In-situ curing and pile combined bearing foundation structure for protecting box culvert
Through the composite foundation treatment technology combined with on-site curing and cement mixing piles, the problems of long construction period, high cost and limited load sharing effect in the existing technology are solved, and efficient and economical foundation reinforcement effect is achieved, the existing box culvert structure is protected and the roadbed settlement deformation is controlled.
Patent Information
- Application Number
- CN202420732680.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-10
- Publication Date
- 2025-04-15
- Estimated Expiration
- 2034-04-10
AI Technical Summary
When protecting the culvert structure, existing foundation reinforcement technology has problems such as long construction period, high cost, and limited load sharing effect on existing structures.
Using composite foundation treatment technology combined with on-site curing and cement mixing piles, a solidified hard shell layer is formed on the silt soft soil layer and a cement mixing pile is set up under the silt clay layer to penetrate deep into the stable layer to improve the foundation bearing capacity and reduce the subgrade settlement deformation.
It realizes local foundation reinforcement with efficient construction and low cost, which can effectively protect the existing box culvert structure, reduce its stress, improve the foundation bearing capacity, control the subgrade settlement deformation, and ensure construction stability and safety.
Smart Images
Figure CN222758936U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of foundation reinforcement, in particular to an in-situ solidified and pile-combined bearing foundation structure for protecting a box culvert. Background Art
[0002] Common protection measures for existing tunnel box culvert structures on existing roadbeds include pile-sheet structure protection, lightweight concrete replacement, and roadbed cavity weight reduction. The existing protection measures have the following defects and deficiencies: the pile-sheet structure has a good protective effect on the existing box culvert components and can bear the upper load stress and deformation. The disadvantage is that the construction period is long and the operation of urban main roads is greatly disturbed; lightweight concrete replacement can reduce the upper load to a certain extent, but its disadvantage is that the effect is limited and it is not suitable for high roadbed filling. It is only a load reduction measure and cannot share the load for the existing structure; road cavity weight reduction can also reduce the load to a certain extent. Its disadvantage is that special waterproofing or drainage design needs to be considered for the roadbed cavity, which is not conducive to the long-term operation of the roadbed; it is only a load reduction measure and cannot share the load for the existing structure. Therefore, it is urgent to provide a composite stratum combined with in-situ solidification and cement mixing piles, which has high construction efficiency, provides foundation bearing capacity to control roadbed settlement and deformation, and provides protection for the existing tunnel box culvert structure. Summary of the invention
[0003] The utility model aims to provide a foundation structure with in-situ solidification and pile combination bearing for protecting a box culvert, so as to solve the problems raised in the above-mentioned background technology.
[0004] In order to achieve the above purpose, the utility model provides the following technical solutions:
[0005] A foundation structure with in-situ solidification and pile combination bearing for protecting a box culvert, comprising a silt soft soil layer, wherein a roadbed fill is provided above the silt soft soil layer; below the silt soft soil layer is a silt clay layer, wherein below the silt clay layer is a stable stratum; a box culvert is provided in the silt soft soil layer, wherein the lower end of the box culvert is arranged in the silt clay layer and fixedly connected thereto; a solidified hard shell layer is provided in the silt soft soil layer, wherein the solidified hard shell layer is arranged above the box culvert; a plurality of stirring piles are provided in the solidified hard shell layer, wherein the bottoms of the stirring piles penetrate the silt clay layer and extend into the stable stratum.
[0006] Preferably, the diameter of the mixing pile is 0.8-1.2 m, wherein the length of the mixing pile is 8-12 m.
[0007] Preferably, the curing depth of the cured hard shell layer is 3 m, wherein the depth of the top of the mixing pile inserted into the cured hard shell layer is not less than 1 m.
[0008] Preferably, the solidified crust layer is divided into several blocks on the silt soft soil layer, wherein the size of each solidified crust layer is a rectangular block with a length of 5 m and a width of 5 m.
[0009] Preferably, an overlap width of 0.05 m to 0.1 m is provided between two adjacent cured hard shell layers.
[0010] Preferably, the bottom of the mixing pile extends into the stable stratum to a depth of not less than 3 m, wherein the distance between two adjacent mixing piles is 4 m.
[0011] Compared with the prior art, the utility model has the advantages of flexible construction and low construction cost. It does not need to reinforce the entire stratum, and can locally reinforce the soil according to the stress characteristics to form a protective body for the existing structure. Local reinforcement can save a lot of cost compared with traditional foundation treatment and reinforcement methods. By adopting a composite foundation treatment technology of in-situ solidification combined with cement mixing piles, the foundation treatment can be carried out quickly. The hard shell layer formed by in-situ solidification can bear the load at the same time, reducing the stress on the existing box culvert, thereby protecting the existing box culvert. At the same time, it can also provide a better construction platform for the mixing piles. The cement mixing piles are used to penetrate into the stable stratum below the silt soft soil layer to improve the bearing capacity of the foundation. It can effectively control the settlement and deformation of the roadbed, ensure the stability and safety during the construction process, and have good promotion value and application prospects. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 It is a structural schematic diagram of the utility model;
[0013] Figure 2 yes Figure 1 An enlarged schematic diagram of the structure at point A is shown.
[0014] Among them: 1. Silt soft soil layer; 2. Silty clay layer; 3. Stable stratum; 4. Box culvert; 5. Solidified hard crust layer; 6. Roadbed fill; 7. Mixing piles. DETAILED DESCRIPTION
[0015] The utility model is further described in detail below in conjunction with the accompanying drawings.
[0016] Please refer to Figure 1 to Figure 2 To achieve the above purpose, the utility model provides the following technical solutions:
[0017] A foundation structure for protecting a box culvert by in-situ solidification and pile combination bearing, comprising a silt soft soil layer 1 located on the ground, wherein the depth of the silt soft soil layer 1 is 3m; the bottom of the silt soft soil layer 1 is a silt clay layer 2, the depth of the silt clay layer 2 is 3m, wherein a stable stratum 3 is arranged below the silt clay layer 2, and the stable stratum 3 comprises a strongly weathered rock layer and a medium weathered rock layer, wherein the strongly weathered rock layer is located above the medium weathered rock layer; a box culvert 4 is installed in the silt soft soil layer 1, wherein the clear size of the pipe gallery of the box culvert 4 is 3.2m×2.8m, the thickness of the box culvert 4 is 0.4m, and the bottom of the box culvert 4 is arranged It is installed in the silty clay layer 2 and fixedly connected thereto; a solidified hard shell layer 5 of the same thickness as the silt soft soil layer 1 is provided in the solidified hard shell layer 5, wherein the solidified hard shell layer 5 has a certain rigidity, can share part of the shear force generated by the load, bear part of the bending moment and resist deformation; the solidified hard shell layer 5 is arranged above the box culvert 4, wherein the depth of the box culvert 4 buried in the solidified hard shell layer 5 is not less than 1m; the solidified hard shell layer 5 is filled with roadbed fill 6, wherein the height of the roadbed fill 6 is 9m; a plurality of stirring piles 7 are provided in the solidified hard shell layer 5, wherein the bottom of the stirring piles 7 penetrates the silty clay layer 2 and extends into the stable stratum 3.
[0018] In the above-mentioned scheme, the foundation treatment can be carried out quickly through the composite treatment of in-situ solidification of the silt soft soil layer 1 and mixing piles 7, wherein the solidified hard shell layer 5 formed by in-situ solidification can bear the load at the same time, reduce the stress on the existing box culvert 4, and thus protect the existing box culvert 4. At the same time, it can also provide a better construction platform for the mixing piles 7. The mixing piles 7 are used to penetrate into the stable stratum 3 below the silt soft soil layer 1, thereby improving the bearing capacity of the foundation, effectively controlling the settlement and deformation of the roadbed, and ensuring the stability and safety during the construction process.
[0019] See also Figure 1 As an embodiment of the utility model, the curing depth of the cured hard shell layer 5 is 3m, wherein the depth of the cured hard shell layer 5 and the silt soft soil layer 1 is the same, the diameter of the mixing pile 7 is 0.8-1.2m, wherein the length of the mixing pile 7 is 8-12m; the depth of the bottom of the mixing pile 7 extending into the stable stratum 3 is not less than 3m, wherein the depth of the top of the mixing pile 7 extending into the cured hard shell layer 5 is not less than 1m, and the distance between two adjacent mixing piles 7 is 4m; the cured hard shell layer 5 is divided into several blocks on the silt soft soil layer 1, wherein the size of each cured hard shell layer is a rectangular block of 5m in length and 5m in width, and a lap width of 0.05m-0.1m is provided between two adjacent cured hard shell layers 5.
[0020] In the above scheme, the curing agent for in-situ curing of the silt soft soil layer 1 is a mixture of one or more materials selected from cement, fly ash, lime or gypsum, wherein the curing agent is added to the silt soft soil layer 1 in an amount of 5% to 10%. In the process of in-situ curing of the silt soft soil layer 1, the original silt soft soil is stirred by a powerful stirring head, and then the curing agent is sprayed in. The stirring lifting or lowering rate is controlled at 10 to 20 s / m, and the curing agent spraying rate is controlled at 70 to 160 kg / min. The cement, lime and other materials in the curing agent react chemically with the mineral components and water in the silt soft soil layer 1 to produce a gelling substance, thereby forming a cured hard crust layer 5. At the same time, in the process of in-situ curing construction, the area to be cured in the silt soft soil layer 1 can be divided into a plurality of treatment area units for sequential curing operations, wherein the size of the curing block is a rectangular shape with a length of 5 m and a width of 5 m. Blocks, and the on-site solidification adopts the form of solidification and advancement, and the adjacent solidification blocks are connected in the form of overlap, and the overlap width is 0.05m~0.1m, so as to avoid leakage of the solidification construction of the entire foundation pit bottom surface. The on-site solidification construction around the box culvert 4 should strictly control the construction scope, and the construction distance from the box culvert 4 shall not be less than 0.1m; when the construction of the solidified hard shell layer 5 is completed and before solidification, cement mixing piles 7 are constructed, wherein the mixing piles 7 extend vertically from the surface of the solidified hard shell layer 5 to below the surface of the stable stratum 3, that is, the pile bottom of the mixing pile 7 extends into the strongly weathered rock layer, the depth of the mixing pile 7 extending into the strongly weathered rock layer is not less than 3m, and the depth of the top of the mixing pile 7 inserted into the solidified hard shell layer 5 is not less than 1m; after the solidification of the solidified hard shell layer 5 is completed and the mixing pile 7 is constructed to the specified strength, the planned roadbed is backfilled in layers with the roadbed fill 6 and rolled until the planned design roadbed height. By adopting the composite foundation treatment technology of in-situ solidification combined with mixing piles, the bearing capacity of the foundation can be improved, the settlement and deformation of the roadbed can be effectively controlled, and guarantees can be provided for the subsequent entry of construction machinery to ensure stability and safety during the construction process.
[0021] Although the specific embodiments of the present invention are described above, those skilled in the art should understand that these are only examples, and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principle and essence of the present invention, but these changes and modifications fall within the protection scope of the present invention.
Claims
1. A foundation structure for protecting a box culvert by combining in-situ solidification and pile bearing, comprising a silt soft soil layer (1), wherein a roadbed fill (6) is provided above the silt soft soil layer (1); characterized in that: Below the silt soft soil layer (1) is a silty clay layer (2), wherein below the silt clay layer (2) is a stable stratum (3); a box culvert (4) is provided in the silt soft soil layer (1), wherein the lower end of the box culvert (4) is arranged in the silt clay layer (2) and fixedly connected thereto; a solidified hard shell layer (5) is provided in the silt soft soil layer (1), wherein the solidified hard shell layer (5) is arranged above the box culvert (4); a plurality of stirring piles (7) are provided in the solidified hard shell layer (5), wherein the bottom of the stirring piles (7) penetrates the silt clay layer (2) and extends into the stable stratum (3).
2. The in-situ solidified and pile-combined bearing foundation structure for protecting a box culvert according to claim 1, characterized in that: The diameter of the mixing pile (7) is 0.8-1.2 m, wherein the length of the mixing pile (7) is 8-12 m.
3. The in-situ solidified and pile-loaded foundation structure for protecting a box culvert according to claim 1, characterized in that: The solidification depth of the solidified hard shell layer (5) is 3 m, wherein the depth to which the top end of the stirring pile (7) is inserted into the solidified hard shell layer (5) is not less than 1 m.
4. The in-situ solidified and pile-combined bearing foundation structure for protecting a box culvert according to claim 1, characterized in that: The solidified hard crust layer (5) is divided into a plurality of blocks on the silt soft soil layer (1), wherein the size of each solidified hard crust layer (5) is a rectangular block with a length of 5 m and a width of 5 m.
5. The in-situ solidified and pile-combined bearing foundation structure for protecting a box culvert according to claim 4, characterized in that: An overlap width of 0.05 m to 0.1 m is provided between two adjacent cured hard shell layers (5).
6. The in-situ solidified and pile-combined bearing foundation structure for protecting a box culvert according to claim 2, characterized in that: The bottom of the mixing pile (7) extends into the stable stratum (3) to a depth of not less than 3m, wherein the distance between two adjacent mixing piles (7) is 4m.