METODE GROUTING UNTUK MENINGKATKAN DAYA DUKUNG TANAH DI BANGUNAN STASIUN POMPA DRAINASE SIBULANAN, PEKALONGAN, JAWA TENGAH

Abstract

Sibulanan drainage pump station located on Slamaran beach recreation area, have an excessive settlement due to a lack of soil bearing capacity on the study site. Soil material in study site is transported soil, with a fine sandy clay silt lithology. The type of soil that is a young alluvium sediments which have not been consolidated resulted a low bearing capacity in study site, drives an excessive settlement. In this study, sounding is used to gather the data. Determination of soil types and soil consistencyuse fr and qc relationship from Bowles, 1997 and classification of soil consistency from Terzaghi and Peck, 1984. Soil bearing capacity calculations using the bearing capacity of pile foundation formulas from Wesley, 1977. Based on field observations in study site, low bearing capacity of the soil caused by transported soil and influence of tides. While based on sondir data analysis, the study found, type of soil in study site form of clay until silty clay with qc values = 1.17 to 1.96 mpa and soil consistency is very soft until firm with qc values = 2.00 to 20.00 kg/cm² in depth of 23 meters. Soil bearing capacity at depth of 12 meter is only 3.8 tons. Grouting that was carried out by 52 points aimed to improving soil consistency and soil bearing capacity in study site until greater than 4.8 tons at depth 12 meters. Once grouting done, soil consistency of the study site turns into very soft until very stiff with qc values = 2.00 to 90.00 kg/cm² at depth 8.20 meters. Soil bearing capacity at depth 12 meters turns into 39.75 tons. Grouting methods in this study has been successfully increasing soil bearing capacity at depth 12 meters to be greater than 4.8 tons, making soil bearing capacity in the sudy to be secure.