BENEFITS OF USING GEOSYNTHETICS IN RAILWAY LINES CULVERTS

When culverts beneath a rail line are replaced, operators often struggle to construct a firm base for the culvert base to be founded especially when in majority of cases the subgrade materials are of inferior quality. Deep excavations and backfill are often required which is time consuming and could potentially prolong the closedown timeframe. The Presto Geoweb® load support system will provide rail operators an economical and time saving solution by reducing both the excavation and backfill requirements.

The Presto Geoweb load support system is a highly effective, economical solution to problems that result from subgrade material failure or surface or base material instability. Under concentrated or distributed loads, the 3D cellular structure confines infill material and controls shearing, lateral and vertical movement of the infill material. As a base stabilisation system, the Geoweb material significantly improves performance and when confined, base material requirements can be reduced by 50% or more by substantially reducing the loading on sub-surface soils. As a result, reduced excavation and granular infill needs reduce overall installation cost.

Geoweb System Benefits:

• Produces a stiff base with high flexural strength.
• Acts like a semi-rigid slab by distributing loads laterally.
• Minimizes impact of differential and overall settlement.
• Reduces fill depth requirement by 50%.
• May allow use of poor-quality granular fills, e.g. Fouled Ballast, in place of more costly imported materials.
• Allows subgrade materials to withstand more than 10 times the number of cyclic-load applications before accumulating the same amount of permanent deflection.
• Provides over 30% stress reduction when supporting aggregate under pavement.

The Geoweb system is selected based on 30 years of rail industry use and independent testing conducted in 1998 at AAR FAST High Tonnage Loop in Pueblo, CO. The testing examined soft sub grade solutions for tracks subjected to heavy loads and determined that the Geoweb load support system significantly improves load distribution, therefore reducing the vertical stresses reaching the sub grade. The system’s three-dimensional structure performs like a semi-rigid slab.

Geoweb a Complete Solution which includes proper components which have a critical role in contributing to the overall design strength of the engineered solution. Presto’s Geoweb accessories provide higher design strength than alternative methods. They are also designed to save contractors time and money during installation and minimise the potential for incorrect installations.

For over thirty years, Geoweb material has been manufactured from only the highest quality blend of High Density Polyethylene (HDPE) and it is recognised in the geosynthetics industry as the original high quality, high-performance geocell.