Lateral confinement settlement reduction road composite foundation suitable for deep soft foundation

Abstract

The utility model discloses a lateral confinement settlement reduction road composite foundation suitable for a deep soft foundation, which belongs to the technical field of foundation treatment and comprises a filling embankment, a reinforced drainage cushion layer, a plurality of precast piles and a plurality of precast cushion pieces. According to the mortise and tenon joint structure principle, the prefabricated cushion piece and the prefabricated pile are assembled together, construction is more convenient, and the structural integrity is higher; a soft soil layer under the roadbed can be subjected to three-dimensional strengthening in three dimensions of length, width and depth within a large depth range, lateral flow deformation of the soft soil foundation is effectively limited, and the stability coefficient of the composite foundation is improved; auxiliary drainage holes are formed in the prefabricated cushion piece in the depth range, a drainage sand well / pile can be replaced, drainage consolidation of a soft soil layer is accelerated, the site bearing capacity is rapidly improved, follow-up construction is facilitated, and post-construction settlement is effectively controlled.

Description

Technical Field

[0001] The utility model relates to the technical field of foundation treatment, in particular to a side-limited settlement-reducing road composite foundation suitable for deep soft foundations. Background Art

[0002] Soft soil areas, which are widely distributed along my country's coasts, lakes, and rivers and are primarily composed of water-saturated, weak clay deposits, are known as soft soil areas. These areas have low bearing capacity and a high deformation modulus, making them prone to embankment instability and excessive settlement when roads pass through them. When constructing roads in these soft soil areas, the soft soil layers along the roads must be treated. For soft soil foundations, a composite foundation structure combining embankment fill preloading with flexible piles (gravel piles, compaction piles), rigid piles, or multiple pile types is typically used.

[0003] In traditional composite foundations, multiple pile types are arranged at equal intervals and piled individually. There is an original soil layer between the piles. The overall stress-bearing performance of the pile group is poor, and it is easy to cause flow damage between piles. In particular, the original soft soil has low bearing capacity, high natural water content, and low compression modulus. In order to control the non-uniform settlement of the reinforced area and enhance the overall stability of the pile group, it is often necessary to increase the pile diameter and pile length, which makes the pile foundation project larger and the construction inconvenient.

[0004] Chinese utility model patent application number 202222310852.3 proposes a composite pile foundation, Chinese utility model patent application number 202220771063.7 proposes a shallow soft soil composite pile foundation structure, as well as soft soil foundation treatment under the rigid foundation of large-scale buildings, Chinese utility model patent application number 202211636742.4 discloses a rigid-flexible pile composite foundation for reducing the settlement of soft foundation under rigid foundation, and Chinese utility model patent application number 202321401132.6 proposes a composite pile foundation structure for reinforcing soft soil foundation. These multiple applications combine rigid piles and flexible cement-soil mixing piles to solve the problem of soft soil foundation.

[0005] However, there are some defects in the above-mentioned multiple applications:

[0006] (1) Flexible cement-soil mixing piles are commonly used as auxiliary piles in the existing technology. However, they have disadvantages such as low construction accuracy, high cement consumption, large environmental impact, difficult quality control, and large comprehensive carbon emissions. In particular, as the depth increases, the bite quality and bite strength between adjacent cement-soil mixing piles are difficult to ensure, making it difficult to effectively limit the lateral deformation of the soil, and the risk of inter-pile flow damage has not been reduced.

[0007] (2) The cement-soil mixing pile itself has a low permeability coefficient. In highway construction, the excess pore pressure in the soil under the action of preload is difficult to dissipate. It is necessary to add additional drainage sand wells / sand piles in advance to drain and consolidate the site. This is not conducive to the construction period and post-construction settlement control, and increases the risk of road cracking in the later stage and the construction, operation and maintenance costs.

[0008] The above problems need to be solved urgently. Therefore, a side-limited settlement-reducing composite foundation for roads suitable for deep soft foundations is proposed. Utility Model Content

[0009] The technical problem to be solved by the present invention is how to solve the problem of embankment instability or excessive settlement when a highway passes through a soft soil foundation, and provides a side-limited settlement-reducing composite road foundation suitable for deep soft foundations.

[0010] The present invention solves the above-mentioned technical problems through the following technical solutions. The present invention includes an embankment, a reinforced drainage cushion layer, a plurality of prefabricated piles and a plurality of prefabricated pads; a two-dimensional array of the plurality of prefabricated piles is inserted into the soft soil foundation of the road path, and the plurality of prefabricated pads are inserted into the soil between two adjacent prefabricated piles, distributed in a two-dimensional array, and the two sides of each prefabricated pad are respectively connected to the upper parts of the two adjacent prefabricated piles, the reinforced drainage cushion layer is laid on the upper surface of the plurality of prefabricated parts, and the embankment is laid on the reinforced drainage cushion layer.

[0011] Furthermore, the prefabricated pad includes a horizontal upper wing plate, a vertical lower web and two mounting parts. The vertical lower web is arranged on the lower surface of the horizontal upper wing plate and is an integral component therewith, and the vertical lower web is arranged along a diagonal line of the horizontal upper wing plate. The two mounting parts are respectively arranged at both ends of the vertical lower web, and the two mounting parts are respectively connected to the upper parts of the two prefabricated piles.

[0012] Furthermore, the mounting portion is a vertical plug plate, and the ends of the vertical plug plate and the vertical lower web are T-shaped in cross section; a mortise is provided at the upper end of the precast pile, and the cross section of the mortise is T-shaped, and the vertical plug plate is plugged into the mortise.

[0013] Furthermore, a row of the prefabricated piles located at the edges of both sides of the road path are prefabricated long piles, and the remaining prefabricated piles are prefabricated short piles.

[0014] Furthermore, the mortise provided on the prefabricated long pile includes a first longitudinal mortise and two first transverse mortise. The two first longitudinal mortise are symmetrically arranged in the same direction as the road axis, and the first transverse mortise is located on the inner side in the road width direction.

[0015] Furthermore, the mortise provided on the prefabricated short piles includes two second transverse mortises and two second longitudinal mortises, the two second longitudinal mortises are symmetrically arranged in the same direction as the road axis, and the two second transverse mortises are symmetrically arranged in the same direction as the road width.

[0016] Furthermore, a plurality of drainage holes are provided on the horizontal upper wing plate and the vertical lower belly plate, and a drainage groove is provided on the upper surface of the horizontal upper wing plate.

[0017] Furthermore, the lateral distance l between two adjacent precast piles x Less than the longitudinal spacing l y , and 1≤l y / l x ≤2, l x It is 4 to 6 times the diameter of the precast pile.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. The utility model utilizes the mortise and tenon structure principle to assemble prefabricated cushions and prefabricated piles together, which makes construction more convenient and the structural integrity stronger. It can make the soft soil layer under the roadbed obtain three-dimensional reinforcement in length, width and depth within a larger depth range, effectively limit the lateral flow deformation of the soft soil foundation, and improve the stability coefficient of the composite foundation.

[0020] 2. Prefabricated pads are equipped with auxiliary drainage holes along the depth range, which can replace drainage sand wells / piles, accelerate the drainage and consolidation of soft soil layers, quickly improve the bearing capacity of the site, facilitate subsequent construction, and effectively control post-construction settlement.

[0021] 3. All components in the plan are prefabricated in the factory, and the on-site construction process has a high degree of assembly, which can effectively reduce the difficulty of construction and facilitate process management and quality control. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic cross-sectional structural diagram of a side-limited settlement-reducing road composite foundation suitable for deep soft foundations in an embodiment of the present utility model;

[0023] Figure 2 This is a schematic diagram of the longitudinal cross-sectional structure of a composite foundation for side-limited settlement reduction roads suitable for deep soft foundations in an embodiment of the present utility model;

[0024] Figure 3 This is a schematic diagram of the top view of the structure when the prefabricated cushion and the prefabricated pile are connected in cooperation with each other in an embodiment of the present utility model;

[0025] Figure 4 for Figure 3 Schematic diagram of the local structure;

[0026] Figure 5a This is a schematic structural diagram of a prefabricated long pile in an embodiment of the present utility model;

[0027] Figure 5b This is a schematic structural diagram of a prefabricated short pile in an embodiment of the present utility model;

[0028] Figure 6 This is a schematic structural diagram of the prefabricated cushion and prefabricated short piles in the embodiment of the present utility model;

[0029] Figure 7 This is a schematic structural diagram of a prefabricated cushion in an embodiment of the present utility model.

[0030] The numbers in the figure represent:

[0031] 1-Embankment; 2-Reinforced drainage cushion; 3-Precast long piles; 4-Precast short piles; 5-Soft soil foundation; 6-Precast cushion; 61-Horizontal upper wing plate; 62-Vertical lower web plate; 63-Drainage hole; 64-Drainage groove; 65-Mounting part; 71-First longitudinal mortise; 72-First transverse mortise; 73-Second longitudinal mortise; 74-Second transverse mortise; 8-Drainage pattern. DETAILED DESCRIPTION

[0032] The following is a detailed description of an embodiment of the present invention. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process. However, the protection scope of the present invention is not limited to the following embodiment.

[0033] This embodiment provides a technical solution: a side-limited settlement-reducing road composite foundation suitable for deep soft foundation, comprising a fill embankment 1, a reinforced drainage cushion layer 2, a plurality of prefabricated piles and a plurality of prefabricated pads 6.

[0034] A corresponding road path is planned on the soft soil foundation 5, and precast piles are inserted into the path with a pile diameter of not less than 0.8m. A two-dimensional array of multiple precast piles is plugged and distributed in the soft soil foundation 5 of the road path, and a two-dimensional array of multiple precast pads 6 is installed on the upper part of the multiple precast piles to form a hard structural layer to prevent sinking. The two sides of each precast pad 6 are respectively connected to the upper part of two adjacent precast piles. The precast pads 6 and the precast piles are assembled together, the connection is more reliable, and the structural integrity is stronger, so as to effectively support the hard structural layer. The reinforced drainage pad layer 2 is laid on the upper surface of the multiple precast pads 6 to play the role of drainage and coordinated deformation. The fill embankment 1 is laid on the reinforced drainage pad layer 2, and the width of both sides of the reinforced drainage pad layer 2 needs to be greater than the width of both sides of the fill embankment 1.

[0035] In this embodiment, the prefabricated pad 6 includes a horizontal upper wing plate 61, a vertical lower web 62, and two mounting portions 65. The vertical lower web 62 is fixed to the lower surface of the horizontal upper wing plate 61. In this embodiment, the horizontal upper wing plate 61 is a rectangular structure. The vertical lower web 62 is fixed along a diagonal line located on the horizontal upper wing plate 61. The two mounting portions 65 are respectively provided at the two ends of the vertical lower web 62, and the two mounting portions 65 are respectively connected to the upper ends of the two prefabricated piles. The mounting portions 65 are vertical plugs fixed to the ends of the vertical lower web 62. The vertical plugs and the ends of the vertical lower web form a T-shaped structure in transverse cross-section. The upper ends of the prefabricated piles are provided with mortises with a T-shaped cross-section. The mounting portions 65 can be inserted into the mortises, thereby connecting the individual prefabricated piles to each other, and ultimately connecting the independent single piles into a grid-like structure.

[0036] In this embodiment, a row of precast piles located at both sides of the road path are precast long piles 3, and the remaining precast piles are precast short piles 4, so as to increase the stability of the road path edge.

[0037] In this embodiment, the mortise grooves provided on the prefabricated long piles 3 include a first transverse mortise groove 72 and two first longitudinal mortises 71. The two first longitudinal mortises 71 are symmetrically arranged in the same direction as the road axis, and the first transverse mortise groove 72 is located on the inner side in the width direction of the road.

[0038] In this embodiment, the mortise grooves provided on the prefabricated short piles 4 include two second transverse mortises 74 and two second longitudinal mortises 73. The two second transverse mortises 74 are symmetrically arranged in the same direction as the road axis, and the two second longitudinal mortises 73 are symmetrically arranged in the same direction as the road width direction. The different mortise groove opening methods of the prefabricated long piles 3 and the prefabricated short piles 4 are more reasonable and reduce the process steps in the production process.

[0039] In this embodiment, multiple drainage holes 63 are provided on the horizontal upper wing plate 61 and the vertical lower web 62, and drainage grooves 64 are provided on the upper surface of the horizontal upper wing plate 61, which are beneficial to the pre-compression drainage and consolidation of the soft soil roadbed. The drainage grooves 64 on the multiple horizontal upper wing plates 61 form drainage patterns 8.

[0040] In this embodiment, the lateral distance between two adjacent precast piles is l x Should be less than the longitudinal spacing l y , and 1≤l y / l x ≤2, l x It is 4 to 6 times the diameter of the precast pile.

[0041] The construction in this embodiment is carried out in the following order:

[0042] (1) Surveying and setting out: determining the location of pile foundation points;

[0043] (2) Construction of prefabricated long piles 3: Adjust the angle of the prefabricated long pile 3, confirm that the first longitudinal mortise 71 is parallel to the road axis, and then vertically insert the prefabricated long pile 3 at a predetermined point along the direction of the route;

[0044] (3) Construction of prefabricated short piles 4: Adjust the angle of the prefabricated short pile 4, confirm that the second longitudinal mortise 73 is parallel to the road axis, and then vertically insert the prefabricated short piles 4 one by one in the order from outside to inside and from back to front;

[0045] (4) Construction of prefabricated cushion members 6: After the construction of the prefabricated short piles 4 and the prefabricated long piles 3 is completed, the prefabricated cushion members 6 are inserted between two adjacent prefabricated piles in the same order from outside to inside and from back to front;

[0046] (5) Filling of embankment 1: After laying the reinforced drainage cushion layer 2, the embankment 1 is laid on top. The subsequent pre-compression consolidation and other construction processes can be carried out according to the ordinary process, which will not be repeated here.

[0047] The assembled side-limited settlement-reducing soft soil composite foundation structure for a highway proposed in this embodiment utilizes the mortise and tenon structure principle to assemble prefabricated pads and prefabricated piles in the stratum. Compared with mutually interlocking flexible cement-mixed piles, the structure is stronger and more reliably connected, so that the soft soil layer under the roadbed is three-dimensionally reinforced in length, width and depth within the design depth range, and has strong integrity. The compaction effect of the soil can be fully utilized to enhance the lateral resistance of the pile body, improve the bearing capacity, and reduce the uneven settlement of the highway. The overall stability of the embankment and the bearing capacity requirements of the composite foundation can be taken into account in the design, and the risk of instability of the composite foundation can be effectively controlled. Auxiliary drainage drainage holes 63 and drainage grooves 64 are provided in the web and wing plates of the plug plate, which can replace drainage sand wells / sand piles, promote the dissipation of excess pore pressure in the soil, and effectively control post-construction settlement.

[0048] This embodiment uses a prefabricated T-shaped structure to replace the flexible cement-mixed soil piles in the existing technical solution as the side limit structure, which greatly reduces the cement consumption and total carbon emissions, and significantly reduces the impact on the environment; it effectively increases the component prefabrication rate, and can truly achieve design standardization, industrialized production, and assembled construction, effectively reducing the construction difficulty and facilitating construction site management and quality control.

[0049] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are illustrative and cannot be understood as limitations on the present invention. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A composite foundation for side-limited settlement reduction roads suitable for deep soft foundations, characterized in that: It includes an embankment, a reinforced drainage cushion layer, a plurality of prefabricated piles and a plurality of prefabricated pads; a plurality of the prefabricated piles are inserted in a two-dimensional array into the soft soil foundation of the road path, and a plurality of the prefabricated pads are inserted into the soil between two adjacent prefabricated piles, distributed in a two-dimensional array, and the two sides of each prefabricated pad are respectively connected to the upper parts of two adjacent prefabricated piles, the reinforced drainage cushion layer is laid on the upper surface of the plurality of prefabricated pads, and the embankment is laid on the reinforced drainage cushion layer.

2. The composite foundation for side-limited road settlement reduction suitable for deep soft foundation according to claim 1, characterized in that: The prefabricated pad includes a horizontal upper wing plate, a vertical lower web and two mounting parts. The vertical lower web is arranged on the lower surface of the horizontal upper wing plate and is an integral component therewith, and the vertical lower web is arranged along a diagonal line of the horizontal upper wing plate. The two mounting parts are respectively arranged at both ends of the vertical lower web, and the two mounting parts are respectively connected to the upper parts of the two prefabricated piles.

3. The composite foundation for side-limited road settlement reduction suitable for deep soft foundation according to claim 2, characterized in that: The mounting portion is a vertical plug plate, and the vertical plug plate and the end of the vertical lower web form a T-shaped structure in the transverse cross section; a mortise is provided at the upper end of the prefabricated pile, and the cross section of the mortise is a T-shaped structure, and the vertical plug plate is plugged into the mortise.

4. The composite foundation for side-limited road settlement reduction suitable for deep soft foundation according to claim 3, characterized in that: The prefabricated piles in a row located at the edges of both sides of the road are prefabricated long piles, and the remaining prefabricated piles are prefabricated short piles.

5. The composite foundation for side-limited settlement reduction roads suitable for deep soft foundations according to claim 4, characterized in that: The mortise grooves provided on the prefabricated long piles include a first longitudinal mortise groove and two first transverse mortise grooves. The two first longitudinal mortise grooves are symmetrically arranged in the same direction as the road axis, and the first transverse mortise grooves are located inside in the road width direction.

6. The composite foundation for side-limited settlement reduction roads suitable for deep soft foundations according to claim 5, characterized in that: The mortise grooves provided on the prefabricated short piles include two second transverse mortises and two second longitudinal mortises. The two second longitudinal mortises are symmetrically arranged in the same direction as the road axis, and the two second transverse mortises are symmetrically arranged in the same direction as the road width.

7. The composite foundation for side-limited road settlement reduction suitable for deep soft foundation according to claim 2, characterized in that: A plurality of drainage holes are provided on the horizontal upper wing plate and the vertical lower belly plate, and a drainage groove is provided on the upper surface of the horizontal upper wing plate.

8. The composite foundation for side-limited settlement reduction roads suitable for deep soft foundations according to claim 1, characterized in that: The horizontal distance between two adjacent precast piles l x Less than the longitudinal spacing l y , and 1≤l y / l x ≤2, l x It is 4 to 6 times the diameter of the precast pile.

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