HYDRAULIC CONDUCTIVITY CHARACTERISTICS OF A FINE-GRAINED SOIL POTENTIAL FOR LANDFILL LINER APPLICATION
Keywords:
Hydraulic conductivity, Permeability, Landfill Liner, Sanitary LandfillAbstract
Sanitary landfills (SLFs) are usually employed as final waste disposal facility to protect public
health and the environment. As a result of rapid population growth and urbanization, there is currently a great
demand to construct SLFs in the Philippines. The hydraulic conductivity characteristics of remolded samples
of a locally abundant fine-grained soil compacted at different compaction energy level is investigated to
determine the suitability of the soil as landfill liner material. The hydraulic conductivity of lining system is one
very salient feature of the SLF to prevent contamination of nearby soil and water sources. The physical
properties of the soil are determined through a series of laboratory tests which includes the grain-size
distribution, specific gravity, Atterberg limits, soil classification, Cation Exchange Capacity (CEC), X-ray
powder diffraction (XRD) and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEMEDS). The falling head laboratory test was conducted to determine the saturated coefficient of hydraulic
conductivity. A numerical model was formulated that can predict hydraulic conductivity as a function of the
void ratio. The resulting coefficient of hydraulic conductivity ranges from 1.98 x 10-6
to 1.0 x 10-7cm/sec meet the Philippine standard requirement. The soil being classified as clay loam can readily be used as top lining
material. However, additional study on unconfined compressive strength and volumetric shrinkage among
other parameters is recommended prior to use of the fine-grained soil as bottom lining material as soil
amendment maybe necessary.