The Influence of the Number and Height Steps of Terraced Model on Slope Stability Analysis

Abstract

Wonogiri is an area with a high volume of private, public, and logistics vehicles because it is located in the border connecting East Java, Central Java, and the Special Region of Yogyakarta. This area also has high susceptibility to landslide due to its topography. These landslides occur due to the weight of the slope and excess external traffic loads. Therefore, this research aims to determine the influence of the number and height steps of the terraced model on slope stability analysis in Wonogiri. Data were collected from 3 types of traffic loads, namely Own Weight (BS) + pavement + truck's load on two paths, BS + pavement + truck’s load on one path, and BS + pavement. The road class was designed with an assumed average daily traffic (ADT) of 3000 pcu/day (local road) with a width of 3 m (Direktorat Jenderal Bina Marga in Tata Cara Perencanaan Geometrik Jalan. Antar Kota, No.038/T/BM/1997. Badan Penerbit Pekerjaan Umum, Jakarta, 1997 [1]). Furthermore, the slope stability analysis was determined using the limit equilibrium method. The result showed that the addition of steps increases the value of the safety factor (SF) significantly. The greater the steps of the terracing model, the higher the SF value of slope stability. The height variation with the same number of steps proves that it affects the safety factor value. Therefore, the more step height designs, the higher the steps cloud the ability to resist the traffic load.