Soft foundation section light roadbed structure

Abstract

The utility model discloses a soft foundation section light roadbed structure, which belongs to the technical field of road engineering and comprises a deep soft soil foundation and a foam light soil roadbed paved on the surface of the deep soft soil foundation. The foam light soil roadbed is composed of a broken stone hardcore, a geogrid, a light foam soil cushion layer and an iron gauze, the broken stone hardcore is laid on the upper surface of the deep soft soil foundation, the geogrid is embedded in the broken stone hardcore, the light foam soil cushion layer is laid on the surface of the broken stone hardcore, and the iron gauze is embedded in the light foam soil cushion layer. The multiple light foam soil cushion layers are arranged, the steel wire meshes are laid between every two adjacent light foam soil cushion layers, and after sludge with the extremely high content of organic matter or humus on the surface layer is removed, soft foundation treatment can be carried out through a reinforced broken stone cushion layer method, that is, the geogrids are laid in the broken stone cushion layers, and then the soft foundation treatment is carried out through the reinforced broken stone cushion layer method. The method is used for improving foundation bearing capacity, reducing differential settlement and facilitating construction.

Description

TECHNICAL FIELD

[0001] The utility model relates to road engineering technical field more specifically, relate to a kind of soft base section light roadbed structure. BACKGROUND

[0002] Soft soil roadbed refers to a kind of special area roadbed commonly seen. It needs special design and treatment. It is mostly distributed along the coast of river, sea, inland lake, pond, basin and mountainous valley. Soft soil has the characteristics of high water content, poor permeability, low natural strength and high compressibility. If the critical height is exceeded, the foundation will lose stability. Common treatment measures for soft soil foundation include soil replacement, drainage sand cushion, reverse pressure guard road, stone throwing and silt squeezing, cement soil mixing, surface reinforcement with civil engineering fabric and sand well reinforcement, etc.

[0003] Patent No. CN207452609U discloses a thick cushion foam light soil roadbed structure for deep and thick soft foundation road section, which comprises a thick cushion, a foam light soil roadbed and a pavement layer from bottom to top. The thick cushion is laid on the deep and thick soft foundation along the longitudinal direction of the road. The foam light soil roadbed is poured on the thick cushion in layers, and a galvanized steel wire mesh is arranged between every two layers of the foam light soil roadbed. The top surface of the foam light soil roadbed is provided with a pavement layer. A deformation joint is arranged along the longitudinal direction of the foam light soil roadbed. The foam light soil roadbed is surrounded by soil on both sides to form a protective layer. The utility model has the characteristics of strong ability to adapt to uneven settlement, convenient construction and investment saving, and is suitable for deep and thick soft foundation, especially for wide roadbed, and successfully solves the technical problem of uneven settlement of deep and thick soft foundation roadbed.

[0004] However, the foam light soil roadbed on the deep and thick soft soil in Patent No. CN207452609U has obvious "bridge" effect, the intermediate ground reaction force is small, the ground reaction force on both sides is large, and the ground reaction force distribution graph is in the shape of a saddle, so the bending moment and shear force of the roadbed structure are large, and the roadbed is prone to brittle failure. The cushion can reduce the stress concentration of the foundation and adjust the uneven settlement of the roadbed, thereby reducing the tensile stress and shear stress of the roadbed structure. However, for the soft foundation road section with high content of surface organic matter or humus, the use of thick cushion for the base layer leads to low structural strength and small bearing capacity, and is prone to settlement. Therefore, the soft foundation section light roadbed structure is proposed to solve the above problems. UTILITY MODEL CONTENTS

[0005] 1. Technical problem to be solved

[0006] In view of the problems in the prior art, the purpose of the utility model is to provide a soft foundation section light roadbed structure, which can remove the silt with high content of surface organic matter or humus and then use the reinforced gravel cushion method for soft foundation treatment, i.e. lay geotechnical baffle in the gravel cushion to improve the bearing capacity of the foundation, reduce uneven settlement and facilitate construction.

[0007] 2. Technical solution

[0008] To solve the above problems, the utility model adopts the following technical scheme.

[0009] A soft foundation section light roadbed structure, including deep soft soil foundation and foamed light soil roadbed laid on the surface of the deep soft soil foundation, the foamed light soil roadbed is composed of gravel cushion, geogrid, light foamed soil cushion and wire mesh;

[0010] The gravel cushion is laid on the upper surface of the deep soft soil foundation;

[0011] The geogrid is buried in the gravel cushion;

[0012] The light foamed soil cushion is laid on the surface of the gravel cushion, and the light foamed soil cushion is provided with multiple layers;

[0013] The wire mesh is laid between two adjacent light foamed soil cushion layers;

[0014] The top of the foamed light soil roadbed is provided with a drainage slope surface, and the surface of the drainage slope surface is provided with a road surface layer;

[0015] The foamed light soil roadbed is longitudinally provided with expansion joints.

[0016] Further, the foamed light soil roadbed is laid with road shoulder fillings on both sides;

[0017] The slope ratio of the road shoulder filling is 1:1.5, and the thickness of the road shoulder filling is not less than 1m.

[0018] Further, the layer thickness of the gravel cushion is set to 0.7-1m, and each side of the gravel cushion is wider than the deep soft soil foundation by 1m.

[0019] Further, the geogrid is laid with two layers at the bottom of the gravel cushion and 50cm above, and the geogrid of the bottom layer wraps the gravel cushion with an anchoring length of not less than 2.0m.

[0020] Further, the thickness of each layer of the light foamed soil cushion is 0.5m, and a stepped slope is adopted, that is, the width of the later poured layer is less than that of the previous layer, and the slope ratio of the two sides is not less than 1:1.5.

[0021] Further, the design value of the slope of the drainage slope surface is 0.3%-2%.

[0022] Further, the foamed light soil roadbed is provided with one expansion joint every 10m-20m, and the width of the expansion joint is 1cm-2cm.

[0023] 3. Beneficial effects

[0024] Compared with the prior art, the utility model has the advantages that:

[0025] (1) The scheme can remove the silt with high content of surface organic matter or humus in the deep soft soil foundation, and then use the reinforced gravel cushion method to process the soft foundation, that is, lay the geogrid in the gravel cushion to improve the foundation bearing capacity, reduce the uneven settlement and facilitate the construction.

[0026] (2) The foam light soil roadbed on the deep soft soil foundation has obvious "bridging" effect, the intermediate ground reaction force is small, the two sides are large, the ground reaction force distribution diagram is saddle-shaped, so the bending moment and shear force of the roadbed structure are large, and the roadbed is easy to be broken in brittleness; the cushion can reduce the stress concentration of the foundation and adjust the uneven settlement of the roadbed, thereby reducing the tensile stress and shear stress of the roadbed structure. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a three-dimensional structural schematic view of the utility model;

[0028] Figure 2 It is a side view schematic view of the foam light soil roadbed of the utility model;

[0029] Figure 3 It is a cross-sectional view schematic view of the foam light soil roadbed A-A of the utility model;

[0030] Figure 4 It is a cross-sectional view schematic view of the foam light soil roadbed of the utility model.

[0031] Explanation of reference numerals in the drawing:

[0032] 1, deep soft soil foundation; 2, foam light soil roadbed; 3, gravel cushion; 4, geogrid; 5, light foam soil cushion; 6, steel mesh; 7, shoulder fill; 8, drainage slope; 9, expansion joint. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model; obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments; based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model.

[0034] Embodiment:

[0035] Please refer toFigures 1-4 A soft foundation section light roadbed structure, comprising a deep soft soil foundation 1 and a foamed light soil roadbed 2 laid on the surface of the deep soft soil foundation 1, wherein the foamed light soil roadbed 2 is composed of a gravel cushion 3, a geogrid 4, a light foamed soil cushion 5 and a steel wire mesh 6;

[0036] The gravel cushion 3 is laid on the upper surface of the deep soft soil foundation 1;

[0037] The geogrid 4 is embedded in the gravel cushion 3;

[0038] The light foamed soil cushion 5 is laid on the surface of the gravel cushion 3, and the light foamed soil cushion 5 is provided with multiple layers;

[0039] The steel wire mesh 6 is laid between two adjacent layers of the light foamed soil cushion 5;

[0040] The top of the foamed light soil roadbed 2 is provided with a drainage slope 8, and the surface of the drainage slope 8 is provided with a road surface layer;

[0041] The foamed light soil roadbed 2 is longitudinally provided with expansion joints 9;

[0042] The layer thickness of the gravel cushion 3 is set to be 0.7-1m, and the gravel cushion 3 is wider than the deep soft soil foundation 1 by 1m on each side;

[0043] The geogrid 4 is laid in two layers at the bottom of the gravel cushion 3 and above 50cm, and the bottom layer of the geogrid 4 wraps the gravel cushion 3 with an anchoring length of not less than 2.0m;

[0044] The thickness of each layer of the light foamed soil cushion 5 is 0.5m, and a step slope is adopted, that is, the width of a later poured layer is smaller than that of a previous layer, and the slope rate of the two side steps is not less than 1:1.5;

[0045] The foamed light soil roadbed 2 on the deep soft soil foundation 1 has a clear "bridging" effect, the ground reaction force is small in the middle and large on both sides, the ground reaction force distribution diagram is saddle-shaped, so the bending moment and shear force of the roadbed structure are large, and the roadbed is prone to brittle failure; the cushion can reduce the stress concentration of the foundation and adjust the uneven settlement of the roadbed, thereby reducing the tensile stress and shear stress of the roadbed structure;

[0046] For the case of the deep soft soil foundation 1 with a high content of surface organic matter or humus, the surface organic matter or humus with a high content of silt can be removed, and a reinforced gravel cushion method is used for soft foundation treatment, that is, the geogrid 4 is laid in the gravel cushion 3 to improve the bearing capacity of the foundation, reduce uneven settlement and facilitate construction, and the road section treated by this method must ensure a certain pre-compaction period

[0047] Both sides of the foam light soil subgrade 2 are paved with shoulder fill 7;

[0048] The slope ratio of the shoulder fill 7 is 1:1.5, and the thickness of the shoulder fill 7 is not less than 1m.

[0049] The design value of the slope of the drainage slope surface 8 is 0.3%-2%.

[0050] The foam light soil subgrade 2 is provided with a expansion joint 9 every 10m-20m, and the width of the expansion joint 9 is 1cm-2cm.

[0051] The construction method of the thick cushion foam light soil subgrade structure of the deep and thick soft foundation road section comprises the following steps:

[0052] 1. The construction site is cleaned and leveled, and branches and silt in the site are removed. Before the cushion construction, there is no obvious accumulated water and no soft soil in the basement, and the basement is accepted after being qualified. Then the gravel cushion 3 is paved according to the design requirements.

[0053] 2. The geogrid 4 is paved in two layers at the bottom of the gravel cushion 3 and above 50cm, and the anchor length of the geogrid 4 in the bottom layer wrapping the gravel cushion 3 is not less than 2.0m.

[0054] 3. The lateral baffle and the sectional formwork are installed. The foam light soil subgrade is poured in sections, zones and layers. The light foam soil cushion 5 is poured on the gravel cushion 3 in layers, and the thickness of each layer is 0.5m. The step slope is adopted, that is, the width of the later poured layer is smaller than that of the previous layer, and the slope ratio of the two side steps is not less than 1:1.5. The length of the longitudinal section is 10m-20m, and the temporary formwork is used between the adjacent longitudinal pouring sections. The 1-2cm thick foam plastic plate is laid behind the formwork. After the strength reaches the demolding strength, the temporary formwork is removed, and the foam plastic plate is left as a deformation joint. The deformation joint must be vertical. A layer of steel mesh 6 is laid after each layer of foam light soil is poured. The steel mesh 6 must be disconnected at the expansion joint 9. The next layer is poured before the light foam soil cushion 5 of the previous layer is initially set. The surface of the uppermost light foam soil cushion 5 is provided with a drainage slope surface 8, and the design value of the slope of the drainage slope surface 8 is 0.3%-2%.

[0055] 4. After the light foam soil cushion 5 reaches the design strength and is accepted, the shoulder fill 7 forms a protective layer. The thickness of the shoulder fill 7 is not less than 1m, and the slope ratio is 1:1.5.

[0056] 5. The road surface layer and other auxiliary facilities are constructed.

[0057] The above merely describes a preferred embodiment of the present application; the scope of protection of the present application is not limited thereto. Any skilled person in the art, according to the technical scheme and improvement concept of the present application, makes equivalent replacement or change within the technical range disclosed by the present application, which should be covered in the scope of protection of the present application.

Claims

1. A soft foundation section light subgrade structure comprising a deep soft soil foundation (1) and a foamed light soil subgrade (2) laid on the surface of the deep soft soil foundation (1), characterized in that: The foam light soil roadbed (2) is composed of a gravel cushion (3), a geogrid (4), a light foam soil cushion (5) and a steel mesh (6); The gravel cushion (3) is laid on the upper surface of the deep thick soft soil foundation (1); The geogrid (4) is embedded in the gravel cushion (3); The light foam soil cushion (5) is laid on the surface of the gravel cushion (3), and the light foam soil cushion (5) is provided with multiple layers; The steel mesh (6) is laid between two adjacent light foam soil cushion (5) layers; The top of the foam light soil roadbed (2) is provided with a drainage slope (8), and the surface of the drainage slope (8) is provided with a pavement layer; The foam light soil roadbed (2) is longitudinally provided with a contraction joint (9).

2. The soft ground segmental lightweight roadbed structure according to claim 1, wherein: Both sides of the foam light soil roadbed (2) are laid with a road shoulder fill (7); The slope ratio of the road shoulder fill (7) is 1:1.5, and the thickness of the road shoulder fill (7) is not less than 1m.

3. The soft ground segmental lightweight roadbed structure according to claim 1, wherein: The layer thickness of the gravel cushion (3) is set to 0.7-1m, and each side of the gravel cushion (3) is wider than the deep thick soft soil foundation by 1m.

4. The soft ground segmental lightweight roadbed structure according to claim 1, wherein: The geogrid (4) is laid in two layers at the bottom of the gravel cushion (3) and 50cm above, and the geogrid (4) of the bottom layer wraps the gravel cushion (3) with an anchoring length of not less than 2.0m.

5. The soft ground segmental lightweight roadbed structure according to claim 1, wherein: The thickness of each layer of the light foam soil cushion (5) is 0.5m, and a step slope is adopted, that is, the width of the post-poured layer is smaller than that of the previous layer, and the slope rate of the two side steps is not less than 1:1.

5.

6. The soft ground segmental lightweight roadbed structure according to claim 1, wherein: The design value of the slope of the drainage slope (8) is 0.3%-2%.

7. The soft ground segmental lightweight roadbed structure according to claim 1, wherein: The foam light soil roadbed (2) is provided with one contraction joint (9) every 10m-20m, and the width of the contraction joint (9) is 1cm-2cm.

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