Evaluation of rockfalls at a historical settlement area in the Ihlara valley (Cappadocia, Turkey) using different methods

Rockfalls are one of the most dangerous natural events in hilly terrains. This study presents the results of an investigation program to analyze the possibility of a rockfall from a slope to nearby residential buildings in a historical settlement area. Various rockfall analysis techniques were implemented in the study for this purpose. The kinematical analysis revealed the potential of different structurally controlled modes of failure in the slope, especially wedge type and block toppling were the most significant ones. Finite element analysis suggested a stable slope considering the safety factor of 2.19 for the existing geological and geotechnical conditions of the studied slope case. A possible rockfall trajectory was determined and located as an input in the 2D rockfall program based on the field measurements. Different shapes and sizes of blocks were used in the rigid body model for a more realistic numerical simulation of rockfall events. According to the 2D model results, there was no danger of rockfall for the investigated downslope buildings. However, to stay on a safe side, a suitable control measure with a specified dimension was proposed to manage rockfalls in the study area.

Physics and Modeling of Various Hazardous Landslides

In 2014, the Varnes classification system for landslides was updated. Complex landslides can still be a problem to classify as the classification does not include the flow type in the hydrodynamical sense. Three examples of Icelandic landslides are presented and later used as case studies in order to demonstrate the methods suggested to analyze the flow. The methods are based on the different physical properties of the flow types of the slides. Three different flow types are presented, named type (i), (ii), and (iii). Types (i) and (ii) do not include turbulent flows and their flow paths are sometimes independent of the velocity. Type (iii) include high velocity flows; they are treated with the translator wave theory, where a new type of a slope factor is used. It allows the slide to stop when the slope has flattened out to the value that corresponds to the stable slope property of the flowing material. The type studies are for a fast slide of this type, also a large slip circle slide that turns into a fast-flowing slide farther down the path and finally a large slide running so fast that it can run for a kilometer on flat land where it stops with a steep front.

Earthflow reactivation assessment by multichannel analysis of surface waves and electrical resistivity tomography: A case study

In this study, we investigated the stability and reactivation of preexisting Tonghua landslide deposits in China, including the adjacent stable slope. We used an integrated approach, combining a multichannel analysis of surface waves (MASW) and electrical resistivity tomography (ERT). We used ERT to determine groundwater seepage paths, weathering conditions, water content, and the depth to bedrock. High-resolution two-dimensional (2D) shear-wave velocity MASW images, on the other hand, played an essential role in detecting both horizontal and vertical compositions, disjointedness, and sliding surfaces related to lithological borders. Based on seismic models, we considered four geological layers encountered in the stable slope, including fractured (gravel) and weathered (phyllite) materials, as a sliding mass. We combined the 2D resistivity profiles obtained to create pseudo-three-dimensional ERT images to estimate water-saturated and unsaturated masses. From the tomography results, we identified different preexisting deposits, including buried arable clay deposits, old accumulated earthflow deposits, a water accumulation zone, and a fissure runoff. Based on the resistivity results, the bottom of the earthflow deposits is susceptible to water, and oversaturation can reactivate the earthflow.

Assessment of Rock Slope Stability along Sulaimaniyah -Qaradagh Main Road, Near Dararash Village, Sulaimaniyah, NE-Iraq

The road network in the Baranan mountain, near Dararash village, connecting Sulaymaniyah city with Qaradagh town, plays a major role in socio- economic activities of Qaradagh town and its surrounding villages. Any type of slope failure in the area may cause breaking up in traffic, loss of lives, and injuries. For assessing the stability of rock slopes in the area, seven stations (rock-cut slopes) were selected along the road and evaluated by kinematic analysis, using DIPS v6.008 software and slope mass rating system (SMRTool - v205 software). The kinematic analysis revealed that planar and wedge sliding may occur in stations no.2, 5, 6, and 7, flexural toppling may occur in station no.1, direct toppling may occur in station no.2, and oblique toppling may occur in station no.3. SMR- Tool software for discrete-SMR and continuous-SMR (CSMR) revealed that stations no.2, 5, 6 and 7 are unstable slopes (class IV of a bad slope type) with failure probability of 0.6, with an exception for station no.7 which is a partially stable slope (class III of a normal slope type) with failure probability of 0.4. Station no.1 is partially stable slope (class III of a normal slope type) with failure probability of 0.4 and station no.3 is stable slope (class II of a good slope type) with failure probability of 0.2. Due to the lack of structural and failure surface data (attitude of discontinuities and slumping surface) in station no.4, stability analysis was interpreted by using the general conventional method, depending on the field criterion and vision. The station can be interpreted as a rotational failure, the upper part of which consists of slump motion and the lower part of flow motion.

Why is the Tuaheni Landslide Complex a spreading failure?

<p>Numerous subaqueous landslides exhibit spreading failure morphologies which are typically characterized by repetitive patterns of parallel ridges and troughs oriented perpendicular to the direction of movement. Whilst these spreading failures are commonly attributed to (i) downslope removal of material causing unloading of the temporary stable slope or (ii) significant loss of shear strength of the substratum allowing blocks of overlying sediment to detach and slide downslope, their movement rates and potential triggers remain poorly constrained. <!-- Suggest wording this to set up motivation of research -->Spreading appears to be a dominant failure mechanism within the Tuaheni Landslide Complex (TLC)<!-- I’m not wedded to this name but makes some sense to stick with the same --> on the Hikurangi Subduction Margin off the coast of Gisborne, New Zealand. A combination of swath bathymetric, 2D and 3D seismic data, drilling investigations and laboratory experiments on sediments recovered from the TLC indicate that this geomorphology has been generated by translational failure. Failure could occur through episodic cycles of movement-arrest in response to either elevated pore fluid pressures or undrained loading during earthquakes<!-- We now have some data from dynamic experiments which would be good to include in the model -->. <!-- You will know better than me Morelia but it might pay to be a little more circumspect at this stage? -->We developed numerical models that integrate this unique data set to explore the processes that lead to spreading failure and determine how large shear strains can be accommodated without accelerating to catastrophic failure. The results provide a novel approach that demonstrates how seafloor morphology can, in part, be controlled by the underlying failure processes</p>

Analisis Pengaruh Kedudukan Struktur terhadap Potensi Longsoran menggunakan Proyeksi Stereografis

The stability of open pit slopes is one of the important factors that can guarantee the continuity of production and safety of workers and mining equipment. One effort to obtain a stable slope is to avoid the slope design that triggers the potential for landslides. The type and geometry of avalanches that may occur on the slopes are largely determined by the position of the slope and the geological structure. Analysis using stereographic projections has been used extensively for initial slope stability assessments before proceeding with the calculation of safety factors. Open cone shaped reverse geometry with a planned depth of up to 1 km with a diameter of ± 3 km. This causes the formation of potential landslides due to the intersection of the face of the slope with the structure of continuity is absolute. The only thing that can be done at the initial stage is analyzing the direction and slope of which slopes have the potential to form landslides. The potential of landslides by dividing the structure of weak field data is adjusted to 36 strike directions and the distribution of measurement areas to 484 domains produces 370 domains with potential landslides.Abstrak. Kestabilan lereng tambang terbuka merupakan salah satu faktor penting yang mampu menjamin kelangsungan produksi dan keselamatan pekerja dan peralatan tambang. Salah satu upaya untuk memperoleh lereng yang stabil adalah dengan menghindari desain lereng yang memicu potensi longsoran. Jenis dan geometri longsoran yang mungkin terjadi pada lereng sangat ditentukan oleh kedudukan lereng dan struktur geologi. Analisis menggunakan proyeksi stereografi telah digunakan secara luas untuk penilaian awal kestabilan lereng sebelum dilanjutkan dengan perhitungan faktor keamanan. Geometri open pit berbentuk kerucut terbalik dengan rencana kedalaman hingga 1 km dengan diameter ± 3 km. Hal ini menyebabkan terbentuknya potensi longsor akibat perpotongan muka lereng dengan struktur ketidakmenerusan merupakan sesuatu yang mutlak. Satu-satunya yang bisa dilakukan pada tahap awal ialah menganalisis arah dan kemiringan lereng mana yang berpotensi membentuk longsoran. Potensi longsoran dengan cara membagi data struktur bidang lemah disesuaikan dengan 36 arah strike dan pembagian wilayah pengukuran menjadi 484 domain dihasilkan 370 domain yang memiliki potensi longsoran.

Automated Stability Analysis of Soil Slopes

Herein there is a description of algorithm of the automated forecast of stability for soil slope structures including input of initial data regarding physical and mechanical properties and geometrical parameters of a structure, building of the most intense sliding face, computation of the slope stability by the polygon of forces method. Developed on algorithm basis, The Stable Slope software package has been implemented in open pit located in the Altai region. There are calculation results of the parameters of the Eastern steady side (slope angle at a given height) depending on the inclination angle of contact of the friable Quaternary deposit with a parent rock. Recommendations can improve work safety under adverse natural and man-made conditions causing formation of unstable water-saturated zones.

Peran Ilmu Dasar dalam Geoteknik untuk Menunjang Pembangunan Berkelanjutan yang Berwawasan Lingkungan

Geoteknik adalah salah satu dari cabang dari ilmu geologi yang erat hubungannya dengan pembangunan berkelanjutan yang berwawasan lingkungan. Kajian-kajian geoteknik memerlukan ilmu dasar seperti matematika, statistika, fisika, biologi, dan kimia. Beberapa kajian geoteknik berhubungan dengan pembangunan infrastruktur seperti jalan tol, jalan kereta api, jembatan, menara, pondasi gedung, desain lereng rekayasa, dan lain-lain. Makalah ini memperlihatkan beberapa penelitian geoteknik yang memanfaatkan ilmu dasar, yaitu desain lereng stabil, desain pondasi, hubungan antar variabel tanah, maupun perbaikan tanah. Penelitiannya a.l.: 1) Analisis kestabilan lereng, tujuan untuk mendapatkan lereng stabil, metode menggunakan model Starlet, hasil yang didapatkan adalah desain lereng stabil dan antisipasi keruntuhan lereng pada zona kerentanan gerakan tanah. 2) Analisis dayadukung tanah, tujuan untuk menentukan dayadukung yang aman bagi fondasi, metode yang digunakan adalah melalui cara Terzaghi, hasil yang didapatkan adalah nilai dayadukung tanah yang diijinkan untuk peletakan fondasi. 3) Soil improvement, tujuan untuk perkuatan fondasi, metode melalui pencampuran tanah dasar dengan kapur (CaO), hasil yang didapatkan adalah meningkatnya kekuatan dayadukung tanah pada tanah ekspansif. Kesimpulan dari semua penelitan geoteknik tersebut adalah kajian geoteknik tidak bisa lepas dari ilmu dasar matematika dan ilmu pengetahuan alam. Kata Kunci: geoteknik, pembangunan berkelanjutan, lereng stabil, dayadukung tanah, soil improvement Geotechnics is one of branches of geological science are closely related to environmentally sustainable development. Geotechnical studies require some basic sciences such as mathematics, statistics, physics, biology, and chemistry. Some geotechnical studies related to the development of infrastructure such as toll roads, railways, bridges, towers, building foundation, slope design engineering, and others. This paper shows some geotechnical studies that utilize basic sciences, namely: stable slope design, foundation design, the relationship between variables soil, and soil improvement. The study included: 1) Slope stability analysis, objective research is to get a stable slope, the method is using the Starlet model, the results obtained are stable slope design and anticipation of the slope landslide on vulnerability zone of mass movement, 2) Analysis of soil bearing capacity, in order to determine safety bearing capacity for the foundation, the method is using Terzaghi equtaion, the results obtained are allowable soil bearing capacity for safety foundation. 3) Soil improvement, the goal of strengthening the foundation, the basic method by mixing soil with lime (CaO), the results obtained are the increasing strength of the soil bearing capacity on expansive soil. The conclusion of all geotechnical research are geotechnical studies cannot be separated from the basic sciences of mathematics and natural science. Keywords: geotechnical, sustainable development, stable slope, soil bearing capacity, soil improvement

Simple criteria for ploughing and runout in post-failure evolution of submarine landslides

This paper extends shear band propagation analysis of slope failures to the investigation of ploughing and runout phenomena in submarine landslides. The ability to predict the two different modes of post-failure landslide evolution is critical for determining the tsunami hazard and type of landslide impact on offshore structures. The proposed analysis is based on the analogy between ploughing and spreading failures. It uses the energy balance approach to develop the criterion for progressive shear band propagation driven by accumulation of sliding material on top of the stable slope. This criterion is then combined with the kinematic passive block mechanism to produce analytical ploughing failure criteria formulated in terms of the critical rise in the seabed level. If the minimum rise of the seabed level at which ploughing can take place is larger than the maximum possible free-standing step in the seabed surface, the first passive failure block will start crumbling over top the stable zone causing the landslide to runout. Application of the derived criteria to the analysis of observed geomorphological features is demonstrated using an example of a paleolandslide complex in the Caspian Sea.