Effect of material quality on cemented sand and gravel (CSG) dam slope design of Cibeet

Abstract

The construction of the Cibeet Dam is crucial to mitigate downstream flooding in the Citarum River. Initially planned as an embankment dam with a 1:3.50 upstream slope, a 1:30 downstream slope, and a height of 47 meters, challenges arose due to foundation and earthquake considerations. The excessive requirement of embankment material at the dam site, which was insufficiently available, prompted the exploration of a more resource-efficient alternative. Consequently, a slimmer type of dam, specifically a Cemented Sand and Gravel (CSG) dam, was deemed necessary. The CSG dam, designed with minimal cement (80 kg/m3) and a mixture of sand and gravel (105.5 kg/m3), boasts a more upright slope, reducing material demand. This research examines the impact of material quality on the CSG dam slope. The finite element method assesses the dam’s stability using dynamic seismic forces. To achieve a stable dam slope design with existing materials, an extensive analysis was conducted on various slopes upstream and downstream, ranging from 1:0.70 to 1:1.20. The results indicate that a slope of 1:1.10 with a cement compound of 105.5 kg/m3 offers optimal stability. Implementing the CSG Dam effectively minimizes material requirements, mitigating the need for excessive exploration of material supplies.