Soft soil roadbed structure based on foam concrete

Abstract

The utility model discloses a soft soil roadbed structure based on foam concrete, which comprises a soft soil base layer, a roadbed groove body is arranged on the soft soil base layer, a pretreatment layer is arranged at the inner bottom of the roadbed groove body, and a foam concrete functional layer is arranged at the top of the pretreatment layer. A first geogrid is arranged between the foam concrete functional layer and the pretreatment layer, a second geogrid is arranged between the foam concrete functional layer and the pretreatment layer, a stiffening transition layer is installed on the top of the foam concrete functional layer, and through the arrangement of the anchor rod assembly, the first geogrid can be matched with a plurality of sets of connecting anchor rods; a bridge effect is achieved between the foam concrete functional layer and the pretreatment layer and between the anchored soft soil base layer and the stiffening transition layer, loads are transmitted to the anchor rods through the stiffening transition layer, then stress is dispersed to the deep-layer stable foundation through the anchor rods, an upper-pulling and lower-anchoring cooperative stress system is formed, stress of different layers is effectively transmitted and dispersed, and the stability of the foundation is improved. Therefore, the foam concrete layer is prevented from sliding.

Description

TECHNICAL FIELD

[0001] The utility model relates to soft soil roadbed technical field, concretely is a kind of soft soil roadbed structure based on foam concrete. BACKGROUND

[0002] Affected by geological conditions, in the process of road engineering construction in lake, coastal and other areas, soft soil roadbed is often encountered, and soft soil roadbed has the characteristics of high water content, poor permeability, low natural strength, high compressibility and poor shear resistance, so the strength and stability of the roadbed are relatively low, and the geological conditions are relatively complex, so the requirements for soft soil foundation engineering construction are higher, and the stability of the foundation is directly related to the durability and safety of the project.

[0003] For example, a kind of soft soil roadbed structure ((publication number: CN220013247U)), including soft soil base layer;Soft soil base layer: its inside is uniformly provided with embedded hole, the inside of embedded hole is placed with concrete pipe pile, the gap between the outer arc surface of concrete pipe pile and the inner wall surface of adjacent embedded hole is filled with gravel block, the inside of concrete pipe pile is filled with gravel soil, the upper end of soft soil base layer is provided with clean slag cushion layer, the upper end of clean slag cushion layer is provided with composite geotextile, the upper end of composite geotextile is provided with foam concrete layer, the upper end of foam concrete layer is provided with reinforced concrete slab, the outer arc surface upper side of concrete pipe pile is provided with connecting plate, the inside of connecting plate is provided with grouting pipe, the outer arc surface lower side of grouting pipe is provided with slurry outlet hole, the soft soil roadbed structure, the installation stability of concrete pipe pile is good, the connection tightness between concrete pipe pile and soft soil base layer is higher, the anti-settling effect is good, and the application range is wide.

[0004] Based on the above patent search, and combined with the equipment in the prior art, the above-mentioned equipment lacks anti-slippage structure for the foam concrete layer when applied, and the foam concrete layer, soft soil base layer, clean slag cushion layer, composite geotextile and reinforced concrete slab are directly laid, the material properties, thermal expansion coefficient and deformation characteristics of the foam concrete and clean slag cushion layer and reinforced concrete slab may differ, and interlayer slippage may occur due to temperature changes or load effects, so we need to propose a soft soil roadbed structure based on foam concrete. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing a kind of soft soil roadbed structure based on foam concrete, through the setting of anchor rod assembly, the stress of different layers can be effectively transmitted and dispersed by the cooperation of first geogrid and several groups of connecting anchor rod, which plays a bridge role between foam concrete functional layer and pretreatment layer, anchor into soft soil base layer and stiffened transition layer, to prevent the slippage of foam concrete layer, to solve the problems raised in the above background technology.

[0006] To achieve the above object, the utility model provides the following technical scheme:

[0007] A soft soil subgrade structure based on foam concrete, including soft soil base layer, the soft soil base layer is provided with subgrade groove body, the inner bottom of subgrade groove body is equipped with pretreatment layer, the top of pretreatment layer is installed with foam concrete function layer, the second geogrid is arranged between foam concrete function layer and pretreatment layer, the top of foam concrete function layer is installed with stiff transition layer, and the anti -skidding anchor rod assembly is equipped between stiff transition layer and foam concrete function layer.

[0008] Preferably, the pretreatment layer includes an aggregate bottom layer, which is arranged on the inner bottom of the subgrade groove body, a long-fiber geotextile layer on the top of the aggregate bottom layer, and a water-permeable cushion layer on the top of the long-fiber geotextile layer.

[0009] Preferably, the aggregate bottom layer is composed of building waste broken materials and laid on the bottom of the subgrade groove body, and the water-permeable cushion layer is composed of a graded gravel layer and laid on the top of the long-fiber geotextile layer and formed by vibration rolling, with a particle size range of 5-40 mm.

[0010] Preferably, the foam concrete function layer is composed of a top foam concrete high-strength layer and a bottom foam concrete buffer layer.

[0011] Preferably, the bottom foam concrete buffer layer is composed of a plurality of groups of prefabricated foam concrete modules arranged at equal intervals, 20 mm deformation joints are reserved between two adjacent groups of prefabricated foam concrete modules and filled with polyurethane sealant, and a drainage blind ditch is arranged below the polyurethane sealant.

[0012] Preferably, the anchor rod assembly includes a first geogrid installed between the top foam concrete high-strength layer and the stiff transition layer, a plurality of groups of connecting anchor rods arranged in a rectangular array on the first geogrid, the bottoms of the plurality of groups of connecting anchor rods penetrating the foam concrete function layer and the pretreatment layer and anchored into the inside of the soft soil base layer, and the tops of the plurality of groups of connecting anchor rods extending into the inside of the stiff transition layer.

[0013] Preferably, the top of the connecting anchor rod is provided with a 90° hook, and the 90° hook of the connecting anchor rod is fixedly bound with the first geogrid.

[0014] Preferably, a plurality of groups of water-permeable rods are inserted into the water-permeable cushion layer at equal intervals, the tops of the plurality of groups of water-permeable rods penetrating the second geogrid and extending into the inside of the drainage blind ditch, and the bottoms of the plurality of groups of water-permeable rods penetrating the long-fiber geotextile layer and the aggregate bottom layer and extending into the soft soil base layer.

[0015] Compared with the prior art, the utility model has the advantages that:

[0016] The utility model discloses through the setting of anchor rod subassembly, can through the cooperation of first geogrid and several groups of connecting anchor rod, play the bridge function between foam concrete function layer and pretreatment layer, anchor into soft soil base layer and stiffened transition layer, load is passed through stiffened transition layer and is delivered to anchor rod, and then stress is dispersed to deep stable foundation by anchor rod, forms the collaborative stress system of " upper pull down anchor", effectively transmits and disperses the stress of different layers to prevent the slippage of foam concrete layer. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is the side view three-dimensional structure schematic diagram of the utility model;

[0018] Figure 2 It is the structure schematic diagram of the utility model explosion;

[0019] Figure 3 It is the structure schematic diagram of pretreatment layer and foam concrete function layer of the utility model;

[0020] Figure 4 It is the structure schematic diagram of pretreatment layer and water permeable stick of the utility model.

[0021] In the drawing: 1, soft soil base layer;2, pretreatment layer;21, aggregate bottom layer;22, filament geotextile layer;23, water permeable cushion layer;3, foam concrete function layer;31, top foam concrete high strength layer;32, bottom foam concrete buffer layer;33, polyurethane sealant;34, drainage blind ditch;4, stiffened transition layer;5, anchor rod subassembly;51, first geogrid;52, connecting anchor rod;6, water permeable stick;7, second geogrid. DETAILED DESCRIPTION

[0022] The technical scheme in the embodiments of the utility model will be apparently and completely described in combination with the drawings in the embodiments of the utility model, and 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 the person skilled in the art without making creative labor belong to the range of protection of the utility model.

[0023] Please refer to Figures 1-4 The utility model provides a technical scheme:

[0024] A kind of soft soil subgrade structure based on foam concrete, including soft soil base layer 1, soft soil base layer 1 is opened with subgrade slot body, the excavation depth of subgrade slot body can be dynamically adjusted (1.5-2 times design subgrade height), adapt to different soft soil thickness working condition, the inner bottom of subgrade slot body is equipped with pretreatment layer 2, the top of pretreatment layer 2 is equipped with foam concrete functional layer 3, second geogrid 7 is arranged between foam concrete functional layer 3 and pretreatment layer 2, second geogrid 7 enhances interlayer shear strength (≥40kPa), avoid foam concrete layer and pretreatment layer dislocation, the top of foam concrete functional layer 3 is equipped with stiff transition layer 4, and there is anchor rod assembly 5 between stiff transition layer 4 and foam concrete functional layer 3.

[0025] Further, pretreatment layer 2 includes aggregate bottom layer 21, aggregate bottom layer 21 is arranged on the inner bottom of subgrade slot body, the top of aggregate bottom layer 21 is equipped with long filament geotextile layer 22, the top of long filament geotextile layer 22 is equipped with water-permeable mat layer 23.

[0026] Aggregate bottom layer 21 is made of construction waste broken material, is laid on the bottom of subgrade slot body, realizes soft soil replacement and preliminary promotion of bearing capacity, construction waste utilization rate ≥90%, reduces natural aggregate consumption, water-permeable mat layer 23 is made of graded gravel layer, is laid on the top of long filament geotextile layer 22 and is formed by vibration compaction, and the particle size range is 5-40mm.

[0027] Long filament geotextile layer 22: 400g / m² specification bidirectional isolation layer, equivalent aperture O 95 ≤0.08mm, prevents fine particle migration, prevents soft soil particles from entering water-permeable mat layer, avoids drainage system blockage, and graded gravel (Cu=15-20, Cc=1-3) in water-permeable mat layer 23 forms horizontal drainage channel, and the permeability coefficient is ≥1×10⁻² cm / s, guides and drains foam concrete layer seepage, and reduces the risk of rising groundwater level.

[0028] Foam concrete functional layer 3 is composed of top foam concrete high-strength layer 31 and bottom foam concrete buffer layer 32.

[0029] Aggregate bottom layer 21: construction waste broken material compaction degree ≥93% (heavy compaction standard), CBR ≥15%;

[0030] Water-permeable mat layer 23: layered compaction (each layer virtual paving thickness ≤300mm), flat vibration compaction, compaction degree ≥96%, and the continuous grading of particle size 5-40mm ensures the balance of water permeability and bearing capacity.

[0031] The bottom foam concrete buffer layer 32 is composed of a plurality of groups of prefabricated foam concrete modules arranged at equal intervals, and a 20mm deformation joint is reserved between adjacent two groups of prefabricated foam concrete modules and filled with polyurethane sealant 33, and the bottom foam concrete buffer layer 32 is provided below the polyurethane sealant 33 with a drainage blind ditch 34.

[0032] The top foam concrete high-strength layer 31 has a density of 800-1000kg / m³, 0.5% nano-SiO2 is added, and the 28d compressive strength is ≥3.0MPa.

[0033] The bottom foam concrete buffer layer 32 has a density of 400-600kg / m³, a porosity of ≥60%, is a prefabricated module, the high-strength layer bears the vehicle load, the buffer layer absorbs the soft soil creep deformation, the interlayer stress difference is reduced by 50%, the prefabricated module improves the assembly efficiency compared with cast-in-place, the drainage blind ditch 34 and the water permeable rod 6 form a three-dimensional drainage network, and the saturated water content is reduced to below 25%.

[0034] The anchor rod assembly 5 includes a first geogrid 51 installed between the top foam concrete high-strength layer 31 and the stiffening transition layer 4, a plurality of groups of connecting anchor rods 52 arranged in a rectangular array on the first geogrid 51, the bottoms of the plurality of groups of connecting anchor rods 52 penetrating the foam concrete functional layer 3 and the pretreatment layer 2 and anchored into the inside of the soft soil base layer 1, and the tops of the plurality of groups of connecting anchor rods 52 extending into the inside of the stiffening transition layer 4.

[0035] The connecting anchor rod 52 is a Φ12 threaded steel bar (HRB400) with a spacing of 1m×1m, and the anchoring depth of the connecting anchor rod 52 is ≥300mm at the bottom into the soft soil base layer 1 and ≥200mm at the top into the stiffening transition layer 4.

[0036] The connecting anchor rod 52 and the first geogrid 51 form a spatial grid framework to improve the overall rigidity of the roadbed.

[0037] The top of the connecting anchor rod 52 is provided with a 90° hook, and the 90° hook of the connecting anchor rod 52 is fixedly bound with the first geogrid 51.

[0038] A plurality of groups of water permeable rods 6 are inserted into the water permeable cushion layer 23 at equal intervals, the tops of the plurality of groups of water permeable rods 6 penetrate the second geogrid 7 and extend into the inside of the drainage blind ditch 34, and the bottoms of the plurality of groups of water permeable rods 6 penetrate the long-fiber geotextile layer 22 and the aggregate bottom layer 21 and extend into the soft soil base layer 1.

[0039] The water permeable rod 6 is a φ75 water permeable concrete prefabricated pipe wrapped with 200g / m² needle-punched geotextile (equivalent pore size O 90 ≤0.1mm), and the geotextile outer layer prevents fine particles from entering the water permeable rod.

[0040] Working principle: the aggregate bottom layer 21 is paved by building waste crushing material to form a rough interface, increase the friction with the soft soil base 1, and provide an initial drainage channel at the same time, the filament geotextile layer 22: as a filter layer, intercepts small particles with water loss, maintains the stability of the aggregate layer structure, the water-permeable cushion layer 23: graded gravel is formed into a dense framework by vibration rolling, further promotes the transverse discharge of free water, and the 5-40mm particle size range ensures the balance between water permeability and strength;

[0041] The foam concrete functional layer 3: hierarchical bearing and deformation control

[0042] The buffer layer 32 is spliced by using prefabricated modules, the 20mm deformation joint between the modules is filled with polyurethane sealant 33, the small displacement generated by the soft soil creep is adapted, the structure cracking is avoided, the bottom drainage blind ditch 34 is communicated with the water-permeable rod 6, a longitudinal drainage channel is formed, the pore water pressure accumulation is eliminated, and the high-strength layer 31 provides a direct bearing surface.

[0043] After the connection between the top 90° hook of the anchor rod 52 and the first geogrid 51 is bound in the anchor rod assembly 5, the anchor rod assembly 5 penetrates the foam concrete functional layer 3 and the pretreatment layer 2, and is anchored into the soft soil base 1 to form a deep engagement, the anchor rod arranged in a rectangular array (spacing ≤1m) produces a group anchor effect, and limits the vertical peeling of the foam concrete functional layer 3 and the soft soil base 1.

[0044] Although the embodiments of the utility model have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the utility model, and the scope of the utility model is defined by the appended claims and their equivalents.

Claims

1. A foamed concrete based soft soil subgrade structure, characterized by, Include: Soft soil base (1); The soft soil base (1) is provided with a roadbed groove body, the inner bottom of the roadbed groove body is provided with a pretreatment layer (2), the top of the pretreatment layer (2) is provided with a foam concrete functional layer (3), the foam concrete functional layer (3) and the pretreatment layer (2) are provided with a second geogrid (7), the top of the foam concrete functional layer (3) is provided with a reinforced transition layer (4), and the reinforced transition layer (4) and the foam concrete functional layer (3) are provided with an anti-skid anchor rod assembly (5).

2. A foamed concrete based soft soil subgrade structure according to claim 1, characterized in that: The pretreatment layer (2) comprises an aggregate bottom layer (21), the aggregate bottom layer (21) is arranged on the inner bottom of the roadbed groove body, the top of the aggregate bottom layer (21) is provided with a filament geotextile layer (22), and the top of the filament geotextile layer (22) is provided with a water-permeable cushion layer (23).

3. A foamed concrete based soft soil subgrade structure according to claim 2, characterised in that: The aggregate bottom layer (21) is composed of building waste broken materials and is laid on the bottom of the roadbed groove body, the water-permeable cushion layer (23) is composed of a graded gravel layer and is laid on the top of the filament geotextile layer (22) and is formed by vibration rolling, and the particle size range is 5-40 mm.

4. A foamed concrete based soft soil subgrade structure according to claim 2, characterized in that: The foam concrete functional layer (3) is composed of a top foam concrete high-strength layer (31) and a bottom foam concrete buffer layer (32).

5. A foamed concrete based soft soil subgrade structure according to claim 4, characterised in that: The bottom foam concrete buffer layer (32) is composed of a plurality of groups of prefabricated foam concrete modules arranged at equal intervals, 20mm deformation joints are reserved between adjacent two groups of prefabricated foam concrete modules and are filled with polyurethane sealant (33), and the bottom foam concrete buffer layer (32) is provided below the polyurethane sealant (33) with a drainage blind ditch (34).

6. A foamed concrete based soft soil subgrade structure according to claim 1, characterized by: The anchor rod assembly (5) comprises a first geogrid (51), the first geogrid (51) is arranged between the top foam concrete high-strength layer (31) and the reinforced transition layer (4), a plurality of groups of connecting anchor rods (52) are arranged on the first geogrid (51) in a rectangular array, the bottoms of the plurality of groups of connecting anchor rods (52) penetrate the foam concrete functional layer (3) and the pretreatment layer (2) and are anchored into the soft soil base (1), and the tops of the plurality of groups of connecting anchor rods (52) extend into the inside of the reinforced transition layer (4).

7. A foamed concrete based soft soil subgrade structure according to claim 6, characterised in that: The top of the connecting anchor rod (52) is provided with a 90° hook, and the 90° hook of the connecting anchor rod (52) is fixedly bound with the first geogrid (51).

8. A foamed concrete based soft soil subgrade structure according to claim 4, characterized by: A plurality of groups of water-permeable rods (6) are inserted into the water-permeable cushion layer (23) at equal intervals, the tops of the plurality of groups of water-permeable rods (6) penetrate the second geogrid (7) and extend into the inside of the drainage blind ditch (34), and the bottoms of the plurality of groups of water-permeable rods (6) penetrate the filament geotextile layer (22) and the aggregate bottom layer (21) and extend into the soft soil base (1).

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