Influence of Alstonia Angustiloba Tree Water Uptake on Slope Stability: A Case Study at the Unsaturated Slope, Pahang, Malaysia

Abstract

This study examines the effects of tree water uptake at different depths and distances on the improvement of induced water uptakes in soil owing to transpiration. This study is performed to examine the tree water uptake profile in a vegetated slope with the existence of Alstonia Angustiloba mature tree at the top and the permanence of the slope during various precipitation penetration events by which the data of the tree water uptake produced within this section of the slope is recorded and implemented to evaluate the factor of safety (FOS). Slope stability analysis is further conducted to explore how plant transpiration affects slope stability. The results portrayed that, higher tree water uptake lead to the greatest FOS of the slope up to 53% (from 2.17 to 4.57). The highest tree water uptake recorded was at the slope station with the existence of the Alstonia Angustiloba tree with a depth of 0.25 m and a distance of 1.1 m from the tree. The tree water uptake utilized in this study can contribute to a carbon-free and eco-friendly approach which can be implemented globally to prevent slope catastrophe.

Effectiveness of Silica Fume Eggshell Ash and Lime Use on the Properties of Kaolinitic Clay

“…5. The unaltered kaolinitic clay had an MDD of 1.55 g/cm 3 and an OMC of 21%, which is identical to the findings reported by previous investigations [23][24]. The kaolinitic clay samples showed a reduction in MDD and OMC value when the soil was altered with 2% SF, with an MDD and OMC of 0.04 g/cm 3 and 3.0%.…”

“…The kaolinitic clay samples showed a reduction in MDD and OMC value when the soil was altered with 2% SF, with an MDD and OMC of 0.04 g/cm 3 and 3.0%. MDD steadily increased to 1.51 g/cm 3 and 1.52 g/cm 3 when SF levels of 4% and 6% were used, while OMC continuously decreased to 17.5% and 17.9%, respectively. The increase in OMC was symmetrically limited, due to the lower specific gravity and heterogeneous particle size of the SF, resulting in the formation of enlarged cavities However, the findings were contradictory to the research by Türköz et al [22], which showed that the use of 2%, 4%, and 6% of SF reduced the specific gravity of kaolinitic clay but did not substantially affect its grain size, resulting in a slight reduction in OMC for the different utilization ratios of SF.…”

“…Meanwhile, Kaolinitic clay contains a significant proportion of kaolinite minerals [2]. Kaolinitic soil is a challenging soil type commonly encountered in construction projects, known for its problematic properties related to changes in moisture levels [1][2][3]. These soils are characterized by a range of engineering characteristics and weaknesses, which include significant sediment retention, low shearing strength, insufficient plasticity, excessive compressibility, dispersion, enlargement, erosion, or vulnerability to environmental factors [4][5].…”

Stabilization of Expansive Soil using Silica Fume and Lime

“…This continuous rise in PL with the addition of SF can be attributed to cation exchange between kaolinite clay minerals and positive cations present in SF. The decrease in plasticity properties of kaolinite clay was a consequence of substituting highly plastic clay particles with less reactive SF particles, leading to flocculation and a subsequent reduction in consistency limits, as discussed by Zaini et al [15] and Zaini et al [16]. The PL and LL value of the stabilized kaolinite clay were also reduced when different percentages of lime were utilized with 6% of SF.…”

Shear Strength of Soft Soil Reinforced with Singular Bottom Ash Column

“…Therefore, it has a high potential to replace conventional aggregates for various engineering purposes. Beneficial use of bottom ash as replacement material in stone column offer an attractive alternative of disposal due to the substantial economic savings which can be attained by the reduction of ash disposal costs and the conservation of natural soils and lands [17][18][19]. This study is therefore aimed in investigating the enhancement of strength of soft clays when it is reinforced with singular bottom ash column as a replacement for the stone column.…”