PARAMETERS OF PHYSICAL PROPERTIES AND STRENGTH OF SOIL SHIFT RESULTING FROM THE ADDITION OF NACL (Case Study: Rungkut District, Surabaya City, East Java)
Tanah lempung merupakan jenis tanah yang memiliki karakteristik unik, seperti plastisitas tinggi, permeabilitas rendah, serta sifat kembang susut yang signifikan akibat fluktuasi kadar air. Namun, penelitian ini berfokus pada penggunaan NaCl sebagai alternatif stabilisasi, mengingat kemampuannya memodifikasi sifat fisis dan mekanis tanah lempung, termasuk meningkatkan kepadatan dan mengurangi plastisitas.
Metode penelitian yang digunakan bersifat kuantitatif dengan pendekatan statistik dan pengujian laboratorium terhadap sampel yang diambil. NaCl dipilih sebagai bahan stabilisasi karena komposisinya yang sederhana dan efektif dalam memperbaiki karakteristik tanah. Penelitian ini menguji variasi campuran Garam NaCl (10% dan 15%) dan air laut untuk melihat pengaruhnya terhadap nilai kuat geser tanah lempung dari wilayah Gunung Anyar, Surabaya, yang memiliki masalah stabilitas tanah.
Hasil penelitian menunjukkan bahwa tanah asli memiliki kohesi 8,312 kPa dan sudut geser 19,367°. Dengan tambahan 10% Garam (NaCl), kohesi menjadi 9,930 kPa dan sudut geser menjadi 21,405°. Penambahan 15% Garam (NaCl) menghasilkan kohesi 11,984 kPa dan sudut geser 22,343°. Serta pada penambahan Air Laut menghasilkan kohesi 12,690 kPa dan sudut geser 24,228°. Dengan demikian, stabilisasi tanah lempung menggunakan NaCl terbukti mampu meningkatkan kekuatan direct shear, menjadikannya solusi potensial untuk perbaikan tanah di daerah berkarakteristik lempung seperti Surabaya Timur.
Clay soil is a type of soil that has unique characteristics, such as high plasticity, low permeability, and significant swelling and shrinkage properties due to fluctuations in water content. However, this study focuses on the use of NaCl as an alternative stabilizer, given its ability to modify the physical and mechanical properties of clay soil, including increasing density and reducing plasticity.
The research method used is quantitative, employing statistical analysis and laboratory testing on samples collected. NaCl was selected as a stabilizing agent due to its simple composition and effectiveness in improving soil characteristics. This study tested variations in NaCl salt mixtures (10% and 15%) and seawater to assess their impact on the shear strength values of clay soil from the Gunung Anyar area in Surabaya, which faces soil stability issues.
The research results indicate that the original soil has a cohesion of 8.312 kPa and a shear angle of 19.367°. With the addition of 10% salt (NaCl), cohesion increased to 9.930 kPa and the angle of repose to 21.405°. Adding 15% salt (NaCl) resulted in cohesion of 11.984 kPa and an angle of repose of 22.343°. Additionally, adding seawater produced cohesion of 12.690 kPa and an angle of repose of 24.228°. Thus, soil stabilization using NaCl has proven effective in enhancing direct shear strength, making it a potential solution for soil improvement in clay-dominated areas such as East Surabaya.
Keywords: Clay soil, soil stabilization, NaCl, direct shear.