Bambang Risharnanda, Suhardjono, H. Andre Primantyo, Runi Asmaranto
Grouting plays an important role in improving the dam foundation and reducing the permeability in Lugeon values. The precise assessment of the dam foundation grouting's quality has grown to be a top priority. The effectiveness of the grouting method for decreasing Lugeon values in the dam foundation has not been certainly revealed. The foundation of the dam is weathered lapilli tuff and gravelly sand is a typical porous weathered rock. The grouting has been performed as a down-stage, in which the grout hole is drilled in stages using a pneumatic packer. The improvement of the dam foundation by grouting is evaluated by comparing the first permeability (permeability before grouting) and secondary permeability (permeability after grouting) by using Lugeon values with a water pressure test (WPT). This test employed 608 data which included the first permeability, depth, grout take, and secondary permeability. This study has revealed that the first permeability for low permeability values (1 – 5 Lu) in depths of 5-30 m does not exist. The grout take ranges from 12.79 to 2212.09 kg/m. Finally, secondary permeability for depths of 5, 10, 15, 20, 25, and 30m is 15.00%,20.00%, 19.30%, 43.81%, 48.05%, 69.57% respectively. This paper focuses on evaluating dam foundation improvement with a grouting method in Bajulmati Dam by using the permeability, grout takes and conditions of rock mass discontinuities. Thus, the results are expected to be applicable to assess the quality of curtain grouting. © 2023 by authors, all rights reserved.
Doctoral Program in Department of Civil Engineering, Faculty of Engineering, University of Brawijaya, Indonesia; Brantas River Basin Organization, Directorate General of Water Resource, Ministry of Public Works and Housing, Indonesia; Department of Water Resources, Faculty of Engineering, University of Brawijaya, Indonesia