<![CDATA[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 dasarsungai mencapai 5–36 m (dari dasar sungai) dengan rerata kualitas batuan dari nilai RQD adalah very poordan poor. Dari hasil Water Pressure Test menunjukkan masih banyak nilai lugeon > 3. Denganpertimbangan kondisi geologi pondasi, maka untuk memperbaiki kondisi geologi pondasi secara efektifdan efisien dibutuhkan perbaikan pondasi kombinasi plastic concrete cut off wall dan grouting. Kedalamanplastic concrete cut off wall direncanakan dengan mempertimbangkan kedalaman lapisan kollovial danmaterial mengacu pada ICOLD (1985). Grouting yang direncanakan pada Bendungan Tugu meliputicurtain, 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 resultof geological investigation on foundation of Tugu Dam found the depth of alluvial kollovial river basinreach 5-36 m (from river bed) with mean of rock quality from RQD value is very poor and poor. From theresults of Water Pressure Test shows that there are still many lugeon values > 3. With consideration of thefoundation's geology condition, to improve the foundation's geological condition effectively and efficientlyit is needed to improve the foundation of plastic concrete cut off wall and grouting combination. The depthof the plastic concrete cut off wall is planned by considering the depth of the kollovial layer and the materialrefers to ICOLD (1985). Grouting planned at Tugu Dam covers curtain, sub curtain and consolidationgrouting. Conducted a dam safety analysis (seepage discharge, piping and deformation) shows that thedam is in safe condition after the foundation repair.Keywords: Tugu Dam, Geology, Foundation Improvement, Plastic Concrete Cut Off Wall, and Grouting.]]>
