling flowable backfill

Abstract

The application discloses a filling method of flow state backfill soil, which comprises the following steps: providing a filling auxiliary device, which comprises a driving structure and a lifting assembly, and a channel capable of allowing the flow of backfill soil is arranged in the lifting assembly; digging raw soil on the ground to form a foundation pit on the ground; screening the dug raw soil and crushing the screened raw soil; adding an additive slurry to the crushed raw soil and stirring to obtain backfill soil; after the depth of the foundation pit is measured and marked, the upper end of the lifting assembly is connected with the backfill soil through a pipeline, and the lower end of the lifting assembly is abutted to the mark; the backfill soil flows into the foundation pit through the pipeline and the channel in sequence until the height of the backfill soil rises to the level of the lower end of the lifting assembly, and then the driving structure drives the lifting assembly to rise to the adjacent mark. The method can save the process of continuously compacting the backfill soil in the traditional earthwork backfill, and is particularly obvious in the case of encountering special-shaped and narrow spaces.

Description

Technical Field

[0001] This invention relates to the field of building construction, and in particular to a method for filling fluidized backfill soil. Background Technology

[0002] With urban land use becoming increasingly scarce, underground space construction projects are becoming more and more widespread. In many cases, such as foundation pits, trenches, and underground spaces in building construction and municipal engineering, backfilling is required to fill the foundation pits or underground spaces.

[0003] Traditional backfilling methods typically involve cleaning the foundation pit, then laying backfill soil in layers and compacting each layer to ensure compaction, thus completing the backfilling. However, this method is inconvenient when encountering irregularly shaped or confined spaces. Therefore, a backfilling method that can be easily used for filling irregularly shaped and confined spaces is needed. Summary of the Invention

[0004] Therefore, it is necessary to provide a filling method that can facilitate the filling of irregular and narrow spaces.

[0005] To address the above problems, this invention provides a method for constructing fluidized backfill soil, comprising the following steps:

[0006] A backfilling auxiliary device is provided, the backfilling auxiliary device including a drive structure and a lifting assembly connected to the drive structure, the drive structure driving the lifting assembly to rise or fall, wherein the lifting assembly is provided with a channel for the backfill soil to flow through;

[0007] The ground in the construction area is excavated to remove the raw soil and form a foundation pit.

[0008] The excavated raw soil is screened to remove impurities, and the screened raw soil is crushed to control the size of the raw soil to be less than 40mm.

[0009] Backfill soil is prepared by adding an admixture slurry to the crushed raw soil and stirring. The admixture slurry includes a curing agent, a water-reducing agent, and water. The mixing ratio of the curing agent, the water-reducing agent, and the water is 22-24:1:29-31. The mixing ratio of the raw soil to the admixture slurry is 1:2.5-3.2.

[0010] After measuring the elevation of the foundation pit, the two side walls inside the foundation pit are marked in layers. The first mark is made at a height less than 0.5m from the bottom of the foundation pit, and then the marks are made at uniform intervals of less than 2m, thereby controlling the filling thickness of each layer of backfill soil.

[0011] The filling auxiliary device is installed above the foundation pit to be filled. The upper end of the lifting assembly is connected to the backfill soil through a pipe, and the lower end of the lifting assembly is abutted against the mark to determine the filling height of the backfill soil.

[0012] The backfill soil is sequentially fed into the foundation pit through the pipes and channels until the height of the backfill soil rises to be level with the lower end of the lifting assembly. Then, the drive structure is controlled to lift the lifting assembly to the adjacent mark, and the backfill soil is continuously fed into the foundation pit through the pipes and channels until the foundation pit is filled.

[0013] In one embodiment, the process of adding an admixture slurry to the crushed raw soil and stirring to obtain backfill soil further includes the following steps: first, stirring the curing agent, the water-reducing agent, and the water to obtain the admixture slurry, wherein the backfill soil is obtained by stirring the admixture slurry and the raw soil, and the stirring time of the admixture slurry and the raw soil is at least 60 seconds.

[0014] In one embodiment, after the operation of bringing the lower end of the lifting assembly to the mark and before the operation of flowing the backfill soil into the foundation pit through the pipe and the channel in sequence, the following operation is performed: the fluidity of the backfill soil is detected so that the fluidity of the backfill soil is between 100mm and 130mm.

[0015] In one embodiment, after the operation of detecting the fluidity of the backfill soil and before the operation of sequentially flowing the backfill soil into the foundation pit through the pipe and the channel, the following operation is performed: a local area outside the construction area is selected as a test area, the backfill soil is filled into the test area, the flow state of the backfill soil is observed, and the strength of the backfill soil is detected as greater than 0.3 MPa, thereby determining the mix proportion of the backfill soil.

[0016] In one embodiment, the length of the test area is 3 to 6 meters.

[0017] In one embodiment, the curing agent is silicate cement.

[0018] In one embodiment, the lifting assembly includes a lifting member and an expanding member, the channel is provided through the lifting member, the pipe is connected in the channel so that the backfill soil flows from the channel into the foundation pit, and the expanding member is connected to the lower end of the lifting member so that the expanding member abuts against the mark.

[0019] In one embodiment, the expanding member is threadedly connected to the lower end of the lifting member.

[0020] In one embodiment, the lifting assembly further includes a clamping member, one end of which is disposed within the channel, and the other end of which is connected to the side wall of the clamping member. Driving the other end of the clamping member causes the one end of the clamping member to clamp the pipe within the channel.

[0021] In one embodiment, the driving structure includes a lead screw assembly and a transmission assembly. The transmission assembly is connected to the lead screw assembly to drive the lead screw assembly to move. The lead screw assembly includes a lead screw and a moving part. The moving part is connected to the lead screw, so that the transmission assembly drives the lead screw to rotate and causes the moving part to move along the lead screw. One end of the moving part is connected to the lifting member, so that the lifting member moves along the lead screw.

[0022] By implementing the embodiments of the present invention, the filling method of fluidized backfill soil can facilitate the observation of the backfill height by setting up a filling auxiliary device. When the liquid level of the backfill soil rises to the lower end of the lifting component, the filling can be stopped. The fixed lifting component will not shake, and the liquid level of the backfill soil can be easily observed.

[0023] It can reuse the raw soil excavated from the ground, making full use of resources, saving costs, and realizing the resource utilization of waste. By mixing the raw soil and additives, backfill soil can be obtained. Such backfill soil is uniformly mixed and has fluidity. Furthermore, the soil particles are filled and consolidated by the solidifying agent, making the backfill soil impermeable. It can prevent groundwater from damaging the backfill soil itself and can also be tightly integrated with the foundation structure to prevent surface water from seeping down along the interface between the structure and the backfill soil. Moreover, liquid filling produces no dust and is more environmentally friendly.

[0024] Therefore, fluid backfill soil can be directly filled into the space in layers, and can be left to solidify. This eliminates the need for continuous compaction of the backfill soil in traditional earthwork backfilling, while ensuring the strength requirements and construction quality of the fill. This filling method is particularly advantageous when encountering irregular and narrow spaces, which are difficult for machinery to enter and are prone to insufficient compaction, leading to foundation quality problems such as settlement and cracking later on. However, fluid backfill soil eliminates the need for compaction and is also convenient for filling irregular and narrow spaces. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] in:

[0027] Figure 1 This is a flowchart of a backfilling method as one embodiment.

[0028] Figure 2 This is a schematic diagram of a backfilling auxiliary device in one embodiment of a backfilling method.

[0029] Figure label:

[0030] 12-Lead screw assembly, 122-Lead screw, 124-Moving component, 142-Driving bevel gear, 144-Driven bevel gear, 18-Handle;

[0031] 22-Lifting component, 24-Clamping component, 242-Main body, 244-Clamping part, 26-Expanding component. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indications will also change accordingly.

[0034] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" and "second" may explicitly or implicitly include at least one of the stated features. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0035] Combination Figure 1 This invention discloses a method for constructing fluidized backfill soil according to one embodiment, comprising the following steps:

[0036] S10. Provide a filling auxiliary device, which includes a drive structure and a lifting assembly connected to the drive structure. The drive structure drives the lifting assembly to rise or fall. The lifting assembly is provided with a channel for the flow of backfill soil.

[0037] Combination Figure 2 The lifting assembly includes a lifting component 22 and an expanding component 26. A channel is provided through the lifting component 22, and a pipe is connected in the channel so that the backfill soil flows from the channel into the foundation pit. The expanding component 26 is connected to the lower end of the lifting component 22 so that the expanding component 26 abuts against the marked position.

[0038] Preferably, the lower end of the expanding member 26 is detachably connected to the lifting member 22.

[0039] In one embodiment, the expanding member 26 is threadedly connected to the lower end of the lifting member 22.

[0040] Specifically, by driving the lifting assembly to rise and fall through the drive structure, the height of the lifting component 22 can be easily controlled, allowing the lower end of the lifting component 22 to be adjusted to be level with the required liquid level.

[0041] By setting an expansion member 26 at the lower end of the lifting member 22, the expansion member 26 expands along the lower end of the lifting member 22, so that the size of the expansion member 26 is larger than the size of the lifting member 22. This allows for observation of whether the liquid level of the backfill soil reaches the level of the expansion member 26. This facilitates the observation of the liquid level of the backfill soil during the backfilling process, making the filling of the foundation pit more convenient, accurate, and less prone to errors.

[0042] The threaded connection between the expansion component 26 and the lower end of the lifting component 22 facilitates the installation and disassembly of the expansion component 26. This allows for easy replacement of expansion components 26 with different shapes and sizes according to the actual needs of the foundation pit. Furthermore, the detachable expansion component 26 is beneficial for the storage and organization of the filling auxiliary device.

[0043] Furthermore, the lifting assembly also includes a clamping member 24, one end of which is disposed in the channel, and the other end of which is connected to the side wall of the clamping member 24. Driving the other end of the clamping member 24 causes one end of the clamping member 24 to clamp the pipe in the channel.

[0044] Specifically, the clamping member 24 includes a body 242 and a clamping part 244. One end of the body 242 is disposed within the channel and connected to the clamping part 244, while the other end of the body 242 penetrates the side wall of the clamping member 24. The body 242 is threadedly connected to the side wall of the clamping member 24. Therefore, by rotating the body 242, it can move towards or away from the channel, thereby clamping the pipe between the clamping part 244 and the side wall of the clamping member 24. This facilitates fixing one end of the pipe within the channel, allowing backfill soil to flow from the pipe into the channel and then into the foundation pit, thus facilitating the filling of the foundation pit.

[0045] Preferably, the lifting component 22 is cylindrical, the channel is cylindrical, and the clamping part 244 is an arc-shaped plate structure, which facilitates clamping the pipe.

[0046] Preferably, the drive structure includes a lead screw assembly 12 and a transmission assembly. The transmission assembly is connected to the lead screw assembly 12 to drive the lead screw assembly 12 to move. The lead screw assembly 12 includes a lead screw 122 and a moving member 124. The moving member 124 is connected to the lead screw 122, so that the transmission assembly drives the lead screw 122 to rotate and drive the moving member 124 to move along the lead screw 122. One end of the moving member 124 is connected to a lifting member 22, so that the lifting member 22 moves along the lead screw 122.

[0047] Specifically, by driving the transmission assembly, the lead screw 122 can be rotated. The rotation of the lead screw 122 causes the moving part 124 to move up and down along the lead screw 122. Since one end of the moving part 124 is connected to the lifting part 22, the up and down movement of the moving part 124 along the lead screw 122 can drive the lifting part 22 to move up and down. The up and down movement of the lifting part 22 can adjust the height of the expanding part 26 so that the height of the expanding part 26 can be adjusted to be horizontal with the required filling height.

[0048] Furthermore, a guide rod is connected to the other end of the moving part 124. The guide rod is arranged parallel to the lead screw 122 and passes through the other side of the moving part 124, thereby restricting the movement of the moving part 124 so that the moving part 124 can only move up and down along the lead screw 122.

[0049] Specifically, the transmission assembly is driven by the handle 18. The transmission assembly includes a driving bevel gear 142 and a driven bevel gear 144 meshing with the driving bevel gear 142. The handle 18 is connected to the driving bevel gear 142. By driving the driving bevel gear 142 through the handle 18, the driven bevel gear 144 can be rotated. The driven bevel gear 144 is coaxially connected to the lead screw 122. Therefore, the driving bevel gear 142 through the handle 18 can drive the driven bevel gear 144 to rotate, and the rotation of the driven bevel gear 144 can cause the lead screw 122 to rotate synchronously.

[0050] In one embodiment, the filling aid includes a base disposed below the transmission assembly, thereby facilitating the installation of the lead screw assembly 12, the transmission assembly, and the lifting assembly into the appropriate position.

[0051] Preferably, the lead screw assembly 12 is installed inside the housing. One side of the housing has an opening for the lifting assembly to move up and down, and the other side of the housing is transparent and has a scale for observing the position of the moving part 124. The scale allows for easy observation of the position of the moving part 124, enabling control of the height of the moving part 124 as it rises and falls, thereby controlling the height of the lifting part 22 as it rises and falls.

[0052] S20. Excavate the ground in the construction area to remove the raw soil and form a foundation pit on the ground.

[0053] An excavation pit is a pit dug at the foundation design location according to the base elevation and foundation plane dimensions. It is formed by excavating raw soil. Before excavation, the excavation plan is determined based on geological and hydrological data and the situation of nearby buildings. Waterproofing and drainage work is also carried out. The excavation pit in this plan has undergone waterproofing and other treatments and needs to be filled. The raw soil used in this plan is the raw soil excavated during the excavation of the excavation pit, which can save energy.

[0054] S30. Screen the excavated raw soil, remove impurities from the excavated raw soil, and crush the screened raw soil to control the size of the raw soil to be less than 40mm.

[0055] Specifically, impurities are removed from the excavated raw soil. These impurities include unbreakable stones, organic matter, wood, grass, and other objects other than the raw soil. The raw soil is then crushed to ensure that the particle size is less than 40mm to prevent the pipes from becoming clogged due to excessively large particle size.

[0056] S40. Add admixture slurry to the crushed raw soil and stir to obtain backfill soil. The admixture slurry includes curing agent, water-reducing agent and water. The mixing ratio of curing agent, water-reducing agent and water is 22-24:1:29-31. The mixing ratio of raw soil and admixture slurry is 1:2.5-3.2.

[0057] The specific operation for preparing backfill soil is as follows: first, the curing agent, water-reducing agent and water are mixed to obtain an admixture slurry. The backfill soil is obtained by mixing the admixture slurry and the raw soil. The mixing time between the admixture slurry and the raw soil is at least 60 seconds.

[0058] Preferably, the curing agent is silicate cement.

[0059] Water-reducing agents are admixtures that can reduce the amount of mixing water and increase the strength of concrete; or save cement usage while maintaining workability and strength. The main components of water-reducing agents include: polyethylene oxide, acrylic acid, methacrylic acid, sodium acrylate sulfonate, ammonium persulfate, ferrous sulfate, and sodium hydroxide.

[0060] Specifically, the backfill soil is obtained by mixing the raw soil with the admixture slurry. Specifically, the mixing ratio of the curing agent, water-reducing agent and water is 170:7.3:222, and the mixing ratio of the raw soil and the admixture slurry is 399.3:1150.

[0061] Specifically, after preparing the admixture slurry, the admixture slurry, which is made by mixing the curing agent, water-reducing agent and water, is stirred with the raw soil. During the stirring process, it is necessary to stir for at least 60 seconds.

[0062] S50. After measuring the elevation of the foundation pit, mark the two side walls inside the foundation pit in layers. The first mark is made at a height less than 0.5m from the bottom of the foundation pit, and then marks are made at uniform intervals of less than 2m, so as to control the filling thickness of each layer of backfill soil.

[0063] Specifically, because the foundation pit is deep, it needs to be filled in layers. In order to ensure that the height of each layer is basically the same, the foundation pit needs to be marked from bottom to top before filling. The first mark is less than 0.5m away from the bottom of the foundation pit, and the subsequent marks are spaced at the same intervals, with an interval of less than 2m.

[0064] In detail, the surveying team marks the measurements on both side walls to control the thickness of the backfill. Marking facilitates layered filling of the foundation pit and allows for control of the height of each layer, preventing instability in the quality of the backfill.

[0065] S60. Install the filling auxiliary device above the foundation pit to be filled, connect the upper end of the lifting assembly to the backfill soil through a pipe, and abut the lower end of the lifting assembly to the marked position in order to determine the filling height of the backfill soil.

[0066] Specifically, the filling auxiliary device needs to be installed above the foundation pit first, then one end of the pipe is fixed into the channel of the lifting component 22, and then the lifting component 22 is adjusted so that the expansion component 26 abuts the mark, so that the height of the expansion component 26 is level with the height of the mark, so that the required filling height can be determined before filling.

[0067] After the lower end of the lifting assembly is brought into contact with the marked position, the fluidity of the backfill soil needs to be tested to ensure that the fluidity of the backfill soil is between 100mm and 130mm.

[0068] After the backfilling auxiliary equipment is installed, the foundation pit is in a state of waiting to be filled. At this time, the backfill soil needs to be tested to ensure its quality. Specifically, the flowability of the backfill soil in the external container is tested to ensure that the flowability is between 100mm and 130mm. This is to meet the backfilling requirements and ensure that the backfill soil can flow normally after entering the foundation pit.

[0069] Furthermore, after testing the fluidity of the backfill soil, a local area outside the construction area was selected as the test area. Backfill soil was then poured into the test area to observe its fluidity and to test whether its strength was greater than 0.3 MPa, thereby determining the backfill soil mix ratio.

[0070] Preferably, the length of the test area is 3 to 6 meters.

[0071] Specifically, after testing the fluidity of the backfill soil and ensuring that the fluidity is within the range of 100mm to 130mm, a test area can be selected for filling. The test area can be 5 meters long, which allows for observation of the fluidity of the backfill soil to ensure that it can flow, and also allows for testing of the strength of the backfill soil after filling to ensure that the foundation pit has sufficient strength after backfilling.

[0072] During implementation, another filling auxiliary device can be installed in the test area using the above installation method to backfill the test area, or the same filling auxiliary device can be used to move the location.

[0073] In the specific operation process, the test area should also be marked with an elevation and then filled in layers to ensure that it is consistent with the filling steps and methods of the foundation pit.

[0074] S70. The backfill soil is sequentially fed into the foundation pit through pipes and channels until the height of the backfill soil rises to be level with the lower end of the lifting assembly. Then, the drive structure is controlled to lift the lifting assembly to the adjacent marked position. The backfill soil is then sequentially fed into the foundation pit through pipes and channels until the foundation pit is filled.

[0075] Specifically, after the test in the test area is passed, the backfill soil mix that passed the test can be used to backfill the foundation pit. The external container is connected to the other end of the pipeline, so that the backfill soil flows from the external container through the other end of the pipeline to the other end of the pipeline, and then flows from the other end of the pipeline through the channel into the foundation pit, thereby filling the foundation pit.

[0076] During the filling process, due to the installation of the expansion member 26, it is easy to observe whether the height of the backfill soil liquid level reaches the height of the expansion member 26. When the height of the backfill soil liquid level reaches the height of the expansion member 26, the backfill filling is stopped. The lifting member 22 is then driven to rise by the handle 18 until the expansion member 26 abuts against an adjacent marker. The backfill filling continues until the height of the backfill soil liquid level reaches the height of the expansion member 26, until the foundation pit is filled.

[0077] Therefore, by implementing the embodiments of the present invention, the filling method of fluidized backfill soil can facilitate the observation of the backfill height by setting up the filling auxiliary device. When the liquid level of the backfill soil rises to the lower end of the lifting component, the filling can be stopped. The fixed lifting component will not shake, and the liquid level of the backfill soil can be easily observed.

[0078] It can reuse the raw soil excavated from the ground, making full use of resources, saving costs, and realizing the resource utilization of waste. By mixing the raw soil and additives, backfill soil can be obtained. Such backfill soil is uniformly mixed and has fluidity. Furthermore, the soil particles are filled and consolidated by the solidifying agent, making the backfill soil impermeable. It can prevent groundwater from damaging the backfill soil itself and can also be tightly integrated with the foundation structure to prevent surface water from seeping down along the interface between the structure and the backfill soil. Moreover, liquid filling produces no dust and is more environmentally friendly.

[0079] Therefore, fluid backfill soil can be directly filled into the space in layers, and can be left to solidify. This eliminates the need for continuous compaction of the backfill soil in traditional earthwork backfilling, while ensuring the strength requirements and construction quality of the fill. This filling method is particularly advantageous when encountering irregular and narrow spaces, which are difficult for machinery to enter and are prone to insufficient compaction, leading to foundation quality problems such as settlement and cracking later on. However, fluid backfill soil eliminates the need for compaction and is also convenient for filling irregular and narrow spaces.

[0080] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A method for constructing fluidized backfill soil, characterized in that, Includes the following steps: A filling auxiliary device is provided, the filling auxiliary device including a drive structure and a lifting assembly connected to the drive structure; wherein, the drive structure includes a lead screw assembly and a transmission assembly, the transmission assembly is connected to the lead screw assembly to drive the lead screw assembly to move, the lead screw assembly includes a lead screw and a moving part, the moving part is connected to the lead screw, thereby causing the transmission assembly to drive the lead screw to rotate and drive the moving part to move along the lead screw, one end of the moving part is connected to the lifting assembly; The lifting assembly includes a lifting component, an expanding component, and a clamping component. The lifting assembly has a channel that allows the backfill soil to flow through it. The channel passes through the lifting component. The expanding component is threaded to the lower end of the lifting component. One end of the clamping component is disposed in the channel, and the other end of the clamping component is connected to the side wall of the clamping component. The drive structure drives the lifting component to rise or fall; The ground in the construction area is excavated to remove the raw soil and form a foundation pit. The excavated raw soil is screened to remove impurities, and the screened raw soil is crushed to control the size of the raw soil to be less than 40mm. Backfill soil is prepared by adding an admixture slurry to the crushed raw soil and stirring. The admixture slurry includes a curing agent, a water-reducing agent, and water. The mixing ratio of the curing agent, the water-reducing agent, and the water is 22~24:1:29~31. The mixing ratio of the raw soil to the admixture slurry is 1:2.5~3.

2. After measuring the elevation of the foundation pit, the two side walls inside the foundation pit are marked in layers. The first mark is made at a height less than 0.5m from the bottom of the foundation pit, and then the marks are made at uniform intervals of less than 2m, thereby controlling the filling thickness of each layer of backfill soil. The filling auxiliary device is installed above the foundation pit to be filled. The upper end of the lifting assembly is connected to the backfill soil through a pipe. The other end of the clamping member is driven to clamp the pipe in the channel. The lower end of the lifting assembly is abutted against the mark to determine the filling height of the backfill soil. The backfill soil is sequentially fed into the foundation pit through the pipes and channels until the height of the backfill soil rises to be level with the lower end of the lifting assembly. Then, the drive structure is controlled to lift the lifting assembly to the adjacent mark, and the backfill soil is continuously fed into the foundation pit through the pipes and channels until the foundation pit is filled.

2. The filling method for fluidized backfill soil according to claim 1, characterized in that, Adding an admixture slurry to the crushed raw soil and stirring it to obtain backfill soil further includes the following operation: first stirring the curing agent, the water-reducing agent and the water to obtain the admixture slurry, and the backfill soil is obtained by stirring the admixture slurry and the raw soil, wherein the stirring time of the admixture slurry and the raw soil is at least 60 seconds.

3. The method for constructing fluidized backfill soil according to claim 2, characterized in that, It also includes performing the following operation after the operation of bringing the lower end of the lifting assembly to the mark and before the operation of letting the backfill soil flow into the foundation pit through the pipe and the channel in sequence: performing a flowability test on the backfill soil so that the flowability of the backfill soil is between 100mm and 130mm.

4. The filling method for fluidized backfill soil according to claim 3, characterized in that, The procedure also includes, after testing the fluidity of the backfill soil and before sequentially channeling the backfill soil into the foundation pit through the pipe and the channel, performing the following operation: selecting a local area outside the construction area as a test area, filling the test area with the backfill soil, observing the fluidity of the backfill soil, and testing whether the strength of the backfill soil is greater than 0.3 MPa, thereby determining the mix proportion of the backfill soil.

5. The method for constructing fluidized backfill soil according to claim 4, characterized in that, The length of the test area is 3 to 6 meters.

6. The method for constructing fluidized backfill soil according to claim 1, characterized in that, The curing agent is silicate cement.

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