Stabilization of soft soil with rice husk and coconut fibre

• Published in: IOP conference series. Earth and environmental science 2024-06, Vol.1347 (1), p.12058
• Main Authors: Zulkafli, M H, Noorasyikin, M N, Roslan, L F
• Format: Article
• Language: English
• Subjects: Atterberg limits; Compaction; Curing; Dry density; Liquid limits; Mechanical properties; Moisture content; Natural resources; Physical properties; Rice; Rice fields; Shear strength; Shear stress; Shear tests; Silica; Soil bearing capacity; Soil compaction; Soil improvement; Soil mechanics; Soil mixtures; Soil moisture; Soil physical properties; Soil properties; Soil stabilization; Soil structure; Soil testing; Soil types; Stabilization; Water content
• ISSN: 1755-1307; 1755-1315
• DOI: 10.1088/1755-1315/1347/1/012058

This study focuses on the stabilization of soft soil, which has a low bearing capacity and is prone to significant deformations and high moisture content. Soft soil is one type of soil with a poor bearing capacity, and when loaded, it significantly reduces the likelihood of a nonuniform decline. The aim of this study is to determine the physical properties of soft soil and to determine the mechanical properties of soft soil mixture with rice husk and coconut fibre with curing days of 14, and 21 days. The significance of this study lies in its contribution to establish a strong foundation and stabilizing soil, which plays a crucial role in constructing solid and durable structures, ensuring their stability and longevity. By utilizing rice husk and coconut fiber as soil stabilizers, the study also addresses environmental concerns by substituting natural resources with unwanted or discarded materials. Furthermore, this approach offers an economically viable solution for soft soil stabilization. The study involved two types of soil samples. The first type served as a control sample without any rice husk or coconut fiber, while the second type included rice husk and coconut fiber. The second type of sample was further divided into two ratios, with curing durations of 14 days and 21 days. A soil sample was collected from a paddy field in Sg Balang, Muar, Johor. The rice husk was burned at temperatures below 800 °C, resulting in silica-rich ash. The physical and mechanical properties of the soft soil mixture with rice husk and coconut fiber were determined through various tests. The preliminary tests were conducted to assess the physical qualities of the soil, including the Atterberg Limit Method, Compaction Test, and Direct Shear Test. The results showed that the Liquid Limit (LL) was 20.1%, with moisture content ranging from 15.56% to 27.38%. The compaction test indicated that a ratio of 2 with a 21-day curing duration achieved a maximum dry density of 0.56 and an optimum moisture content of 47.8%. The Direct Shear Test demonstrated that a ratio of 1 with a 21-day curing period exhibited the highest shear strength and shear stress at 3.25 kg and 10.45 kPa, respectively. Moreover, the cohesive and friction angle increased with longer curing days, with the mixture of ratio 1 and 21 days showing the highest values at 4.7 kPa and 35.03°, respectively. In summary, the presence of rice hush and coconut fibre significantly improve the soft soil stabilization. The stud