THE USE OF GYPSUM WASTE IN SOFT SOIL AS HEAP CONSTRUCTION MATERIAL

Abstract

Before building construction  on  the  ground with different contours  or on the  soft soil
conditions  be required an  embankment construction. A construction of embankment will
form new slopes that cause stress and strain changing of soil ,therefore so slope stability
must be analyzed  cause that embankment.. This   research  used the  soft clay mixed by
the gypsum waste   as embankment  material, because gypsum contained calcium to bind
the mineral soil, in increasing  the strength of the soil,  than that based on research
results mix of soft soil  with gypsum qualified as a embankment  material. Soft clay as
embankment material  was mixed by the gypsum waste about 1% - 6% to dry weight of
the soil. The results of testing the index  properties soil and the  parameter of shear
strength soil to he  mixture was used to analyze  the  stability of embankment slope
through embankment construction model using PLAXIS software as much as 7 modeling,
embankment construction model with soft clay as  embankment material  was mixed by
the gypsum waste about 0% - 6% . The results of the analyzing  the slope stability was
shown by the safety factor (SF) slope on the material  embankment  model with gypsum
waste  about 0% to 6% for instances SF 3,21 SF; SF 3,63; SF 3,89; SF 4,06; SF 4,21; SF
4,36; SF 4,50. Increased of slopes  safety factor (SF) until the addition of 6% of waste
gypsum to the soil reaches 40,19% .Based  on the research, the gypsum waste   provide
benefits for  ground construction  especially on improving the stability of  slope
embankment.