scholarly journals Case Study on Slope Stability Changes Caused by Earthquakes—Focusing on Gyeongju 5.8 ML EQ

2018 ◽  
Vol 10 (10) ◽  
pp. 3441 ◽  
Author(s):  
Sangki Park ◽  
Wooseok Kim ◽  
Jonghyun Lee ◽  
Yong Baek
Keyword(s):  
Slope Stability ◽  
South Korea ◽  
Safety Factor ◽  
Peak Ground Acceleration ◽  
Construction Projects ◽  
Slope Failure ◽  
Ground Acceleration ◽  
Property Data ◽  
Gyeongju Earthquake ◽  
Slope Safety

Slope failure is a natural hazard occurring around the world and can lead to severe damage of properties and loss of lives. Even in stabilized slopes, changes in external loads, such as those from earthquakes, may cause slope failure and collapse, generating social impacts and, eventually causing loss of lives. In this research, the slope stability changes caused by the Gyeongju earthquake, which occurred on 12 September 2016, are numerically analyzed in a slope located in the Gyeongju area, South Korea. Slope property data, collected through an on-site survey, was used in the analysis. Additionally, slope stability changes with and without the earthquake were analyzed and compared. The analysis was performed within a peak ground acceleration (PGA) range of 0.0 (g)–2.0 (g) to identify the correlation between the slope safety factor and peak ground acceleration. The correlation between the slope safety factor and peak ground acceleration could be used as a reference for performing on-site slope stability evaluations. It also provides a reference for design and earthquake stability improvements in the slopes of road and tunnel construction projects, thus supporting the attainment of slope stability in South Korea.

scholarly journals RESPONSE OF STABLE OVERALL SLOPE GEOMETRY OF OPEN PIT COAL MINE IN WARUKIN FORMATION TO DEWATERING AND PEAK GROUND SEISMIC IN SOUTH KALIMANTAN, INDONESIA

2016 ◽  
Vol 11 (1) ◽  
pp. 55-72
Author(s):  
Agus W Oscar ◽  
Ir. H. Dicky Muslim M.Sc. ◽  
Nana Sulaksana ◽  
Febri Hirnawan
Keyword(s):  
Slope Stability ◽  
Safety Factor ◽  
Driving Force ◽  
Peak Ground Acceleration ◽  
Probabilistic Method ◽  
Open Pit ◽  
Ground Acceleration ◽  
Mine Slope ◽  
Broad Dimension ◽  
Regression Correlation

Understanding of the response of the mine slope stability is very important regarding the safety of life and investment / productivity / environment, as anticipation of landslide prevention based on the latest research. Mine slope behavior previously discussed widely in terms of the response due to dewatering and seismic (Peak Ground Acceleration) as well through verification. This paper aims to obtain a broad dimension of design criteria that are not only unstable slopes, but the slope is stable under various conditions of the rock mass saturation (dewatering) and seismic condition. Response of slope stability per geotechnical rocks unit from different formations or any engineering formation as a result of environmental influences, for example, the same quake, will be different. This means that the geometry of the same slope in other formation will have different stability conditions (safety factor of the slope) due to the same seismic acceleration. This is also similar due to dewatering. The method used for this study is the deductive-probabilistic method with a hypothetical verification approach. The Standard statistical analysis is used to test the data normality and homogeneity, average and independent differences, as well as regression-correlation test. The research results show that dewatering activitycan decrease ground water level (GWL/MAT) of the slope, so the durability of sliding along the sliding plane is reduced (increasing slope safety factor). At the same time earthquake reduces shear strength and increases driving force, so the safety factor of the slope suddenly downs. Slope stability decreased due to the earthquake, but dewatering improves slope stability. Thus, the slope in dewatering conditions will be kept stable through simulation to anticipate earthquake.

scholarly journals Application of Harmony Search Algorithm to Slope Stability Analysis

Land ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1250
Author(s):  
Sina Shaffiee Haghshenas ◽  
Sami Shaffiee Haghshenas ◽  
Zong Woo Geem ◽  
Tae-Hyung Kim ◽  
Reza Mikaeil ◽  
...  
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Safety Factor ◽  
Search Algorithm ◽  
Limit Equilibrium ◽  
Harmony Search ◽  
Harmony Search Algorithm ◽  
Slope Stability Analysis ◽  
Unit Weight ◽  
Slope Safety

Slope stability analysis is undoubtedly one of the most complex problems in geotechnical engineering and its study plays a paramount role in mitigating the risk associated with the occurrence of a landslide. This problem is commonly tackled by using limit equilibrium methods or advanced numerical techniques to assess the slope safety factor or, sometimes, even the displacement field of the slope. In this study, as an alternative approach, an attempt to assess the stability condition of homogeneous slopes was made using a machine learning (ML) technique. Specifically, a meta-heuristic algorithm (Harmony Search (HS) algorithm) and K-means algorithm were employed to perform a clustering analysis by considering two different classes, depending on whether a slope was unstable or stable. To achieve the purpose of this study, a database made up of 19 case studies with 6 model inputs including unit weight, intercept cohesion, angle of shearing resistance, slope angle, slope height and pore pressure ratio and one output (i.e., the slope safety factor) was established. Referring to this database, 17 out of 19 slopes were categorized correctly. Moreover, the obtained results showed that, referring to the considered database, the intercept cohesion was the most significant parameter in defining the class of each slope, whereas the unit weight had the smallest influence. Finally, the obtained results showed that the Harmony Search algorithm is an efficient approach for training K-means algorithms.

scholarly journals Faktor Keamanan Stabilitas Lereng pada Kondisi Eksisting dan Setelah Diperkuat Dinding Penahan Tanah Tipe Counterfort dengan Program Plaxis

2019 ◽  
Vol 5 (1) ◽  
pp. 1
Author(s):  
Rizki Ramadhan ◽  
Munirwansyah Munirwansyah ◽  
Munira Sungkar
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Safety Factor ◽  
Slope Failure ◽  
Retaining Wall ◽  
Retaining Walls ◽  
Slope Stability Analysis ◽  
Safety Factors ◽  
Failure Patterns ◽  
Volume Weight

The Aceh Tengah / Gayo Lues-Blangkejeren road segment (N.022) Km 438 + 775 is one of the Central Cross National Roads in the Province of Aceh, which often experiences landslides due to being in hilly areas. Landslides that occur in these locations are caused by scouring of road runoff, lack of optimal drainage and the absence of outlets for drainage and soil layers under asphalt pavement consisting of loose material. Therefore, a slope reinforcement study with Counterfort type retaining wall is needed. This study aims to analyze slope stability by obtaining safety factor numbers and identifying slope failure patterns. Analysis was carried out to obtain safety factors and slope failure patterns by using 2D Plaxis and slice methods. The calculation of safety factors for Counterfort type retaining walls is done manually. The input soil parameters used are dry volume weight (gd), wet volume weight (gw), permeability (k), modulus young (Eref), paisson's ratio (υ), shear angle (f), cohesion (c) . The results of slope stability analysis on the existing conditions using the Plaxis program and the slice method with radius (r) 65.06 meters found that safety factors were 1.038 and 1.079 with unsafe slope conditions (FK <1.25). The results of the analysis after reinforced counterfort and minipile type retaining wall with a length of 12 meters found 1,268 safety factor numbers with unsafe slope conditions (FK <1,5). Thus, additional reinforcement is needed by using anchor on the counterfort. The results of slope stability analysis after reinforced counterfort, minipile and anchor type retaining walls with a length of 20 meters and a slope of 30 ° were obtained with a safety factor number of 1.513 with safe slope conditions (SF> 1.5).ABSTRAKRuas jalan batas Aceh Tengah/Gayo Lues-Blangkejeren (N.022) Km 438+775 merupakan salah satu ruas jalan Nasional Lintas Tengah Provinsi Aceh, yang sering mengalami terjadi tanah longsor karena berada di daerah perbukitan. Longsoran yang terjadi pada lokasi tersebut disebabkan oleh gerusan air limpasan permukaan jalan, kurang optimalnya drainase dan tidak adanya outlet untuk pembuangan air serta lapisan tanah di bawah perkerasan aspal terdiri dari material lepas. Oleh karena itu, diperlukan kajian perkuatan lereng dengan dinding penahan tanah tipe Counterfort. Kajian ini bertujuan untuk menganalisis stabilitas lereng dengan mendapatkan angka faktor keamanan dan mengidentifikasi pola keruntuhan lereng. Analisis dilakukan untuk mendapatkan faktor keamanan dan pola keruntuhan lereng yaitu dengan menggunakan program Plaxis 2D dan metode irisan. Perhitungan faktor keamanan untuk dinding penahan tanah tipe Counterfort dilakukan secara manual. Adapun parameter  tanah input yang digunakan adalah berat volume kering (gd), berat volume basah (gw), permeabilitas (k), modulus young (Eref), paisson’s rasio (υ), sudut geser (f), kohesi (c). Hasil analisis stabilitas lereng pada kondisi eksisting menggunakan program Plaxis dan metode irisan dengan jari-jari (r) 65,06 meter didapatkan akan faktor keamanan sebesar 1,038 dan 1,079 dengan kondisi lereng tidak aman (FK < 1,25). Hasil analisis setelah diperkuat dinding penahan tanah tipe counterfort dan minipile dengan panjang 12 meter didapatkan angka faktor keamanan 1,268 dengan kondisi lereng tidak aman (FK < 1,5). Dengan demikian, maka diperlukan perkuatan tambahan dengan menggunakan angkur pada counterfort. Hasil analisis stabilitas lereng setelah diperkuat dinding penahan tanah tipe counterfort, minipile dan angkur dengan panjang 20 meter serta sudut kemiringan 30° didapatkan angka faktor keamanan 1,513 dengan kondisi lereng aman (SF > 1,5).Kata kunci : longsoran; counterfort; plaxis 2D; faktor keamanan.

scholarly journals Repair Performance Landslide and Slope Using Bore pile and Ground Anchor on Cipali Toll Road Km 103

UKaRsT ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 236
Author(s):  
Akhmudiyanto Akhmudiyanto ◽  
Paulus Pramono Rahardjo ◽  
Rinda Karlinasari
Keyword(s):  
Finite Element ◽  
Slope Stability ◽  
Safety Factor ◽  
Slope Failure ◽  
Retaining Wall ◽  
Traffic Load ◽  
Parameter Determination ◽  
Toll Road ◽  
Bore Pile ◽  
Ground Anchor

One of the causes of on-road collapse slopes is traffic load. Slope failure by road loads usually occurs due to several factors such as soil type, rainfall, land use. This study aims to determine landslide and slope repair performance using bore pile and ground anchor on Cipali Toll Road KM 103. The research method used in this study is the Finite element method. In this research, data collection, modeling parameter determination, slope stability analysis, slope reinforcement analysis, and reinforcement design were carried out with variations in bore pile and ground anchor dimensions. The software program used is a finite element program in the form of PLAXIS to analyze slope stability and estimate the slope failure area. The result of the study is that the R-Value inter is 0.25 with a 1.0341 safety factor. Best repair performance obtained from the addition of reinforcement with ground anchor 2 layer on bore pile 2 with a distance of 2 meters increased the safety factor to 1,913; Borepile capacity calculation with the calculation of normal force and moment iteration, the largest occurs in the DPT (Retaining Wall) stage with a normal load of -37.9 and a moment force of -471.15 which is still able to be borne by bore pile 1. The result of this study is expected to be benchmark and repair material to improve slope stability at km 103 Tol Cipali

scholarly journals Unsaturated seepage and stability of double-layer slope under rainfall infiltration

2021 ◽  
Vol 248 ◽  
pp. 03024
Author(s):  
Yuan Zhang ◽  
Haifeng Lu
Keyword(s):  
Slope Stability ◽  
Pore Water ◽  
Safety Factor ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Soil Parameters ◽  
Lag Period ◽  
Rainfall Patterns ◽  
Continuous Rainfall ◽  
Slope Safety

Taking a homogeneous double-layer soil slope as an example, the SEEP/W module and SLOPE/W module in the finite element analysis software GeoStudio were used in this paper. Then, the changes of pore water pressure and stability under different rainfall patterns and soil parameters were studied. Finally, the variation curves of pore water pressure and slope safety factor with rainfall time were obtained. The results show that: Soil parameters a and m are directly proportional to the slope safety factor, while n is inversely proportional to the slope safety factor. Under the condition of continuous rainfall, the decreasing rate of slope safety factor is directly proportional to the rainfall intensity.Under different rainfall patterns, the continuous rainfall in the advanced and normal rainfall patterns will cause the slope stability to decline and then gradually recover, while delayed and averaged rainfall patterns rainfall will cause the slope stability to decline continuously.In addition, there is a lag period in the change of slope safety factor, and the whole lag period lasts about 6 hours. During the lag period, the pore water pressure inside the soil began to decrease, while the slope safety factor continued to decrease. The safety factor starts to recover after the lag period ends.

Limit equilibrium slope stability analysis using the nonlinear strength failure criterion

2015 ◽  
Vol 52 (5) ◽  
pp. 563-576 ◽  
Author(s):  
Dong-ping Deng ◽  
Lian-heng Zhao ◽  
Liang Li
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Safety Factor ◽  
Failure Criterion ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Current Method ◽  
Slope Stability Analysis ◽  
Strength Failure ◽  
Slope Safety

The limit equilibrium stability analysis of two- and three-dimensional slopes with the nonlinear failure strength criterion uses a number of variables to determine the normal and shear stress on the slip surface. The equation for the nonlinear strength failure criterion is expressed using a Taylor series after analyzing the stress of an elemental slice or column. Multivariate linear equations are then derived to determine these variables based on the force and moment equilibrium conditions the sliding body is subject to. The stress on the slip surface can also be obtained to calculate the slope safety factor. The validity of the current method was verified by comparing it with established examples. Charts were produced for slope stability analysis with the nonlinear strength failure criterion under general conditions using the current method. The results of this study show that the slope safety factor decreases with an increase in the geotechnical material parameter m in the nonlinear strength failure criterion. The results of the current method are in close correspondence with other traditional limit equilibrium methods and are more reliable than the Swedish method. The charts can be used to determine slope design parameters that meet specific requirements.

Mechanisms of slope failure on Pyramid Mountain, a subglacial volcano in Wells Gray Provincial Park, British Columbia

2006 ◽  
Vol 43 (2) ◽  
pp. 147-155 ◽  
Author(s):  
Daniel P Neuffer ◽  
Richard A Schultz ◽  
Robert J Watters
Keyword(s):  
British Columbia ◽  
Rock Mass ◽  
Slope Stability ◽  
Slope Failure ◽  
Limit Equilibrium ◽  
Friction Angle ◽  
Ground Acceleration ◽  
Surrounding Water ◽  
The North ◽  
Provincial Park

Pyramid Mountain is a subglacial volcano in Wells Gray Provincial Park in east-central British Columbia. Landslides deform the north and east flanks of the volcano. Field strength testing and rock mass classification designate the hyaloclastite breccia in which the landslides originated as a weak, massive rock mass: uniaxial compressive strengths (UCS) range from 24 to 35 MPa, and geologic strength index (GSI) and rock mass rating (RMR) values are 60–70. The shear strength of fracture surfaces in the hyaloclastite breccia, as measured by laboratory direct shear tests, can be characterized by a friction angle ϕ of 18° and cohesion c of 0.11–0.66 MPa. Limit-equilibrium slope stability analyses show that the landslides were probably triggered by the rapid drawdown of a surrounding englacial lake with no seismic ground acceleration required. Slope measurements and slope stability modeling indicate that Pyramid Mountain was asymmetric prior to failure: the north and east flanks had slope angles of 35°–40°, and the south and west flanks had slope angles of 21°–33°. Slope asymmetry may result from closer ice confinement on up-gradient (north and east) flanks due to higher ice flux in this direction relative to down-gradient (south and west) flanks. At the time of failure, the volcanic edifice was at least partially lithified, with cohesive strengths of 0.19–0.52 MPa. Failures of lithified subglacial and subaqueous volcanic edifices may be triggered by rapid drawdown of surrounding water without seismic loading.

Slope Stability Analysis of High Rockfill Cofferdam Considered with its Construction and Working Processing

2012 ◽  
Vol 212-213 ◽  
pp. 922-927
Author(s):  
Li Zhe Luo ◽  
Kun Xiong ◽  
Yong Sheng Ou
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Safety Factor ◽  
Equivalent Stress ◽  
Critical Time ◽  
Slope Stability Analysis ◽  
Construction Process ◽  
Analysis Model ◽  
Dangerous Condition ◽  
Slope Safety

Slope stability of high rockfill cofferdam is related not only to the structure and shape, material characterization, working characteristics of the cofferdam body, but also to the construction process. The influences of rock mechanics parameters are analyzed, which caused by the changes of structural stress state and transfusion equivalent stress in cofferdam construction process. Based on the slope stability strength reduction method, the slope stability analysis model of high rockfill cofferdam mirroring the construction process is established. At the same time, the parameter calculation methods are submitted and the correctness is proved. By the slope stability analysis of construction-running process, the results show that the most dangerous condition of cofferdam slope appears in the period of water level falling after pit excavation finished. With the increase of level falling speed, the position of the cofferdam dangerous sliding surface shifted from downstream slope to upstream slope. When the front weir level falling speed is determinate, the slope safety factor is appearing downward trend firstly and then upward trend, the minimum slope safety factor and the critical time is related with the level felling speed.

Analisis Percepatan Tanah Puncak Akibat Gempa Pada Kota Sorong Sebagai Upaya Mitigasi Bencana

2018 ◽  
Vol 4 (2) ◽  
pp. 14
Author(s):  
Imam Trianggoro Saputro ◽  
Mohammad Aris
Keyword(s):  
Peak Ground Acceleration ◽  
Ground Acceleration ◽  
Papua Barat

Sorong merupakan salah satu kota yang terletak di Provinsi Papua Barat. Daerah ini memiliki tingkat kerentanan yang tinggi terhadap ancaman bahaya gempa bumi karena lokasinya terletak di antara pertemuan lempengan tektonik dan beberapa sesar aktif. Tingkat kerawanan terhadap gempa pada daerah ini cukup tinggi. Pada September 2016, BMKG mencatat bahwa terjadi gempa bumi dengan skala magnitudo sebesar 6,8 SR (Skala Ritcher) dengan kedalaman 10 meter dari permukaan laut dan berjarak 31 km arah timur laut kota Sorong. Gempa ini bersifat merusak. Akibat gempa ini, sebanyak 62 orang terluka dan 257 rumah rusak. Untuk itu diperlukan suatu analisis terhadap percepatan tanah puncak (Peak Ground Acceleration) terbaru sebagai langkah mitigasi yang nantinya dapat digunakan untuk perencanaan gedung tahan gempa.Pengumpulan data gempa pada peneltian ini yaitu data gempa yang terjadi sekitar kota Sorong pada rentang waktu 1900-2017. Data gempa yang diambil adalah yang berpotensi merusak struktur yaitu dengan magnitudo (Mw) ≥ 5 dengan radius gempa 500 km dari kota Sorong dan memiliki kedalaman antara 0 - 300 km. Setelah diperoleh data gempa maka dibuat peta sebaran gempa di wilayah kota Sorong. Percepatan tanah puncak dihitung berdasarkan fungsi atenuasi matuscha (1980) dan menggunakan pendekatan metode Gumbel.Hasil penelitian menunjukkan bahwa nilai percepatan tanah puncak (PGA) di wilayah kota Sorong pada periode ulang 2500 tahun atau menggunakan probabilitas terlampaui 2% dalam 50 tahun umur rencana bangunan diperoleh sebesar 708.9520 cm/dt2 atau 0.7227 g. Apabila melihat peta gempa SNI 1726-2012 yang menggunakan probabilitas yang sama maka nilai percepatan tanah puncak (PGA) ketika gempa bumi berkisar antara 0.4 g - 0.6 g. Nilai ini mengalami peningkatan yang berarti tingkat resiko terhadap gempa bumi pada wilayah kota Sorong meningkat.

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