Slope mass rating-based analysis to assess rockfall hazard on Yogyakarta Southern Mountain, Indonesia

Abstract

In the Parangtritis Beach tourism area located in the Southern Mountain of Yogyakarta, karst hills were excavated to build the main accessing road and produce some of long and very steep slopes along the sides of the road. But still, there was none of the slope reinforcement installed along the road. Meanwhile, at several nearby locations within Southern Mountain, rockfall incidents have occurred many times even caused casualties. The potential of rockfall hazard also could be found in the main road of Parangtritis Beach as the study area. The purpose of this study is to determine the rockfall hazard assessment along the main road using Slope Mass Rating (SMR) analysis with the additional parameter of the slope height and the rock block size. The necessary data obtained by direct measurement and laboratory test. Geomechanics analysis, stereographic projection analysis, and hazard parameters weighting were carried out to produce the Rockfall Hazard Zonation Map of the study area. Based on 17 measurement stations, there are 4 (four) rockfall hazard classes in the study area, i.e., very low, low, moderate, and high. The class of very low, which also included road segments without slope, has the largest percentages of 83.83%, followed by the classes of moderate, low, and high with the percentage of 7.16%, 4.28%, and 4,19%, respectively. SMR was assumed as the most significant parameter that influences the rockfall hazard zonation. Historical rockfall points were overlaid over the Rockfall Hazard Zonation Map to validate the predicted hazard zones. Since 91.23% of the rockfall occurred in the moderate and high hazard classes, the zonation map considered reliable to predict future rockfall. This study also identified several landslide potential zones and provides the recommendation of slope reinforcement to be installed in the study area.

Novel methods for quantitative analysis of kinematic stability and slope mass rating in jointed rock slopes with the aid of a new computer application

“…Several works have been done to assess rock slope stability on the basis of slope mass rating (Singh et al 2014(Singh et al , 2015Sarkar et al 2016;Mahanta et al 2016;Siddique et al 2017;Sardana et al 2019). In addition to the application in rock slopes, recently, SMR classification system has also been applied to check stability in open pit mines (Prasetya et al 2015;Zakaria et al 2016;Morales et al 2019) and detect rockfall hazards in mountainous region (Triana and Hermawan 2020;Albarelli et al 2021). When there is such a wide application of the classification system, the ratings should be determined in a more precise way.…”

Determinasi dan penerapan Rock Mass Rating untuk penilaian stabilitas lereng andesit di Seloharjo, Bantul

“…Stabilitas lereng batuan di Seloharjo memiliki peran penting dalam mendukung kawasan wisata Parangtritis, yang di bagian utara terdapat obyek wisata gua bersejarah seperti Goa Surocolo atau Goa Sunan Mas, peninggalan Mataram Hindu abad ke-10 dan Mataram Islam abad ke-17, serta Goa Jepang yang menjadi bagian sejarah masa penjajahan Jepang pada tahun 1940 an [9]. Meskipun sebelumnya telah dilakukan analisis stabilitas lereng di Seloharjo, Parangtritis, dan sekitarnya dengan menggunakan sistem klasifikasi massa batuan seperti Rock Mass Rating (RMR) [10], Slope Mass Rating [11], Rock Quality Designation (RQD) [12], penilaian RMR versi 1979 yang dilengkapi dengan analisis kinematika bersama parameter lainnya seperti orientasi bidang diskontinuitas dan orientasi lereng belum pernah dilakukan untuk penilaian stabilitas lereng yang lebih akurat. Menurut Bieniawski, metode RMR masih memerlukan penyempurnaan, khususnya dalam parameter yang berkaitan dengan orientasi bidang diskontinuitas dan orientasi lereng.…”

Rock slope stability assessment using kinematic analysis at Gunung Batu, Lembang, West Java, Indonesia

“…The fastest method in the decision-making for slope stability analysis is an empirical method. A few of the empirical methods used for the rock mass classification are Q-System [4], Rock Mass Rating (RMR) [5], Mining Rock Mass Rating (MRMR) [6], and Slope Mass Rating (SMR), that is an RMR modification [7][8][9][10]. The SMR method uses the discontinuity plane as the boundary factor.…”