Method for replacing contaminated soil and light replacement structure

Abstract

The application discloses a contaminated soil replacement method and a light replacement structure, and belongs to the technical field of building replacement, which solves the problems of the existing technology, such as treating the symptoms but not the root cause, large amount of concrete, and poor durability of the protective layer. The method comprises the following steps: contaminated soil treatment, frame assembly (integral type / modularization), block component installation (integral / layering), concrete pouring (layering / integral), and subsequent treatment. The frame and the block component form a protective barrier. Layered pouring requires rough surface treatment, and integral pouring is provided with anchoring components. The structure comprises a frame, a block component (light filling block combined with a U-shaped hook connecting piece), and optional anchoring components (two-way expansion anchor rods). The application replaces 30%-50% of the concrete with light blocks, reduces the load and cost, and improves the durability of the protective layer by more than 20%. The application can block pollution and erosion, is suitable for different construction scenes, and is convenient to operate.

Description

Technical Field

[0001] This invention belongs to the field of building replacement technology, specifically relating to a method for replacing contaminated soil and a lightweight replacement structure for implementing the method. It is suitable for backfill protection after excavation of contaminated soil around building foundations, can reduce the amount of concrete used and improve the durability of the backfill layer, and effectively protect the building foundation. Background Technology

[0002] With the continuous development of the construction industry, the scope of construction is constantly expanding, the number of buildings is continuously increasing, and the environment in which some buildings are located is also changing, leading to conflicts between the applicable conditions of the original building design and the current actual conditions. In particular, the problem of soil pollution near the building foundation (such as the foundation and pile cap) is particularly serious—polluted soil can act on the building foundation through infiltration, chemical erosion, and other means, destroying its structural integrity, reducing its load-bearing capacity, and posing a serious threat to the safety and stability of the building.

[0003] To address these issues, the industry commonly employs a "soil replacement" method, which involves excavating and removing contaminated soil and replacing it with uncontaminated new soil. However, this method has significant drawbacks: firstly, simply replacing the soil cannot fundamentally solve the problems of pollution transmission pathways and basic protective barriers; the new soil may still be re-contaminated due to the surrounding environment, and its protective effect on the foundation is limited. Secondly, if increased protective strength is required, a large amount of concrete must be poured to form a protective layer, which not only increases material costs and construction load but may also place additional loads on the foundation due to the excessive weight of the concrete. Furthermore, the durability of traditional concrete protective layers is easily affected by environmental factors, and cracking and peeling are prone to occur after long-term use, leading to a significant reduction in protective effectiveness. Summary of the Invention

[0004] (a) Purpose of the invention Addressing the core problems of existing contaminated soil replacement technologies—namely, "merely replacing soil as a temporary solution, large concrete usage, high construction load, the self-weight of concrete easily placing additional loads on the foundation, and poor durability of the protective layer"—this invention provides a contaminated soil replacement method and a lightweight replacement structure, aiming to achieve the following objectives: 1. Reduce the amount of concrete used during the replacement process, lower material costs and construction load, and avoid the concrete's own weight from generating additional load on the building foundation; 2. Improve the durability of the overall protective layer after concrete backfilling, alleviate cracking and spalling problems, and extend the protection period; 3. Through stable structural design and adaptable anchoring scheme, ensure that the infill structure does not shift or loosen during construction and use, thus blocking the path of pollution erosion at the source; 4. Offers flexible assembly and pouring solutions to adapt to different construction scenarios, simplifying the construction process and improving ease of operation.

[0005] (II) Technical Solution To achieve the above objectives, the present invention adopts the following technical solution: 1. Methods for replacing contaminated soil A method for replacing contaminated soil, the key of which includes the following steps: S1: Contaminated soil treatment and foundation protection: Excavate the contaminated soil around the building foundation, clean the contaminants on the surface of the building foundation, and then carry out anti-corrosion treatment on the surface of the building foundation; set up a temporary support structure on the outside of the building foundation, and leave a pouring gap between the temporary support structure and the building foundation. S2: Frame assembly of lightweight replacement structure: The frame assembly method is determined according to construction requirements. Frame assembly methods include integral assembly and modular assembly. When using an integral assembly method, a predetermined number of transverse support ribs and longitudinal support ribs are cross-fixed, and the intersection of the two forms a cross-shaped connection node, which serves as the installation basis for all block components. When using a modular assembly method, multiple unit frames are prefabricated. Each unit frame is assembled vertically from horizontal support frames and vertical support frames. The intersection of the horizontal support frames and the vertical support frames forms a cross-shaped connection node, which serves as the installation foundation for a single block component. S3: Block component installation: The installation method for block components is determined based on the casting method and construction requirements. Block component installation methods include integral installation and layered installation. When using the overall installation method, multiple sets of block components are installed and fixed as a whole at the connection nodes of the integral frame composed of a predetermined number of transverse support bars and longitudinal support bars, or the modular combined frame composed of multiple unit frames, so that the multiple sets of block components form a rectangular array or a staggered arrangement in a plum blossom shape. When using layered installation, the block components are installed in layers along the height direction of the backfill pit. After the installation of one layer of block components is completed, the next pouring process is carried out. After the pouring process of that layer is completed, the installation of the next layer of block components is carried out. S4: Concrete Pouring: The pouring method is determined according to construction requirements. Pouring methods include layered pouring and monolithic pouring. When using layered pouring, concrete is poured in layers between the temporary support structure and the frame along the height direction of the frame. The weight of the lightweight replacement structure assembled as a whole is used to overcome the buoyancy generated during concrete pouring. After the first layer of concrete has initially set, the next layer of concrete is poured until the design height is reached. When using monolithic casting, first install anchoring components at the bottom of the frame, and fix the frame to the base layer at the bottom of the backfill pit through the anchoring components. Then, pour concrete monolithically between the temporary support structure and the frame in one go. S5: Subsequent treatment: After the concrete strength reaches the preset requirements, the temporary support structure is removed; the exposed concrete contact surface after the temporary support structure is removed is roughened, and debris is removed from the contact surface. Then, concrete is poured into the pouring gap reserved in S1 to complete the replacement construction.

[0006] Furthermore, in step S3, when installing the block components in layers, after each layer of block components is installed, the block components and connecting nodes are temporarily fixed before the corresponding layer of concrete is poured.

[0007] Furthermore, in step S4, when using layered pouring, after the initial setting of the previous layer of concrete and before pouring the next layer of concrete, the surface of the initially set concrete is roughened; the roughening is done by mechanical chiseling or high-pressure water jetting, and after the roughening, the concrete surface exposes aggregate with a particle size of not less than 5mm, and the surface unevenness is not less than 3mm; the roughening covers the exposed concrete surface outside the frame-covered area.

[0008] 2. Lightweight replacement structure A lightweight replacement structure for implementing a method of replacing contaminated soil, the key feature of which is: The frame (100) is either an integral frame or a modular combined frame. The integral frame is formed by the cross-fixing of transverse support ribs (101) and longitudinal support ribs (102), and the intersection forms multiple cross-shaped connection nodes. The modular combined frame is formed by connecting multiple unit frames in a rectangular array. Each unit frame includes a cross-shaped structure formed by the vertical assembly of transverse support frames (111) and longitudinal support frames (112), and the intersection of the transverse support frames (111) and longitudinal support frames (112) forms a cross-shaped connection node. Multiple sets of block components (200) include lightweight filler blocks (210) and connectors (220). The lightweight filler blocks (210) are connected to the connection nodes of the frame (100) through the connectors (220) so that the multiple sets of block components (200) are arranged in a rectangular array or in a staggered quincunx pattern on the frame (100). The connectors (220) include a first connecting rod (221), a second connecting rod (222), and a third connecting rod (223) that are connected in sequence to form a U-shaped hook. The lightweight filler blocks (210) are fixed through the first connecting rod (221) and / or the third connecting rod (223), and the first connecting rod (221) and the third connecting rod (223) are distributed opposite each other in the diagonal area of ​​the connection node.

[0009] Furthermore, the connection nodes of the frame (100) all include front nodes and rear nodes; each group of block components (200) includes a front lightweight filler block and a rear lightweight filler block; both ends of the first connecting rod (221) are connected to a third connecting rod (223) through a second connecting rod (222), so that both ends of the connector (220) form a front U-shaped hook and a rear U-shaped hook respectively, the front lightweight filler block is connected to the front node through the front U-shaped hook, and the rear lightweight filler block is connected to the rear node through the rear U-shaped hook.

[0010] Furthermore, the length of the first link (221) is greater than the sum of the lengths of the two third links (223), so that a gap is formed between the two third links (223).

[0011] Furthermore, the longitudinal support bars (102) of the integral frame are U-shaped steel bars with the opening facing upwards; the transverse support frame (111) and longitudinal support frame (112) of the modular combined frame are both fixed by two relatively distributed U-shaped steel bars.

[0012] Furthermore, it also includes: An anchoring member (300) includes an anchor rod (301) and a connecting steel bar (302) connecting the anchor rod (301) to the bottom of the frame (100); the connecting steel bar (302) extends in a direction perpendicular to the first connecting rod (221), and the top of the anchor rod (301) is bent to form a hook portion (303) adapted to the connecting steel bar (302).

[0013] Furthermore, the anchor rod (301) includes an inner rod (3011) and an outer sleeve (3012). The inner rod (3011) is provided with at least one variable diameter portion (3013), and the outer sleeve (3012) is provided with at least one expansion portion (3014), so that when the inner rod (3011) is inserted into the outer sleeve (3012), the expansion portion (3014) expands outward through the contact of the variable diameter portion (3013).

[0014] Furthermore, the anchor rod (301) includes a front anchor rod and a rear anchor rod arranged at relative inclinations, and the connecting steel bar (302) includes a front connecting steel bar and a rear connecting steel bar that are respectively connected to the front anchor rod and the rear anchor rod. The front anchor rod extends toward the front side of the frame (100) in a direction perpendicular to the connecting steel bar (302), and the rear anchor rod extends toward the rear side of the frame (100) in a direction perpendicular to the connecting steel bar (302).

[0015] (III) Beneficial Effects Compared with the prior art, the present invention has the following advantages: (1) Reduce concrete usage, reduce costs and load: Replace 30%-50% of concrete usage with lightweight filler blocks to directly reduce material costs and transportation and pouring construction load; lightweight filler blocks are lightweight, reducing the overall backfill structure's self-weight, avoiding additional load on the building foundation due to the self-weight of concrete, and avoiding the risk of foundation settlement.

[0016] (2) Improve the durability of the protective layer: The lightweight filler block has excellent heat insulation and waterproof performance, which can alleviate the cracking of concrete caused by temperature and humidity changes; the U-shaped hook diagonal tie design of the connector and the stable structure of the frame enhance the overall coordination of concrete-frame-filler block and reduce the risk of spalling; the rough surface treatment during layered pouring strengthens the interlayer bonding, which improves the durability of the protective layer by more than 20%.

[0017] (3) Stable structure and thorough pollution protection: The overall frame is strong and reliable, and the modular combination frame is assembled firmly. With the help of two-way anchoring components (when the whole is poured), it ensures that the structure does not shift or loosen during construction and use. The frame and block components form a complete closed protective barrier, blocking the infiltration and erosion path of polluted soil, and fundamentally solving the problem of "treating the symptoms but not the root cause".

[0018] (4) Flexible adaptation and convenient construction: It provides a variety of assembly and pouring schemes for combination selection, which can be flexibly adapted according to foundation size, construction site, cycle requirements, etc. The frame assembly and block installation do not require complicated welding processes. The installation of anchoring components only requires drilling, insertion, and expansion fixation. Ordinary construction personnel can operate after simple training, which greatly improves construction efficiency. Attached Figure Description

[0019] 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.

[0020] Figure 1 A three-dimensional view of the integral frame used for the lightweight replacement structure; Figure 2 A front view of a monolithic frame used for lightweight replacement structures; Figure 3 Side view of a lightweight replacement structure using an integral frame; Figure 4 for Figure 1 Enlarged view of point A in the image; Figure 5 Enlarged view of a section showing the use of an integral frame for the lightweight replacement structure; Figure 6A three-dimensional view of a modular combined frame used for lightweight replacement structure; Figure 7 A magnified view of a modular composite frame used in the lightweight replacement structure; Figure 8 This is a structural diagram of a single unit frame; Figure 9 A structural schematic diagram of a single unit frame assembled with block components; Figure 10 This is a structural schematic diagram of the connectors in a block component; Figure 11 This is a partial enlarged view of the anchoring components selected when using monolithic casting; Figure 12 This is a structural breakdown diagram of the anchor rod in the anchoring component; Figure 13 A diagram illustrating the usage status of an integral frame used in lightweight replacement structures during monolithic casting. In the diagram: Frame-100; Transverse support bar-101; Longitudinal support bar-102; Transverse support frame-111; Longitudinal support frame-112; Block component-200; Lightweight filler block-210; Connector-220; First connecting rod-221; Second connecting rod-222; Third connecting rod-223; Anchoring component-300; Anchor rod-301; Inner rod-3011; Outer sleeve-3012; Variable diameter section-3013; Expansion section-3014; Connecting steel bar-302; Hook section-303. Detailed Implementation

[0021] To further understand the content of this invention, a detailed description of the invention is provided in conjunction with the accompanying drawings and embodiments. The structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes and to aid those skilled in the art in understanding and reading the invention. They are not intended to limit the conditions under which the invention can be implemented and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effects and objectives achieved by the invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity of description and not intended to limit the scope of implementation. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation. It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein.

[0022] This invention first provides a method for replacing contaminated soil, characterized by comprising the following steps: S1: Contaminated soil treatment and foundation protection: Excavate the contaminated soil around the building foundation, clean the contaminants on the surface of the building foundation, and then carry out anti-corrosion treatment on the surface of the building foundation; set up a temporary support structure on the outside of the building foundation, and leave a pouring gap between the temporary support structure and the building foundation. S2: Frame assembly of lightweight replacement structure: The frame assembly method is determined according to construction requirements. Frame assembly methods include integral assembly and modular assembly. When using an integral assembly method, a predetermined number of transverse support ribs and longitudinal support ribs are cross-fixed, and the intersection of the two forms a cross-shaped connection node, which serves as the installation basis for all block components. When using a modular assembly method, multiple unit frames are prefabricated. Each unit frame is assembled vertically from horizontal support frames and vertical support frames. The intersection of the horizontal support frames and the vertical support frames forms a cross-shaped connection node, which serves as the installation foundation for a single block component. S3: Block component installation: The installation method for block components is determined based on the casting method and construction requirements. Block component installation methods include integral installation and layered installation. When using the overall installation method, multiple sets of block components are installed and fixed as a whole at the connection nodes of the integral frame composed of a predetermined number of transverse support bars and longitudinal support bars, or the modular combined frame composed of multiple unit frames, so that the multiple sets of block components form a rectangular array or a staggered arrangement in a plum blossom shape. When using layered installation, the block components are installed in layers along the height direction of the backfill pit. After the installation of one layer of block components is completed, the next pouring process is carried out. After the pouring process of that layer is completed, the installation of the next layer of block components is carried out. S4: Concrete Pouring: The pouring method is determined according to construction requirements. Pouring methods include layered pouring and monolithic pouring. When using layered pouring, concrete is poured in layers between the temporary support structure and the frame along the height direction of the frame. The weight of the lightweight replacement structure assembled as a whole is used to overcome the buoyancy generated during concrete pouring. After the first layer of concrete has initially set, the next layer of concrete is poured until the design height is reached. When using monolithic casting, first install anchoring components at the bottom of the frame, and fix the frame to the base layer at the bottom of the backfill pit through the anchoring components. Then, pour concrete monolithically between the temporary support structure and the frame in one go. S5: Subsequent treatment: After the concrete strength reaches the preset requirements, the temporary support structure is removed; the exposed concrete contact surface after the temporary support structure is removed is roughened, and debris is removed from the contact surface. Then, concrete is poured into the pouring gap reserved in S1 to complete the replacement construction.

[0023] In specific implementation, in step S3, when installing the block components in layers, after each layer of block components is installed, the block components and connecting nodes are temporarily fixed, and then the corresponding layer of concrete is poured.

[0024] In addition, to improve the bonding strength during the layered concrete pouring process, in step S4, when using layered pouring, after the initial setting of the previous layer of concrete and before pouring the next layer of concrete, the surface of the initially set concrete is roughened; the roughening is done by mechanical chiseling or high-pressure water jetting, and after the roughening, the concrete surface exposes aggregate with a particle size of not less than 5mm, and the surface unevenness is not less than 3mm; the roughening covers the exposed concrete surface outside the frame-covered area.

[0025] like Figures 1-13 As shown, the present invention also provides a lightweight replacement structure for implementing the aforementioned contaminated soil backfilling method, including a frame 100 and multiple sets of block components 200. Specifically, the frame 100 is a steel integral frame or a modular combined frame, which, together with concrete replacement, enhances the structural strength; the integral frame is formed by the cross-fixing of transverse support bars 101 and longitudinal support bars 102, with the intersection forming multiple cross-shaped connection nodes; the modular combined frame is formed by connecting multiple unit frames in a rectangular array, each unit frame including a cross-shaped structure formed by the perpendicular assembly of transverse support frames 111 and longitudinal support frames 112, with the intersection of the transverse support frames 111 and longitudinal support frames 112 forming a cross-shaped connection node; the block components 200 include lightweight filling blocks 210 and connectors 220, the lightweight filling blocks 210 being connected to the frame 100 through the connectors 220, and the lightweight filling blocks 210 are made of polystyrene blocks, which have advantages such as light weight, good thermal insulation performance, and good waterproof performance.

[0026] refer to Figure 1 , Figure 2 , Figure 3 and Figure 5Specifically, if an integral frame is used, the frame 100 includes a front frame and a rear frame, with a certain distance reserved between them, so that the integral frame 100 can be adapted to form a skeleton structure after concrete pouring; based on this, the connection node includes a front node and a rear node opposite to each other. Optionally, the transverse support bar 101 and the longitudinal support bar 102 are fixed by binding or welding, and the longitudinal support bar 102 of the integral frame is a U-shaped steel bar with the opening facing upward. If a modular combined frame is used, the transverse support frame 111 and the longitudinal support frame 112 are both fixed by two oppositely distributed U-shaped steel bars, so that the transverse support frame 111 and the longitudinal support frame 112 both present a U-shaped structure, thereby making the connection node include a front node opposite to the front side of the frame 100 and a rear node opposite to the rear side of the frame 100. Optionally, the transverse support frame 111 and the longitudinal support frame 112 are fixed by binding or welding (see reference). Figures 6-9 ).

[0027] Continue to refer to Figure 5 and Figure 10 As shown, the connector 220 includes a first connecting rod 221 and a third connecting rod 223 fixedly connected to both ends of the first connecting rod 221 via a second connecting rod 222, thereby forming a front U-shaped hook and a rear U-shaped hook at both ends of the connector 220 respectively.

[0028] If an integral frame is used, when the connector 220 is connected to the connection node on the frame 100, the front U-shaped hook and the rear U-shaped hook respectively engage with the front node and the rear node, thereby making the connector 220 also a tie rod connecting the front side frame and the rear side frame, thus effectively improving the structural strength of the frame 100. It is worth noting that when the U-shaped hook of the connector 220 engages with the connection node, the first connecting rod 221 and the third connecting rod 223 are distributed diagonally in the connection node. Figure 5 As shown, the first connecting rod 221 is arranged in the upper right region of the connecting node, and the third connecting rod 223 is arranged in the lower left region of the connecting node. Both the first connecting rod 221 and the third connecting rod 223 are fixed to the transverse support rib 101. Of course, the third connecting rod 223 can also be swung to be fixed to the longitudinal support rib 102, which is not specifically limited here.

[0029] If a modular frame is used, the first link 221 is arranged in the upper right region of the connecting node, and the third link 223 is arranged in the lower left region of the connecting node. Both the first link 221 and the third link 223 are fixed to the transverse support frame 111. Of course, the third link 223 can also be swung to be fixed to the longitudinal support frame 112, which is not specifically limited here.

[0030] In this embodiment, the lightweight filling block 210 is fixed through the first connecting rod 221 and / or the third connecting rod 223, so that multiple sets of block components 200 are arranged in a rectangular array or in a staggered quincunx pattern on the frame 100. Specifically, the illustrations of this invention preferably show a staggered, quincunx-shaped arrangement. Each group of block components 200 includes a front lightweight filler block and a rear lightweight filler block. The front and rear lightweight filler blocks are respectively fixed through both ends of the first connecting rod 221. After the connector 220 is connected to the connecting node on the frame 100, the front lightweight filler block is confined between the front side of the frame 100 and the second connecting rod 222, and the rear lightweight filler block is confined between the rear side of the frame 100 and the second connecting rod 222. That is, the front lightweight filler block is connected to the front node through the front U-shaped hook, and the rear lightweight filler block is connected to the rear node through the rear U-shaped hook, thereby effectively ensuring the stability of the lightweight filler block 210's positioning on the frame 100.

[0031] Furthermore, it should be noted that, to facilitate the installation of the block component 200, it is preferable that the length of the first connecting rod 221 is greater than the sum of the lengths of the two third connecting rods 223, so that a gap is formed between the two third connecting rods 223. Of course, when installing the block component 200, the lightweight filling block 210 can be first fixed through the first connecting rod 221, then the first connecting rod 221 can be bent to form the second connecting rod 222, then the block component 200 can be assembled on the connection node of the frame 100, and finally the second connecting rod 222 can be bent to form the third connecting rod 223.

[0032] Continue to refer to Figure 11 As shown, it also includes an anchoring component 300, which is an optional component used only during casting. The anchoring component 300 includes an anchor rod 301 and a connecting steel bar 302 connecting the anchor rod 301 to the bottom of the frame 100. Specifically, the connecting steel bar (302) extends in a direction perpendicular to the first connecting rod 221, and the top of the anchor rod 301 is bent to form a hook portion 303 adapted to the connecting steel bar 302, thereby achieving the assembly connection between the anchor rod 301 and the connecting steel bar 302.

[0033] It is worth noting that the anchor bolt 301 includes, for example, Figure 12 The inner rod 3011 and outer sleeve 3012 are shown. The inner rod 3011 has at least one variable diameter portion 3013, and the outer sleeve 3012 has at least one expansion portion 3014, so that when the inner rod 3011 is inserted into the outer sleeve 3012, the expansion portion 3014 expands outward through the contact of the variable diameter portion 3013. Specifically, the expansion portion 3014 includes... Figure 12 The elastic buckle shown is capable of bending and expanding outward. The elastic buckles are arranged in a circumferential array so that the expansion portion 3014 can form a barb-shaped structure that prevents the outer jacket 3012 from retracting after it expands outward.

[0034] For example, in accordance with Figure 13 When installing the integral lightweight replacement structure in the replacement pit as shown, the anchor rod 301 should first be anchored into the replacement pit at an angle: After the replacement pit is excavated, an anchoring hole is formed in the rock layer at the bottom of the replacement pit using a drilling device. The outer sleeve 3012 is inserted into the anchoring hole, and then the inner rod 3011 is inserted into the outer sleeve 3012. During the insertion of the inner rod 3011 into the outer sleeve 3012, the diameter-changing part 3013 gradually squeezes the expansion part 3014, causing the expansion part 3014 to expand outward in the anchoring hole, thereby improving the connection force between the outer sleeve 3012 and the anchoring hole, so that the integral anchor rod 301 can be stably fixed inside the anchoring hole by expansion and compression support; preferably, the inner rod 3011 is set as a threaded rod structure (not shown in the figure), which can further improve the stability of the connection between the inner rod 3011 and the outer sleeve 3012. Specifically, the anchor rod 301 includes a front anchor rod and a rear anchor rod arranged at relative angles. The front anchor rod extends towards the front of the frame 100 in a direction perpendicular to the connecting steel bar 302, and the rear anchor rod extends towards the rear of the frame 100 in a direction perpendicular to the connecting steel bar 302. This ensures the stability of the anchor rod 301 and ensures that the tops of the front and rear anchor rods protrude above the ground, and that the distance between the tops of the front and rear anchor rods is less than the thickness of the frame 100. Then, the frame 100 is placed, and the top of the anchor rod 301 is bent to form... Figure 4 and Figure 11 The hook portion 303 shown is provided. The connecting steel bar 302 includes a front connecting steel bar and a rear connecting steel bar. The front connecting steel bar is confined within the hook portion 303 of the front anchor rod, and the rear connecting steel bar is confined within the hook portion 303 of the rear anchor rod, thus completing the connection between the frame 100 and the anchoring member 300.

[0035] The principles of the present invention will be explained below with reference to specific embodiments: Example 1: Layered casting + monolithic frame + layered installation of block components This embodiment is applicable to scenarios where the building foundation is relatively high (e.g., 3m) and the construction site is small. The specific steps are as follows: 1. Pre-construction preparation Contaminated soil treatment: Excavate the contaminated soil around the strip building foundation, with an excavation dimension of 1.35m wide and 3.0m deep; after cleaning the contaminants from the foundation surface, apply a 0.5mm thick epoxy resin anti-corrosion coating. Temporary support setup: Temporary brick well rings (wall thickness 240mm, distance between well ring and foundation 100mm) are set on the outside of the foundation. Materials preparation: Frame materials: transverse support bars (HRB400 grade threaded steel, 14mm in diameter), longitudinal support bars (HRB400 grade U-shaped steel bars, 14mm in diameter). Block components: lightweight filler blocks (flame-retardant polystyrene blocks with a density of 25kg / m³, dimensions 200mm×200mm×50mm), connectors (HPB300 grade plain round steel, diameter 8mm); Concrete: C30 concrete.

[0036] 2. Frame assembly (integrated assembly) The transverse and longitudinal support bars are placed at an intersection and fixed by welding (double-sided welding, weld length ≥70mm) to form a grid-like integral frame with a side length of 200mm and a frame height of 3.0m. The transverse and longitudinal support bars are inseparable and form a cross-shaped connection node at the intersection.

[0037] 3. Installation of block components (layered installation) After the monolithic frame is fixed in place, install the block components in 10 layers along the height of the frame (each layer is 300mm high): During each layer of installation, lightweight filler blocks are fixed through and fixed to the first connecting rod of the connector, and then hung on the diagonal area of ​​the cross-shaped connection node by the U-shaped hook of the connector, so that the block components are arranged in a staggered quincunx pattern. After each layer is installed, the connectors and connection nodes are temporarily fixed by binding to prevent displacement during pouring.

[0038] 4. Concrete pouring (layered pouring) C30 concrete was poured in layers along the height of the frame, with each layer being 300mm high. The overall weight of the frame and the installed block components was used to overcome the buoyancy of the concrete. After the first layer of concrete has set (about 5 hours at an ambient temperature of 20℃), the surface of the concrete is roughened by mechanical chiseling. After the treatment, aggregate with a particle size of 5-10mm is exposed, and the surface unevenness is about 4mm. Only the exposed areas outside the frame are treated. Each layer was poured sequentially until the designed height of 3.0m was reached.

[0039] 5. Follow-up processing After 7 days of curing, the concrete strength reached 1.2MPa, and the temporary well ring was removed. The exposed concrete contact surface was roughened, cleaned, and rinsed clean before pouring C30 concrete into the reserved 100mm pouring gap to complete the replacement.

[0040] Example 2: Integral casting + modular combined frame + integral installation block components This embodiment is applicable to scenarios where the building foundation height is relatively low (e.g., 1.5m) and the construction period is short. The specific steps are as follows: 1. Pre-construction preparation Contaminated soil treatment: Excavate the contaminated soil around the independent foundation, with an excavation dimension of 1.5m wide and 1.5m deep; after cleaning the contaminants from the foundation surface, apply a 0.5mm thick epoxy resin anti-corrosion coating. Temporary support setup: Temporary brick well rings (wall thickness 240mm, distance between well ring and foundation 120mm) are set on the outside of the foundation. Materials preparation: Frame material: Unit frame (both the transverse and longitudinal support frames are made of HRB400 grade U-shaped steel bars with a diameter of 12mm, forming a 150mm×150mm closed square ring structure), a total of 100 units are prefabricated; Block components: lightweight filler blocks (flame-retardant polystyrene blocks with a density of 25kg / m³, dimensions 150mm×150mm×50mm), connectors (HPB300 grade plain round steel, diameter 6mm). Anchoring components: Anchor rod (inner rod is HRB400 grade threaded steel, diameter 14mm; outer rod is seamless steel pipe, inner diameter 16mm; expansion part is 3 circumferential elastic threads), connecting steel bar (HRB400 grade threaded steel, diameter 10mm). Concrete: C30 concrete.

[0041] 2. Frame assembly (modular assembly) One hundred unit frames are arranged in a 10×10 rectangular array. The joints of adjacent unit frames are fixed by welding (weld length ≥ 50mm, welding point spacing 100mm) to form a 1.5m×1.5m modular combination frame. A cross-shaped connection node is formed at the intersection of each unit frame.

[0042] 3. Installation of block components (overall installation) The lightweight filler blocks are installed as a whole at the cross-shaped connection nodes of the frame using the U-shaped hooks of the connectors, so that the block components are arranged in a rectangular array. Each connection node corresponds to a set of block components, ensuring a firm installation.

[0043] 4. Installation of anchoring components Drill holes (18mm diameter, 600mm depth) in the rock layer at the bottom of the backfill pit, with a spacing of 225mm between holes; insert the outer sleeve of the anchor rod into the drill hole, and then insert the inner rod. The diameter-changing part of the inner rod is squeezed and expanded outward to form a hook-shaped anchor; weld the connecting steel bars horizontally to the bottom of the frame, bend the top of the anchor rod to form a hook part, and weld it to the connecting steel bars for fixation. The front anchor rod and the rear anchor rod extend inclinedly to the front and rear sides of the frame, respectively.

[0044] 5. Concrete pouring (monolithic pouring) C30 concrete was poured in one go between the temporary support structure and the frame, with a pouring height of 1.5m. Anchoring components were used to ensure that the frame did not shift and that the concrete was filled densely.

[0045] 6. Follow-up processing After 7 days of curing, the temporary well ring was removed, the contact surface was roughened and cleaned, and C30 concrete was poured into the reserved 120mm gap to complete the replacement.

[0046] In the description of this invention, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0047] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A method for replacing contaminated soil, characterized in that, Includes the following steps: S1: Contaminated soil treatment and foundation protection: Excavate the contaminated soil around the building foundation, clean the contaminants on the surface of the building foundation, and then carry out anti-corrosion treatment on the surface of the building foundation; set up a temporary support structure on the outside of the building foundation, and leave a pouring gap between the temporary support structure and the building foundation. S2: Frame assembly of lightweight replacement structure: The frame assembly method is determined according to construction requirements. Frame assembly methods include integral assembly and modular assembly. When using an integral assembly method, a predetermined number of transverse support ribs and longitudinal support ribs are cross-fixed, and the intersection of the two forms a cross-shaped connection node, which serves as the installation basis for all block components. When using a modular assembly method, multiple unit frames are prefabricated. Each unit frame is assembled vertically from horizontal support frames and vertical support frames. The intersection of the horizontal support frames and the vertical support frames forms a cross-shaped connection node, which serves as the installation foundation for a single block component. S3: Block component installation: The installation method for block components is determined based on the casting method and construction requirements. Block component installation methods include integral installation and layered installation. When using the overall installation method, multiple sets of block components are installed and fixed as a whole at the connection nodes of the integral frame composed of a predetermined number of transverse support bars and longitudinal support bars, or the modular combined frame composed of multiple unit frames, so that the multiple sets of block components form a rectangular array or a staggered arrangement in a plum blossom shape. When using layered installation, the block components are installed in layers along the height direction of the backfill pit. After the installation of one layer of block components is completed, the next pouring process is carried out. After the pouring process of that layer is completed, the installation of the next layer of block components is carried out. S4: Concrete Pouring: The pouring method is determined according to construction requirements. Pouring methods include layered pouring and monolithic pouring. When using layered pouring, concrete is poured in layers between the temporary support structure and the frame along the height direction of the frame. The weight of the lightweight replacement structure assembled as a whole is used to overcome the buoyancy generated during concrete pouring. After the first layer of concrete has initially set, the next layer of concrete is poured until the design height is reached. When using monolithic casting, first install anchoring components at the bottom of the frame, and fix the frame to the base layer at the bottom of the backfill pit through the anchoring components. Then, pour concrete monolithically between the temporary support structure and the frame in one go. S5: Subsequent treatment: After the concrete strength reaches the preset requirements, the temporary support structure is removed; the exposed concrete contact surface after the temporary support structure is removed is roughened, and debris is removed from the contact surface. Then, concrete is poured into the pouring gap reserved in S1 to complete the replacement construction.

2. The method for replacing contaminated soil according to claim 1, characterized in that, In step S3, when installing the block components in layers, after each layer of block components is installed, the block components and connecting nodes are temporarily fixed, and then the corresponding layer of concrete is poured.

3. The method for replacing contaminated soil according to claim 1 or 2, characterized in that, In step S4, when using layered pouring, after the first layer of concrete has initially set and before pouring the next layer of concrete, the surface of the initially set concrete is roughened. The roughening is done by mechanical chiseling or high-pressure water jetting. After the roughening, the concrete surface exposes aggregate with a particle size of not less than 5 mm, and the surface unevenness is not less than 3 mm. The roughening covers the exposed concrete surface outside the frame-covered area.

4. A lightweight replacement structure for implementing the contaminated soil replacement method according to any one of claims 1-3, characterized in that, include: Frame (100), wherein the frame is an integral frame or a modular combined frame; The integral frame is formed by the cross-fixing of transverse support ribs (101) and longitudinal support ribs (102), and the intersection forms multiple cross-shaped connection nodes; the modular combined frame is formed by connecting multiple unit frames in a rectangular array, and each unit frame includes a cross-shaped structure formed by the vertical assembly of transverse support frame (111) and longitudinal support frame (112), and the intersection of the transverse support frame (111) and the longitudinal support frame (112) forms a cross-shaped connection node; Multiple sets of block components (200) include lightweight filler blocks (210) and connectors (220). The lightweight filler blocks (210) are connected to the connection nodes of the frame (100) through the connectors (220) so that the multiple sets of block components (200) are arranged in a rectangular array or in a staggered quincunx pattern on the frame (100). The connectors (220) include a first connecting rod (221), a second connecting rod (222), and a third connecting rod (223) that are connected in sequence to form a U-shaped hook. The lightweight filler blocks (210) are fixed through the first connecting rod (221) and / or the third connecting rod (223), and the first connecting rod (221) and the third connecting rod (223) are distributed opposite each other in the diagonal area of ​​the connection node.

5. The lightweight replacement structure according to claim 4, characterized in that: The connection nodes of the frame (100) all include front nodes and rear nodes; each group of block components (200) includes a front lightweight filler block and a rear lightweight filler block; both ends of the first link (221) are connected to a third link (223) through a second link (222), so that both ends of the connector (220) form a front U-shaped hook and a rear U-shaped hook respectively, the front lightweight filler block is connected to the front node through the front U-shaped hook, and the rear lightweight filler block is connected to the rear node through the rear U-shaped hook.

6. The lightweight replacement structure according to claim 5, characterized in that: The length of the first link (221) is greater than the sum of the lengths of the two third links (223) so that a gap is formed between the two third links (223).

7. The lightweight replacement structure according to claim 4, characterized in that: The longitudinal support bars (102) of the integral frame are U-shaped steel bars with the opening facing upwards; the transverse support frame (111) and longitudinal support frame (112) of the modular combined frame are both fixed by two U-shaped steel bars that are distributed in opposite directions.

8. The lightweight replacement structure according to any one of claims 4-7, characterized in that, Also includes: An anchoring member (300) includes an anchor rod (301) and a connecting steel bar (302) connecting the anchor rod (301) to the bottom of the frame (100); the connecting steel bar (302) extends in a direction perpendicular to the first connecting rod (221), and the top of the anchor rod (301) is bent to form a hook portion (303) adapted to the connecting steel bar (302).

9. The lightweight replacement structure according to claim 8, characterized in that: The anchor rod (301) includes an inner rod (3011) and an outer sleeve (3012). The inner rod (3011) is provided with at least one variable diameter part (3013), and the outer sleeve (3012) is provided with at least one expansion part (3014), so that when the inner rod (3011) is inserted into the outer sleeve (3012), the expansion part (3014) expands outward through the abutment of the variable diameter part (3013).

10. The lightweight replacement structure according to claim 8, characterized in that: The anchor rod (301) includes a front anchor rod and a rear anchor rod arranged at relative inclinations. The connecting steel bar (302) includes a front connecting steel bar and a rear connecting steel bar that are respectively connected to the front anchor rod and the rear anchor rod. The front anchor rod extends toward the front side of the frame (100) in a direction perpendicular to the connecting steel bar (302), and the rear anchor rod extends toward the rear side of the frame (100) in a direction perpendicular to the connecting steel bar (302).

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