What is a composite geogrid ?
Composite geogrid is a multifunctional geosynthetic material that combines geogrid and geotextile through processes such as thermal bonding, adhesive bonding, or needle punching. It is mainly used for reinforcement, isolation, filtration, and stabilization in roads, soft soil foundations, slopes, and municipal engineering.
Structural Components of Composite Geogrids
Reinforcing Layer (Geogrid Layer)
Common Materials: PP/HDPE biaxial plastic geogrid/PET polyester warp-knitted geogrid/glass fiber geogrid
Main Functions: Improves foundation bearing capacity/limits lateral soil displacement/distributes vehicle or structural loads
Functional Layer (Geotextile Layer)
Common Types: Non-woven needle-punched geotextile / High-strength woven geotextile
Main Functions: Isolates soil layers with different particle sizes / Prevents fine material loss / Provides drainage and filtration functions
Core performance advantages of composite geogrids
High Tensile Strength Reinforcement
Composite geogrids use geogrid layers as the main load-bearing skeleton, possessing high longitudinal and transverse tensile strength:
Tensile strength: 20–200 kN/m. This significantly improves the shear strength of the soil and effectively limits the lateral displacement of roadbeds and foundations.
Multifunctional Integration of Reinforcement, Isolation, and Filtration
Unlike single-material geogrids, a single layer can achieve multiple functions:
Geogrid: Load bearing, reinforcement, and load distribution
Geotextile: Isolation of different soil layers, filtration of fine materials, and auxiliary drainage
Application Scenarios of Composite Geogrids
Road and Highway Engineering
Composite geogrids are widely used in various road structural layers, primarily for subgrade and base course reinforcement.
Typical Applications:
New Road Subgrade Reinforcement
Existing Road Reconstruction, Expansion, and Widening Projects
Heavy-Duty Traffic Roads, Rutting Prevention
Rural Roads, Temporary Construction Roads
Treatment of Soft Soil and Silt Foundations
Composite geogrids perform particularly well in soft soil, silt, and high water content foundation conditions.
Applicable Scenarios:
Industrial Park Foundations
Warehouse and Logistics Yards
Port Backyard Land Area
Land Reclamation Projects
Railway, Airport, and High Dynamic Load Projects
Composite geogrids provide long-term, stable reinforcement for high-frequency vibration and heavy-load conditions.
Applications:
Railway subgrade structure
Airport runways and taxiways
Heavy-duty storage yards and container yards
Slope Protection and Retaining Structures
Composite geogrids are commonly used in various reinforced soil structures to improve the overall stability of slopes.
Common Applications:
Embankment Slope Reinforcement
Reinforced Soil Retaining Walls
Embankment Slope Protection
Frequently Asked Questions about Composite Geogrids
Q1: What is the difference between composite geogrids and ordinary geogrids?
A: Ordinary geogrids mainly serve as reinforcement and load-bearing structures, while composite geogrids are made by bonding geotextile to a geogrid base. In addition to reinforcement, they also provide isolation, filtration, and auxiliary drainage functions. Multiple functions can be achieved with a single layer of material, resulting in higher overall stability.
Q2: How much can composite geogrids increase the bearing capacity?
A: Depending on the engineering conditions, proper selection can increase the bearing capacity of the foundation or subgrade by approximately 30%–50% and significantly reduce the risk of uneven settlement.
Q3: Can composite geogrids replace crushed stone subbase layers?
A: In some soft soil foundation or temporary road projects, the thickness of the crushed stone subbase layer can be reduced, but it usually cannot completely replace the structural layer. The base course materials still need to be configured according to design requirements.
Q4: What is the service life of composite geogrids?
A: Composite geogrids made from high-quality PET, PP, or HDPE raw materials have a design service life of over 50 years under normal installation and design conditions.
Should you choose composite geogrids for your project?
Composite geogrids can significantly improve the bearing capacity of foundations and subgrades, effectively controlling uneven settlement and structural deformation. Furthermore, their integrated design reduces the number of construction layers, shortens the construction period, and lowers overall construction costs while ensuring project safety.
More importantly, composite geogrids possess excellent durability and long-term stability, maintaining reliable performance in complex geological and high-load environments, providing long-term, safe, and sustainable technical protection for engineering structures.
