Metode Pelaksanaan Pekerjaan Consolidation Grouting dan Analisis Stabilitas Diversion Tunnel pada Proyek Pembangunan Waduk Bendo Ponorogo

INDAHSARI PERTIWI, Dr. Ing. Ir. Agus Maryono

2018 | Tugas Akhir | D3 TEKNIK SIPIL

Konstruksi terowongan pengelak merupakan bagian penting dalam pelaksanaan bendungan. Terowongan pengelak berperan sebagai media pengalihan aliran air sungai, sehinga pekerjaan timbunan maindam dapat dimulai. Struktur terowongan yang berada di bawah tanah, dan penggalian dengan metode peledakan (blasting) menyebabkan terjadinya deformasi maupun terbentuknya rekahan pada sekitar terowongan. Untuk itu perlu dilakukan adanya perbaikan struktur tanah dan batuan sekitar terowongan dengan grouting konsolidasi. Tujuan dari studi ini adalah untuk mengetahui gaya-gaya dan deformasi yang terjadi pada terowongan, serta mengetahui metode pelaksanaan grouting konsolidasi. Metodologi penulisan yang digunakan dalam studi ini adalah metode observasi (pengamatan di lapangan), metode interviu (wawancara langsung), metode deskriptif, dan metode analisis dengan menggunakan Plaxis 2D. Hasil analisa diketahui total regangan maksimal sebesar -0,02495% dan tegangan efektif maksimal sebesar -1,75.103 kN/m2. Gaya aksial terbesar terjadi pada wall (N= -12,609 kN/m) dan momen terbesar terjadi pada invert (M= -3,8002 kNm/m). Total perpindahan yang terjadi akibat gaya gaya yang bekerja addalah sebesar 0,524.10-3 mm. Pekerjaan grouting konsolidasi terdiri dari drilling (pengeboran), Water Pressure Test (uji kelulusan air), dan injeksi campuran (grouting). Metode yang digunakan dalam pelaksanaan grouting konsolidasi adalah sistem lompat katak atau split spacing yang berguna untuk meminimalisir terjadinya kebocoran saat injeksi.

Diversion tunnel is an important part of dam construction, this tunnel is necessary to deflect water flow from the river so that main dam works can be begin. Its structure that lies undergorund and excavation by blasting lead to deformation and fractures around the tunnel. Therefore consolidation grouting need to be done to improve soil and rock structures around the tunnel. This study aims to know the forces and deformation that may happen to tunnel, and to know the implementation works of consolidation grouting are done. Methods used in this study are observation, interview, descriptive, and analytical method by using Plaxis 2D. From analysis by using Plaxis 2D are known that the total maximum strain that happen is -0,02495% and the maximum effective stress is -1,75.103 kN/m2. Biggest value of axial forces is happened to wall section (N= -12,609 kN/m) and biggest value of bending moment is happened to invert section (M= -3,8002 kNm/m). Total displacement that caused by those forces is 0,524.103 mm. From observation in field can be known that there are three main steps in consolidation grouting works which is drilling, Water Pressure Testing, and mixture injecting. This work is using split spacing method, so the leaks of water or mixture during injection can be minimized.Diversion tunnel is an important part of dam construction, this tunnel is necessary to deflect water flow from the river so that main dam works can be begin. Its structure that lies undergorund and excavation by blasting lead to deformation and fractures around the tunnel. Therefore consolidation grouting need to be done to improve soil and rock structures around the tunnel. This study aims to know the forces and deformation that may happen to tunnel, and to know the implementation works of consolidation grouting are done. Methods used in this study are observation, interview, descriptive, and analytical method by using Plaxis 2D. From analysis by using Plaxis 2D are known that the total maximum strain that happen is -0,02495% and the maximum effective stress is -1,75.103 kN/m2. Biggest value of axial forces is happened to wall section (N= -12,609 kN/m) and biggest value of bending moment is happened to invert section (M= -3,8002 kNm/m). Total displacement that caused by those forces is 0,524.103 mm. From observation in field can be known that there are three main steps in consolidation grouting works which is drilling, Water Pressure Testing, and mixture injecting. This work is using split spacing method, so the leaks of water or mixture during injection can be minimized.

Kata Kunci : Diversion Tunnel, Plaxis 2D, Deformasi, Consolidation Grouting, LugeonDiversion Tunnel, Plaxis 2D, Deformasi, Consolidation Grouting, LugeonDiversion Tunnel, Plaxis 2D, Deformasi, Consolidation Grouting, Lugeon