No abstract

This work describes the application of the electrical resistivity (ER) method to delineating subsurface structures and cavities in Kuala Lumpur Limestone within the Batu Cave area of Selangor Darul Ehsan, Malaysia. In all, 17 ER profiles were measured by using a Wenner electrode configuration with 2 m spacing. The field survey was accompanied by laboratory work, which involves taking resistivity measurements of rock, soil, and water samples taken from the field to obtain the formation factor. The relationship between resistivity and the formation factor and porosity for all the samples was established. The porosity values were plotted and contoured. A 2-dimensional and 3-dimensional representation of the subsurface topography of the area was prepared through use of commercial computer software. The results show the presence of cavities and sinkholes in some parts of the study area. This work could help engineers and environmental managers by providing the information necessary to produce a sustainable management plan in order to prevent catastrophic collapses of structures and other related geohazard problems.

In this study, the effects of simulated acid rain (SAR) on the engineering properties of primary and secondary kaolinite clays (PK and SK) were investigated. Tests of consistency limit, compressive strength, compressibility, hydraulic conductivity, and compaction characteristics were conducted to investigate the changes in the physico-chemical and engineering properties of PK and SK clays after being exposed to SAR at different pH levels of 2, 3, 4, 5, and 5.6 and at different fluxes of SAR equivalent to precipitation for 1, 5, 10, and 20 years. In addition, scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX), zeta potential and atomic adsorption spectroscopy (AAS) studies were conducted to identify the underlying mechanisms involved. The results revealed that for both PK and SK, the low pH value of SAR and higher flux of SAR resulted in a reduction in soil strength, maximum dry density, and increased compressibility, hydraulic conductivity, liquid limit, and optimum moisture contents. The AAS tests confirmed that reduction of more traced elements in PK and SK specimens when they were infiltrated by the SAR. Also, the formation of relatively a weak structure was observed through the SEM tests. The sensitivity of the PK specimen was higher than that of the SK specimen for SAR intrusion.

No abstract

No abstract