KARAKTERISTIK KUAT GESER TANAH GAMBUT AKIBAT PEMAMPATAN

Peat has different characteristics compared to clay. It is physically recognized as soil with organic materials content, great amount of water, high void ratio, and the existence of fibers. However, it technically has high compressibility and low shear strength. To identify how big is the influence of compression behaviour towards the increment of peat`s shear strength, some consolidation and vane shear test need to be performed in order to obtain a proper method to initiate constructions on peat. This research used amorphous peat samples which were taken from Tambang, Kampar district in disturbed condition. They consisted of two variations, i.e.: natural condition, and non-fiber condition. The used equipments were modified consolidometer with diameter of 15 cm and height of 15 cm, and also vane shear instruments. The loads were gradually applied with magnitude of 10 kPa, 20 kPa, 40 kPa, 80 kPa, 160 kPa and 320 kPa, each of them were elevated every ±14 days, and a vane shear test was performed before the load was added. The results showed that the shear strength has been increasing due to the higher compression, as well as the void ratio. In case the void ratio gets smaller, the shear strength has increased. Hence, peat`s bearing capacity will increase along with the higher shear strength