Foundation pit fat groove backfilling method adopting flowing solidified soil filling bags for layered construction

Abstract

The invention discloses a foundation pit fat groove backfilling method adopting flowing solidified soil filling bag layered construction, and relates to the technical field of foundation pit supporting and backfilling in civil engineering, the method comprises the following steps: S1, preparing flowing solidified soil; s2, layered construction of the filling bags is conducted, specifically, a support structure is built through a transverse supporting pipe structure and a longitudinal supporting pipe structure, the filling bags are arranged on the support structure, and grouting pipes are arranged above the filling bags of all layers and on the side wall of the foundation pit; and S3, layered grouting construction is conducted, specifically, flowing solidified soil is injected into the filling bags of all the layers and gaps between the filling bags from bottom to top. The flowing solidified soil is adopted to replace traditional backfill soil, the filling bag type construction method and the layered grouting construction method are combined, the construction condition that the operation space is limited during backfill of the foundation pit fat groove is overcome, the construction efficiency and quality are improved, and meanwhile the influence on the environment is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of foundation pit support and backfilling in civil engineering, in particular to a method for backfilling a foundation pit trench by using flowable solidified soil to fill a bag in a layered construction. BACKGROUND

[0002] In civil engineering construction, backfilling of a foundation pit trench is one of the common construction links. The quality of backfilling of the trench directly affects the long-term stability of the supporting structure. The traditional backfilling method mainly uses plain soil, lime soil for backfilling and layered compaction, or uses sand, plain concrete for backfilling and vibration compaction. The above traditional backfilling methods have the following defects: first, the mechanical compaction or vibration method in the traditional backfilling method has a large noise during construction, which has a greater impact on the surrounding environment. Second, the adaptability of the materials used in the traditional backfilling method is poor, plain soil compaction needs large machinery and cannot achieve self-compaction; concrete shrinkage produces interface cracks; graded sand has high cost and is easily washed away by underground water. In addition, in some cases, the working space of the foundation pit trench is limited and cannot be fully compacted or vibrated by machinery, which will make it difficult to meet the requirements of the density and the quality of the backfilling will be difficult to guarantee. Finally, the mechanical compaction method has relatively low construction efficiency and cannot meet the rapid construction needs of large-scale projects. SUMMARY

[0003] The purpose of the present application is to provide a method for backfilling a foundation pit trench by using flowable solidified soil to fill a bag in a layered construction, which ensures the density and strength of the backfilling structure of the trench.

[0004] To achieve the above-mentioned purpose, the present application provides the following solutions:

[0005] The present application provides a method for backfilling a foundation pit trench by using flowable solidified soil to fill a bag in a layered construction, comprising the following steps:

[0006] S1: preparing flowable solidified soil;

[0007] S2: filling a bag in a layered construction: building a support structure through a transverse support pipe structure and a longitudinal support pipe structure, setting a filling bag on the support structure, and setting a grouting pipe above each layer of the filling bag and on the side wall of the foundation pit;

[0008] S3: layered grouting construction: injecting flowable solidified soil into each layer of the filling bag and the gap between the filling bags from bottom to top.

[0009] In some specific solutions, the flowable solidified soil is prepared from granite residual soil, a solidifying agent and water, the ratio of the mass of water to the sum of the mass of granite residual soil and the mass of the solidifying agent is between 0.55 and 1.20, the solidifying agent includes mineral powder, desulfurized gypsum and carbide slag, and the ratio of mineral powder, desulfurized gypsum and carbide slag is 0.8:0.15:0.05.

[0010] In some specific embodiments, the filling bag is made of geotextile, and the upper end of the filling bag is provided with an opening, and the lower end of the filling bag is closed.

[0011] In some specific embodiments, the grouting pipe above the filling bag is arranged in parallel with the transverse support pipe structure.

[0012] In some specific embodiments, the grouting pipe above the filling bag of each layer is connected with the transverse support pipe structure.

[0013] In some specific embodiments, the grouting holes of the grouting pipe above the filling bag of each layer are uniformly arranged, and the spacing of the grouting holes of the grouting pipe of the side wall of the foundation pit gradually decreases from bottom to top.

[0014] In some specific embodiments, the transverse support pipe structure and the longitudinal support pipe structure are arranged vertically, and the transverse support pipe structure and the longitudinal support pipe structure are connected to form a support structure having a space for placing the filling bag.

[0015] In some specific embodiments, the transverse support pipe structure comprises a plurality of first transverse support pipes and a plurality of second transverse support pipes, the first transverse support pipes and the second transverse support pipes are both arranged horizontally, the first transverse support pipes and the second transverse support pipes are arranged vertically, and the first transverse support pipes and the second transverse support pipes are both provided with through holes for the longitudinal support pipe structure to pass through; the first transverse support pipes, the second transverse support pipes and the longitudinal support pipe structure all comprise a plurality of support pipes, a plurality of sleeves and a plurality of connecting heads, one end of each support pipe is provided with a sleeve, the other end of each support pipe is provided with a connecting head, and when adjacent support pipes are connected, the sleeve of one support pipe and the connecting head of another support pipe are connected.

[0016] In some specific embodiments, when the flow solidified soil is injected, the grouting pressure is between 0.25 MPa and 0.55 MPa, and the grouting flow rate is between 0.3 m 3 / h and 0.5 m 3 / h.

[0017] In some specific embodiments, when the flow solidified soil is injected into the filling bag of the same layer, the gap between the filling bags, and the gap between the filling bag and the side wall of the foundation pit, the overflow amount of the grouting pipe or the filling bag in the adjacent area is less than 5%, which is the grouting pipe grouting termination standard.

[0018] The present application has the following technical effects compared with the prior art:

[0019] The application adopts flow solidified soil to fill the inside of filling bags and the gap between filling bags layer by layer, utilizes the characteristics of flow solidified soil with good fluidity, and the support structure built by the transverse support pipe structure and the longitudinal support pipe structure enhances the stability of the overall structure. The application solves the problems of uneven compaction, low construction efficiency and great influence on the environment in the traditional foundation trench fat groove backfill construction, and has the characteristics of high efficiency, environmental protection and strong stability. By accurately controlling the proportioning and construction process of flow solidified soil, the density and strength of the fat groove backfill structure are ensured, especially in complex geological conditions and high requirement projects. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0021] Fig. 1 The flow chart of the foundation trench fat groove backfill method using flow solidified soil to fill the bag layer by layer in some embodiments of the present application is shown in the figure.

[0022] Fig. 2 The structure arrangement sectional view in some embodiments of the present application is shown in the figure.

[0023] Fig. 3 The structure arrangement plan view in some embodiments of the present application is shown in the figure.

[0024] In the figure: 1-first transverse support pipe, 2-second transverse support pipe, 3-filling bag, 4-flow solidified soil, 5-longitudinal support pipe structure, 6-grouting pipe. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0026] The purpose of the present application is to provide a foundation trench fat groove backfill method using flow solidified soil to fill the bag layer by layer, which ensures the density and strength of the fat groove backfill structure.

[0027] In order to make the above-mentioned purposes, characteristics and advantages of the present application more obvious and easy to understand, the present application will be further described in combination with the drawings and specific embodiments.

[0028] As Figs. 1 to 3 shown, the embodiment provides a foundation trench backfilling method using flow solidified soil to fill the capsule bag and layer construction, including the following steps:

[0029] S1: preparing flow solidified soil 4;

[0030] S2: filling the capsule bag 3 layer construction: building a support structure through the transverse support pipe structure and the longitudinal support pipe structure 5, setting the filling capsule bag 3 on the support structure, and setting the grouting pipe 6 above each layer of the filling capsule bag 3 and the side wall of the foundation pit, the grouting pipe 6 is preferably a flower pipe;

[0031] S3: layer grouting construction: injecting flow solidified soil 4 into each layer of the filling capsule bag 3 and the gap between the filling capsule bags 3 from bottom to top.

[0032] In S1 of the specific embodiment of some embodiments, when preparing the flow solidified soil 4, a suitable soil sample is selected, the soil is mixed with the curing agent at a predetermined ratio, the type and mixing ratio of the curing agent are adjusted according to the soil quality and water content of the specific project, an appropriate amount of water is added according to the determined water-cement ratio, the water-cement ratio is controlled between 0.55 and 1.20, so that the mixture has good fluidity, and the fluidity and strength after solidification of the flow solidified soil 4 in the construction process are ensured. For example, for clay with a water content of 20%, the mixing ratio of the curing agent can be 20%, and the water-cement ratio can be 1. The curing agent uses mineral powder + desulfurized gypsum + carbide slag, and the strength and curing effect of the material prepared by using the ternary curing agent are better. For granite residual soil, the curing agent dosage is 15%, the water-cement ratio is 1, and the mineral powder: desulfurized gypsum: carbide slag = 0.8:0.15:0.05. The flow value of the material prepared by this ratio can reach 180 mm, and the compressive strength after 3 days of curing can reach 1.5 MPa. When curing other different soil bodies, the ratio and dosage of the curing agent can be adjusted appropriately. When mixing soil and curing agent, a forced mixer is used to mix granite residual soil with a water content of about 19.8% with the curing agent to ensure uniform mixing. The mixing time is not less than 3 minutes to ensure the uniformity of the mixture. The embodiment uses a full-solid waste cementitious material to prepare granite flow solidified soil, and the full-solid waste cementitious material has better curing effect, lower energy consumption and carbon emission than cement.

[0033] In S2 of the specific embodiment of some embodiments, the filling capsule bag 3 is made of high-strength geotextile with a tensile strength greater than 20 kN / m and a water permeability coefficient less than 1 x 10 -2cm / s, the upper end of the filling bag 3 is provided with an opening, and the lower end of the filling bag 3 is closed. The size and shape of the filling bag 3 can be customized according to the width and depth of the trench and the capacity of the construction equipment. The cross-sectional size of the filling bag 3 is 1.0m x 1.0m to 2.5m x 2.5m, which can be adjusted according to the specific engineering requirements. For example, a cubic or cuboid filling bag 3 with a cross-sectional size of 1.5m x 1.5m can be customized. The shape of the filling bag 3 matches the shape of the side wall near the side wall of the foundation pit. The filling bag 3 is placed at the predetermined filling position, and mechanical auxiliary equipment is used to ensure that the filling bag 3 is flat and stable. Laser level or level is used to ensure that the filling bag 3 is placed flat, without wrinkles or inclination, and the flatness error should be less than 5mm. High-strength binding materials such as wire or special binding tape can be used to bind and fix the bag opening of the filling bag 3 to the transverse support pipe structure.

[0034] The backfill construction of the foundation pit trench will eventually be built layer by layer by the multi-layer filling bag 3. Before arranging the upper filling bag 3, the grouting pipe 6 is placed on the top surface of the lower filling bag 3 to facilitate the subsequent S3 grouting construction of the interlayer horizontal grouting belt. In some embodiments, the grouting pipe 6 above the filling bag 3 is arranged parallel to the first transverse support pipe 1 or the second transverse support pipe 2 of the transverse support pipe structure. The grouting pipe 6 above each layer of filling bag 3 is bound to the transverse support pipe structure with a positioning bracket. The number and spacing of the grouting pipe 6 are determined according to the specific engineering requirements. For example, nylon binding belt rings and ratchet locks can be used to fix the grouting pipe 6 to the first transverse support pipe 1 or the second transverse support pipe 2 to ensure firm installation. The grouting pipe 6 above the filling bag 3 is arranged with two pipes above each row of filling bag 3, and the spacing is uniform.

[0035] In some embodiments, the grouting pipe 6 has a pipe diameter of DN20 (outer diameter 25.0±0.3mm, inner diameter 20.5±0.2mm) or DN25 (outer diameter 32.0±0.4mm, inner diameter 26.5±0.3mm); wall thickness ≥1.8mm (material is glass fiber reinforced PVC) or ≥2.5mm (material is galvanized steel pipe).

[0036] In the specific implementation of some embodiments S2, the transverse support pipe structure and the longitudinal support pipe structure 5 are vertically arranged, and the transverse support pipe structure and the longitudinal support pipe structure 5 are connected to form a support structure having a space for placing the filling bag 3. The transverse support pipe structure and the longitudinal support pipe structure 5 are both steel pipes with a diameter of 50 mm to 80 mm. The transverse support pipe structure includes a plurality of first transverse support pipes 1 and a plurality of second transverse support pipes 2. The first transverse support pipes 1 and the second transverse support pipes 2 are both horizontally arranged and vertically arranged. The length of the first transverse support pipes 1 and the second transverse support pipes 2 can be adjusted according to the spacing of the filling bag 3. The first transverse support pipes 1 and the second transverse support pipes 2 are both steel pipes with a length of 1500 mm and a diameter of 50 mm. The material of the first transverse support pipes 1 and the second transverse support pipes 2 is Q235B. The first transverse support pipes 1 and the second transverse support pipes 2 are both provided with through holes for the longitudinal support pipe structure 5 to pass through. At the position where the longitudinal support pipe structure 5 passes through the transverse support pipe structure, the transverse support pipe structure and the longitudinal support pipe structure 5 are connected by welding. The first transverse support pipes 1, the second transverse support pipes 2, and the longitudinal support pipe structure 5 all include a plurality of support pipes, a plurality of sleeves, and a plurality of connecting heads. One end of each support pipe is provided with a sleeve, and the sleeve is provided with external threads. The other end of each support pipe is provided with a connecting head, and the connecting head is provided with internal threads. When adjacent support pipes are connected, the sleeve of one support pipe and the connecting head of another support pipe are threadedly connected to ensure the firmness and sealing of the connection. The tensile strength of the connecting piece formed by the sleeve and the connecting head should be 375 MPa to 540 MPa. When the first transverse support pipes 1, the second transverse support pipes 2, and the longitudinal support pipe structure 5 are constructed in layers, the connection can be achieved through the form of support pipes, sleeves, and connecting heads.

[0037] After the arrangement and construction of the lower filling bag 3 are completed, the arrangement of the upper filling bag 3 is continued. Before arranging the upper filling bag 3, a grouting pipe 6 is placed on the top surface of the lower filling bag 3 for subsequent grouting construction of the interlayer horizontal grouting belt. The longitudinal pipe passes through the vertically arranged through holes of each layer of transverse support pipe structure and is welded at the connection. The longitudinal pipe of the upper layer is rotated so that its connecting head is screwed into the sleeve of the lower layer longitudinal pipe. The first transverse support pipe 1 and the second transverse support pipe 2 are arranged. The steps of binding and fixing the filling bag 3, placing, and arranging and fixing the grouting pipe 6 are repeated. The above steps are repeated to perform multi-layer filling bag 3 construction in layers to form a space grid as the overall framework of the foundation pit trench backfill structure.

[0038] In the specific implementation of some embodiments in S2, the grouting holes of the grouting pipes 6 above the filling capsules 3 of each layer are uniformly arranged, the diameter of the grouting pipes 6 above the filling capsules 3 of each layer is 25 mm, and the opening rate is 35%; the grouting pipes 6 of the side wall of the foundation pit are arranged close to the side wall of the foundation pit, the spacing of the grouting holes of the grouting pipes 6 of the side wall of the foundation pit gradually decreases from bottom to top, forming an upper dense and lower sparse form. The number, arrangement spacing and opening rate of the grouting holes of the grouting pipes 6 at all positions are determined according to the specific engineering needs, and the opening rate can be 20%-60%. When the grouting pipes 6 of the side wall of the foundation pit are constructed, a conical alloy drill bit (HRC45) is used to make the grouting pipes 6 of the side wall of the foundation pit penetrate into the basement layer by ≥300 mm. The opening rate of the grouting pipes 6 of the side wall of the foundation pit is arranged in a gradient, the opening rate of the dense area is 50%-60%, preferably 55%, the opening rate of the transition area is 30%-40%, preferably 20%, the opening rate of the sparse area is 10%-20%, and the spacing of the grouting pipes 6 of the side wall of the foundation pit is preferably 1.5 m.

[0039] In the specific implementation of some embodiments in S3, the sequence of layered grouting follows the principle of first bottom and then top, uses intelligent pumping equipment, pre-sets the ratio of curing agent, pressure value, transportation rate and other parameters, one-key start and stop, and pumps the flowable solidified soil 4 prepared in S1 through the grouting pipes 6 to the filling capsules 3 and the gaps between the filling capsules 3, to ensure uniform filling and improve the compactness and stability of the overall structure, forming an overall stable filling structure. When the flowable solidified soil 4 is injected, the grouting pressure is between 0.25 MPa and 0.55 MPa, the grouting flow is between 0.3 m 3 / h and 0.5 m 3 / h (i.e. between 5 L / min and 8.3 L / min).

[0040] In the specific implementation of some embodiments in S4, when the flowable solidified soil 4 is injected into the filling capsules 3 of the same layer, the gaps between the filling capsules 3 and the gaps between the filling capsules 3 and the side wall of the foundation pit, the grouting pipe 6 or the overflow amount of the filling capsule of the adjacent area (adjacent area in the same layer) is taken as the grouting pipe 6 grouting termination standard. After the grouting of the lower layer is completed, the grouting of the upper layer is continued to ensure uniform filling and improve the compactness and stability of the overall structure. The distributed optical fiber (OFDR) + ultrasonic tomography is used, and the optical fiber strain mutation rate ≥85% and the acoustic wave velocity ≥1800 m / s are taken as the standards to determine the filling compactness.

[0041] Unless otherwise specified, the materials of the above structures are all commercially available.

[0042] This embodiment uses fluidized solidified soil 4 to replace traditional backfill soil, without the need for mechanical compaction or vibration, which significantly improves construction efficiency and shortens construction period; the fluidized solidified soil 4 has low noise during preparation and construction, has little impact on the surrounding environment, and is environmentally friendly and meets environmental protection requirements; compared with other backfill materials, the fluidized solidified soil 4 can be self-compacted after filling, and has higher strength and better durability; the filling bag 3 forms the skeleton of the basic structure, while filling the gaps to increase the density, enhance the overall stability of the structure, and prevent local deformation or collapse; the filling bag 3 provides a constraint for the fluidized solidified soil 4 The method can reduce the waste of mobile solidified soil 4 in disordered flow, improve material utilization and reduce costs; adopt grouting pipe 6 to carry out layered grouting, so that the gaps between filling bags 3 and filling bags 3 are effectively filled and penetrated, enhance the uniformity of soil layer, and improve the bearing capacity and stability of foundation; compared with the method of backfilling foundation pit fertilizer trough with filled filling bags 3, the unfilled filling bags 3 are small in size and light in weight, which can better cope with the narrow space and complex construction conditions in foundation pit fertilizer trough, have greater construction flexibility, lower construction cost and safer construction process. This embodiment adopts the construction method of filling bags 3 and layered grouting to improve the stability of the project. This method is applicable to a variety of soil types and geological conditions, and is particularly applicable to backfill projects under soil layers with high water content and complex geological conditions.

[0043] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third" and the like are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0044] In the description of the present invention, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; they may refer to mechanical or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application.

[0045] If the present application discloses or relates to mutually fixedly connected parts or structural members, unless otherwise stated, the fixed connection can be understood as: detachably fixedly connected (for example, connected using bolts or screws), and can also be understood as: non-detachable fixed connection (for example, riveting, welding), of course, the mutually fixed connection can also be replaced by an integral structure (for example, manufactured by integral forming process) (obviously, integral forming process cannot be used).

[0046] In addition, the terms used to represent the positional relationship or shape in any technical solution disclosed by the present application include states or shapes similar, similar or close to them, unless otherwise stated.

[0047] Any component provided by the present application can be assembled from multiple individual components, or can be a single component manufactured by integral forming process.

[0048] It should be noted that the structure, proportion, size, etc. shown in the drawings of the present application are only used to illustrate the content disclosed in the specification, to enable those skilled in the art to understand and read, and are not used to limit the conditions under which the present application can be implemented, so they do not have technical significance. Any modification of structure, change of proportion relationship or adjustment of size, without affecting the effect and purpose that the present application can produce, should still fall within the scope of the technical content disclosed by the present application.

[0049] It should be noted that the same reference signs in the embodiments of the present application represent the same component or the same part.

[0050] Adaptive changes according to actual needs are within the scope of protection of the present application.

[0051] The present application uses specific examples to explain the principles and implementation methods of the present application. The above examples are only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in specific implementation methods and application scope. In conclusion, the content of the present application should not be understood as a limitation of the present application.

Claims

1. A foundation pit fertilizer trough backfilling method using fluidized solidified soil filled bags for layered construction, characterized by: The following steps are involved: S1: Preparation of mobile solidified soil; S2: Layered construction of filling bags: Build a support structure through horizontal and vertical support pipe structures, set filling bags on the support structure, and set grouting pipes above the filling bags of each layer and on the side walls of the foundation pit; S3: Layered grouting construction: inject flowing solidified soil into the filling bags of each layer and the gaps between the filling bags from bottom to top.

2. The method for backfilling a foundation pit fertilizer tank using fluidized solidified soil filling bags in layered construction according to claim 1 is characterized in that: The fluidized solidified soil is prepared from granite residual soil, a solidifying agent and water, wherein the ratio of the mass of water to the sum of the mass of the granite residual soil and the solidifying agent is between 0.55 and 1.20, and the solidifying agent includes mineral powder, desulfurization gypsum and carbide slag, and the ratio of mineral powder, desulfurization gypsum and carbide slag is 0.8:0.15:0.

05.

3. The method for backfilling a foundation pit fertilizer tank using fluidized solidified soil filling bags in layered construction according to claim 1 is characterized in that: The filling bag is made of geotextile, the upper end of the filling bag is provided with an opening, and the lower end of the filling bag is closed.

4. The method for backfilling a foundation pit fertilizer trough by layered construction using fluidized solidified soil filling bags according to claim 1 is characterized in that: The grouting pipe above the filling bag is arranged parallel to the transverse support pipe structure.

5. The method for backfilling a foundation pit fertilizer tank using fluidized solidified soil filling bags in layered construction according to claim 1 is characterized in that: The grouting pipes above the filling bags of each layer are connected to the transverse support pipe structure.

6. The method for backfilling a foundation pit fertilizer tank using fluidized solidified soil filling bags in layered construction according to claim 1 is characterized in that: The grouting holes of the grouting pipes above the filling bags of each layer are evenly arranged, and the spacing between the grouting holes of the grouting pipes on the side walls of the foundation pit gradually decreases from bottom to top.

7. The method for backfilling a foundation pit fertilizer trough by layered construction using fluidized solidified soil filling bags according to claim 1 is characterized in that: The transverse support tube structure and the longitudinal support tube structure are vertically arranged, and the transverse support tube structure and the longitudinal support tube structure are connected to form a support structure with a space for placing a filling bag.

8. The method for backfilling a foundation pit fertilizer tank using fluidized solidified soil filling bags in layered construction according to claim 1 is characterized in that: The transverse support tube structure includes several first transverse support tubes and several second transverse support tubes, the first transverse support tubes and the second transverse support tubes are both arranged horizontally, the first transverse support tubes and the second transverse support tubes are arranged vertically, and the first transverse support tubes and the second transverse support tubes are both provided with through holes for the longitudinal support tube structure to pass through; the first transverse support tube, the second transverse support tube and the longitudinal support tube structure each include several support tubes, several sleeves and several connectors, one end of each support tube is provided with the sleeve, and the other end of each support tube is provided with the connector, when adjacent support tubes are connected, the sleeve of one support tube is connected to the connector of another support tube.

9. The method for backfilling a foundation pit fertilizer tank using fluidized solidified soil filling bags in layered construction according to claim 1 is characterized in that: When injecting fluidized solidified soil, the grouting pressure is between 0.25MPa and 0.55MPa, and the grouting flow rate is 0.3m 3 / h to 0.5m 3 / h.

10. The method for backfilling a foundation pit fertilizer tank by layered construction using fluidized solidified soil filling bags according to claim 1, characterized in that: When injecting flowing solidified soil into the filling bags in the same layer, the gaps between the filling bags, and the gaps between the filling bags and the side walls of the foundation pit, the grouting termination standard for the grouting pipe is that the overflow of the adjacent grouting pipe or filling bag is less than 5%.

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