Road structure suitable for valley terrain
By using a combination of EPS infill blocks and reinforced concrete structures in gully terrain, the problems of poor bearing capacity and drainage in soft soil foundations were solved, thereby improving the stability of the road structure and construction efficiency.
Patent Information
- Application Number
- CN202422924196.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-29
- Publication Date
- 2025-11-04
- Estimated Expiration
- 2034-11-29
AI Technical Summary
The soft soil foundation in the valley has poor bearing capacity, which leads to uneven settlement of the road structure and poor drainage.
The road structure consists of EPS filler blocks, cement concrete piles, sand cushion layers, cement concrete slabs, waterproof geotextiles, cement concrete walls, geocells, and culverts. Multiple rows of culverts and sand cushion layers are combined with EPS filler blocks to reduce the self-weight of the roadbed. Reinforced concrete is used to construct the structure and waterproof structural layer to ensure smooth drainage and roadbed stability.
It effectively reduced roadbed settlement and lateral slippage, improved the stability and construction efficiency of roads in valley terrain, and reduced project costs.
Smart Images
Figure CN223510227U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of highway bridge and culvert construction technology, specifically a road structure suitable for valley terrain. Background Technology
[0002] Gullyon topography is a specific landform, typically a narrow valley formed by river erosion. As rivers flow, they erode the riverbed and banks, creating narrow gullies. The cross-section of a gully typically presents a steep, narrow V-shape, with a very pronounced slope break on either side. Its longitudinal section is significantly different from the surrounding slope, generally exhibiting a concave curve that slopes gently downwards. Gullyon topography presents unique challenges in soft soil foundation treatment, posing a significant technical challenge in mountain highway construction. Due to the substantial differences in soil composition between the transverse and longitudinal directions, appropriate treatment methods must be selected based on the specific conditions of each road section to ensure the stability and safety of the foundation and prevent geological disasters such as landslides.
[0003] Expanded polystyrene (EPS) foam is a lightweight polymer made from expanded polystyrene granules. It is produced by adding a foaming agent to polystyrene resin, simultaneously heating to soften it and generate gas, forming a rigid, closed-cell foam plastic. EPS is lightweight, significantly lighter than traditional roadbed materials such as gravel or soil. This reduces the load on the structure and lowers the risk of settlement in soft soil foundations. EPS reduces soil compaction, which helps reduce the need for heavy machinery and manpower during construction, thus lowering project costs. EPS has some resistance to water, reducing the risk of soil erosion from rainwater and helping to maintain roadbed stability. Compared to some traditional materials, EPS is less corrosive to chemicals and salt water, making it more durable in certain environments. Utility Model Content
[0004] The purpose of this utility model is to provide a road structure suitable for valley terrain, in order to solve the problem of uneven settlement of road structure caused by poor bearing capacity and poor drainage of soft soil foundation in valley terrain.
[0005] To achieve the above objectives, this utility model provides the following technical solution:
[0006] A road structure suitable for valley terrain includes in-situ excavation steps, cement concrete piles, sand cushion layer, cement concrete slab, culvert, waterproof geotextile, cement concrete wall, geocell, pavement structure, and EPS infill blocks.
[0007] Furthermore, in addition to the stepped structure, the original foundation excavation steps also include cement concrete wall support grooves and cement concrete pile holes.
[0008] Furthermore, the cement concrete piles, cement concrete slabs, and cement concrete walls are all composed of reinforcing cages and cement concrete casting structures.
[0009] Furthermore, the EPS filler block includes an EPS square filler block (10-1) and an EPS irregularly shaped filler block (10-2).
[0010] Furthermore, the sand cushion layer is made of medium-coarse sand and has a thickness of 10-20cm.
[0011] Furthermore, the cement concrete piles and cement concrete slabs are constructed using a cement concrete pouring method, while the cement concrete walls are constructed using a method of pre-filling aggregate concrete followed by cement grout pouring.
[0012] Furthermore, the reinforcing cage must be centered and completely encased in cement concrete, with no exposed reinforcing bars allowed.
[0013] Furthermore, when the strength of the cement concrete slab reaches 2.5 MPa, the EPS filling blocks are laid. A layer of waterproof geotextile with a thickness of 0.5 mm is laid on the original roadbed excavation steps and above the concrete slab to prevent groundwater or rainwater in the original roadbed from seeping into the EPS roadbed structure and affecting the roadbed performance.
[0014] Furthermore, the EPS filling block is divided into several units by a cement concrete wall, and each EPS filling block unit is wrapped with a cement concrete wall and the original foundation excavation steps on the bottom and sides.
[0015] Furthermore, the EPS filling blocks are laid crisscrossingly on the waterproof geotextile along the edge of the reinforcing steel cage. Each EPS filling unit enclosed by a single reinforcing steel cage has no continuous seams, but staggered seams greater than 0.5m are provided. Adjacent EPS filling blocks are connected and fixed using claw-shaped connectors. The EPS filling blocks are fixed by driving pins into the excavated steps of the original foundation, with the pins inserted into the foundation to a depth of not less than 20cm.
[0016] Furthermore, the lower end of the cement concrete wall is connected to the top surface of the unencased portion of the culvert to fix the culvert and prevent it from moving.
[0017] Furthermore, the geocells are made of high-strength polyethylene (HDPE) and are laid on top of the EPS filling blocks and cement concrete walls. The length of the geocells is more than 20cm longer than the top EPS filling blocks, and the geocells are backfilled with plain soil until they are completely covered.
[0018] Furthermore, the density of the EPS filler block is not less than 20 kg / m³.3 The compressive strength is not less than 200 kPa.
[0019] Preferably, the sand cushion layer is made of river sand from the local area where the construction project is located.
[0020] Preferably, the culvert is made of fiberglass reinforced plastic (FRP) with a wall thickness of 50mm.
[0021] Preferably, the cement concrete structure uses C30 cement and HRB335 steel reinforcement.
[0022] Due to the adoption of the above-described structure, the technological advancement of this utility model compared to the prior art lies in the following:
[0023] (1) By combining multiple rows of culverts with sand cushion layers, the drainage of the gully terrain is ensured.
[0024] (2) The setting of EPS filling blocks reduces the self-weight of the roadbed and protects the culverts, reducing uneven settlement of the road surface caused by soft soil foundation and culvert setting.
[0025] (3) The reinforced concrete pouring structure and the waterproof structure layer ensured the waterproof effect of the roadbed.
[0026] (4) Pile foundation can transfer the load to deeper soil layers with higher bearing capacity, avoid complex compaction operations, and is easy to construct without noise. It can effectively reduce uneven settlement of the roadbed.
[0027] (5) Cast-in-place concrete structures can connect EPS roadbeds and pile foundations into one unit, preventing lateral slippage of the roadbeds due to water flow impact.
[0028] (6) The cement concrete wall is poured using pre-filled aggregate concrete, which effectively reduces the amount of cement used while achieving the desired layout effect.
[0029] In summary, this utility model is suitable for soft soil foundations in gully terrain, is simple and quick to construct, can effectively reduce roadbed settlement and lateral slippage, has good economic benefits, and is applicable to the field of roadbed construction technology. Attached Figure Description
[0030] Figure 1 This is a cross-sectional view of a road structure suitable for valley terrain, along the driving direction, according to this utility model.
[0031] Figure 2 This is a schematic diagram of in-situ foundation trenching and drilling for a road structure suitable for valley terrain according to this utility model;
[0032] Figure 3 This is a steel cage layout diagram for a road structure suitable for valley terrain according to this utility model;
[0033] Figure 4 This is a layout diagram of a cement concrete-EPS composite roadbed in a road structure suitable for valley terrain according to this utility model;
[0034] Figure 5 This is an overall structural diagram of a road structure suitable for valley terrain according to the present invention;
[0035] Figure 6 This is a schematic diagram of vertical steel bar binding in a road structure suitable for valley terrain according to this utility model;
[0036] Figure 7 This is a schematic diagram of the transverse steel reinforcement binding in a road structure suitable for valley terrain according to this utility model.
[0037] In the diagram: 1-Excavation steps of the original foundation, 2-Cement concrete pile, 3-Sand cushion layer, 4-Cement concrete slab, 5-Culvert, 6-Waterproof geotextile, 7-Cement concrete wall, 8-Geocell, 9-Road structure, 10-EPS infill block, 11-Reinforcing steel, 10-1-Square EPS infill block, 10-2-Irregular EPS infill block, 101-Cement concrete wall support trench, 102-Cement concrete pile hole, 01-Vertical limiting reinforcement, 202-Vertical reinforcement, 203-Thickness of concrete pouring structure, 204-Horizontal limiting reinforcement, 205-Top formwork reinforcement, 206-Horizontal reinforcement. Detailed Implementation
[0038] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0039] This utility model discloses a road structure applicable to valley terrain, such as Figure 1As shown, a sand cushion layer 3 is laid on the original foundation excavation step 1. Cement concrete piles 2 are poured into the cement concrete pile holes 102 of the original foundation excavation step 1. The reinforcing cages of the cement concrete piles 2 are tied to the reinforcing cages of the cement concrete slab 4 and the cement concrete wall 7. The EPS filling blocks 10 are laid in the filling area enclosed by the reinforcing cages of the cement concrete wall 7 and the original foundation excavation step 1. The gaps between each EPS filling unit are separated by the tied reinforcing cages of the cement concrete wall 7 and filled with aggregate and cement slurry. Waterproof geotextile 6 is laid between the EPS filling blocks 10 and the original foundation excavation step 1. The culvert 5 is wrapped by EPS irregular filling blocks 10-2 and fixed by steel bars along the tangent direction of the culvert layout. Geocells 8 are laid between the EPS filling blocks 10 and the road structure 9. After backfilling with plain soil, a water-stabilized crushed stone base structure is laid. The geocells 8 serve to reinforce the plain soil.
[0040] This example demonstrates a road structure suitable for valley terrain, achieved through the following construction steps:
[0041] S1. Construction Material Preparation: ① Precast EPS hexahedral filler blocks 10-1 and EPS irregular-shaped filler blocks 10-2 for wrapping the culvert 5. The compressive strength, waterproofness, fire resistance, and density of the EPS filler blocks 10 must meet the corresponding requirements before use. The density of the EPS filler blocks 13 is not less than 20 kg / m³. 3 ① The compressive strength shall not be less than 200 kPa. ② Select a fiberglass reinforced plastic (FRP) pipe of a certain size corresponding to the drainage flow as the culvert 5. The length of the culvert shall be the same as the width of the road cross-section structure. ③ Select aggregates of a certain grade and cement of a certain strength that meet the design requirements. ④ Select steel bars of a certain diameter and strength grade that meet the design requirements. The selected steel bars shall be free from bending and corrosion. ⑤ Calculate the length of each steel bar according to the design dimensions and cut it. For those requiring corners, bend them. The bending angle and bending location shall meet the design specifications. ⑤ According to the design requirements, tie the steel cages for cement concrete piles 2, cement concrete slabs 4, and cement concrete walls 7 and 9 on-site. When tying the steel bars, use a straight tie or figure-eight tie. All intersections of the outer steel bars should be tied, and the remaining points can be tied alternately. If the steel bar length is insufficient, connection is required. Welding or mechanical connection can be used. Welding must ensure a full weld without slag inclusions, porosity, or other defects. Mechanical connections must use qualified connectors, and the connection quality must be checked after connection.
[0042] S2. Foundation treatment: Excavate and step out the original foundation, clean up large particles and gravel, and lay a sand cushion layer 3 with a thickness of 10-20cm on the roadbed surface as the construction base and leveling layer for concrete slab pouring.
[0043] S3. Trenching and Drilling Construction: Road structure and pile location layout are carried out, and the trenching machine, drilling machine, and mud pump are tested and adjusted. Based on design and section requirements, the trenching machine is used to excavate the cement concrete wall support trench 101, and the drilling machine is used to construct the cement concrete pile hole 102. After drilling, the hole is cleaned, and mud is used to remove the stone debris from the borehole. The drilling depth and straightness are checked using a borehole gauge.
[0044] S4. Formwork erection: The formwork should be laid out around the cement concrete slab and the concrete pouring area. The formwork joints should be tight to avoid grout leakage and misalignment. The inside of the formwork should be coated with a release agent, which should not contaminate the reinforcing steel.
[0045] S5. Reinforcing cage installation: Weld the reinforcing cages of cement concrete pile 2, cement concrete slab 4, and cement concrete wall 7. Part of the reinforcing cage of cement concrete pile 2 is lowered into the hole. The reinforcing cages of cement concrete slab 4 and cement concrete wall 7 are arranged along the original roadbed excavation step 1.
[0046] S6. Cement Concrete Pile Pouring: Insert a tremie pipe into the borehole, with the outlet 0.3-0.5m from the bottom of the hole. Use a funnel to collect concrete at the top of the tremie pipe. Continuously inject cement concrete into the borehole through the tremie pipe, measuring the depth of the concrete surface every half hour. Calculate the number of tremie pipe sections and gradually reduce the depth of the tremie pipe outlet. Concrete should be poured in layers, with each layer not exceeding 500mm in thickness. Pouring should not be interrupted; the next layer should be poured and vibrated before the previous layer has initially set. When vibrating the next layer, the vibrator should penetrate 100-150mm into the previous layer. After grouting begins, the tremie pipe outlet must always be kept at least 0.5m below the concrete. If the outlet is too shallow, it can easily lead to pile breakage; if the outlet is too deep, the old concrete may have set prematurely, preventing the pouring of fresh concrete and also causing pile breakage.
[0047] S7. Cement Concrete Slab Pouring: The concrete slab and concrete pile should be poured tightly together. The free fall difference during concrete slab pouring should generally not exceed 1m. If it exceeds 1m, a duct or chute should be used for transportation. After the concrete slab is poured, it is advisable to use an immersion vibrator for compaction. The vibrator should be inserted in a straight line, and the moving distance should not exceed 1.5 times the radius of action of the vibrator. Vibration should continue until the concrete no longer settles, there are no significant air bubbles, and the surface is flat and uniform. A clear distance of 50mm-100mm should be maintained between the vibrator and the formwork. Areas where vibrator vibration is not suitable should be compacted manually.
[0048] S8. Culvert Layout: Lay a layer of waterproof geotextile with a thickness of 0.5mm on the original foundation excavation steps and cement concrete slab. After wrapping the fiberglass reinforced plastic (FRP) sand-filled pipe with EPS shaped filler blocks, fill it into the cement concrete wall reinforcement cage. Use bent steel bars to tie the culvert 5 wrapped with EPS shaped filler blocks 10-2 to the cement concrete slab 4 reinforcement cage as a whole.
[0049] S9. EPS Filler Block Laying: Lay EPS filler blocks 10. EPS filler blocks 10 are filled according to the cement concrete wall 7 steel cage division unit. EPS filler blocks 10 should be staggered, with no continuous joints in the same arrangement unit, and staggered joints greater than 0.5m should be set. EPS filler blocks are connected with claw-shaped connectors. After the bottom layer of EPS is laid in place, steel nails made of round steel are inserted into the original foundation for fixation. The depth of the steel nails inserted into the original foundation should not be less than 20cm.
[0050] S10. Cement Concrete Wall Pouring: Wall pouring can only proceed after the cement concrete slab strength reaches 2.5 MPa or higher. A 15mm-20mm thick layer of reduced-aggregate concrete of the same strength grade as the wall concrete must be poured evenly at the bottom joint with the concrete slab. The remaining portion should be poured in layers using pre-filled aggregate concrete, with each layer not exceeding 300mm in thickness. First, aggregate equal to the layer thickness is shoveled into the trench, then cement slurry is poured until the aggregate gaps are filled, and then vibrated with a vibrator. Concrete construction joints should preferably be located at expansion joints. After the concrete layers are poured and vibrated, the top edge of the wall is leveled with a wooden trowel according to the design elevation control line.
[0051] S11. Cement Concrete Curing: After the concrete is poured, it should be covered and watered within 12 hours. The watering frequency should be sufficient to keep the concrete sufficiently moist. The curing period is generally no less than 7 days.
[0052] S12. Formwork Removal: Side formwork can only be removed when the concrete strength reaches 2.5 MPa or above. During removal, care should be taken to protect the wall from damage.
[0053] S13. Pavement Structure Construction: Cover the well-cured cement concrete-EPS structure with geocells 11, backfill with plain soil, compact, and then pave the pavement structure.
[0054] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A road structure suitable for valley terrain, characterized in that: It includes the original foundation excavation steps (1), cement concrete piles (2), sand cushion layer (3), cement concrete slab (4), pipe culvert (5), waterproof geotextile (6), cement concrete wall (7), geocell (8), pavement structure (9) and EPS filling block (10). In addition to the original foundation excavation step (1) being a stepped structure, it also includes a cement concrete wall support groove (101) and a cement concrete pile hole (102). The cement concrete pile (2), cement concrete slab (4), and cement concrete wall (7) are all composed of a steel cage and a cement concrete casting structure. The EPS filler blocks include EPS square filler blocks (10-1) and EPS irregular-shaped filler blocks (10-2); A layer of waterproof geotextile (6) is laid on top of the sand cushion layer (3). The filling area of the EPS filling block (10) is divided into multiple units by the cement concrete wall (7). Each EPS filling block unit is wrapped by the cement concrete wall (7) and the original foundation excavation steps (1) to cover the bottom and the sides. The EPS filling block (10) includes EPS irregular filling blocks (10-2) that wrap the culvert (5) and EPS square filling blocks (10-1) that fill the roadbed. The EPS filling blocks (10) are laid in a crisscross pattern on the waterproof geotextile (6) along the edge of the steel reinforcement cage of the cement concrete wall (7). The lower end of the cement concrete wall (7) is connected to the top surface of the unwrapped part of the culvert (5). The geocell (8) is laid on top of the EPS filling block (10) and the cement concrete wall (7). The road structure (9) is laid on the plain soil reinforced by the geocell (8).
2. A road structure suitable for valley terrain according to claim 1, characterized in that: The sand cushion layer (3) is made of medium-coarse sand and has a thickness of 10-20cm.
3. A road structure suitable for valley terrain according to claim 1 or 2, characterized in that: The cement concrete piles (2) and cement concrete slabs (4) are constructed using the cement concrete pouring method, while the cement concrete wall (7) is constructed using the cement grouting method after prefilling with aggregate.
4. A road structure suitable for valley terrain according to claim 3, characterized in that: The cement concrete reinforcing cage needs to be centered and completely encased in cement concrete.
5. A road structure suitable for valley terrain according to claim 3, characterized in that: When the strength of the cement concrete slab (4) reaches 2.5 MPa, the EPS filling block laying begins. A layer of waterproof geotextile (6) with a thickness of 0.5 mm is laid on the original roadbed excavation steps (1) and above the cement concrete slab (4).
6. A road structure suitable for valley terrain according to claim 4 or 5, characterized in that: The EPS filling blocks (10) are laid in a crisscross pattern on the waterproof geotextile along the edge of the steel reinforcement cage. The EPS filling unit formed by a single steel reinforcement cage has no continuous seam and is staggered with a spacing greater than 0.5m. Adjacent EPS filling blocks are connected and fixed with claw-shaped connectors. The EPS filling blocks (10) are fixed by driving pins into the original foundation excavation steps. The depth of the pins inserted into the foundation is not less than 20cm.
7. A road structure suitable for valley terrain according to claim 1, characterized in that: The lower end of the cement concrete wall (7) is connected to the top surface of the unencased part of the culvert (5) to fix the culvert (5) and prevent it from moving.
8. A road structure suitable for valley terrain according to claim 1, characterized in that: The geocell (8) is made of high-strength polyethylene geocell, which is laid on top of EPS filling block (10) and cement concrete wall (7), with a length more than 20cm longer than the top EPS filling block (10), and backfilled with plain soil until the geocell (8) is completely covered.
9. A road structure suitable for valley terrain according to claim 1, characterized in that: The density of the EPS filler block (10) is not less than 20 kg / m³. 3 The compressive strength is not less than 200 kPa.