Measurement of Peat Soil Shear Strength Using Wenner Four-Point Probes and Vane Shear Strength Methods

Abstract

The general objective of this research was to measure the peat soil shear strength using Wenner four-point probes and vane shear strength methods. Specifically, the objective of this study was two-fold, namely, (a) investigating the relationship between laboratory soil resistivity and undrained shear strength and (b) determineing the relationship between in-situ soil resistivity and undrained shear strength. Data were randomly collected over six locations in Meranek, Sarawak, for in-situ test and three repetitions for each data were set based on three parameters. The selected parameters were soil density, moisture content, and salinity for both laboratory and in-situ test using Wenner four-point probes and vane shear method. The soil resistivity and vane shear strength readings for laboratory test were correlated with soil salinity, moisture content, and density. The R2 values showed a good correlation for soil salinity (R2 =0.8468) and density (R2 =0.9475), respectively. However, a weak correlation of R2 =0.1205 was observed for soil moisture. The R2 value for in-situ correlation between soil resistivity and three parameters (soil salinity, moisture content, and density) was R2 =0.8916. It can be concluded that the peat soil shear strengths of the study area using Wenner four-point probes from in-situ were (4.38 ohm.m) and laboratory was (2.47 ohm.m) and when using the vane shear strength method, in-situ was (23 kPA) and laboratory was (5 kPA). This study implies that the peat soil of the study area can be categorized as texture (soft loamy soil) and it is suitable for agriculture instead of construction. The relationship established between Wenner four-point probes and vane shear method can be beneficial for ground engineering design to enhance investigation on site suitability. Future work on DUALEM-421 technique should be emphasised for better subsurface exploration accuracy and resolve peat depth for an in-situ test.

Physicochemical and Microstructural Characterization of Klias Peat, Lumadan POFA, and GGBFS for Geopolymer Based Soil Stabilization

“…Figures 8-a to 8-d illustrate the FESEM micrographs for Klias peat, GGBFS, pre-treated POFA, and GPOFA used in this research. In Figure 8-a, Klias peat showed the presence of voids, similar to those reported by Sutarno & Mohamad [26], Latifi et al [99], and Hassan et al [100], interspersed with particles possessing honeycomb structures, an indication that the peat soil is fibrous [101]. Meanwhile, the GGBFS material seen in Figure 8-b shows particles that are smooth and possess semi-polygonal shapes [102], that are angular [97], and that are sharp-edged in nature [73].…”

“…In the case of pre-treated POFA, Figure 8-c shows that it consists of particles with a porous cellular surface, as reported by Khalid et al [65] and Noorvand et al [103], which denotes the presence of fibric content [101] and is consistent with the origins of the POFA material produced by burning palm oil waste [29]. Figure 8-c shows that the pre-treated POFA contains clustered spherical particles with minimal voids between these particles, similar to the findings of Lim et al [67].…”

Estimation of Geotechnical Parameters for Coal Exploration from Quasi-3D Electrical Resistivity Measurements

“…Assessing soil's in situ strength properties is crucial for various geotechnical and civil engineering applications. Numerous instruments and methods are employed for this purpose, each offering specific insights into soil behavior [18][19][20][21][22][23][24][25][26][27]. Accurate information about soil properties typically entails high-resolution drilling data, which can be expensive, time-consuming, and labor-intensive.…”

Electrical resistivity survey for evaluating the undrained shear strength of soft Bangkok clay at some of the canal-side road investigation sites

“…The increment of soil resistivity was reported with an increase of the unconfined compressive strength, saturation rate, and compaction blow number, but a decrease in the moisture content in the sandy soil. The correlation between the unconfined compressive strength and the resistivity of peat soil was investigated by Afip et al (2019). The study revealed that an increment of the resistivity and shear strength was found with an increment in the soil density but a decrease in the soil moisture.…”