scholarly journals Slope stability analysis of a landfill subjected to leachate recirculation and aeration considering bio-hydro coupled processes

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Shi-Jin Feng ◽  
Shao-Jie Wu ◽  
Wen-Ding Fu ◽  
Qi-Teng Zheng ◽  
Xiao-Lei Zhang
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Gas Flow ◽  
Slope Failure ◽  
Slope Stability Analysis ◽  
Coupled Processes ◽  
Horizontal Distance ◽  
Bioreactor Landfill ◽  
Leachate Recirculation ◽  
Pore Pressures

AbstractDuring the operation of landfills, leachate recirculation and aeration are widely applied to accelerate the waste stabilization process. However, these strategies may induce high pore pressures in waste, thereby affecting the stability of the landfill slope. Therefore, a three-dimensional numerical analysis for landfill slope stability during leachate recirculation and aeration is performed in this study using strength reduction method. The bio-hydro coupled processes of waste are simulated by a previously reported landfill coupled model programmed on the open-source platform OpenFOAM and then incorporated into the slope stability analysis. The results show that both increasing the injection pressure for leachate recirculation and maximum anaerobic biodegradation rate will reduce the factor of safety (FS) of the landfill slope maximally by 0.32 and 0.62, respectively, due to increased pore pressures. The ignorance of both waste biodegradation and gas flow will overestimate the slope stability of an anaerobic bioreactor landfill by about 20–50%, especially when the landfilled waste is easily degradable. The FS value of an aerobic bioreactor landfill slope will show a significant reduction (maximally by 53% in this study) when the aeration pressure exceeds a critical value and this value is termed as the safe aeration pressure. This study then proposes a relationship between the safe aeration pressure and the location of the air injection screen (i.e., the horizontal distance between the top of the injection screen and the slope surface) to avoid landfill slope failure during aeration. The findings of this study can provide insights for engineers to have a better understanding of the slope stability of a bioreactor landfill and to design and control the leachate recirculation and aeration systems in landfills.

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 Behavior analysis by model slope experiment of artificial rainfall

2015 ◽  
Vol 3 (6) ◽  
pp. 4159-4187
Author(s):  
M. C. Park
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Pore Water ◽  
Slope Failure ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Matric Suction ◽  
Slope Stability Analysis ◽  
Model Slope ◽  
Rainfall Seepage

Abstract. In this study, we performed a model slope experiment with rainfall seepage, and the results were compared and verified with the unsaturated slope stability analysis method. In the model slope experiment, we measured the changes in water content and matric suction due to rainfall seepage, and determined the time at which the slope failure occurred and the shape of the failure. In addition, we compared and verified the changes in the factor of safety and the shape of the failure surface, which was calculated from the unsaturated slope stability analysis with the model experiment. From the results of experiment and analysis, it is concluded that the unsaturated slope stability analysis can be used to accurately analyze and predict rainfall-induced slope failure. It is also concluded that in seepage analysis, setting the initial conditions and boundary conditions is very important. If engineers will use the measured pore water pressure or matric suction, the accuracy of analysis can be enhanced. The real-time monitoring system of pore water pressure or matric suction can be used as a warning of rainfall-induced slope failure.

scholarly journals Integrated Analysis Method for Stability Analysis and Maintenance of Cut-Slope in Urban

2021 ◽  
Author(s):  
Mincheol Park ◽  
Heuisoo Han ◽  
Yoonhwa Jin
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Slope Failure ◽  
Slope Stability Analysis ◽  
Velocity Curve ◽  
Integrated Analysis ◽  
Cut Slope ◽  
Analysis Method ◽  
Cut Slopes ◽  
Inverse Velocity

In the process of constructing roads for the development of the city, cut-slopes are made by excavating mountains. However, these cut-slopes are degraded in strength by time-deterioration phenomenon, and progressive slope failure is caused. This study developed an integrated analysis method for stability analysis and maintenance of cut-slopes in urban. The slope stability analysis was performed using the finite element model, and the progressive slope failure by time-dependent deterioration was quantified by using the strength parameters of soil applying the strength reduction factor (SRF). The displacements until the slope failure by slope stability analysis were quantified by cumulative displacement curve, velocity curve, and inverse velocity curve and, applied to the slope maintenance method. The inverse-velocity curve applied to the prediction of the time of slope failure was regressed to the 1st linear equation in the brittle material and the 3rd polynomial equation in the ductile material. This is consistent with the proposed formula of Fukuzono and also shows similar behavior to the failure case in literature. In the future, integrated analysis method should be improved through additional research. And it should be applied to cut-slope to prevent disasters.

scholarly journals Probabilistic Of Slope Failure Grasberg Open Pit Mining PT Freeport Indonesia

PROMINE ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 01-07
Author(s):  
Iswandaru Iswandaru ◽  
Rully Nurhasan R. ◽  
Made Astawa Rai ◽  
Ridho K. Wattimena
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Slope Failure ◽  
Clay Content ◽  
Slope Stability Analysis ◽  
Open Pit ◽  
Rock Properties ◽  
Open Pit Mining ◽  
Clay Material ◽  
Rock Mechanical Properties

The stability of a slope in mining activities is highly influenced by geology, especially thenature of rocks and geological structures. Slope stability analysis will be faced with severalproblems in the uncertainty of rock properties and rock mass. Slope stability analysis usingprobabilistic methods offers a more systematic way of treating conditions of uncertainty andprovides other alternatives to the value factor approach to security regarding information onthe probability of a slope failure.Grasberg Open Mine rock type classification based ongeotechnical parameters or Geotechnical Rock Code (GTRCK) classifies rocks based onrock type, rock mechanical properties, hydrothermal alteration type, clay content and RockQuality Designation (RQD) to 46 types of GTRCK. The GTRCK type which has a low rockmass strength value is a change in intrusive rock minerals and a low RQD value such as alot of clay material is exposed in the Northeast and Southwest of the Grasberg Open PitMine.The overall slope probabilistic modeling of the Grasberg mine uses a cross section of220o (northwest) with the effect of a 0.02g seismic factor which is the maximum criterionaccording to the probability of slope failure received with the average FK 1.13 and PK 0%.

scholarly journals Assessments of Geotechnical Condition of Landslide Sites and Slope Stability Analysis Using Limit Equilibrium Method in Goncha Siso Eneses Area, Northwestern Ethiopia

2020 ◽  
Author(s):  
Azemeraw Wubalem
Keyword(s):  
Land Use ◽  
Soil Moisture ◽  
Stability Analysis ◽  
Slope Stability ◽  
Factor Of Safety ◽  
Slope Failure ◽  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
Slope Stability Analysis ◽  
Equilibrium Method

Abstract Goncha Siso Eneses area is located in northwestern Ethiopia where landslide incidence is active. The landslide incidence in the area resulted in the devastation of 233.1 hectares of cultivated and non-cultivated land, death of eight people, demolition of five houses, displaced 90 households, and 45 households are under risk. The slope failure in this area also caused tilting of the power line, tilting of two houses, cracking of three-houses floor, failed of bridge and blocking of streams as well as springs. The purpose of this research is to evaluate the cause, failure mechanism, landslide distribution, geotechnical condition of the site, slope stability analysis, and factor of safety determination. Soil sampling, laboratory test, terrain characteristics, groundwater-surface manifestation characterization, groundwater depth determination, slope stability analysis, and factor of safety calculation were the most important activities employed in this research work. Using disturbed and undisturbed soil samples of the selected slope section, Atterberg limit (liquid limit & plastic limit), natural soil moisture, unit weight, specific gravity, and shear strength parameters (cohesion & internal friction angle) test were carryout as ASTM standard. The most marginal factor of safety of the area is determined based on the general limit equilibrium method that encompasses different methods inside using slope/w in GeoStudio 2018 software package considering various groundwater conditions for all selected slope sections. The factor of safety for all selected slope sections of the various method under different groundwater conditions is less than one. Based on the finding of field observation and laboratory results, landslide types (rock/soil slides, rock/earth fall, debris/earth flow, & soil creeping) and landslide factors of the study area (slope angle, slope shape, slope modification, land use, groundwater, soil type, and rainfall) are determined. This research finds out that the soil has a great contribution to slope failure in the study area, besides the soil moisture and improper land use practice.

scholarly journals Analisis Geologi Teknik Longsor di Desa Kuatae, Kecamatan Kota Soe, Nusa Tenggara Timur

EKSPLORIUM ◽  
2021 ◽  
Vol 42 (1) ◽  
pp. 55
Author(s):  
Heri Syaeful ◽  
Dhatu Kamajati ◽  
Yoshi Rachael ◽  
Ebenheser Damaledo
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Slope Failure ◽  
Stable State ◽  
Standard Penetration Test ◽  
Slope Stability Analysis ◽  
Geological Mapping ◽  
Base Layer ◽  
Slope Failures ◽  
High Consistency

ABSTRAK Bencana alam longsor di Desa Kuatae, Kecamatan Kota Soe sering terjadi pada musim hujan. Longsor telah menyebabkan rusaknya rumah dan infrastruktur lainnya. Penelitian longsor dilakukan dengan pemetaan geologi teknik, pengeboran geologi teknik, uji laboratorium, analisis kestabilan lereng, dan identifikasi opsi penanggulangan. Berdasarkan hasil pemetaan, longsor terjadi dalam dua model, yaitu blok batugamping terumbu yang mengalami longsor translasi di atas napal dan batulempung serta longsor rotasi pada napal yang dikontrol oleh lapisan dasar yang kontak dengan batulempung. Hasil uji penetrasi standar pada batulempung dan napal menunjukkan nilai konsistensi yang sangat tinggi. Hasil analisis kestabilan lereng menunjukkan lereng dalam keadaan stabil tapi ternyata longsor masih terjadi di beberapa tempat pada area napal dan batulempung. Hal tersebut mengindikasikan bahwa material batuan mengalami degradasi kuat geser pada beberapa kondisi. Penelitian lebih lanjut terkait degradasi material batuan, seperti sifat tahan lekang dan lempung mengembang sangat penting untuk menentukan opsi penanggulangan yang paling tepat dilakukan pada kasus longsor di Desa Kuatae.ABSTRACT Landslides in Kuatae Village, Kota Soe District often occur during the rainy season. The slope failures cause damage to houses and other infrastructures. The research of slope failure has been carried out by using engineering geological mapping, engineering geological drilling, laboratory test, slope stability analysis, and identification of countermeasure options. Based on the mapping results, slope failures occur in two models, the first one was coral limestone blocks translation failure over marl and claystone, and the second one was rotation failure on marl that controlled by the base layer which contact with claystone. The result of the standard penetration test on claystone and marl showed a very high consistency value. The slope stability analysis had shown the slope is in a stable state, but slope failure occurred in several places on the marl and claystone area. Those indicated that the material had encounter shear strength degradation under several circumstances. Further investigation on the degradation of the rock material, such as slake durability and swelling clay are very important to determine the most appropriate countermeasure option to be applied in the landslide case of Kuatae Village.

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