JALAN MAJENANG-WANAREJA (CILACAP) DAN PENANGANANNYA DENGAN GEOTEKSTIL

Abstract

There have been significant number of road damages due to soil base instability, and this problem should be solved immediately because road (highway) is an important transportation infrastructure. One of alternative solution for this problem is using geotectile as strengthening material. According to direct visual inspection, soil is consisted of red clay soil which has high plasticity and shrinkage. This research took place at Majenang – Wanareja Road (KM 89 +100 – KM 89 +600). The research method for Wanareja soil was using direct survey at KM 89 +150 and taking soil sample, and then doing some laboratory experiment at Civil Engineering Laboratory Faculty of Engineering UMS. The laboratory experiment was done to find and analyse the soil physics and mechanic characteristic including soil cohessivity, the angle of soil shear, and the CBR value. After finding the soil characteristic, woven geotectile was designed. The result of soil characteristic test was data required in calculation, i.e., flatten load = 26,148 ton/m; saturated soil specific gravity for filled-soil = 1,6794 ton/m3 , the angle of inner shear = 29,637o, and soil cohessivity = 1,813 ton/m2; whereas for base soil, saturated soil specific gravity = 1,5061 ton/m3, the angle of inner shear = 25,106o, and soil cohessivity = 2,044 ton/m2. The final result of this analysis was that the use of woven geotectile WG – 350 with ult σ = 11,072 ton/m2 is feasible to be used as strengthening material, because it can detain moment with safety factor (SF = 3,153 > 1,5); can detain shear with safety factor (SF = 2,405 > 1,5); and can detain soil strength compression with safety factor (SF = 3,097 > 2,0).