POINT DETERMINATION AND DEPTH OF PYLON AND ANCHOR POSITIONS FOR DETERMINING SPAN LENGTH MUNA - BUTON BRIDGE
Keywords:bridge, geology, span, pylon, anchor
Planning of the Muna - Buton Bridge which is will connect two large islands in Southeast Sulawesi Province Muna Island and Buton Island, based on the results of the analysis so as not to disturb flight and ship lanes height is limited to 200 m, and bridge clearance height is limited to 50,88 m, so selected suspension bridge for bridge type. The result of preliminary survey found a lot fracture in Buton Island that will have an effect of bridge span determination. Detailed geological mapping, geoelectrical survey and drill log correlation, carried out to determine the placement of pylon dan anchor so that efficient and safe span can be obtained. The results of the study there are 21 fractures at the location plan of the Muna - Buton (Buton Island), and there are 5 fractures passed by bridge center line directional fractures are NE – NW. Lithology that composes subsurface geology Muna Island are silt, claystone and marl and lithology that composes subsurface geology Buton Island are soil, limestone, and claystone. Laterally the Pylon and Anchor Laying on the Buton Island are in the Moderate Zone, vertically the pylon and anchor are located in claystone at depth 60 meter under the ground. In Muna Island Vertically the pylon and anchor are located in the Low Risk Zone and no fracture effect. Pylon and anchor are located in claystone at depth 60 meter under the ground. The span obtained by pulling the two pylon points is 765 m which is a medium cost and safe span for the construction of the Muna - Buton Bridge.