THE SLOPE STABILITY OF WATER CANAL AND LANDSLIDE MANAGEMENT AT DADAHUP WATER CANAL CONSTRUCTION IN CENTRAL KALIMANTAN

Abstract

Dadahup Swamp Irrigation Area in Central Kalimantan Province has a land area of 21,226 Ha which carries out the water management system of Barito River, Kapuas Murung River and Mangkatip River. The site has many waterways that are parts of the Food Estate national strategic program which is aimed to supply the food demand. Dadahup Swamp Irrigation Area also has secondary canal that drains and supplies the water to rice fields. A slope failure occurred during the construction of new waterways nearby the traffic access road. The landslide site was in Bina Jaya Village, Jalan DIR Dadahup, Central Kalimantan Province. PLAXIS software was used in slope stability analysis. Seen from the soil characteristics, particularly at the canal bottom and canal slopes, soft clay soil dominated to a depth of 20 meters from the surface. Soft clay has a small shear strength and slides when triggered. Sheet piles of 18 meters long was selected as the slope reinforcement to handle the landslide around the Sluice Gate construction area. The sheet pile reinforcement improved the slope stability as seen from the value of the safety factor which exceeded the minimum requirements set in SNI 8460 of 2017