Case Study on the Use of Ocean Uniaxial Geogrid 40 kN in Road Construction

Project Overview

• Project Name: Road Project
• Location: Guwahati, Assam
• Product Supplied and Used: Ocean Uniaxial Geogrid 40 kN
• Quantity: 5,000 SQM
• Client Sector: Public road infrastructure (urban and peri-urban connectivity)

Guwahati is the primary gateway to Northeast India and a critical logistics and mobility hub for Assam and surrounding states. Rapid urban growth, increasing traffic loads, and challenging ground conditions make road construction and maintenance in this region technically demanding. This project involved the strengthening of a road section exposed to heavy vehicular movement, seasonal flooding, and subgrade variability. Ocean Non Wovens supplied 5,000 SQM of Ocean Uniaxial Geogrid 40 kN to improve pavement performance and long-term structural stability.

Why Geogrids Are Critical in Modern Road Construction

The Function of Uniaxial Geogrids

Uniaxial geogrids are engineered polymer grids designed primarily to provide tensile reinforcement in one principal direction. In road and embankment applications, they work by:

• Increasing the load-bearing capacity of weak subgrades
• Reducing lateral spreading of base and sub-base aggregates
• Distributing traffic loads over a wider area
• Minimizing rutting and differential settlement

In pavement systems, geogrids interact with aggregate layers through mechanical interlock. When traffic loads are applied, this interlock restrains lateral movement of aggregates, maintaining layer integrity and reducing deformation. Studies have shown that geogrid reinforcement can significantly improve bearing capacity and reduce permanent deformation in flexible pavements, particularly over weak subgrades (Giroud & Han, 2004; Koerner, 2012).

Broader Infrastructure Applications of Geosynthetics

Beyond roads, geosynthetics play a foundational role across multiple civil engineering domains:

• Soil stabilization: Improving shear strength in weak or expansive soils
• Erosion control: Surface protection on embankments and slopes
• Drainage improvement: Use of geotextiles and geocomposites to maintain permeability while preventing soil migration
• Environmental protection: Lining systems in landfills and water containment to prevent contamination

Globally, geosynthetics are recognized for extending service life of infrastructure while reducing construction material requirements, leading to both technical and environmental benefits (FHWA, Geosynthetic Design Guidelines; ISO 10318).

Site Conditions and Challenges in Guwahati, Assam

Subgrade Variability and Soil Conditions

The Brahmaputra basin region, including Guwahati, is characterized by alluvial soils with variable bearing capacity. These soils often exhibit:

• Low California Bearing Ratio (CBR) values
• High moisture sensitivity
• Seasonal changes in strength due to fluctuating groundwater levels

Such subgrades are prone to deformation under repeated traffic loads. Without reinforcement, pavements constructed over these soils can develop early-stage rutting and cracking.

Monsoon Impact and Drainage Stress

Assam experiences intense monsoon rainfall, leading to:

• Saturation of subgrade layers
• Reduced shear strength of soils
• Increased risk of pumping and loss of fines

Water ingress is one of the most underestimated factors in pavement deterioration. Field observations and IRC guidelines indicate that poor drainage and prolonged moisture exposure can reduce pavement life by more than 50 percent in high rainfall zones (IRC SP: 42; MoRTH Specifications).

Construction Constraints in Urbanizing Corridors

Road projects in and around Guwahati often face:

• Limited construction windows due to traffic management requirements
• Irregular existing formation levels
• Challenges in maintaining uniform compaction across varying soil strata

These realities demand reinforcement systems that are forgiving of minor subgrade inconsistencies while still delivering performance gains.

Application of Ocean Uniaxial Geogrid 40 kN

Design Intent and Placement

For this project, the Ocean Uniaxial Geogrid 40 kN was installed at the interface between the prepared subgrade and the granular base layer. The design objective was to:

• Improve load distribution
• Reduce base layer thickness requirement where feasible
• Enhance resistance to lateral deformation under repeated axle loads

The 40 kN tensile strength category was selected based on anticipated traffic loads and the need for long-term performance in a high-stress corridor.

Installation Complexities and Quality Control

In real-world conditions, geogrid performance depends as much on installation quality as on material properties. Key practical aspects addressed on site included:

• Subgrade preparation: Achieving a reasonably level surface free from sharp protrusions to prevent local stress points on the geogrid
• Tensioning and alignment: Ensuring the uniaxial geogrid was laid in the correct orientation relative to traffic direction to mobilize tensile strength effectively
• Overlap and anchorage: Maintaining specified overlaps and edge anchorage to prevent movement during aggregate placement
• Aggregate placement technique: Placing the first lift of base material carefully to avoid displacement or damage to the geogrid

Quality control checks focused on visual inspection, alignment verification, and ensuring that no construction traffic directly traversed the exposed geogrid prior to cover placement. These steps, while rarely discussed openly, are often the difference between theoretical performance and actual field outcomes.

Long-Term Performance Considerations

Durability Under Heavy Traffic and Environmental Stress

Uniaxial geogrids used in road construction must withstand:

• Repeated cyclic loading from heavy vehicles
• Temperature variations
• Long-term exposure to moisture and soil chemicals

Polymer-based geogrids designed for infrastructure applications are tested for creep behavior, chemical resistance, and durability under simulated environmental conditions. Long-term design strength is typically derived by applying reduction factors to short-term tensile strength, as recommended in international design methodologies (Koerner, 2012; FHWA NHI-07-092).

Maintenance Implications and Lifecycle Benefits

One of the less discussed advantages of geogrid-reinforced pavements is the impact on maintenance cycles. Reinforced sections tend to exhibit:

• Reduced rut depth over time
• Slower progression of surface cracking
• Lower frequency of structural rehabilitation

While initial construction may involve additional material costs, lifecycle assessments often show reduced total cost of ownership due to extended service life and lower intervention frequency. In high rainfall regions like Assam, this lifecycle benefit becomes even more pronounced, as water-related distress is a major driver of premature pavement failure.

Outcomes and Technical Value Delivered

The integration of Ocean Uniaxial Geogrid 40 kN into the Guwahati road project contributed to:

• Improved subgrade support in weak soil zones
• Enhanced structural capacity of the pavement system
• Greater resilience against monsoon-induced weakening
• A more predictable performance profile under heavy traffic conditions

From an engineering standpoint, the project demonstrated how targeted use of geosynthetics can address region-specific challenges rather than applying generic pavement solutions that may not perform reliably in Northeast India’s climatic and geotechnical context.

References and Technical Sources

• Giroud, J. P., & Han, J. (2004). Design method for geogrid-reinforced unpaved roads and working platforms. Journal of Geotechnical and Geoenvironmental Engineering.
• Koerner, R. M. (2012). Designing with Geosynthetics (6th Edition). Pearson.
• FHWA. Geosynthetic Design and Construction Guidelines. Federal Highway Administration, USA.
• IRC SP: 42 and MoRTH Specifications for Road and Bridge Works, Government of India.
• ISO 10318. Geosynthetics terminology and definitions.

About Ocean Non Wovens

With a strong manufacturing base and project experience across diverse geographies in India, Ocean Non Wovens continues to support complex infrastructure challenges with reliable geosynthetic solutions. From road reinforcement and soil stabilization to drainage and environmental protection systems, the company brings technical depth, consistent product quality, and on-ground execution understanding to large-scale projects. For infrastructure developers seeking dependable geosynthetics backed by practical field insight, Ocean Non Wovens remains a trusted partner for building durable, future-ready assets.