Curtain Grouting Effectivity Analysis On Foundation Rocks In Blocks 37 – 40 In The Body Of Randugunting Dam, Blora Regency, Central Java

Abstract

Blora Regency is a barren area in Indonesia and has drought disaster potential, to address those problems Indonesian Governments launched Randugunting Dam’s construction program. The research area was located at Block 37 – 40, Radugunting Dam, Japah District, Blora Region. Dam as a water retention building should have foundation rocks that are resistant towards seepage potential, therefore curtain grouting was conducted to seal geological fractures on the foundation rocks. The purpose of these research was to understand the seepage potential on foundation rocks, foundation rocks curtain grouting requirement, and curtain grouting effectiveness. Research method used were water pressure test (WPT) data analysis, in the form of water flow discharge data processed through calculation to produces Lugeon value (Lu). The Lugeon value (Lu) would be further analyzed to determine the curtain grouting effectiveness value. The result of the analysis shows that around 18.15% of the research area have seepage potential that was shown by medium (3 < Lu < 10) – high (Lu > 10) Lugeoun (Lu) value. After the curtain grouitng was conducted, it effectiveness value on Block 37 was 88.34% (good), on Block 38 was 81.43% (good), on Block 39 was 70,62% (good), and on Block 40 was 79.41% (good).