Assessment to the comparison between the initial state and insitu conditions of Bengawan Solo river embankment during the dry and monsoon seasons at Kanor-Village

Abstract

Water level fluctuation during dry and monsoon seasons might be the cause of river embankment condition changing. The insitu soil properties exhibits different behavior among these seasons, such as soil density, soil shear strength and soil suction. This paper is mainly the comparison between the Bengawan Solo river embankment's initial state and insitu conditions at Kanor village section, Bojonegoro, East Java, Indonesia. Furthermore, the field investigations at upper and lower embankment were conducted to obtain the insitu soil properties (dry density, shear strength and suction) during dry and monsoon season. In addition, soil sampling was also performed for laboratory investigation. The laboratory investigations were carried out to understand the initial fresh compacted soil (standard Proctor test) condition and to obtain soil properties. The results showed that the upper and lower insitu density condition were affected by the water level fluctuation. The upper and lower sections upon water fluctuation were found to be around 65-85 % and 60-80 % of the optimum Proctor. The soil suction was found to be greatly higher comparing to the soil shear strength during the dry season. Moreover the cracks was developed in upper embankment rather than in lower section embankment.