Alternatif Perencanaan Terowongan Pengelak (Diversion Tunnel) Bendungan Pamukkulu

Natalia Anga (Fakultas Teknik Sipil Universitas Kristen Indonesia Paulus)
Melly Lukman (Fakultas Teknik Sipil Universitas Kristen Indonesia Paulus)
Erni Rante Bungin (Fakultas Teknik Sipil Universitas Kristen Indonesia Paulus)

Paulus Civil Engineering Journal
Vol 4 No 3 (2022): Paulus Civil Engineering Journal Volume 4 No.3

In the construction of the Pamukkulu Dam, the initial design used in planning the evasion tunnel was a horseshoe shape. However, in this study an alternative planning in the form of a circle is proposed.The regional average rainfall was calculated by the Thiessen Polygon method and the design rainfall analysis calculation with a return period of 2,5,10,25 years using the Gumbel method, Log Normal method, and Pearson Type III Log method. By using the distribution suitability test Smirnov-Kolmogorov Test and Chi- Square Test. The design discharge was analyzed using the Nakayasu. Synthesis Unit Hydrograph method.Based on the results of this study, the 25-year design flood discharge was 291.548 m3/second and the circular escape tunnel design was 6 m in diameter with an energy loss height of 11.821 m and the design height of the cofferdam crest was +85.571 m.