Evaluating the Effectiveness of Geotextile and Sub-Drainage in Addressing Road Subsidence on Bumiayu–Sirampog Road, Brebes Regency

Abstract

Road subsidence commonly occurs in highlands which have poor soil parameters, supported by a lack of proper treatment to prevent subsidence. Common problems are the unequal bearing capacity of the subgrade at each location and variations in settlement caused by the presence of soft soil layers beneath the subgrade. This is why using a geotextile approach is the first step. Like the road subsidence incident located in Sridadi Village, Kec. Sirampog, Kab. Brebes, to be precise at KM 116+100 to KM 116+250, was caused by ground movement which was influenced by a fault from the North East to the South West. Based on the collection and processing of primary and secondary data, the results of the technical evaluation of road repairs on soft soil were obtained, namely treatment with geotextile reinforcement, namely class 1 stabilizer type. Use of 5″ PVC pipe sub-drainage and Ø 1 m Armco to drain water below the ground surface. Through 2D V20 plaxis modeling, the condition of soil stability can be determined before and after the use of geotextiles and sub-drainage at that location. Namely, it can minimize the extreme value of land displacement (Utot) which was originally 5.126 m to 1,414 m. And the reduction value obtained based on field observations was smaller than the laboratory calculation, namely 0.700 m < 0.845 m.