Sub-surface Profiling Using Electrical Resistivity Tomography (ERT) with Complement from Peat Sampler

Abstract

The pre-construction works include the geotechnical investigation which comprises the surface and subsurface exploration. Sub-surface exploration often causes several difficulties such as high cost, time consuming, localized investigation and intrusive. Furthermore, investigation on soft soil such as peat often raises several additional problems such as high risk of sample disturbance, difficult access for heavy equipment and inconsistent data due to the heterogeneity of peat. The advancement of geophysical method such as Electrical Resistivity Tomography (ERT) allows the determination of soil profile in time-efficient manner, economic, larger volume of investigation and non-intrusive. This study focused on the determination of soil profile, particularly peat layer using ERT method with complement from peat sampler data. The study was conducted at Parit Nipah, Johor. The results revealed a high accuracy profile delineated by the ERT method with only less than 8% percentage of error as compared to peat sampler profile. The comparison between Schlumberger and Wenner array showed that; the Schlumberger showed superior depth of penetration, with almost 3 times deeper penetration relative to Wenner. The Schlumberger array is also able to delineate lateral variation within the peat layer. Finally, the resistivity value of peat obtained ranged from 100.8 to 139.5 ohm.m with both arrays having consistent results.

Investigating Peat Soil Stratigraphy and Marine Clay Formation Using the Geophysical Method in Padas Valley, Northern Borneo

“…e underlain conductive unit identified as marine clay appears to provide a great contrast of resistivity values with the peat soil layer. e inversion images indicate a gradually decreasing resistivity with depth in the peat soil apart from the top 2 m. A similar finding was obtained [8,35], where peat soil conductivity gradually increases with depth. Slightly lower peat soil resistivity values were observed on the top 2 m. is condition was mainly contributed by the wide electrode spacing as zero reading was obtained, causing extrapolation of the shallowest available values.…”

The Optimum Field Configuration for Active MASW Survey on Peat Soil

“…The location was chosen as the peat soil thickness was among the thickest in Peninsular Malaysia. The peat thickness and groundwater table determined in the area were approximately 4 m and 0.5 m depth respectively [18]. The peat soil type was categorised as hemic peat according to the Von Post classification [19].…”

Estimating the Small Strain Stiffness of Peat Soil Using Geophysical Methods

“…The locations were chosen as all three sites represent different classification of peat thickness. According to the peat sampler investigation, the peat thickness at Medan Sari, Pontian and Parit Nipah were 1.5 m, 3.0 m and 4.0 m respectively [21]. The peat soil at Medan Sari, Pontian and Parit Nipah were classified as shallow peat (< 1.5m), moderate deep peat (1.5 to 3 m), deep peat (> 3m) correspondingly.…”