Gerakan massa tanah terjadi pada tanggal 28 November 2017 di Dusun Bengle, Desa Dlepih, Kecamatan Tirtomoyo, Kabupaten Wonogiri, Provinsi Jawa Tengah. Tujuan dari penelitian ini untuk mengetahui tipe gerakan massa tanah dan mengetahui nilai faktor keamanan pada lereng berdasarkan sifat fisik dan mekanika tanah. Metode yang digunakan dalam pengumpulan data adalah metode survei dan pemetaan lapangan. Teknik pengambilan sampel tanah yaitu purposive sampling ditentukan berdasarkan jarak panjang

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... soran. Hasil laboratorium digunakan untuk menghitung kestabilan lereng menggunakan Metode Fellenius. Data pendukung yang diperoleh dengan pemetaan diantaranya kemiringan lereng, ketebalan dan tekstur tanah, penggunaan lahan dan kapasitas infiltrasi kemudian curah hujan diperoleh dari analisis data sekunder. Seluruh data yang diperoleh dianalisis sesuai dengan kondisi rona lingkungan. Tipe gerakan massa tanah di daerah penelitian adalah debris slide. Nilai faktor keamanan lereng diperoleh nilai 0,687 yang termasuk ke dalam klasifikasi tidak stabil. The ground mass movement took place on 28th November 2017 in Bengle Hamlet, Dlepih Village, Tirtomoyo Sub-District, Wonogiri Regency, Central Java Province. The purpose of this study was to determine type of soil mass movements and determine the value of safety factors on slopes based on physical and mechanical properties of the soil. The methods used in collecting the data were survey and field mapping methods. The soil sampling technique used in this study was purposive sampling based on the long of the avalanche distance. The laboratory results were used to calculate slope stability using the Fellenius Method. The Supporting data obtained by mapping were include the slope of land, the soil thickness and texture, land use and infiltration capacity and rainfall obtained from secondary data analysis. All data obtained were analyzed according to environmental conditions. The type of soil mass movement is debris slide. The value of slope safety factor was 0.687 which was included in the unstable classification.