Roof backfilling method and subway station construction structure

Abstract

The invention discloses a roof backfilling method and a subway station construction structure. The roof backfilling method comprises the steps that soil material curing treatment is conducted, specifically, the soil material and a curing agent are mixed and stirred to form a flow-state mixed soil material; building a station roof grid, building a grid-shaped partition structure on the protective layer of the constructed roof main body structure, and dividing the roof into a plurality of partition areas; soil material backfilling is conducted, specifically, flow-state mixed soil materials are backfilled into the separated areas; the geogrids are arranged on the separation structures, and the two sides of the geogrids are connected with the solidified soil bodies in the adjacent separation areas correspondingly; the reinforcing mesh is arranged on the geogrid, and the two sides of the reinforcing mesh are located on the adjacent separation areas correspondingly; and repeating the steps from construction of the separation net to arrangement of the reinforcing meshes until the designed elevation is reached. After the backfilling effect is optimized based on the method, differential settlement occurring in the later period is effectively avoided, then cracks or damage of the outer waterproof layer is avoided, and the waterproof effect of the station is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of subway station roof construction, in particular, to a roof backfilling method. In addition, the present invention also relates to a subway station construction structure including the roof backfilling method. Background Art

[0002] With the rapid development of urban rail transit, subway station construction has become an important part of urban infrastructure. Subway stations are generally located under existing roads, and this construction method usually affects the normal use of roads. Before the construction of subway stations, the roads must be broken and the ground excavated to provide construction space for the main structure of the station.

[0003] After completing the construction of the top slab of the main structure of the station, in order to restore the road's traffic function, the construction party usually carries out backfilling work. After backfilling, the ground often needs to be compacted to ensure the flatness and stability of the road. However, since the burial depth of the subway station top slab is usually shallow, the compaction effect after backfilling is difficult to be uniform, resulting in uneven distribution of the bearing capacity of the soil under the top slab, resulting in uneven settlement. This settlement will directly affect the flatness of the road surface, easily causing cracks or potholes on the road surface, affecting driving safety. In addition, the outer waterproof layer of the subway station top slab is also easily damaged during the backfilling process. The settlement of the soil during the backfilling of the top slab may cause cracks or damage to the outer waterproof layer, which in turn affects the waterproof effect of the station, and may even cause water leakage in the main structure of the station, which will bring huge pressure to subsequent operation and maintenance.

[0004] Existing construction methods usually rely on traditional backfill and compaction techniques, but these methods cannot effectively solve the problems caused by uneven settlement due to the shallow depth of the top plate and the fact that settlement after backfilling is often difficult to avoid. Therefore, an innovative construction method is urgently needed to improve the uniformity of settlement after backfilling and ensure the long-term stability of the road surface and structure. Summary of the invention

[0005] The present invention provides a roof backfilling method and a subway station construction structure to solve the technical problems in the prior art such as poor compaction effect of soil backfilling on the roof of a subway station, uneven settlement, easy damage to the outer waterproof layer, affecting the flatness of the road surface, and low construction efficiency.

[0006] According to one aspect of the present invention, there is provided a roof backfilling method, comprising:

[0007] S1. Soil curing treatment, mixing the soil and curing agent to form a fluid mixed soil;

[0008] S2. Construction of station roof grid: building a grid-like partition structure on the protective layer of the completed roof main structure to divide the roof into multiple partition areas;

[0009] S3. Backfilling of soil materials: backfilling the separated area with fluid mixed soil materials;

[0010] S4. The geogrid is arranged on the partition structure, and the two sides of the geogrid are connected to the solidified soil in the adjacent partition area respectively;

[0011] S5. The steel mesh is arranged on the geogrid and the two sides of the steel mesh are located on adjacent separation areas;

[0012] S6. Repeat steps S2-S5 until the design elevation is reached.

[0013] As a further improvement of the above technical solution, in step S1, the curing agent includes: 10-20 parts of slag powder or 10-20 parts of fly ash or 10-15 parts of cement, 10-15 parts of fly ash or 5-10 parts of lime, 15-20 parts of rice husk ash or 10-20 parts of bamboo ash or 10-20 parts of straw ash, and 60-70 parts of water.

[0014] As a further improvement of the above technical solution, in step S1, the curing agent includes: 10 parts of slag powder, 10 parts of fly ash, 15 parts of rice husk ash, and 60-70 parts of water.

[0015] As a further improvement of the above technical solution, step S1 includes:

[0016] S11. Screen soil materials to remove large particles;

[0017] S12. Matching the water ratio in the curing agent according to the ambient temperature and humidity;

[0018] S13. Add a curing agent to the soil material and mix to form a fluidized mixed soil material.

[0019] As a further improvement of the above technical solution, step S2 includes: planning the longitudinal separation distance of the separation structure based on the construction target scale, the load requirements of the top plate and the soil compaction capacity, and planning the lateral separation distance of the separation structure based on uniform stress of the soil backfill and reduction of local high stress.

[0020] As a further improvement of the above technical solution, step S3 includes:

[0021] S31. Fluid mixed soil material transportation;

[0022] S32. Starting from the preset separation area, backfill the fluid mixed soil material to a preset height within the separation structure;

[0023] S33. Transfer to another partition area and backfill the fluid mixed soil material to a preset height within the partition structure;

[0024] S34. Repeat step S33 until all the separated areas are backfilled with the fluid mixed soil material to a preset height within the separated structure;

[0025] S35. Repeat steps S32-S34 until the backfilling of soil in the separated area is completed.

[0026] As a further improvement of the above technical solution, step S4 includes:

[0027] S41. Soil solidification;

[0028] S42.Soil strength inspection;

[0029] S43. Arrange and secure geogrids.

[0030] As a further improvement of the above technical solution, step S43 includes: arranging the geogrid symmetrically along the center line of the separation structure between the two separation areas, fixing one side of the geogrid to the solidified soil by steel nails, and the steel nails are spaced apart at a preset interval.

[0031] As a further improvement of the above technical solution, step S5 includes: the diameter of the steel mesh is 6-12 mm, and the mesh size is 10-20 cm; the steel mesh is symmetrically arranged with respect to the center line of the partition structure between the two partition areas.

[0032] According to another aspect of the present invention, a subway station construction structure is provided, which includes the above-mentioned roof backfilling method.

[0033] The present invention has the following beneficial effects:

[0034] This construction method solidifies the soil with a high-efficiency geotechnical solidifying agent, and utilizes the operability and solidification of the fluid mixed soil material to make the backfill soil material have high stability and uniformity. The control of the soil during the construction process is more precise, and the construction quality is improved. The soil compaction effect after separation with the grid-like separation structure is better, thereby effectively reducing the uneven settlement caused by uneven soil compaction during the backfill process, ensuring the settlement uniformity and structural stability after the top plate is backfilled, and effectively avoiding the problems of road cracks, potholes and waterproof layer damage caused by uneven settlement in traditional backfill methods; with the grid-like separation structure, geogrids, steel mesh and other structural reinforcements, the backfill soil is significantly improved. The compressive strength and overall stability of the backfill are improved by the separation structure, and the backfill soil is more evenly distributed after solidification, while the geogrid and steel mesh further enhance the soil's ability to resist deformation and settlement, thereby effectively avoiding structural deformation problems during the backfill of the subway station roof; by combining traditional backfill, compaction and reinforcement processes, the construction process is optimized and the construction efficiency is improved; after optimizing the backfill effect based on this method, the uneven settlement that occurs in the later period is effectively avoided, thereby avoiding cracks or damage to the external waterproof layer, and improving the waterproof effect of the station; based on the reasonable casting process of this method, the problem of rupture or leakage of the external waterproof layer during the backfill process is avoided, and the waterproof performance of the station structure is guaranteed.

[0035] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0037] Figure 1 It is a partial top view of a preferred embodiment of the present invention in which a partition structure is arranged on the main structure of the top plate;

[0038] Figure 2 is a cross-sectional view of a preferred embodiment of the present invention in which a partition structure is arranged on the main structure of the top plate;

[0039] Figure 3 yes Figure 2 A partial enlarged view of

[0040] Figure 4 This is a schematic diagram of backfilling 1 / 2 height of soil material in the first layer partition structure of a preferred embodiment of the present invention;

[0041] Figure 5 This is a schematic diagram of the structure of the first layer of the partition structure after backfilling with soil in a preferred embodiment of the present invention;

[0042] Figure 6 It is a structural schematic diagram of the first layer partition structure after the fixing components are arranged in the preferred embodiment of the present invention;

[0043] Figure 7 yes Figure 6 A partial enlarged view of

[0044] Figure 8 is a schematic diagram of the second layer separation structure arrangement of a preferred embodiment of the present invention;

[0045] Fig. 9 This is a schematic diagram of the structure of the first layer of the partition structure after backfilling with soil in a preferred embodiment of the present invention;

[0046] Fig.10 is a cross-sectional view of a top plate backfill construction structure of a preferred embodiment of the present invention;

[0047] Fig.11 It is a cross-sectional view of a subway station construction structure according to a preferred embodiment of the present invention.

[0048] Legend:

[0049] 1. Main structure of the roof; 2. Waterproof layer; 3. Protective layer; 4. Partition structure; 5. Soil; 6. Geogrid; 7. Steel nails; 8. Steel mesh; 9. Road structure layer; 10. Road surface. DETAILED DESCRIPTION

[0050] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0051] Figure 1 It is a partial top view of a preferred embodiment of the present invention in which a partition structure is arranged on the main structure of the top plate; Figure 2 is a cross-sectional view of a preferred embodiment of the present invention in which a partition structure is arranged on the main structure of the top plate; Figure 3 yes Figure 2 A partial enlarged view of Figure 4 This is a schematic diagram of backfilling 1 / 2 height of soil material in the first layer partition structure of a preferred embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the first layer of the partition structure after backfilling with soil in a preferred embodiment of the present invention; Figure 6 It is a structural schematic diagram of the first layer partition structure after the fixing components are arranged in the preferred embodiment of the present invention; Figure 7 yes Figure 6 A partial enlarged view of Figure 8 is a schematic diagram of the second layer separation structure arrangement of a preferred embodiment of the present invention; Fig. 9 This is a schematic diagram of the structure of the first layer of the partition structure after backfilling with soil in a preferred embodiment of the present invention; Fig.10is a cross-sectional view of a top plate backfill construction structure of a preferred embodiment of the present invention; Fig.11 It is a cross-sectional view of a subway station construction structure according to a preferred embodiment of the present invention.

[0052] like Figures 1 to 10 As shown, the roof backfilling method of this embodiment includes:

[0053] S1. The soil material 5 is solidified by mixing the soil material 5 with the curing agent to form a fluidized mixed soil material 5;

[0054] S2. The station roof is divided into grids, and a grid-like partition structure 4 is built on the protective layer 3 of the completed roof main structure 1 to divide the roof into multiple partition areas;

[0055] S3. Backfilling of soil material 5, backfilling of fluid mixed soil material 5 in the separation area;

[0056] S4. The geogrid 6 is arranged on the partition structure 4, and the two sides of the geogrid 6 are connected to the solidified soil in the adjacent partition area;

[0057] S5. The steel mesh 8 is arranged on the geogrid 6 and the two sides of the steel mesh 8 are respectively located on adjacent separation areas;

[0058] S6. Repeat steps S2-S5 until the design elevation is reached.

[0059] It can be understood that the present construction method solidifies the soil through a high-efficiency geotechnical solidifying agent, and utilizes the operability and solidifying properties of the fluid mixed soil material 5 to make the backfill soil material 5 have higher stability and uniformity, and the control of the soil during the construction process is more precise, and the construction quality is improved. The soil compaction effect after separation with the grid-like separation structure 4 is better, thereby effectively reducing the uneven settlement caused by uneven compaction of the soil during the backfill process, ensuring the settlement uniformity and structural stability after the top plate is backfilled, and effectively avoiding the problems of road surface 10 cracks, potholes and damage to the waterproof layer 2 caused by uneven settlement in the traditional backfill method; with the structural reinforcement of the grid-like separation structure 4, geogrid 6 and steel mesh 8, the improvement is significantly improved. The high compressive strength and overall stability of the backfill soil, the separation structure 4 makes the backfill soil more evenly distributed after solidification, and the geogrid 6 and the steel mesh 8 further enhance the soil's ability to resist deformation and settlement, thereby effectively avoiding the structural deformation problem that occurs during the backfilling of the subway station roof; by combining traditional backfilling, compaction and reinforcement processes, the construction process is optimized and the construction efficiency is improved; after optimizing the backfilling effect based on this method, the uneven settlement that occurs in the later period is effectively avoided, thereby avoiding cracks or damage to the outer waterproof layer 2, and improving the waterproof effect of the station; based on the reasonable casting process of this method, the problem of rupture or leakage of the outer waterproof layer 2 during the backfilling process is avoided, ensuring the waterproof performance of the station structure.

[0060] In this embodiment, in step S1, the curing agent includes: 10-20 parts of slag powder or 10-20 parts of fly ash or 10-15 parts of cement, 10-15 parts of fly ash or 5-10 parts of lime, 15-20 parts of rice husk ash or 10-20 parts of bamboo ash or 10-20 parts of straw ash, and 60-70 parts of water; wherein, the slag powder has good activity, can improve the compressive strength, permeability resistance and anti-sedimentation ability of the soil, and the slag powder can react with cement to form a stable hydration product, which enhances the stability of the soil. Qualitatively, slag powder can be replaced by fly ash, industrial waste slag or cement. The activity of fly ash can also react with moisture in the soil to enhance the stability of the soil. Industrial waste slag, namely fly ash, is similar to slag powder and can improve the compressive strength and anti-sedimentation properties of the soil. In specific circumstances, cement can also be used as a substitute for slag powder, such as when the project requires higher hardness. Fly ash is a by-product of the combustion of waste coal. It has good activity and can improve the compressive strength of the soil, enhance the stability of the soil and reduce settlement. Fly ash can also react with water to form stable hydration products; fly ash can be replaced by lime or slag powder. When treating clay soil or moist soil, the use of lime helps to improve the stability of the soil; slag powder has similar stabilizing effects as fly ash; rice husk ash is an environmentally friendly material with a high silicon content, which can improve the compressive strength, impermeability and durability of the soil, and is used to improve the stability of the soil and further enhance its anti-sedimentation performance. Rice husk ash can be replaced by bamboo ash or straw ash. Bamboo ash is similar to rice husk ash and has a high silicon content, which can effectively enhance the stability of the soil. The same is true for straw ash. It should be noted that the addition of water is the key to the solidification process. Too little water may result in incomplete solidification, while too much water may affect the fluidity and stability of the soil material 5. Maintaining an appropriate moisture content can promote the chemical reaction between the curing agent and the soil and ensure the stability of the soil.

[0061] Furthermore, in a specific embodiment, the curing agent in step S1 preferably includes: 10 parts of slag powder, 10 parts of fly ash, 15 parts of rice husk ash, and 60-70 parts of water. The curing agent with this ratio has good performance in practical applications, and can be applied to the curing treatment of most clay, plain fill and sandy soil, and can be fine-tuned based on the aforementioned ratio range according to different soil types and project requirements.

[0062] In this embodiment, step S1 includes:

[0063] S11. Screening soil material 5 to remove large particles;

[0064] Specifically, before adding the curing agent, the soil material 5 needs to be screened to remove oversized particles (such as stones, tree roots, etc.) to ensure that the particles of the soil material 5 are uniform and fine, so as to facilitate the uniform distribution and mixing of the curing agent;

[0065] S12. Matching the water ratio in the curing agent according to the ambient temperature and humidity; in high or low temperature environments, adjusting the water ratio and fine-tuning other ingredients based on the preferred ratio scheme;

[0066] S13. Add a curing agent to the soil material 5 and mix to form a fluid mixed soil material 5; when the curing agent is added to the soil material 5, ensure that the curing agent is fully mixed with the soil, and pay attention to the fluidity of the soil material 5 during the mixing process to prevent the curing agent from agglomerating or stratifying, thereby ensuring the uniformity and stability of the soil.

[0067] It should be noted that the soil body preferably uses the abandoned soil (such as plain fill, clay, silty clay, sand, etc.) of the construction site, and the curing agent uses industrial waste materials such as slag powder, fly ash and rice husk ash as components of the high-efficiency rock and soil curing agent, which realizes the utilization of abandoned soil, greatly reduces the abandonment of waste soil and borrowed soil for backfilling, and reduces the noise generated by construction machinery and equipment, dust and carbon emissions from material transportation. Not only does it save a lot of labor and material costs, it can also greatly reduce the cost of machinery shifts, and the environmental protection effect is obvious.

[0068] In this embodiment, step S2 includes:

[0069] The longitudinal separation distance of the separation structure 4 is planned based on the construction target scale, the load requirements of the top plate and the soil compaction capacity, and the lateral separation distance of the separation structure 4 is planned based on the uniform force of the soil backfill and the reduction of local high stress;

[0070] Specifically, after the construction of the station's roof main structure 1, external waterproof membrane and waterproof membrane protective layer 3 is completed, a grid-shaped partition structure 4 is built on the protective layer 3 to divide the plane above the roof into multiple partition areas to provide structural support for the uniform distribution of the subsequent backfill soil, so as to avoid lateral flow or uneven settlement of the soil material 5 during the backfilling process; wherein, the partition structure 4 is realized by a masonry wall, and the wall material is selected from pressure-resistant and structurally stable materials such as bricks and concrete blocks to withstand the lateral pressure from the backfill soil. The height is planned to be about 50 cm to ensure that sufficient support can be provided during the backfilling process and to avoid damage to the wall by the backfill soil 5; the setting of each partition area takes into account the overall load distribution of the station roof and the compaction effect of the backfill soil, so as to ensure uniform settlement of the soil. Based on this, the longitudinal separation distance of the partition structure 4 is planned based on the construction target scale, the load requirements of the roof and the compaction of the soil, and the longitudinal separation distance of the grid is controlled to be 10 to 20 meters , too long longitudinal separation may lead to excessive local settlement, while too short separation may increase the difficulty of construction, so this distance is set to 10 to 20 meters to ensure the reasonable distribution and stability of the soil; based on the uniform force of the soil backfill and the reduction of local high stress, the lateral separation distance of the separation structure 4 is planned, and the lateral separation distance is controlled at 8-12 meters, preferably about 10 meters; by setting the separation structure 4, the plane above the top plate is divided into multiple separation areas, and the soil in each area will be able to be independently supported after backfilling, avoiding large-scale uneven settlement; when backfilling the soil 5 in each separation area, the range and rate of soil settlement can be effectively controlled to avoid uneven settlement of the overall structure due to too fast or too slow settlement of the soil in a certain area, thereby avoiding the appearance of cracks and potholes in the road surface 10; the separation structure 4 further enhances the structural stability, and provides a stable structural framework for subsequent backfilling and solidification by dividing the area, which can effectively disperse the weight of the soil and reduce the impact of local settlement.

[0071] In this embodiment, step S3 includes:

[0072] S31. Fluid mixed soil material 5 transport;

[0073] Before starting backfilling, the evenly stirred fluidized mixed soil material 5 is first transported to the construction site. The mixed soil material 5 is usually made of soil, rock and soil curing agent and water mixed in a specified proportion to form a fluidized mixed soil material 5 with good fluidity, which is convenient for backfilling. It should be noted that the fluidized mixed soil material 5 has good fluidity and operability, and can be quickly filled into the separation area formed by the field-shaped grid wall, and ensure that the soil evenly covers the bottom of each separation area. Due to its strong fluidity, it is not easy to produce gaps during the backfilling process, which effectively avoids the local gaps and settlement problems caused by uneven filling in the traditional backfilling method. The transportation equipment adopts a pumping device or a designed chute device to transport the mixed soil material 5 to each separation area respectively; the present embodiment preferably uses a chute device to transport the soil material 5

[0074] S32. Starting from the preset separation area, backfill the fluid mixed soil material 5 to a preset height within the separation structure 4;

[0075] S33 is transferred to another partition area, backfilling the fluid mixed soil material 5 to a preset height within the partition structure 4;

[0076] S34. Repeat step S33 until all the separated areas are backfilled with the fluid mixed soil material 5 to a preset height within the separated structure 4;

[0077] S35. Repeat steps S32-S34 until the backfilling of soil material 5 in the separated area is completed;

[0078] It can be understood that, during the transfer process, the backfill operation is performed in the order of transferring from one partition area to the next adjacent partition area to prevent excessive concentration of lateral pressure, and during the backfill process, when pouring reaches a preset proportion (such as 1 / 2) of the wall height of the partition structure 4, the pouring is stopped and transferred to the next adjacent partition area, effectively dispersing the backfill pressure of each partition area, reducing the risk of excessive stress on the masonry wall due to excessive lateral pressure of the soil material 5, effectively protecting the stability of the masonry wall structure, and avoiding the wall from rupture or deformation during the pouring of the soil material 5; after all partition areas are backfilled with the soil material 5 with a preset height proportion in step S34, the previous steps are repeated multiple times to backfill to the masonry wall elevation, and the pouring height is controlled step by step, effectively ensuring uniform settlement of the soil, and preventing the soil in a local area from settling too fast or too slow; wherein, the geotechnical curing agent component in the fluid mixed soil material 5 plays a role in reinforcing the soil during the backfill process, and the reaction of the curing agent and the soil material 5 can enhance the compressive strength and anti-settlement ability of the soil, thereby effectively improving the stability of the overall structure after the top plate is backfilled.

[0079] In this embodiment, step S4 includes:

[0080] S41. Solidification of soil material 5;

[0081] Specifically, before arranging the geogrid 6, it is first necessary to ensure that the fluid mixed soil material 5 has been completely solidified and has reached the expected strength requirements. The solidified soil should be uniform, solid and have good anti-settlement and compressive strength.

[0082] S42.Soil strength inspection;

[0083] Specifically, in order to avoid incomplete solidification leading to instability of subsequent structures, the construction party should use professional equipment to check the solidification degree of the soil to ensure that it meets the engineering standards. The solidification standard is that the mixed soil material 5 after solidification must meet certain compaction and compressive strength indicators, which are specifically set by the construction party according to the actual requirements of the project;

[0084] S43. Arrange the geogrid 6 and fix it;

[0085] Specifically, step S43 includes: arranging the geogrid 6 symmetrically with the center line of the partition structure 4 between the two partition areas, preferably arranging it on the masonry wall extending in the longitudinal direction; fixing one side of the geogrid 6 to the solidified soil by steel nails 7, and the steel nails 7 are arranged at preset intervals; wherein the arrangement of the geogrid 6 is symmetrical based on the center line of the masonry wall to ensure its balanced distribution in the overall backfill area; the geogrid 6 should be arranged along the top surface of the masonry wall and symmetrically with the masonry wall as the center line, and the two sides of the geogrid 6 maintain a distance of 2m from the center line, ensuring the uniform distribution of the geogrid 6 in the backfill area and helping to enhance the overall stability of the soil; the geogrid 6 can be woven from high-strength polyester fiber or glass fiber. The spacing and specifications of the geogrid 6 need to be adjusted according to the characteristics, compaction requirements and tensile strength of the backfill soil. The selected geogrid 6 specifications should be able to effectively enhance the deformation resistance of the soil. In order to ensure the stability and long-term effectiveness of the geogrid 6 in the backfill soil, its side is fixed on the solidified fluid mixed soil material 5, and special steel nails 7 are designed to fix the edge of the geogrid 6 to the soil surface to avoid displacement or deformation during subsequent construction or soil settlement. Preferably, the steel nails 7 are fixed along the fixed side of the geogrid 6 at a preset spacing (such as 1m) to ensure that the geogrid 6 is firmly embedded in the soil. The material of the steel nails 7 takes into account the properties of the soil and its long-term load-bearing requirements, and is preferably a corrosion-resistant galvanized steel nail 7 to ensure its long-term stability.

[0086] It can be understood that the arrangement of the geogrid 6 can significantly improve the tensile strength and deformation resistance of the backfill soil. By combining the geogrid 6 with the solidified soil, the tension and pressure on the soil can be effectively dispersed to prevent excessive settlement or deformation of the soil. The mesh support formed by the grid structure can evenly transfer the external load to a larger range, thereby reducing the risk of local settlement. By symmetrically distributing the geogrid 6 and fixing it with steel nails 7, an additional support layer is provided in the station roof structure to enhance the overall stability of the soil under the roof, especially in the subsequent use under the action of transportation loads, the geogrid 6 It can effectively enhance the compressive strength of the soil and avoid uneven settlement or damage caused by load; the stretching and compression of the soil usually lead to uneven settlement or cracks. The geogrid 6 forms a grid structure in the soil and has a certain restraining effect. The setting of the geogrid 6 can effectively disperse this part of the stress, prevent the backfill soil 5 from cracking or cracking, improve the soil's anti-aging ability in the long term, and prevent the backfill soil from deforming due to long-term loads or environmental factors; its tensile strength and ductility enable it to play an important stabilizing role in the soil, avoiding deformation of the top plate caused by foundation settlement, thereby ensuring the safety of subsequent construction and operation.

[0087] In this embodiment, step S5 includes: the diameter of the steel mesh 8 is 6-12mm, and the mesh size is 10-20cm; the steel mesh 8 is symmetrically arranged with the center line of the partition structure 4 between the two partition areas; it should be noted that before arranging the steel mesh 8, it is necessary to select the steel mesh 8 of appropriate specifications according to the properties of the backfill soil, the structural design requirements and the load requirements, so as to effectively transfer the pressure in the backfill soil and prevent local deformation; galvanized steel bars or stainless steel bars are preferably used to ensure their corrosion resistance in long-term use and avoid moisture or Salt causes corrosion and reduced strength of steel bars; the arrangement method of the steel mesh 8 is similar to that of the geogrid 6, and is symmetrically arranged based on the center line of the masonry wall to ensure uniform distribution of the structure; ensure that the distance between the two sides of the mesh and the center line is about 1m, and the arrangement of the steel mesh 8 is required to be flat, and there should be no bending or twisting to avoid affecting its reinforcement effect; by symmetrically arranging the steel mesh 8 based on the center line of the masonry walls of each part of the separation structure 4, it is evenly distributed in the entire backfill area, stress and load can be smoothly transmitted, and the overall compressive resistance and stability of the soil are effectively enhanced. The symmetrical arrangement ensures that all parts of the backfill area are equally supported and reinforced, thereby avoiding local areas from being subjected to excessive pressure and causing settlement or damage; the steel mesh 8 is fixed by steel nails 7 or wire ties or other fixings, and is firmly fixed to the geogrid 6 or the surface of the solidified soil, ensuring that the steel mesh 8 will not be displaced or deformed during the backfill process; the fixing points are distributed at preset intervals to ensure the stability of the mesh fixation; during the backfill of the subway station roof, the soil is subjected to a large load, especially the traffic load and equipment load above the station. The compressive strength of the backfill soil is improved by setting the steel mesh 8, and its mesh structure effectively disperses the load, reduces the local deformation and compaction of the soil under the load, and enables the soil to distribute the bearing pressure more evenly, thereby It improves the overall stability and bearing capacity, and can effectively prevent the backfill soil from cracking or large-scale deformation due to settlement, vibration or load. The remaining soil is combined to increase the overall rigidity and toughness of the soil, thereby enhancing the stability of the station structure. When encountering external pressure, it effectively shares part of the stress and reduces the displacement and settlement of the soil. The tensile strength of the soil is enhanced by the steel mesh 8, and cracks caused by local settlement or stress concentration are further prevented. In addition, the reinforcement effect of the steel mesh 8 not only improves the stability during the construction phase, but also provides continuous support during the long-term use of the station. During the operation of the station, it is continuously affected by traffic loads and continuously helps to disperse the load, avoiding irreversible deformation of the soil after long-term stress, thereby extending the service life of the station structure.

[0088] It should be understood that step S6 is to repeat steps S2-S5, continue to build the masonry wall at the original masonry wall position, repeat the backfilling, arranging the geogrid 6 and the steel mesh 8 steps, and circulate the operation until the design elevation is reached to form a multi-layer backfill structure;

[0089] The process also includes step S7: performing road structure construction and road surface 10 construction, which is implemented with reference to the prior art and will not be elaborated on in detail.

[0090] On the other hand, reference Fig.11 This embodiment also provides a subway station construction structure, which is applied with the roof backfilling method of the above preferred embodiment, and also includes a road structure layer 9 and a road surface 10 arranged above the roof backfilling structure.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A roof backfilling method, characterized in that: include: S1. Soil curing treatment, mixing the soil and curing agent to form a fluid mixed soil; S2. Construction of station roof grid: building a grid-like partition structure on the protective layer of the completed roof main structure to divide the roof into multiple partition areas; S3. Backfilling of soil materials: backfilling the separated area with fluid mixed soil materials; S4. The geogrid is arranged on the partition structure, and the two sides of the geogrid are connected to the solidified soil in the adjacent partition area respectively; S5. The steel mesh is arranged on the geogrid and the two sides of the steel mesh are located on adjacent separation areas; S6. Repeat steps S2-S5 until the design elevation is reached.

2. The roof backfilling method according to claim 1, characterized in that: In step S1, the curing agent includes: 10-20 parts of slag powder or 10-20 parts of fly ash or 10-15 parts of cement, 10-15 parts of fly ash or 5-10 parts of lime, 15-20 parts of rice husk ash or 10-20 parts of bamboo ash or 10-20 parts of straw ash, and 60-70 parts of water.

3. The roof backfilling method according to claim 2, characterized in that: In step S1, the curing agent includes: 10 parts of slag powder, 10 parts of fly ash, 15 parts of rice husk ash, and 60-70 parts of water.

4. The roof backfilling method according to claim 1, characterized in that: Step S1 includes: S11. Screen soil materials to remove large particles; S12. Matching the water ratio in the curing agent according to the ambient temperature and humidity; S13. Add a curing agent to the soil material and mix to form a fluidized mixed soil material.

5. The roof backfilling method according to claim 1, characterized in that: Step S2 includes: planning the longitudinal separation distance of the separation structure based on the construction target scale, the load requirement of the top plate and the soil compaction capacity, and planning the lateral separation distance of the separation structure based on the uniform stress of the soil backfill and the reduction of local high stress.

6. The roof backfilling method according to claim 1, characterized in that: Step S3 includes: S31. Fluid mixed soil material transportation; S32. Starting from the preset separation area, backfill the fluid mixed soil material to a preset height within the separation structure; S33. Transfer to another partition area and backfill the fluid mixed soil material to a preset height within the partition structure; S34. Repeat step S33 until all the separated areas are backfilled with the fluid mixed soil material to a preset height within the separated structure; S35. Repeat steps S32-S34 until the backfilling of soil in the separated area is completed.

7. The roof backfilling method according to claim 1, characterized in that: Step S4 includes: S41. Soil solidification; S42.Soil strength inspection; S43. Arrange and secure geogrids.

8. The roof backfilling method according to claim 1, characterized in that: Step S43 includes: arranging the geogrid symmetrically with respect to the center line of the partition structure between the two partition areas, fixing one side of the geogrid to the solidified soil by steel nails, and the steel nails are spaced apart at a preset interval.

9. The roof backfilling method according to claim 1, characterized in that: Step S5 includes: the diameter of the steel mesh is 6-12 mm, and the mesh size is 10-20 cm; the steel mesh is symmetrically arranged with respect to the center line of the partition structure between the two partition areas.

10. A subway station construction structure, characterized in that: The roof backfilling method according to any one of claims 1 to 9 is applied.

Images