Subsoil Pavement Drains: Panel Drains v Round Pipe Comparison

Liaison with Australian state road authorities in recent years has been the impetus for reviewing current accepted drainage practice, with tested, technically advanced, cost effective products now readily available in Australia. Premature pavement failure commonly caused by slow drainage response has benefited from design methods incorporating geo-composite panel drains, giving improved drainage response times, high flow infiltration, efficient filtration and economical installation.

Pipe stiffness test results highlight the difference in service performance to show that geo-composite panel drains are superior in structural capacity whilst their rigidity compliments efficient installation.

Comparison of factors affecting inflow capacity and outflow discharge identify the optimum flow performance of panel drains. Inflow considerations can be shown to be more relevant criteria than design for discharge capacity. Geotextile filtration performance is an integral part of geo-composite drainage systems with research highlighting the correct assessment of EOS being critical to efficient long term drainage sustainability.

Type of backfill used, permeability rates for in situ soil, pavement materials and drainage backfill play an integral part in overall design. Design practice should consider location of the system, permeability rates for in situ materials and geotextile filtration along with drainage inflow and discharge capacity.