KAJIAN PERBAIKAN PONDASI KOMBINASI PLASTIC CONCRETE CUT OFF WALL DAN GROUTING PADA PEMBANGUNAN BENDUNGAN TUGU KABUPATEN TRENGGALEK

Abstract

ABSTRAK: Pondasi bendungan merupakan salah satu komponen bendungan yang harus diperhatikan. Dari hasil investigasi geologi pada pondasi Bendungan Tugu dijumpai kedalaman alluvial kollovial dasar sungai mencapai 5–36 m (dari dasar sungai) dengan rerata kualitas batuan dari nilai RQD adalah very poor dan poor. Dari hasil Water Pressure Test menunjukkan masih banyak nilai lugeon > 3. Dengan pertimbangan kondisi geologi pondasi, maka untuk memperbaiki kondisi geologi pondasi secara efektif dan efisien dibutuhkan perbaikan pondasi kombinasi plastic concrete cut off wall dan grouting. Kedalaman plastic concrete cut off wall direncanakan dengan mempertimbangkan kedalaman lapisan kollovial dan material mengacu pada ICOLD (1985). Grouting yang direncanakan pada Bendungan Tugu meliputi curtain, sub curtain dan consolidation grouting. Dilakukan analisa keamanan bendungan (debit rembesan, piping dan deformasi) menunjukkan bahwa bendungan dalam kondisi aman setelah perbaikan pondasi.

Kata kunci: Bendungan Tugu, Geologi, Perbaikan Pondasi, Plastic Concrete Cut Off Wall, dan Grouting.

ABSTRACT: The dam foundation is one of the dam components that must be considered. From the result of geological investigation on foundation of Tugu Dam found the depth of alluvial kollovial river basin reach 5-36 m (from river bed) with mean of rock quality from RQD value is very poor and poor. From the results of Water Pressure Test shows that there are still many lugeon values > 3. With consideration of the foundation's geology condition, to improve the foundation's geological condition effectively and efficiently it is needed to improve the foundation of plastic concrete cut off wall and grouting combination. The depth of the plastic concrete cut off wall is planned by considering the depth of the kollovial layer and the material refers to ICOLD (1985). Grouting planned at Tugu Dam covers curtain, sub curtain and consolidation grouting. Conducted a dam safety analysis (seepage discharge, piping and deformation) shows that the dam is in safe condition after the foundation repair.

Keywords: Tugu Dam, Geology, Foundation Improvement, Plastic Concrete Cut Off Wall, and Grouting.

ABSTRAK: Pondasi bendungan merupakan salah satu komponen bendungan yang harus diperhatikan.
Dari hasil investigasi geologi pada pondasi Bendungan Tugu dijumpai kedalaman alluvial kollovial dasar
sungai mencapai 5–36 m (dari dasar sungai) dengan rerata kualitas batuan dari nilai RQD adalah very poor
dan poor. Dari hasil Water Pressure Test menunjukkan masih banyak nilai lugeon > 3. Dengan
pertimbangan kondisi geologi pondasi, maka untuk memperbaiki kondisi geologi pondasi secara efektif
dan efisien dibutuhkan perbaikan pondasi kombinasi plastic concrete cut off wall dan grouting. Kedalaman
plastic concrete cut off wall direncanakan dengan mempertimbangkan kedalaman lapisan kollovial dan
material mengacu pada ICOLD (1985). Grouting yang direncanakan pada Bendungan Tugu meliputi
curtain, sub curtain dan consolidation grouting. Dilakukan analisa keamanan bendungan (debit rembesan,
piping dan deformasi) menunjukkan bahwa bendungan dalam kondisi aman setelah perbaikan pondasi.
Kata kunci: Bendungan Tugu, Geologi, Perbaikan Pondasi, Plastic Concrete Cut Off Wall, dan Grouting.
ABSTRACT: The dam foundation is one of the dam components that must be considered. From the result
of geological investigation on foundation of Tugu Dam found the depth of alluvial kollovial river basin
reach 5-36 m (from river bed) with mean of rock quality from RQD value is very poor and poor. From the
results of Water Pressure Test shows that there are still many lugeon values > 3. With consideration of the
foundation's geology condition, to improve the foundation's geological condition effectively and efficiently
it is needed to improve the foundation of plastic concrete cut off wall and grouting combination. The depth
of the plastic concrete cut off wall is planned by considering the depth of the kollovial layer and the material
refers to ICOLD (1985). Grouting planned at Tugu Dam covers curtain, sub curtain and consolidation
grouting. Conducted a dam safety analysis (seepage discharge, piping and deformation) shows that the
dam is in safe condition after the foundation repair.
Keywords: Tugu Dam, Geology, Foundation Improvement, Plastic Concrete Cut Off Wall, and Grouting.