Improved mudstone mixed soil composite anti-freezing roadbed structure

Abstract

The utility model discloses an improved mudstone mixed soil composite anti-freezing roadbed structure which comprises a soil base, a mudstone mixed soil filler layer, a hydrophobic layer, a cement stabilized macadam base layer and a surface layer which are sequentially laid from bottom to top, and a central separation zone and a road shoulder which are made of mudstone mixed soil are correspondingly arranged on the two sides of the cement stabilized macadam base layer and the two sides of the surface layer; a wicking geotextile drainage layer is laid in the mudstone mixed soil filler layer. And the moisture content of the mudstone mixed soil filler layer is + / -2% of the optimal moisture content. And the compaction degree of the mudstone mixed soil filler layer is greater than or equal to 96%. The mudstone mixed soil filler layer is formed by mixing mudstone, silty clay and lime. The hydrophobic layer is formed by mixing a hydrophobic material and silty clay. The wicking geotextile drainage layer is arranged at the position 0.8 m below the bottom face of the cement stabilized macadam base layer. And the wicking geotextile drainage layer is a geotextile containing wicking fibers. And roadbed disasters caused by water freezing and thawing are effectively reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of roadbed structures and relates to an improved mudstone mixed soil composite antifreeze roadbed structure. Background Art

[0002] Mixed soil is a mixture of two or more types of soil. Its complex composition makes it difficult to use in engineering construction. With the advancement of tunnel excavation and foundation pit excavation, a large amount of mixed soil is formed and piled up or discarded as construction solid waste. Due to urban foundation pit excavation and subway tunnel excavation, mudstone and silty clay exist in the excavated strata, which are accumulated on the surface after excavation, forming a unique mudstone mixed soil of mudstone particles and silty clay. The Cretaceous mudstone foundation in Changchun will soften when it encounters water, resulting in a significant decrease in strength and an increase in deformation; and Changchun is located in a seasonally frozen area. The mudstone mixed soil will undergo significant water migration during the frequent freezing and thawing cycles, thereby changing the moisture distribution and pore structure of the roadbed fill, which in turn leads to a serious decrease in the bearing capacity of the roadbed, causing serious settlement and deformation of the roadbed, posing a serious hidden danger to road safety. Summary of the invention

[0003] The purpose of the embodiments of the utility model is to provide an improved mudstone mixed soil composite antifreeze roadbed structure to solve the problem of resource utilization of construction solid waste such as mudstone mixed soil with poor stability and low engineering application value, as well as the problem of significant water migration inside the roadbed in cold regions during frequent freezing and thawing cycles, resulting in serious settlement and deformation of the roadbed.

[0004] The technical solution adopted in the embodiment of the utility model is: an improved mudstone mixed soil composite antifreeze roadbed structure, including a soil base, a mudstone mixed soil filling layer, a hydrophobic layer, a cement stabilized crushed stone base layer and a surface layer laid in sequence from bottom to top, wherein:

[0005] The cement stabilized gravel base and the surface layer are provided with a central dividing strip and shoulders composed of mudstone mixed soil on both sides;

[0006] A core-absorbing geotextile drainage layer is laid in the mudstone mixed soil filling layer.

[0007] Furthermore, the moisture content of the mudstone mixed soil filling layer is ±2% of the optimum moisture content.

[0008] Furthermore, the compaction degree of the mudstone mixed soil filling layer is greater than or equal to 96%.

[0009] Furthermore, the mudstone mixed soil filling layer is composed of a mixture of mudstone, silty clay and lime.

[0010] Furthermore, the hydrophobic layer is composed of a mixture of hydrophobic material and silty clay.

[0011] Furthermore, the wicking geotextile drainage layer is arranged 0.8 m below the bottom surface of the cement-stabilized crushed stone base layer.

[0012] Furthermore, the wicking geotextile drainage layer is a geotextile containing wicking fibers.

[0013] Furthermore, the wicking geotextile drainage layer is woven from a first layer of weft yarns, a second layer of weft yarns, wicking fibers along a weaving direction, and warp yarns.

[0014] Furthermore, the surface layer is an asphalt concrete surface layer.

[0015] The beneficial effects of the embodiments of the utility model are:

[0016] 1. The wicking geotextile is used as a drainage layer and laid inside the mudstone mixed soil filling layer. The optimal position of the wicking geotextile drainage layer is determined, and a mixture of hydrophobic material and clay is used as a hydrophobic layer and laid on the top of the mudstone mixed soil filling layer to ensure that the roadbed working area is in a dry or medium-wet state, effectively control the water content of the roadbed, reduce the roadbed disasters caused by water freezing and thawing, and solve the problem of significant water migration inside the cold area roadbed during frequent freezing and thawing cycles, resulting in serious settlement and deformation of the roadbed. There is no need to increase the roadbed height to avoid the roadbed working area being in a high water content state, which effectively reduces the height of the roadbed structure and improves the roadbed stability;

[0017] 2. The improved mudstone mixed soil is used to pave the filling layer of the roadbed, which improves the stability and engineering application value of the mudstone mixed soil, and solves the problem of resource utilization of construction solid waste such as mudstone mixed soil with poor stability and low engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a structural schematic diagram of an improved mudstone mixed soil composite antifreeze roadbed structure of this embodiment.

[0020] Figure 2 Schematic diagram of the structure of the wicking geotextile drainage layer of this embodiment.

[0021] In the figure, 1. soil base, 2. mudstone mixed soil filling layer, 3. hydrophobic layer, 4. cement stabilized gravel base layer, 5. surface layer, 6. wicking geotextile drainage layer. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] This embodiment provides an improved mudstone mixed soil composite antifreeze roadbed structure, such as Figure 1 As shown, it includes a soil base 1, a mudstone mixed soil filling layer 2, a hydrophobic layer 3, a cement stabilized crushed stone base layer 4 and a surface layer 5 which are laid in sequence from bottom to top, wherein:

[0024] The cement stabilized gravel base layer 4 and the surface layer 5 are provided with a central dividing strip and shoulders composed of mudstone mixed soil on both sides;

[0025] A wicking geotextile drainage layer 6 is laid in the mudstone mixed soil filling layer 2 .

[0026] The soil base 1 bears the deadweight of the roadbed and pavement structure as well as the traffic load from the road surface, and diffuses the load received. The mudstone mixed soil filling layer 2 has high strength and the ability to resist deformation. After paving and compaction, it bears the static and dynamic loads of vehicles or road surfaces and traffic loads, and at the same time transfers and diffuses the loads deep into the foundation. The hydrophobic layer 3 can prevent surface water from penetrating into the roadbed, alleviating the phenomenon of excessive moisture content inside the roadbed. The cement stabilized gravel base layer 4 and the surface layer 5 are laid in layers on the roadbed to bear the vehicle load. The wicking geotextile drainage layer 6 can effectively reduce the moisture inside the roadbed, disperse the traffic load stress borne by the roadbed, and enhance the stability and durability of the roadbed.

[0027] In some embodiments, the mudstone mixed soil filling layer 2 is composed of a mixture of mudstone, silty clay, and lime, which improves the stability and engineering application value of the mudstone mixed soil. The rebound modulus test results show that the improved mudstone mixed soil filling layer 2 has a strong dynamic rebound modulus value.

[0028] In some embodiments, the moisture content of the mudstone-mixed soil filling layer 2 is within the range of the optimum moisture content (12.9%) ±2%, and the compaction degree of the mudstone-mixed soil filling layer 2 is greater than or equal to 96%.

[0029] In some embodiments, the hydrophobic layer 3 is composed of a mixture of hydrophobic material and silty clay, which has the hydrophobic properties of the hydrophobic material and can block the penetration of surface water flow and drain it to the roadbed slope.

[0030] In some embodiments, the surface layer 5 is an asphalt concrete surface layer.

[0031] In some embodiments, the optimal embedding depth of the wicking geotextile drainage layer 6 is located at the junction of the roadbed and the embankment, that is, 0.8 m below the top surface of the roadbed (the bottom surface of the cement-stabilized crushed stone base layer 4).

[0032] In some embodiments, the wicking geotextile drainage layer 6 is a geotextile containing wicking fibers, such as Figure 2 As shown, it is woven from a first layer of weft yarn, a second layer of weft yarn, wicking fibers along the weaving direction, and warp yarns, wherein the weft yarn is a high-strength ribbon composed of polyethylene and polypropylene, and the wicking fiber is a multifilament deep groove (4DG) nylon material.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. An improved mudstone mixed soil composite antifreeze roadbed structure, characterized in that: The invention comprises a soil base (1), a mudstone mixed soil filling layer (2), a hydrophobic layer (3), a cement stabilized crushed stone base layer (4) and a surface layer (5) which are laid in sequence from bottom to top, wherein: A central dividing strip and a shoulder composed of mudstone mixed soil are provided on both sides of the cement-stabilized crushed stone base layer (4) and the surface layer (5); A wicking geotextile drainage layer (6) is laid in the mudstone mixed soil filling layer (2).

2. The improved mudstone mixed soil composite antifreeze roadbed structure according to claim 1, characterized in that: The moisture content of the mudstone mixed soil filling layer (2) is the optimum moisture content ±2%.

3. The improved mudstone mixed soil composite antifreeze roadbed structure according to claim 1 is characterized in that: The compaction degree of the mudstone mixed soil filling layer (2) is greater than or equal to 96%.

4. The improved mudstone mixed soil composite antifreeze roadbed structure according to any one of claims 1 to 3, characterized in that: The wicking geotextile drainage layer (6) is arranged 0.8 m below the bottom surface of the cement-stabilized crushed stone base layer (4).

5. The improved mudstone mixed soil composite antifreeze roadbed structure according to any one of claims 1 to 3, characterized in that: The wicking geotextile drainage layer (6) is a geotextile containing wicking fibers.

6. The improved mudstone mixed soil composite antifreeze roadbed structure according to claim 5, characterized in that: The wicking geotextile drainage layer (6) is woven from a first layer of weft yarns, a second layer of weft yarns, wicking fibers along a weaving direction, and warp yarns.

7. The improved mudstone mixed soil composite antifreeze roadbed structure according to any one of claims 1 to 3 or 6, characterized in that: The surface layer (5) is an asphalt concrete surface layer.

Images