Value Of Safety Factor Research Articles

Quantification of stratigraphic boundary uncertainty from limited boreholes and its effect on slope stability analysis

Due to a limited number of boreholes commonly available in geotechnical practice, the subsurface strata interpreted from borehole data unavoidably contain uncertainty, which can affect the subsequent geotechnical analysis, such as slope stability analysis. This paper proposes an integrated framework to quantify the stratigraphic boundary uncertainty (SBU) from limited borehole data and to investigate its effect on slope stability analysis. The fundamental principles and detail steps of the proposed framework are explained for the SBU quantification and simulation and the subsequent SBU-based slope stability analysis. The framework is illustrated and validated by real data from a real estate project site and a slope site from literature. Then, the effect of borehole number on SBU and slope stability analysis are examined using the framework. Results show that the mean value of factor of safety (FS) of the slope approaches gradually to the real FS value with the increase of borehole number, while the standard deviation of FS decreases as the number of boreholes increases.

Analisis Kestabilan Lereng Highwall Berdasarkan Tingkat Kejenuhan Dengan Metode Probabilitas Pada Tambang Batubara PT. X Kalimantan Timur

The existence of water on the slope will cause serious technical problems, especially in the stability of mine slope. Because of this reason, it is necessary to analyze the stability of slope in order to keep the slope in stable condition. The slope is analyzed under unsaturated and saturated conditions by calculating the value of safety factor and the probability of sliding. Rock samples were tested for physical and mechanical characteristic as input data for slope analysis on slide 6.0 program. The results of the analysis show that the FK value of unsaturated slope with a height of 120 meters and an angle of 30 degrees is 1.7. While the saturated slope with the same geometry has FK value of 0.961. Then the geometry of saturated slope is changed to 120 meters with an angle of 25 degrees and it’s got FK value of 1.6. While the probability of landslides for unsaturated slope is 2.3% and saturated slope is 3.0%. There is a significant difference related to the effect of water on the barrels, namely the difference in FK value of 0.846 and PK value of 9.2%. This difference occurs because the existence of water has increased the density of rock and decreased the value of cohesion so that the value of the driving force on the slope becomes larger and causes a high potential for landslides.

Design and Development of Aluminum Frame Unmanned Aerial Vehicle Hexacopter Configuration to Support Heavy Payload

Previous research has proven that the use of Unmanned Aerial Vehicles (UAVs) can increase the efficiency of human work. However, the design of the usefulness of UAV is considered to be limited. This limitation, for example, is that the UAV's lifting capacity is only capable of lifting 3-5 kilograms of load on average. In addition, the main material of the UAV frame also uses carbon fiber produced by build-up factories abroad, this makes the UAV design less economical. Furthermore, this study discusses the development of the UAV's lifting capacity of 25 kilograms to be able to lift the pesticide liquid load and considers the economic value. The hexacopter type multicopter UAV design was chosen in this study, equipped with 6 main propulsion rotors capable of carrying out its main task of lifting heavy loads, compared to the multicopter type of fewer than 6 rotors. The design is carried out by calculating the lifting force and analyzing the strength structure of the frame material with the help of AutoDesk Inventor software. The final result of the study was that the aluminum-based heavy-lift hexacopter drone was able to support heavy loads, as evidenced by structural analysis simulations resulting in a safety factor value of 1.67 ul, equipped with a 120KV rotor, 23x88 inch propeller, and 6S lipo battery 16,000 mAh, with a total weight of the frame 15kg drone flying for 19 minutes, with an additional 10kg of load the drone can fly for 6 minutes. This research can be developed by adding a nozzle or griper so that it can lift the pesticide spraying tank on a large enough agricultural land.

Probabilistic back analysis for rainfall-induced slope failure using MLS-SVR and Bayesian analysis

ABSTRACT Measurement and model uncertainties in soil parameters account for the difference between slope behaviour in the field and expected behaviour. The probabilistic back analysis is an effective approach to quantify these uncertainties in soil parameters. A new methodology for probabilistic back analysis is proposed to evaluate the uncertainties in soil parameters for observed data for slope. The proposed methodology implements multi-output least square support vector regression (MLS-SVR) to replicate the numerical model for slope under precipitation. This methodology also utilises a multi-objective genetic algorithm and Bayesian analysis to estimate updated statistics of soil parameters for observed data for slope. The rainfall-induced slope failure at Malin, Pune, India, in 2014 is used as a case study to validate the proposed methodology. The mean values of soil parameters are updated using multi-objective genetic algorithm for the expected values of safety factor. The uncertainties in soil parameters are estimated using Bayesian analysis. The updated statistics of input parameters suggest that matric suction governs the slope behaviour under rainfall precipitation. The results of the study suggest that continuous updating of the observations reduces the uncertainties involved in soil parameters. It is noted that the values of safety factor calculated using updated parameters are consistent with the slope failure observed in the field. Hence, results of the study can be used for the reliability-based design of slopes and the provision of remedial measures.

DESAIN DAN ANALISIS SPECIAL TOOL POWER SECTION PT6-42 MENGGUNAKAN METODE ELEMEN HINGGA

The goal of this research is to use the finite element method to develop and analyze a frame for supporting the PT6-42 power section. The software SolidWorks 2020 was used to do the static analysis. ASTM 500 and ASTM A36 were utilized for the frame. The load used is 95 kg, which is the power section's burden. The results of the analysis show the design. The safety factor values obtained by using ASTM A36 and ASTM A500 materials on special tools with a thickness of 10 mm are 2.06 and 2.60, respectively. Frame with a size of 5 mm is not recommended because they are only safe to withstand static loads.

TINJAUAN GEOTEKNIK KEAMANAN REMBESAN DAN PEMBEBANAN GEMPA PADA STABILITAS LERENG (Studi: Bendungan Way Sekampung)

Abstract : Way Sekampung Dam is built to optimize the utilization of the Way Sekampung watershed. It is classified as an embankment dam with upright core which is following with a high risk of failure. The research of dam slope stability become an effort to fulfill dam safety. This study is based on the effects of seepage and seismicity. The seepage review is focused on what is the safety of the dam against potential piping, while for seismicity it is carried out under earthquake loading which using a modified earthquake coefficient approach. Based on the calculation of the seepage modeling using SEEP/W at the flood water level (FWL) and normal water level (NWL) obtained a value of the calculated safety factor (SFcal) of ≥ SFmin = 4 and, it can be said to be safe against piping. Slope stability modeling with SLOPE/W at post construction, flood water level (FWL),normal water level (NWL), and low water level (LWL), under earthquake loading conditions, it is found that the calculated safety factor (SFcal) varies in each loading condition. In the OBE loading conditions; the calculated safety factor value (SFcal) is greater than SFmin, indicating that the slope stability at the Way Sekampung Dam is safe. The simulation with MDE loading conditions, show results of the dam slope stability modeling in several variation resulted in SFcal < SFmin. This shows that the slope stability at the Way Sekampung Dam is not safe, have the potential to experience damage and collapse. Keywords: embankment dam, slope stability, seepage, earthquake, SEEP/W and SLOPE/W

Numerical analysis of the use of different lattice designs and materials for reciprocating engine connecting rods

Nowadays, the use of lattice structure designs in metallic parts to produce lightweight systems has gained importance owing to advances in additive manufacturing technology. On the other hand, vehicle manufacturers are constantly looking for new ways to reduce weight due to the depletion of fossil fuels, the demand for vehicles having higher performance, global warming and increasingly stringent emission standards. In this study, in order to reduce the weight of the internal combustion engine, different lattice designs were made in the connecting rods. Four different 2.5D lattice designs, hexagonal, octagonal, square and triangular, were created in reference connecting rod body. The dimension of the lattice designs was 10x10x12 mm with the wall thickness of 1.5 mm. The fatigue behaviors of the connecting rods as well as mechanical properties under static conditions were analyzed using finite element approach. Three different materials were used in the analyzes: AISI 4140, Inconel 718 and Ti6Al4V. As a result, it was seen that weight reduction of up to 15.75% was possible in the connecting rod thanks to the lattice designs and the maximum stresses were below the yield stresses of the materials. Moreover, connecting rods with lattice design had satisfactory safety factor values.

Analisis Perkuatan Lereng Akibat Longsor di Desa Dompyong

An unstable slope is identical to the low value of their factor of safety (FS). Slope with low FS are in critical condition, which can cause landslides. On the other hand, the presence of triggering factor such as rain and human activities will increase the percentage of landslide. It has happened in Dompyong village. The Rocscience Slide Program, used to analyze slope stability in Dompyong village based on the simplified – bishop method. Based on the analysis, the FS value of the initial condition of slope is 0,85. Therefore, the slope is in critical condition because the FS value is less than 1,07. A combination method of retaining wall and micropiles is used to strengthen slope stability. This method can increase the FS value to 1,370. The slope is in a stable condition relatively because the FS value is more than 1,25.

An Analysis of Critical Slopes Stability in Bendosari Village, Pujon, Malang Due to The Effect of Rainwater Infiltration

A disaster is an incident which threatens and disrupts life. This research was purposed to determine the critical slope stability in Bendosari Village, Pujon due to rainwater infiltration. This research was conducted through ground laboratory test to investigate the type and characteristic of the soil, which then followed by testing of the geo-electric and topography to investigate the existing condition and the ground water level on the critical slopes and analyzed safety factor (SF) using SLOPE/ W for slope with rainwater infiltration effect. The analysis results proved that rainwater infiltration in both conditions could reduce the SF (Safety Factor) value. This is because the water content in the soil increased the pore water pressure. In addition, high water content in the soil reduced the soil shear strength

Structural Design and Analysis of Electric Car Engine Mount

In this paper, the analysis of engine mounting structures that will be applied to electric vehicles is conducted. The engine mounting structure will be subjected to static loading from the mounted components assembly, including the assembly of the gearbox, electric motor, and corresponding brackets. In the structure arrangement, HSLA material is mostly used and general structural steel such as AISI 4130 is also used. This study aims to evaluate the existing design so that further optimization steps can be carried out. Simulations and analysis with a static approach were performed using SOLIDWORKS. The stress and displacement contours are then created, and the location of the critical points of maximum stress and maximum deflection can be obtained so that the safety factor of the design can be evaluated. Based on the simulation results, the current safety factor value is very high when compared to using materials with lower physical properties. In addition, it is necessary to develop further studies involving dynamic loading so that it can also be considered to reduce production costs and increase production efficiency.

Dynamics of ultralow-q plasmas in the RFX-mod device

The results are presented of an experimental activity performed in the RFX-mod device aimed at characterizing plasma dynamics in the so-called Ultralow-q (ULq) magnetic configuration, which corresponds to edge safety factor values below 1. The role of the edge safety factor in determining plasma dynamics is studied. In particular, a characterization of MHD activity is performed. The results of dedicated non-linear 3D visco-resistive MHD simulations are in good quantitative agreement with the experimental observations. In particular, the predicted tendency for ULq plasmas to be characterized by magnetic spectra dominated by a single mode (either a kink or a double resonant internal mode) is confirmed by experiment. Magnetic reconnection plays a relevant role in determining the dynamics of the magnetic topology. Both almost quiescent and largely fluctuating plasmas are observed with a strong sensitivity on the edge safety factor. The main MHD properties of the ULq are compared to those of RFP and tokamak discharges, also produced in the RFX-mod device. MHD modes exhibit toroidal rotation at a frequency depending on mode amplitude. Differently from what encountered in RFP plasmas at comparable current levels, no wall locking is detected.

ANALYSIS OF THE LIQUEFACTION POTENTIAL OF PALU CITY USING QUALITATIVE AND QAUNTITATIVE METHODS

In 2018, there was an earthquake measuring 7.7 on the Richter scale that shook the city of Palu, Central Sulawesi. The epicenter was 26 km north of Donggala Regency and 80 km northwest of Palu City. The earthquake caused the land of the location to become saturated and experience liquefaction. This research aims to find out how much potential liquefaction will occur in an area using qualitative methods and quantitative methods. After conducting qualitative analysis consisting of historical, geological, and soil composition criteria the results are still potential liquefaction, with these results, the research continued with quantitative analysis with Simplified Seed method by Idriss Boulanger (2010) with data on 3 boring log samples in the area. Based on the results reviewed using qualitative analysis, the data of 3 boring samples has the potential to occur liquefaction, so it continues with quantitative analysis to support the results of qualitative analysis. From the results of calculations using the largest magnitude value ever occurred, which is 7.7 SR with the result of Safety Factor value < 1. At points SB01, SB02, and SB03 have Safety Factor values of 0.184 – 0.992.

Optimization of the CAT 318B L excavator teeth bucket structure topology design using the finite element method

Infrastructure development in this era has developed rapidly. Excavators are generally used to dredge rivers, dismantle roads, or demolish buildings. One of the most important components in an excavator is the bucket teeth. Bucket teeth generally have two important characteristics, namely maximum performance and wear life. Therefore, the author is interested in discussing one of the problems that exist in the bucket teeth excavator and optimizing the design of the bucket teeth that are already on the market in order to produce a lighter design. In this study, optimization of the bucket teeth excavator CAT 318 BL was carried out. In this simulation used linear static method for topology optimization process. The results obtained after topological optimization were found that the mass reduction in the first variable design was 0.22 kg and in the second variable design was 0.32 kg. In addition, the maximum von misses stress in variation 1 is 141,743 MPa, while in variation 2 is 145,879 MPa. The safety factor value of the first design variable is 2.92 and the second design variable is 2.84 where it can be said that the value of the stress that occurs in both designs, although tends to increase, is still declared safe.

Stability investigation of the flood protection structure at Nava Nakorn industrial estate, Thailand

A flood protection structure was built around the industrial area of Nava Nakorn in Pathum Thani Province, Thailand to ensure the safety of the industrial estate. Three types of flood protection walls were constructed and completed in 2012, which were prestress corrugated concrete sheet pile and reinforced concrete retaining wall. A large-scale experiment using a large navy watercraft for generating the water pressure on the flood protection structure was performed. Finite element analysis for simulation the flooding over 4 months was also performed. Factor of safety (FS) against external and internal failures decreased with increasing the flooding levels; however, all FS values were higher than the typical requirement for geotechnical design. All bending moments and shear stress in the flood protection walls were found to be lower than the required design values. The knowledge gained from this research can be applied to other flood walls, in similar soft clay deposits.

Factors Causing Landslides on Highways in Ogan Komering Ulu Regency, South Sumatra Province

This research focuses on the study of a slope’s Factor of Safety (FOS) in the context of landslides. The slopes under study are located on the outer bend of a river and feature differences in groundwater levels on the slope and outside the slope. This research was conducted on Jalan Kol. Burlian STA 429+312 (case 1) and connecting road IV STA 194+420 (case 2) in OKU Regency, South Sumatra Province, Indonesia. The analysis was carried out using the Slope/W program to obtain the FOS to discover the cause of the landslide. The results of the Slope/W program (Fellenius method) provided an initial condition FOS value for case study 1 of 1.70, and a FOS value after scouring of 1.12. For case study 2 the initial condition FOS value was 1.68, and after scouring 1.05. Based on the results of the analysis, it can be concluded that the cause of the landslide is the occurrence of scouring and the presence of GWT.

Perancangan Burner untuk Reaktor Pirolisis Kapasitas 15 kg dengan Bahan Bakar Refuse Derived Fuel (RDF) dan Gas

This research has several problem formulations, namely how the design stages and what are the main parameters of the burner design for pyrolysis reactors with Refuse Derived Fuel (RDF) and gas fuel. Therefore, the purpose of this research is to produce a burner design for a pyrolysis reactor with Refuse Derived Fuel (RDF) and gas fuel. Burner is a tool that is used to react properly between the fuel and the oxidizing agent, so that the combustion process can occur. The use of a burner can also save fuel used during the combustion process. In this study, the design method used is the Pahl & Beitz method. There are 3 design variants where variant 1 gets a weighting result (2.9), variant 2 (3.7), and variant 3 (3.06). Based on the results of the weighting of the three variants, variant 3 becomes the chosen design which will then be carried out with detailed design and design analysis. From the analysis of the strength of the frame, the safety factor value is while the calorific value needed to burn Low Density Polyethylene (LDPE) plastic in the pyrolysis reactor is 9.3138 kJ/s.

STUDI EKPERIMENTAL RESPON INTENSITAS HUJAN DAN TEKANAN AIR PORI TANAH PENGARUHNYA TERHADAP KERUNTUHAN LERENG

Malalak is one of the youngest sub-districts in Agam Regency, the district was previously included in the administration of the district IV koto. Malalak sub-district officially separated its elf into its own sub-district on May 24, 2007. Simalaka Road (Sicincin-Malalak-Balingka) connects between Balingka nagari in district IV Koto, Malalak nagari in Malalak sub-district, and Tandikek nagari, Patamuan, Sicincin in Padang Pariaman district.This study is classified into applied research. will use soil parameter and rainfal to find out, and analyze the extent of rain characteristics on slope collapse, as well as compare the safe factors obtained using fellenius medote and Geo-studio V Software, due to disturbed soil stability or slope building rocks.In determining the value dari the safety factor of the slope by using software Geo-Slope /W obtained the value of safety factor is 0.70. The result of vibrational influence as well as the frequent rain stability of the slopes experienced a considerable decrease in the safety value of the slopes and showed that the slope conditions unstable. Analisis safety factor from research conducted on malalak road section KM 31 can be summed up a few things as follows. From the analysis obtained a definition of the factors that cause slope unstableness. From the calculation results can be that rainwater infiltration is very influential to the stability of the slope, where safety factors or FK (Safety Factor) slopes decrease along with the length of rainwater infiltration that occurs in the area especially during the soil hoarding process occurs, this can be seen from the results of geostudio analysis and fellenius method that shows reduced slope safety factors.

Rainfall Triggered Slope Instability Analysis with Changing Climate

Slope instability triggered by rainfall is common in tropical countries like India, where the soil of hill slopes are generally in unsaturated condition, having higher strength than in the saturated condition due to matric suction. This study aims to investigate the change in pore water pressure (PWP) with rainfall infiltration into the slope and the corresponding effect of the slope stability on different hill slopes from different regions of India. By applying rainfall on the surface of slope as a flux boundary condition, a transient seepage analysis is performed using SEEP/W, and the corresponding results in the form of PWP distribution within the slope are used as input for SLOPE/W program of Geostudio 2018 R2, to check the stability of slope. This study involves the use of CMIP5 (Coupled model intercomparision project phase 5) simulations for rainfall data of different regions for the duration of 2015–2050, 2051–2075 and 2076–2100; which is completely based on non-stationary approach (i.e., the statistics of extremes changes with time) rather than the conventional methods of extracting rainfall data that are based on stationary approach. The stability of different slopes is checked for 95 percentile rainfall intensity as well as for maximum rainfall intensity for a period of 2015–2100, and the analysis is performed for 5 days for which the duration of rainfall is considered to be 24 h. It is concluded that due to climate change, slopes which may be marginally stable under historical and present rainfall events can fail under projected precipitation estimates, and this can be understood by the results of Haflong slope stability analysis as the 30° slope, which is marginally stable under maximum rainfall intensity for the period 2015–2050 having factor of safety (FOS) value 1.0013, will fail under the maximum rainfall intensity for the period 2051–2075 and 2076–2100 having FOS value 0.9935 and 0.9989, respectively. A continuous decrease in FOS with increasing rainfall intensity is observed for all the study areas under consideration.

Design and Analysis of The Energy Storage and Return (ESAR) Foot Prosthesis Using Finite Element Method

ABSTRACT. Disability issue has increased in recent years due to the high number of accidents and vascular disease. Loss of limb function for people with amputations often results in an abnormal gait. Energy Storage And Return (ESAR) foot prostheses provide an alternative to help improve gait and minimize metabolic energy expenditure during the walking phase of amputees. This study used 3 designs with models from the Catia V5 Software. The finite element method analysis used Ansys Workbench 18.1 software to evaluate the three designs with a loading of 1.2 times the user's body weight with a maximum weight of 70 kg in normal walking activities. The simulated material is carbon fiber prepreg which has tensile strength, Young's modulus, Poisson ratio, and density of 513.72 MPa, 77.71 GPa, 0.14, and 1.37 g/cm3. The decision-making matrix method is used to determine the best foot prosthesis design according to predetermined criteria. The highest value in the decision-making matrix is 76 in Design 3. The chosen design (Design 3) after gait cycle analysis has a maximum von Mises stress value of 76.956 MPa and the safety factor value for each gait cycle heel strike loading model is 1.0762; foot flat 3.2509; toe-off 6.6263.

Design and static testing of electric vehicle chassis trike front-wheel drive

Compared to conventional vehicles, the advantages of electric vehicles are more significant acceleration, no exhaust emissions, making electric vehicles more environmentally friendly, minimal maintenance because there are not many components used in electric cars. This research method is used to develop the chassis design of an electric trike, and then the chassis design is analysed using Solidworks software. The chassis with a thickness of 2.4 mm weights 29.6 kg with a maximum value of stress, displacement, strain, and other factors. Safety as follows: 7,582 x 107 N/m2, 2,567 mm, 3,368 10−4 and 3.5, 2 mm thick chassis weighs 25 kg with maximum stress, displacement, strain, and safety factor values as follows: 1.079x108 N/m2, 3.160 mm, 3.981 10−4 and 2.5 then the chassis thickness of 1.6 mm weights 20.3 kg with the maximum stress, displacement, strain, and safety factor values as follows: 1.809 x 108 N/m2, 4.190 mm, and 9.388 10−4. Chassis with a thickness of 2 mm using a rectangular tube and ASTM A53 material has a safety factor value that is by the requirements and the maximum stress value on the chassis does not exceed the allowable stress value and weight.