Indonesia has a territory that most of its topography consists of highlands. Along with the rapid growth of development, as results the need of lands for housing and transportation such as for road and highway, become scarce. The urgency of this matter caused land exploration on slope areas and highlands could not be stopped.
Research of the slope stability to the danger of slope slides on Jangli-Semarang toll road covers slopes with incisive declivity on Sta 0+550 the right side slope to Mrican, Sta 0+525, Sta 0+650, and Sta 0+675 the left side slope to Mrican. Currently on Sta 0+650 the left side slope to Mrican, had occurred slope slides on February 12, 2003, which on that month the rainfalls heavily caused water saturation. The slope slides problems often happens because of the condition of the area topography that’s too steep, and the geography that has a high frequency of rainfalls, because water can scraped sands layer, lubricate rocks or increase the water void ratio that reduces the shear strength.
Figure, Slope Slides on Jangli-Semarang Toll Road
Research about “Slope Stability to the Danger of Slope Slides” that took location on Jangli-Semarang toll road, uses soil and stone characteristic data, geological condition data, technical drilling data, laboratorial soil test data, and geohydrological data that got from the geotechnical research that was conducted by DPU institute of riset and development road project toll road Jangli- Semarang and the geotechnical research by Litbang PU Bandung on the recovery project of Jangli-Semarang slope on Sta 0+650. The analysis that conducted uses Bishop Method, Janbu Method, Ordinary Method with the help of computer program geo slope specialize on Slope/w.
From the slope stability analysis to the danger of slope slides on Jangli-Semarang toll road, we know that the safety number of the slope on Jangli-Semarang toll road section C decreased around 25% to 47% with the condition of the presence of water void and the slope condition that have incisive declivity with land limitation so that its hard to slope gently, so it needs to gave reinforcement by using geotextile, stones construction, anchor or another reinforcement alternative.
If you want to read the whole of the results of these studies please visit the library of the Faculty of Engineering, Islamic University of Sultan Agung, Semarang, Central Java, Indonesia. Or contact me via email at firstname.lastname@example.org
Skripsi/Tugas Akhir pada Universitas Islam Sultan Agung Semarang, Tahun 2003
“Analisa Kestabilan Lereng Terhadap Bahaya Longsor di Jalan Toll- Jangli Semarang”
Oleh Dwi Kusuma Sulistyorini, Guruh Nurul Yudawati, Prof. Ir. H. Pratikso, MST., Ph.D dan Ir. H. Sumirin, MS