Integration of Electrical Resistivity Imaging with Borehole and Hand Auger Data for Peat Characterisation: A Case Study at Kuala Langat, Selangor, Malaysia

Abstract

Peat is one of the Quaternary sediments found in the Kuala Langat area. Peat contains organic matter where its high natural water content can cause the subsurface to becomes unstable and unsuitable for supporting any building structures. It can either react with a steady settlement, which is generally less harmful or suddenly experience shear failure of the peat, causing sudden subsidence. This study aims to characterise a subsurface peat layer by integrating borehole data and hand auger samples with electrical resistivity imaging (ERI) results. The collected soil samples physical and chemical properties were analysed to determine its moisture content, total organic content (TOC) and von Post’s degree of humifcation. Three electrical resistivity survey lines were conducted using Wenner-Schlumberger protocol at certain key locations in the study area to map the vertical subsurface electrical resistivity profle. The studies show that the thickness of the peat layer from the borehole data and hand auger data is perfectly matched with the electrical resistivity pseudo section. The study area is covered up to 5 meters thick of peat with a resistivity value ranging from 16 Ωm to 24 Ωm, followed by a thick layer of marine clay with a resistivity value ranging from 24 Ωm to 46 Ωm. This study can support the engineer’s selection of site suitability and equipment for engineering construction.