This study investigates the relationship between clay minerals (kaolinite and illite) and rock properties of the claystone, including both mechanical (cohesion, friction angle, stress, and strain) and physical properties (natural water content, void ratio, and wet density), belonging to Warukin Formation of Kalimantan, Indonesia. Mineralogical characteristics of these rocks were studied using petrological and X-ray diffraction techniques, whereas the mechanical and physical properties were tested by conducting uniaxial and triaxial tests. Relationship among the variables was determined using correlation coefficients. It was observed that the mineralogy of the rocks pose strong constraints on their engineering properties. The results showed that an increase in illite content decreases cohesion, friction angle, strength, and safety factor; and increases natural moisture content, void ratio, and wet density. Although illite content of these rocks was just about 10.8% of the total minerals, it has significantly contributed to the modification of physical and mechanical properties. In contrast, kaolinite did not have a significant impact; since the correlation between various parameters was significantly low (correlation coefficient was much less, <0.3). Therefore while selecting the materials for geotechnical engineering applications, illite emerges as a safer alternative to kaolinite, especially when its concentration is less than 10.8% of the total rock mass.

Modifikasi konsep PRA (Participatory Rural Appraisal) diperlukan bagi mahasiswa pada kegiatan KKN di provinsi Jawa Barat, Indonesia. Konsep modifikasi PRA  dapat digunakan sebagai alat komunikasi mahasiswa dengan penduduk desa lokal. Berbagai jenis gerakan tanah (longsor) terjadi di wilayah Jawa Barat. Jawa Barat menjadi wilayah yang paling rawan di dunia. Mahasiswa peserta KKN perlu dilengkapi dengan pengetahuan tentang kondisi wilayah Jawa Barat berdasarkan aspek geologi umum, juga mengenali informasi risiko dan bencana gerakan tanah, memahami penggunaan aplikasi Android yang berkaitan dengan bencana geologi, mahir menggunakan smartphone, mengetahui. beberapa metode penyampaian informasi dengan mudah dan komunikatif. Komunikasi yang baik dengan masyarakat lokal merupakan bagian dari tugas siswa sebagai salah satu agen pentahelix dalam Model Starlet (Stabilisasi dan Rancangbangun Lereng Terpadu). Hasil Pre-Test 58 mahasiswa menunjukkan bahwa 98% belum mengetahui konsep PRA, 91% belum mengetahui konsep pentaheliks dalam model Starlet, 82% tidak mengetahui bahwa Jawa Barat sangat rawan gerakan tanah, 88% belum mengenal konsep Sistem Informasi Geografis Aplikasi Penanganan Bencana Gerakan Tanah (SIGAP Bencana Gerakan Tanah), 83% belum mengenal model Starlet (Stabilisasi dan Rancangbangun Lereng Terpadu). Sebanyak 98% mahasiswa dapat membedakan resiko dan bencana, 72% dapat membedakan kerentanan dan bahaya, dan 100% mereka memerlukan suatu metode penyuluhan agar masyarakat pedesaan mudah menerima informasi dan mengetahui penanganannya.

Sari Para ilmuwan, pemerintah, pengusaha, dan masyarakat mempunyai pandangan yang sama terhadap bencana longsor, yaitu perlunya mengurangi kerugian yang timbul dan menghindari korban jiwa. Untuk menghadapi bencana longsor diperlukan pemahaman terhadap suatu daerah, terutama untuk mitigasi (limitasi dan stabilisasi). Untuk menangani lereng-lereng rawan terhadap longsor, diperlukan suatu pendekatan yang terpadu. Stabilisasi dan rancang bangun lereng terpadu (model starlet) merupakan suatu usulan dalam penanganan lereng rawan longsor dengan keterpaduan antara: (1) sistem pemetaan, (2) analisis kestabilan lereng, (3) simulasi rancang bangun lereng stabil, dan (4) arahan manajemen lingkungan yang disertai monitoring lingkungan. Selain hal di atas, diperlukan pula partisipasi para ilmuwan, aparat pemerintah, masyarakat, dan pengusaha dalam menghadapi bencana longsor ini. Longsoran Citatah membentuk suatu sistem longsoran dengan ukuran terbesar sampai terkecil yang merupakan suatu kesatuan. Longsoran di Pasir Pabeasan bagian barat (Pasir Pabeasan-Citatah) merupakan longsoran majemuk dengan jenis (lateral spread) bentangan lateral (lateral spread). Di sekitarnya terdapat longsoran lain, yaitu: jatuhan batuan, jungkiran batu, nendatan, luncuran bahan rombakan, dan luncuran tanah. Longsoran tersebut memperlihatkan sistem dan dimensi longsoran dari terkecil sampai terbesar. Kemiringan lereng (tanah) di atas 22,29 o sampai 44,28 o patut diwaspadai karena umumnya kritis. Untuk itu diperlukan stabilisasi. Sistem pemetaan wilayah longsoran perlu mempertimbangkan genetika wilayah. Peta genetika wilayah akan menampilkan satuan genetika wilayah (SGW) yang sangat mendukung peta zonasi gerakan tanah.

A regional development requires some analyses in terms of the constraint and the potential. Constraints of a development need to be managed by periodic monitoring, while the potentials need to be maintained or optimally improved. The hexa-helix concept is a development of penta-helix concept with addition in the role of law and regulation. Citatah area is a multipurpose area where there is limestone quarry, factories, tourist attractions, and rock-climbing area as territoral potential. The constraints is found in Citatah are landslides and faults. To support the potential of the region, infrastructures need to be safe from landslide. The stable slopes have been built through terracing and engineered slopes. This research is directed to identify potentials and constraint in development of the Citatah area; evaluate safety factors around landslide prone areas; and inventory the role of hexa-helix agents in the infrastructure of road around the engineeried slope. The result shows that regional potential needs to be managed by utilizing the hexa-helix concept. Besides, the Citatah landslide zone needs to be aware. Environmental management and monitoring are required to avoid failure of development planning in the future. The result of this study will be useful for sustainable regional development in Citatah area.

Swelling potential characterization of clay-silt soil is an essential issue in stabilization, settlement, consolidation, and land suitability studies. This article attempts to explain the swelling characteristics of soils around the area of West Lampung, Lampung Province, Sumatra, Indonesia, in relation to environmental issues. An investigation in relation to the soil swelling potential was carried out using 15 disturbed soil samples collectd in the study area. The methods used were analyses of clay mineral geochemistry, physical characteristics, and the free swell ratio. These results showed that the soil in the study area was Quaternary tropical volcanic residual soil. These soils were formed in a proximal volcanic hydrothermal alteration environment. The soils of the study area have characteristics of high plasticity, a reddish-brown colour, and are clayey silt grained (MH) (USCS). The soils had loose physical characteristics in dry conditions; however, these soils tends to be plastic and sticky in wet conditions. Evidence of groove erosion was found at the soil surface. Based on XRD analysis, kaolinite, halloysite, and montmorillonite were types of clay minerals found in the soil. The soil had a clay content of 11.05–78.9%, a liquid limit value > 50%, a plasticity index value of 16.7–36.9%, a shrinkage value of 14.24–36.89%, a soil activity of 0.38–2.47; and an FSR value of 0.69–0.95. These characteristics have implications for swelling soil potential. The results showed that the soils in the study area had medium to very high swelling potential. These results suggest a risk of erosion in the area, which could cause soil degradation and a change in water quality. These soils are likely to affect land productivity and aquifer replenishment and will cause negative environmental and economic impacts. Thus, soil improvement techniques are needed. It is important to maintaining vegetative cover these soils and revegetation may be required.