PENGARUH PENAMBAHAN SERAT SERABUT KELAPA TERHADAP KUAT GESER TANAH GAMBUT DI KOTA PALANGKA RAYA, KALIMANTAN TENGAH

THE EFFECT OF ADDING COCONUT FIBER TO THE SHEAR STRENGTH OF PEAT SOIL IN THE CITY OF PALANGKA RAYA, CENTRAL KALIMANTAN

Abstract

Masalah  penurunan tanah gambut di kota Palangka Raya merupakan hal yang perlu diperhatikan dalam pekerjaan konstruksi pembangunan, terutama di Jl. Hiu Putih (lingkar luar) sehingga memerlukan stabilisasi pada tanah gambut tersebut. Tujuan penelitian yaitu menganalisis sifat fisik dan sifat mekanik tanah yang distabilisasikan dengan serat serabut kelapa. Hasil pemeriksaan sifat fisik tanah berdasarkan klasifikasi ASTM menunjukkan kadar air sebesar 560,91%  tergolong  kategori moderately absorbent, kadar abu sebesar 4,85% tergolong low ash, dan kadar serat sebesar 61,20%  tergolong Fibric, dan menurut klasifikasi Mac Farlane dan Radfofh (1985) tergolong Fibrous peat. Dalam klasifikasi USCS tergolong Pt (Peat). Hasil pemeriksaan sifat mekanik tanah asli memeproleh nilai sudut geser sebesar 12° dan nilai kohesi sebesar  0,099 kg/cm² dan uji kuat geser sebesar  0,46885 kg/cm² dengan nilai daya dukung tanah (q_ult) sebesar 1,52701 kg/cm² dan nilai daya dukung ijin (q_ijin) sebesar 0,50901 kg/cm². Nilai tertinggi uji kuat geser langsung  diperoleh pada campuran 90% tanah gambut dan 10% serat serabut kelapa dengan massa pemeraman 3 hari yaitu sebesar 0,67297 kg/cm² dengan nilai daya dukung tanah (q_ult) sebesar 2,87152 kg/cm² dan nilai daya dukung ijin (q_ijin) sebesar 0,95717 kg/cm².

 

The problem of subsidence of peat soil in the city of Palangka Raya is a matter that needs to be considered in construction work, especially on Jl. Hiu Putih (Lingkar Luar) so that it requires stabilization on the peat soil with coconut fiber material. The purpose of this research is to analyze the physical properties of the soil, to analyze the mechanical properties of the soil which is stabilized with coconut fibers. The results of laboratory testing of the physical properties of the soil in ASTM showed that the water content of 560.91% was classified as moderately absorbent, the ash content of 4.85% was classified as low ash, and the fiber content of 61.20% was classified as Fibric, and according to Mac Farlane and Radrorth (1985) is classified as fibrous peat. In USCS classified as Pt (Peat). The results of laboratory testing of the original soil mechanical properties obtained a shear angle value of 12° and a cohesion value of 0.099 kg/cm² and a shear strength test of 0.46885 kg/cm² with a soil bearing capacity value (q_ult) of 1.52701 kg/cm² and a strength value of 1.52701 kg/cm². support permit (q_ijin) of 0.50901 kg/cm². The highest value of direct shear strength test was obtained in a mixture of 90% peat soil and 10% coconut fiber fiber with a 3 day ripening mass of 0.67297 kg/cm² with a soil bearing capacity value (q_ult) of 2.87152 kg/cm² and a strength value of 2.87152 kg/cm². permit support (q_ijin) of 0.95717 kg/cm².