LANDSLIDE ON LOCATION OF WATER SOURCE STUDENAC NEAR BIJELJINA, REPUBLIKA SRPSKA

Abstract

ABSTRACTThe landslide is located in the hinterland of water source "Studenac" in the local community GornjaCadjavica near Bijeljina. The field where the triggered landslide occurred is conditionally stable slope.It is overgrown with forest trees and therefore it was not a subject of interest in terms of its stabilityuntil the water source and accompanying local road have been constructed in the lower part of theslope. Additionally the slope was undercut resulting in jeopardizing its conditional natural stability. Atfirst, it was about some slight ground movements requiring no significant interventions.As the time was passing by site conditions have been changing. During winter and spring timemovement of rock blocks is more intense due to large amount of surface and underground waterwhereby such a process was significantly slower and almost calm in the summer time. Such a cycle wasrepeated for several years until late 2010 when massive collapse of the unstable zone, which might becalled ‘landslide’, endangered not only the local road but also the water source.For the purposes of overviewing the site and landslide characteristics as a whole, exhaustive researcheswere carried out within the part of the site affected by sliding at the surface of about 0,4 ha. A fieldsurveying of wider area was also conducted. The landslide is located at relatively steep slope where theheight distance between the crown and the toe of the landslide is 14,0 m. General slope angle is up to100 and in those parts where landslides occur they are up to 250. Sliding plane has been formed at depthof 2,5 to 4 m depending on terrain morphology, in clay of high plasticity (CH groups). The main causeof landslides is surface and underground water.Within the scope of remediation project two restorative measures were applied. The main recoverymeasure was placement of AB retaining concrete wall which was intended to accept the pressures ofsoil mass and to prevent it from slipping, namely to maintain the slope in stable condition. The otherremedial measure was construction of an open perimeter canal at the slope above the retaining wall forthe purposes of collecting surface water flowing towards the main body of the landslide and itsdiversion outside the sliding area.

Key words: landslide, slope, water source, research, rehabilitation