Anti-settling embankment widening roadbed

Abstract

The utility model provides an anti-settling embankment widening roadbed which is characterized in that on the basis that the depths of soft soil layers of foundations on the near-water side and the far-water side of the embankment roadbed are different, the filling depth of a second filling roadbed on the near-water side is increased, and meanwhile, soil of the soft soil layers is mixed with a curing agent to form a first in-situ curing layer and a second in-situ curing layer; the first in-situ curing layer and the second in-situ curing layer are both partially inserted below the soft soil layer of the foundation, so that the compactness and the strength of the foundation are greatly enhanced, and the problems of settlement caused by the soft soil layer of the foundation and non-uniform settlement of two sides of the embankment and the roadbed are reduced; the overall stability and the bearing capacity of the first filling roadbed and the second filling roadbed are obviously improved; meanwhile, the first side slope and the second side slope are designed in a stepped mode, connection and meshing between the embankment roadbed and the first filling roadbed and between the embankment roadbed and the second filling roadbed are enhanced, uniform distribution of stress is promoted, and the problems of roadbed deformation and cracks caused by uneven soil compaction or foundation settlement are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of subgrade widening, in particular to an embankment widening subgrade for preventing settlement. Background Art

[0002] An embankment refers to a filled subgrade with its top surface higher than the original ground, which is a common cross-sectional form in road construction of transportation engineering. Several common cross-sectional forms of embankments include low embankments, high embankments, general embankments, submersible embankments, toe protection embankments, trench-filled embankments, etc. The design and construction of embankments need to consider various factors, including the stability of the foundation, hydrological conditions, slope gradient, and protection measures, etc., to ensure the safety and durability of the embankment.

[0003] For a submersible embankment, since one side or both sides of the embankment body are subjected to long-term or short-term immersion, the foundation of the embankment has the characteristics of high water content, high compressibility, easy settlement deformation, and low bearing capacity; especially for an embankment with one side immersed, the depths of the soft soil layers on the immersed side and the other side are different, resulting in different foundation bearing capacities, which easily cause excessive settlement under the action of the upper load, as well as problems of uneven settlement and damage of the two sides of the foundation, affecting the service performance and service life of the road. Therefore, it is necessary to transform the submersible embankment and provide a foundation for embankment widening that can prevent settlement. Content of the Utility Model

[0004] Aiming at the technical problems in the prior art that the foundation of the submersible embankment is prone to settlement deformation and has low bearing capacity due to high water content, and the settlement of the two sides of the foundation is uneven, the utility model provides an embankment widening subgrade for preventing settlement.

[0005] An embankment widening subgrade for preventing settlement includes an embankment subgrade filled on the foundation, a first filled subgrade filled on the far-water side of the embankment subgrade, and a second filled subgrade filled on the near-water side of the embankment subgrade; the top surfaces of the first filled subgrade and the second filled subgrade are flush with the top surface of the embankment subgrade, a road surface structure layer is provided on the top surfaces of the first filled subgrade, the second filled subgrade and the embankment subgrade, and the filling depth of the second filled subgrade is greater than that of the first filled subgrade; the first filled subgrade successively includes a first in-situ solidification layer, a plain soil layer, and a first backfill structure from bottom to top; the second filled subgrade successively includes a second in-situ solidification layer and a second backfill structure from bottom to top; both the first in-situ solidification layer and the second in-situ solidification layer are partially located below the soft soil layer of the foundation; and both the first in-situ solidification layer and the second in-situ solidification layer are made of a curing agent and the soil of the soft soil layer; the splicing surface between the embankment subgrade and the first backfill structure forms a first slope composed of several steps; the splicing surface between the embankment subgrade and the second backfill structure forms a second slope composed of several steps.

[0006] Furthermore, both the first backfill structure and the second backfill structure include a number of soil layers filled in sequence along the filling direction; the soil layers are arranged corresponding to the steps one by one, and the horizontal plane of the soil layer is flush with the horizontal plane of the corresponding step; a number of spliced soil geogrids are provided in sequence along the filling direction for the first backfill structure and the second backfill structure, and the spliced soil geogrids are respectively located in the gaps between any adjacent soil layers.

[0007] Furthermore, the spliced soil geogrid is a bidirectional soil geogrid, the width of the bidirectional soil geogrid is not less than 3m, the ultimate tensile strength is not less than 60kN / m, and the elongation corresponding to the ultimate tensile strength is less than 5%.

[0008] Furthermore, the curing agent includes cement, fly ash, lime and gypsum.

[0009] Furthermore, filter geotextiles are provided on the surfaces of both the first slope and the second slope.

[0010] Furthermore, the second slope includes a first slope section and a second slope section arranged in sequence along the direction away from the ground structure layer, the slope of the second slope section is less than the slope of the first slope section, the slope of the first slope section is the same as the slope of the first slope, and the depth of the first slope section is the same as the depth of the first slope.

[0011] Furthermore, the slopes of both the first slope and the first slope section are 1:0.4, and the slope of the second slope section is 1:1.

[0012] Furthermore, the curing depth of the first in-situ curing layer is greater than the curing depth of the second in-situ curing layer.

[0013] Furthermore, a drainage ditch is provided on one side of both the first filled subgrade and the second filled subgrade away from the embankment subgrade.

[0014] Furthermore, a soil bag cofferdam formed by stacking a number of soil bags is also provided on one side of the second filled subgrade away from the embankment subgrade.

[0015] The beneficial effects of the present utility model are as follows: The present utility model provides an embankment widening subgrade for preventing settlement. Based on the different depths of the soft soil layers of the foundation on the near-water side and the far-water side of the embankment subgrade, while increasing the filling depth of the second filling subgrade on the near-water side, the soil of the soft soil layer is mixed with a curing agent to form the first and second in-situ curing layers, and both the first in-situ curing layer and the second in-situ curing layer partially penetrate below the soft soil layer of the foundation, greatly enhancing the density and strength of the foundation, reducing the settlement caused by the soft soil layer of the foundation and the uneven settlement on both sides of the embankment subgrade, and significantly improving the overall stability and bearing capacity of the first and second filling subgrades; at the same time, the first and second slopes adopt a stepped design, enhancing the connection and occlusion between the embankment subgrade and the first and second filling subgrades, promoting the uniform distribution of stress, and avoiding the problems of subgrade deformation and cracks caused by uneven soil compaction or foundation settlement. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 FIG. is a schematic structural diagram of an embankment widening subgrade for preventing settlement provided by the present utility model.

[0017] REFERENCE SIGNS

[0018] 1. Embankment subgrade; 2. First filling subgrade; 21. First in-situ curing layer; 22. Plain soil layer; 23. Filling soil layer; 3. Second filling subgrade; 21. Second in-situ curing layer; 4. Pavement structure layer; 5. Connecting soil grid; 6. First slope; 7. Second slope; 71. First slope section; 72. Second slope section; 8. Drainage ditch; 9. Soil bag cofferdam. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] In order to enable those skilled in the art of the present technology to better understand the solution of the present utility model, the present utility model will be further described in detail below with reference to the accompanying drawings. The described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the scope of protection of the present utility model.

[0020] Reference Figure 1 As shown, an embankment widening subgrade for preventing settlement includes an embankment subgrade 1 filled on the foundation, a first filling subgrade 2 filled on the far-water side of the embankment subgrade 1, and a second filling subgrade 3 filled on the near-water side of the embankment subgrade 1.

[0021] Specifically, the top surfaces of the first filling subgrade 2 and the second filling subgrade 3 are flush with the top surface of the embankment subgrade 1, and a pavement structure layer 4 is provided on the top surfaces of the first filling subgrade 2, the second filling subgrade 3, and the top surface of the embankment subgrade 1, providing stable and flat road surface conditions for vehicle driving and ensuring the comfort of driving on the road above the embankment.

[0022] The filling depth of the second filled subgrade 3 is greater than that of the first filled subgrade 2. Based on the different depths of the soft soil layers of the foundation on the near-water side and the far-water side of the embankment subgrade, increasing the filling depth of the second filled subgrade 4 on the near-water side fully considers the greater water pressure and water erosion risks that the foundation on the near-water side may face. By increasing the filling depth, the bearing capacity and stability of this area are enhanced, effectively preventing the problems of subgrade settlement and uneven settlement on both sides of the embankment subgrade 1.

[0023] The first filled subgrade 2 successively includes a first in-situ solidification layer 21, a plain soil layer 22, and a first backfill structure from bottom to top; the second filled subgrade 3 successively includes a second in-situ solidification layer 31 and a second backfill structure from bottom to top. Both the first in-situ solidification layer 21 and the second in-situ solidification layer 31 are partially located below the soft soil layer of the foundation; the solidification depth of the first in-situ solidification layer 21 is greater than that of the second in-situ solidification layer 31.

[0024] Based on the in-situ solidification technology, both the first in-situ solidification layer 21 and the second in-situ solidification layer 31 are made of a mixture of a solidifying agent and the soil of the soft soil layer. In this embodiment, the solidifying agent includes cement, fly ash, lime, and gypsum. Specifically, the proportion of cement in the solidifying agent is relatively large, and 40 - 50% of fly ash, lime, and gypsum are incorporated. The dosage of the solidifying agent is about 5 - 7% of the weight of the soil.

[0025] Using the soil of the soft soil layer and the solidifying agent to make the first in-situ solidification layer 21 and the second in-situ solidification layer 31, and making both the first in-situ solidification layer 21 and the second in-situ solidification layer 31 partially penetrate below the soft soil layer of the foundation greatly enhances the compactness and strength of the foundation, effectively reducing the settlement caused by the soft soil layer of the foundation and the problem of uneven settlement on both sides of the embankment subgrade, and significantly improving the overall stability and bearing capacity of the first filled subgrade 2 and the second filled subgrade 3.

[0026] Both the first backfill structure and the second backfill structure include a number of fill soil layers 23 filled successively along the filling direction. By the method of layered filling, each fill soil layer 23 can form a relatively dense structure during the compaction process, thereby enhancing the overall stability of the entire backfill structure.

[0027] The splicing surface between the embankment subgrade 1 and the first backfill structure forms a first slope 6 composed of a number of steps; the splicing surface between the embankment subgrade 1 and the second backfill structure forms a second slope 7 composed of a number of steps.

[0028] The first slope 6 and the second slope 7 formed by the stepped structure can respectively disperse the contact pressure between the embankment subgrade 1, the first filled subgrade 2 and the second filled subgrade 3, improve the stability of the splicing surface, and reduce the subgrade deformation and crack problems caused by uneven soil compaction or foundation settlement.

[0029] The filling soil layers 23 are arranged corresponding to the steps one by one, and the horizontal plane of the filling soil layer 23 is flush with the horizontal plane of the corresponding step. The first backfilling structure and the second backfilling structure are sequentially provided with a plurality of splicing soil grids 5 along the filling direction, and the splicing soil grids 5 are respectively located in the gaps between any adjacent filling soil layers 23. Specifically, the splicing soil grid 5 is a bidirectional geogrid, the width of the bidirectional geogrid is not less than 3m, the ultimate tensile strength is not less than 60kN / m, and the elongation corresponding to the ultimate tensile strength is less than 5%.

[0030] By arranging the splicing soil grid 5, the mechanical properties of the filling soil layer 23 can be enhanced, enabling it to better resist external loads and deformations, and thus effectively enhancing the overall stability and bearing capacity of the filled subgrade. In this embodiment, the splicing soil grid 5 is laid one layer for every two steps, and the splicing soil grid 5 is fixed on the filling soil layer 23 located below the splicing soil grid 5 and horizontally extends to the horizontal plane of the step 4 corresponding to the filling soil layer 23 located below the splicing soil grid 5.

[0031] The surfaces of the first slope 6 and the second slope 7 are both provided with filter geotextiles (not shown in the figure). The filter geotextile has good water permeability. By arranging the filter geotextiles on the surfaces of the first slope 6 and the second slope 7, the accumulated water on the surfaces of each slope can be quickly drained, reducing the water content of the slope and preventing slope instability caused by water accumulation; at the same time, it can enhance the shear strength and anti-slip ability of the slope soil body, improving the stability of the slope.

[0032] The second slope 7 includes a first slope section 71 and a second slope section 72 arranged in sequence along the direction away from the ground structure layer. The slope of the second slope section 72 is smaller than the slope of the first slope section 71. The slope of the first slope section 72 is the same as the slope of the first slope 71, and the depth of the first slope section 71 is the same as the depth of the first slope 71.

[0033] In this embodiment, the slopes of the first slope 6 and the first slope section 71 are both 1:0.4, and the slope of the second slope section 72 is 1:1. Adopting a steeper slope for the first slope 6 and the first slope section 71 enables the first filled subgrade 2 and the first slope section 71 of the second filled subgrade to have stronger support force in the vertical direction and be able to resist the sliding force of the soil body; adopting a gentler slope for the second slope section 72 helps to disperse the weight of the soil body and reduce the sliding force generated by the action of gravity, thereby enhancing the overall stability of the slope.

[0034] On one side of the first filled subgrade 2 and the second filled subgrade 3 away from the embankment subgrade 1, a drainage ditch 8 is provided. The drainage ditch 8 can effectively collect and drain the accumulated water on the embankment subgrade 1 and the pavement structure layer 4, prevent the water from staying for a long time, reduce problems such as subgrade softening and settlement caused by water penetration, reduce the phenomenon of road waterlogging, improve the anti-skid performance of the pavement of the pavement structure layer 4, and help improve driving safety.

[0035] On the side of the second filled subgrade 3 away from the embankment subgrade, a sandbag cofferdam 9 formed by stacking a number of sandbags is also provided. The second filled subgrade 3 on the water-near side of the embankment subgrade 1 is close to the water body. Setting the sandbag cofferdam 9 on one side of it can effectively block the direct erosion and scouring of the water body on the subgrade, significantly reduce the threat of the water body to the stability of the subgrade, and protect the safety of the subgrade structure.

[0036] Wherein, the sandbag includes a bag body and the soil filled in the bag body; the bag body is a polyethylene woven bag, and the length of the bag body should not be greater than 0.8 m, the width should not be greater than 0.6 m, and the thickness should not be greater than 0.4 m. Using a polyethylene woven bag as the bag body, this material is light, durable, easy to transport and stack. After filling with soil, the required cofferdam structure can be quickly constructed, greatly shortening the construction period and improving work efficiency.

[0037] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention, and do not limit the present invention to the specific embodiments described. Obviously, according to the content of this specification, other modifications and changes can be made. The embodiments selected and specifically described in this specification are to better explain the principle and practical application of the present invention, so that those skilled in the art can well understand and utilize the present invention. It is not a limitation of the present invention. Any simply deformed scheme of the present invention belongs to the protection scope of the present invention.

Claims

1. An embankment widened subgrade for preventing settlement, characterized in that, It includes an embankment subgrade filled on a foundation, a first filled subgrade filled on the far-water side of the embankment subgrade, and a second filled subgrade filled on the near-water side of the embankment subgrade; The top surfaces of the first filled subgrade and the second filled subgrade are flush with the top surface of the embankment subgrade. A pavement structure layer is provided on the top surfaces of the first filled subgrade, the second filled subgrade and the embankment subgrade. And the filling depth of the second filled subgrade is greater than that of the first filled subgrade; The first filled subgrade successively includes a first in-situ solidified layer, a plain soil layer and a first backfill structure from bottom to top; the second filled subgrade successively includes a second in-situ solidified layer and a second backfill structure from bottom to top; both the first in-situ solidified layer and the second in-situ solidified layer are partially located below the soft soil layer of the foundation; and Both the first in-situ solidified layer and the second in-situ solidified layer are made of a mixture of a curing agent and the soil of the soft soil layer; The joint surface between the embankment subgrade and the first backfill structure forms a first slope composed of several steps; the joint surface between the embankment subgrade and the second backfill structure forms a second slope composed of several steps.

2. The widened roadbed of an embankment with anti-settlement according to claim 1, characterized in that, Both the first backfill structure and the second backfill structure include several fill soil layers successively filled along the filling direction; the fill soil layers are arranged in one-to-one correspondence with the steps, and the horizontal plane of the fill soil layer is flush with the horizontal plane of the corresponding step; several splicing soil geogrids are successively provided in the first backfill structure and the second backfill structure along the filling direction, and the splicing soil geogrids are respectively located in the gaps between any adjacent fill soil layers.

3. A widened roadbed of an embankment for preventing settlement according to claim 2, characterized in that, The splicing soil geogrid is a bidirectional geogrid. The width of the bidirectional geogrid is not less than 3m, the ultimate tensile strength is not less than 60kN / m, and the elongation rate corresponding to the ultimate tensile strength is less than 5%.

4. A widened roadbed of an embankment for preventing settlement according to claim 1, wherein The curing agent includes cement, fly ash, lime and gypsum.

5. A widened roadbed of an embankment for preventing settlement according to claim 1, characterized in that, Filter geotextiles are provided on the surfaces of the first slope and the second slope.

6. The widened roadbed of an embankment for preventing settlement according to claim 1, characterized in that, The second slope includes a first slope section and a second slope section successively arranged along the direction away from the ground structure layer. The slope of the second slope section is smaller than that of the first slope section. The slope of the first slope section is the same as that of the first slope, and the depth of the first slope section is the same as that of the first slope.

7. The widened roadbed of an embankment with anti-settlement according to claim 6, characterized in that, The slopes of the first slope and the first slope section are both 1:0.4, and the slope of the second slope section is 1:

1.

8. A widened roadbed of an embankment for preventing settlement according to claim 1, characterized in that, The curing depth of the first in-situ solidified layer is greater than that of the second in-situ solidified layer.

9. A widened roadbed of an embankment for preventing settlement according to claim 1, characterized in that, A drainage ditch is provided on one side of the first filled subgrade and the second filled subgrade away from the embankment subgrade.

10. A widened roadbed of an embankment for preventing settlement according to claim 1, characterized in that, A soil bag cofferdam made of several soil bags is further provided on one side of the second filled subgrade away from the embankment subgrade.

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