Value Of Safety Factor Research Articles

Penggunaan Program Plaxis Dalam Studi Penelitian Perkuatan Geotextile Pada Kestabilan Lereng Buatan

This analytical study is expected to understand the safety factor value of natural slopes using geotextile reinforcement arising on multiple slopes. The finite element method is the method used in this analytical study. The model pattern is implemented through several possibilities for the height of the soil fill and the length of the geotextile itself. The soil benchmark indicators used are secondary data from the West Bandung district and use the Meyerhof shear angle approach. The Meyerhof shear angle approach is also used for slope stability analysis using geotextile reinforcement using a length of 2.10 meters has a slope safety factor value below 1.35 so referring to Bowles has occurred and the safety factor value using a length of 4.1 meters and 6.1 meters has a slope safety factor value above 1.35 so that landslides rarely occur.

Rainfall Infiltration Impact on Road Embankment Stability

This study evaluates the stability of a widened road embankment slope by considering the effect of rain infiltration, which is often ignored in practical design. Rainfall infiltrates the soil and alters pore water pressure, reducing its shear strength and potentially causing slope failure. The Phi Index method is used to determine rain infiltration values, using rainfall data from four nearby rain stations over 10 years. The changes in pore water pressure resulting from rain infiltration are incorporated into the slope stability analysis by the limit equilibrium concept using the Spencer method. Back analysis is used to determine the soil shear strength parameters since the CPT test results provide a correlation with values within a certain range. Soil parameters resulting in a safety factor value close to 1.25 (critical condition) were considered representative field conditions. The analysis shows a decrease in the safety factor from 1.50 to 1.31 (12%). These findings emphasize the importance of accounting for rain infiltration in road embankment stability analyses, particularly in areas with high rainfall where the safety factor may fall below the minimum required by Indonesian geotechnical code. When an infiltration effect analysis is not conducted, the safety factor should be increased at least 12% from normal conditions.

The Slope Instability Potential in the Balaroa area based on the Finite Element Method using Shear Strength Reduction

Balaroa area is an alternative road connecting Palu City with Sigi and Donggala Regencies which experienced landslides due to the September 2018 earthquake. The landslide formed a steep slope and was prone to landslide. This study is to determine slope stability and design of optimal and safe slope geometry against landslides. Input and data analysis based on the Finite Element Method using Shear Strength Reduction with the help of RS2 software. The analysis resulted safety factor (SF) value on the existing slope without an earthquake load at locations 1 and 2 is in a stable condition with SF>1, after being given an earthquake load of 0.35g, the SF<1, while location 2 remained safe under the earthquake load with SF> 1. The total value of displacement on existing slope without earthquake load at location 1 was 0,006-0,040m and location 2 was 0,01-0,1m, after being given an earthquake load, it decreased 0,0045-0,030m at location 1 and increased 0,006-0,15m at location 2. This illustrates the existence of an earthquake greatly affects SF and total displacement. Safe slope geometry design for location 1 is slope height must be 10,2m with angles of 46° for level 1and 32° for level 2, with SF value 1.25.

Study of Liquefaction Potential Using Cone Penetration Test at Balaroa Village Palu

Central Sulawesi Province is one of the areas in Indonesia that is prone to large earthquakes. Balaroa, Petobo, and Sibalaya were among the most fatalities and damaged facilities and infrastructure due to the earthquake on September 28th 2018. Around Balaroa Village, besides the huge damages to Perumnas Housing, the area around the housing was also affected, for example on Jamur, Kelor, and Labu streets, many houses and buildings were damaged. This research aims to assess the potential of the ground in this area to liquefy. Cone Penetration Test (CPT) were conducted at 3 points around Kelor street, and 3 points at Labu street, then the results was used to calculate the Factor of Safety (FS) and Liquefaction Potential Index (LPI). The results indicated that the FS values at each point of the sites obtained on average have an FS value less than 1 which indicates that the area is vulnerable to liquefaction. The results of the analysis of the liquefaction potential index (LPI) value show a range varied from low to high.

Analysis of sheet pile position influence in countermeasure to landslide at the cutting slope in infrastructure project

Slope is a land surface that has a certain angle of inclination in the horizontal plane. The existence of the slope of the land causes the forces that push so that the soil at a higher elevation to move. If the movement is not resisted, the slope may collapse. The purpose of this analysis is to determine the effect of sheet piles where the position and depth of sheet piles, ground water level and earthquake factors on the stability of excavation slopes in infrastructure project of Karawang New Industry City (KNIC) LG area. For this reason, slope stability analysis was carried out using a finite element-based analysis program where the output sought was sheet pile displacement and safety factor. The data used in this study are N-SPT data and W-325 sheet pile property data. The sheet pile position is varied into 6 variations, at positions 2, 4, 6, 8, 10, and 12. The sheet pile length is varied from 4 meters to 12 meters and the slope water level is varied into 6 conditions, namely conditions without ground water, ground water level 5 meters, 4 meters, 3 meters, 2 meters and 1 meter. From this analysis it was found that the position of sheet pile affects the value of the safety factor and the critical depth of sheet piles. The analysis is continued by analyzing the earthquake load at a water level of 1 meter. From this analysis, all positions and depths are not able to withstand earthquake loads, so other alternatives are needed. Considering the earthquake load and the resulting landslide pattern, the slopes require additional reinforcement where sheet piles will be installed in position 10 with a length of 12 meters and at 1 meter from the roadside at a depth of 1 meter with a length of 11 meters. With this reinforcement, the safety factor value is 1.675 in static conditions and 1.131 in earthquake conditions so that sheet piles can meet the minimum limit requirements i.e., 1.5 in static conditions and 1.0 in earthquake conditions.

Calculation of Risk Probability of Levee Landslide Based on Three-dimensional Lequilibrium Theory

Sliding instability is a common form of failure of embankments, and traditional dike safety evaluation often uses the safety factor value to judge whether it is safe or not. However, due to the uncertainty of the rock and soil characteristics of the embankment, the evaluation results of the safety factor method sometimes fail to reflect the reality, and it is reasonable to use the risk analysis of sliding instability considering these uncertainties. In this paper, the uncertainty of rock and soil strength parameters and the randomness of seepage field are considered, and the risk probability of sliding instability of the embankment is solved by relying on the reliability analysis method. In the reliability analysis, a three-dimensional bin method combining slope stability analysis and gradient optimization method of reliability analysis are proposed, which consider the safety performance, so that the stability evaluation is not too conservative, and the corresponding sliding risk probability can be obtained while obtaining reliable indicators. Finally, the calculation program is prepared for the proposed method, and the proposed method is verified to be reasonable and correct through the example.

Determining the Safe Distance for Mining Equipment Operation When Forming an Internal Dump in a Deep Open Pit

In the surface mining of mineral deposits, land resources suitable for agricultural purposes are inappropriately spent in large volumes. When mining deep open pits, overburden rocks are mainly transported to the surface. The optimal solution for reducing the area of disturbed lands is the placement of overburden rocks in internal dumps in the open pit. This is especially suitable when mining a mineral deposit with several open pits where at least one of them is depleted. Therefore, it is important to assess the feasibility of building an internal dump, based on the stability parameters of its slopes and the safe distance for placing mining equipment within its boundaries, which was the focus of this research. Numerical modeling with Slide 5.0 software was used to determine the stability of the dump slope inside the open pit and the safe distance from the upper slope edge for placing mining equipment. This reflected the geomechanical situation occurring within the boundaries of the dump formed in the open-pit field with a high degree of reliability. It was determined that the maximum standard safety factor values of the open-pit slopes are within the limits when the overburden rocks border on the hard bedrock (Ks.s.f ≥ 1.2). Under the condition where the dump slope bordered on sedimentations represented by clays, loams, and sands with a strength of 2–3 on the Mohs scale, the safety factor decreased by 22%. It was determined that the minimum safe distance from the outer contour of the dragline base to the upper edge of a single-tier dump was 15.5 m with a safety factor of 1.21. The maximum safe distance values in the range of 73.5–93 m were concentrated within the boundaries of sections 5–9, with a safety factor from 1.18 to 1.28. When the dragline was located within the boundaries of section 7, the dump construction works should be conducted only if the dump exist for up to 3 years. Based on the identified parameters, on the example of using the ESH-11/70 walking dragline, a technological scheme of its operation was developed with the allocation of safe boundaries for its placement when forming an internal dump. The results obtained are useful for the development of projects for the reclamation of depleted open pits.

CONSTRUCTION DESIGN FOR 4.5 BAR WATER TUBE TYPE BOILER USING SOLIDWORKS 2018 SOFTWARE

Distillation or simple distillation uses the principle of separating two or more liquids based on differences in the boiling points of each component. The distillation process itself has two main stages, namely the evaporation stage and the condensation or condensation stage. Therefore, distillation equipment uses a heating device in the form of a boiler and a cooler in the form of a heat exchanger. In the refining process, the heart of the distillation system lies in the boiler as a steam producing component. Therefore, the effectiveness of the boiler to produce saturated steam greatly determines the results of the refining process. To determine the power of the boiler, it is necessary to analyze the Boiler simulation calculations which include Von misses, displacement and safety factor simulations. The simulation is carried out at a pressure of 4.5 Bar which produces a Von misses max value. of 3.444 MPa, with the highest displacement value of 0.002 mm and the smallest value of 0 mm, and produces a safety factor value of 75. With this safety factor value, it can be said that the frame construction is safe.

Traffic safety assessment method of the immersed tunnel based on small target visual recognition image

The quality of lighting installation performance has a direct impact on the traffic safety of immersed tunnels. To effectively investigate and judge the traffic safety of immersed tunnels having different lighting installations, a traffic safety assessment method for immersed tunnels based on lighting performance degradation was put forward in this study by using big data technology. Numerical simulation was used to simulate the lighting environment in an immersed tunnel under different conditions of lighting performance degradation, conduct the small target recognition test in a physical tunnel, and calculate the traffic safety factor; then, a real-time kinematic assessment model of traffic safety in immersed tunnels was built in combination with the key index factors influencing lighting installations in immersed tunnels. The test results showed that the performance degradation of lighting installations positively correlated with the visual cognition of drivers and passengers. long short-term memory neural network model can effectively assess the traffic safety of immersed tunnels, and the root mean square error (RMSE) and coefficient of determination of the model were separately 1.029 and 0.95, which were superior to the RMSE and coefficient of determination of random forest and recurrent neural network model, and the running time was often less than 1min, complying with the rea; -time assessment requirements; the boundary value of the traffic safety factor of immersed tunnels was 0.6304, and if a value was less than the boundary value, it indicated that the performance of lighting installations was not good and might pose a threat to traffic safety. The research results provided a new perspective for the status assessment of lighting installations in immersed tunnels and also offered a theoretical basis for fine maintenance and repairs of lighting installations.

Numerical analysis of the influence iron type on Von Mises Stress and safety parameters for compost processing machine frame construction

The installation of other engine parts, such as the engine, transmission, shaft, blade, and cover, includes the engine frame. The engine frame must be developed and constructed with the strength to support other components. The building of the waste processing machine frame with variants of square tube type and angle bar type will be analyzed in this study, with a focus on the analysis of von Mises’s stress and safety aspects. Using Solidworks software, finite element analysis is the research methodology used. The examination of the waste processing machine’s frame modelling using square tubes and angular bars yielded maximum von Mises stress values of 3.77e+7 N/m2 and 3.162e+4 N/m2, respectively. The maximum deformation values for the square tube iron and angular bar used in the modelling analysis of the waste processing machine frame are 2,499e+1mm and 9,725e+1mm, respectively . and 8.5 and 1 is the required minimum safety factor value for modelling the frame of a waste processing machine made of square tube iron. The safety factor value of 2-3 is the primary criterion for a suitable design. It is safe and advised to utilize the waste processing machine frame made of square tube iron for this purpose.

The Analysis of Slope Stability using The Simplified Bishop Method and Geometry of Retaining Walls in Palaran District, Samarinda City, East Kalimantan Province

Landslide is one of the natural disasters that often occurs on natural and artificial slopes. This landslide occurs due to an imbalance of forces acting on the slope or the actuator in the slope area is greater than the resisting force on the slope. Handling needs to be done to avoid landslides, one of which is making a retaining wall. Based on the data obtained from the results of the tests and calculations that have been carried out, the value of the slope safety factor at the research location is 0.397. This value is the value of the unsafe factor of safety (Avalanche). So it is necessary to design a retaining wall with dimensions in between, namely for H = 7 m, H1 = 0.7 m, H2 = 6.3 m, H3 = 1.6 m, H4 = 0.7 m, H5 = 4.9 m, H6 = 2.6 m, H7 = 0.5 m, H8 = 2.5 m, H9 = 3.8 m, and D = 2.5 m. And the results of calculating the stability of the retaining wall that has been designed are obtained for Stability Against Overturning, namely 4.37 &gt; 1.5 (Safe), Stability Against Shifting, namely 2.21 &gt; 2 (Safe), and Stability Against Soil Bearing Capacity, namely 4.14 &gt; 3 (Safe).&#x0D;

Correlations between factor of safety with distributed load and crest length – Zariwam landslide as case study

ABSTRACT This paper examines the impact on Factor of Safety (FS) value due to the variation in distributed load (LD), Crest length (CL), shear strength (τ), and shear stress (σ) both in seismic and non-seismic conditions. The main purpose of this paper is to develop correlations between these parameters, which can be used in any slope stability analysis design project. Forty number of analyses are performed by considering different soil material properties. Slope stability analysis is performed using Slide software and correlations are developed using Statistical Package for Social Sciences (SPSS) software as well as with the help of Microsoft Excel. The analysis results indicate that the seismic slope stability analysis gives optimum value for slope FS and therefore it is highly recommended to perform and give preference to seismic slope stability analysis of any soil slope to compute and recommend FS value. The main novelty of this paper are the eight new correlations. These correlations can be used in slope stability projects like earthfill dams design, embankments, or any slope design project or case study to know about the slope factor of safety in detail.

Traffic safety assessment and prediction under different lighting service states in road tunnels

The lighting service state of road tunnels has an important impact on traffic safety. To assess and predict traffic safety in road tunnels under different lighting service states, a traffic safety assessment system of road tunnels was innovatively established by using visual recognition clarity data from 300 field experiments, which uses the proposed traffic safety factor to assess the traffic safety of road tunnels under different lighting service states. Then, the Particle Swarm Optimization (PSO) algorithm is used to optimize the Back Propagation (BP) neural network, and a new traffic safety intelligent prediction method in road tunnels was constructed to predict the traffic safety factor under different lighting service states. The results of the study show that there is a negative correlation between simulated vehicle speed and visual clarity and a positive correlation between lighting attenuation and visual clarity. There is a negative correlation between the number of luminaire failures and the visual recognition clarity. When the lighting attenuation is below 70% or four and above luminaires fail, the lighting service states of road tunnels can seriously threaten traffic safety. The PSO-BP neural network model can accurately predict the traffic safety factor. The critical value of the traffic safety factor is 0.5965. This means that the lighting service state poses a threat to traffic safety in road tunnels when the traffic safety factor is lower than this value. The results of the study can provide the basis for developing a safe and low-carbon tunnel lighting maintenance program.

Hybrid simulations of m/n = 1/1 instability driven by energetic counter-passing particles in tokamak plasmas

A systematic simulation study of the $n/m=1/1$ instability driven by energetic counter-passing particles in tokamak plasmas has been carried out using the kinetic-MHD (Magnetohydrodynamics) hybrid code M3D-K. The safety factor's radial profile is monotonically increasing with central value $q_0$ less than unity. The linear simulation results show that the instability is either a $m/n=1/1$ energetic particle mode or a $m/n=1/1$ global Alfvén eigenmode depending on the value of the central safety factor. The mode frequencies are close to the tip of Alfvén continuum spectrum at the magnetic axis. The excited modes are radially localized near the magnetic axis well within the safety factor $q=1$ surface. The main wave particle resonance is found to be $\omega _\phi +2\omega _\theta =\omega$ , where ω is the mode frequency. The nonlinear simulation results show that there is a long period of quasi-steady-state saturation phase with frequency chirping up after initial saturation. Correspondingly, the energetic particle distribution with low energies is flattened in the core of the plasma. After this quasi-steady phase, the mode amplitude grows again and frequency jumps down to a low value corresponding to a new mode similar to the energetic co-passing particle-driven low-frequency fishbone while the energetic particle distribution is flattened for higher energies in the core of plasma.

The Effect of Geometrical Features of Release Surfaces on the Stability of Tectonically Disturbed Deep Rock Slopes in an Albite Open Pit Mine

An albite deposit formed in orthogneiss has been operated using open pit mining process since 1996. However, landslides have occurred following the excavation works and heavy rainfalls. In the current state, the slopes are still susceptible to mass movement. For this reason, this study aimed to determine the root causes that are influencing continuous movements. In this context, two geometric features of the strike-slip faults that form tectonic slices in the pit were proposed. The first one (α-angle) is the acute angle between the dip direction of the overall slope and the general trend of the strike-slip fault and it was used for the kinematic evaluation of the sliding potential of the tectonic slices. The validity of α-angle was confirmed by investigating its relationship with the factor of safety values. The second one (undulation angle, i) was used to determine the effective surface friction angle (ϕeff). Thereafter, ϕeff value was used in the deterministic finite element (FE) slope stability analyses as well as back analyses. Its effect on the stability of overall slopes was investigated for static and pseudo-static conditions with different water table levels. The FE results confirmed the monitored field displacement measurements. It was found that as α-angle decreases, the ability to resist sliding also decreases since the low α-angle promotes block formation. This study also demonstrated that using the undulation angles on mapped profiles of large-scale discontinuities (≥270 m) would be a promising approach for slope stability assessments of open pit excavations in tectonically disturbed metamorphic rocks.

Strengthening the Slope Beneath Bashtapia Castle at the Highest Expected Tigris River Level

This study has been achieved using Geo-Studio Finite Element Software in two sections. First, to study the changes in pore water pressure (PWP) within the soil layers below Bashtapia Castle at different water levels of the river Tigris. The effect of these changes was in focus to check the slope stability of the Castle. On the other hand, the second section was to increase the safety factor using slope reinforcement using different spacings and lengths of the anchor’s rods. Modeling output showed that the factor of safety (FS) decreased from 2.83 to 0.838 when the water level raised from 0 to 7 m above the bottom slope layer. Accordingly, anchor bars were introduced in the model, and the safety factor increased. The slope layers were treated and strengthened using reinforcing anchor bars at different lengths and numbers. In general, the analysis results showed the positive effect of reinforcing bars on the stability of the castle slope. The FS of the slope castle increases with the increased length and number of anchors to a certain value, and then there is no effect of this increase on the FS value.

Design of One-Leg Cane Handle Using AHP-TOPSIS Comparative Study to Improve The Mobility of The Elderly

The number of elderly people in Indonesia has increased significantly. Indonesia has an elderly population of 29 million or 11% of the total population, and around 39% of the population or 11.5 million live with disabilities. The elderly who experience disabilities caused by physical and cognitive changes can decrease their quality of life. Disability in the elderly is caused by the weakening of the lower extremity muscles, resulting in decreased balance and walking stability. Appropriate walking aids for the elderly are crucial in improving balance and stability to reduce the risk of falling. The most commonly used mobility aid for the elderly is a cane, but the use by the elderly is mostly not appropriately instructed, where up to 70% use the wrong cane handle and use it incorrectly. As a result of incorrect use of canes and inadequate instructions, 30-50% of the elderly stop using the cane after receiving it. So, to keep the elderly using the cane, this study tries to design a cane handle with a comparative study using the AHP-TOPSIS Method. The purpose of designing a cane handle is to mantain the balance and stability of the elderly for mobility to improve quality of life and keep the elderly using a cane to reduce the risk of falling. The output obtained is a visualization of the concept &amp; prototype of the improved cane handle design. The improved cane handle is simulated using Autodesk Inventor software with a loading of 150 N. The maximum stress analysis result is 25.31 Mpa, the maximum displacement analysis is 0.2273 mm, and the safety factor value is 7.54 ul.

Reaction of a crystal lattice of metallic materials to long-term storage in elastic-stressed state

The resistance of the crystal lattice of 08ps structural steel, AD1 aluminum grade and M1 copper grade to long-term action (9 years) of elastic stresses at different levels of static loads was studied by the X-ray diffraction method. It has been established that the annual ambient temperature variation from -50°С in winter to +35°С in summer in the period from 2013 to 2022 does not cause significant changes in the characteristics of the diffraction line profiles of the studied materials. The characteristics of the diffraction line profiles obtained in the winter period of observations indicate a slight decrease in instrumental errors due to the experiment design conditions. A systematic change in the resistance of the studied materials crystal lattice to the action of elastic stresses at values of σ > 0.5 σ0,2 was found. The stepwise process of the occurrence of elementary acts of the crystal lattice reaction in the local zone of X-ray reflection is revealed. This gradation experimentally substantiates the value of the minimum safety factor of materials used in strength calculations of structures.

A comprehensive computer aided approach to design of earthen dams of dry flood-control reservoirs

A generalized, comprehensive approach to geotechnical design of earthen dams of dry flood-control reservoirs is developed. It consists of three steps:•In Step 1 three-dimensional (3D) model of terrain and dam subsoil is created. The arrangement of geotechnical layers is reconstructed based on results of geotechnical investigation using geostatistical interpolation, namely, kriging.•Step 2 involves 3D finite element (FE) analysis of transient groundwater flow through the subsoil. Anti-filtration barrier extent is determined by appropriate parametric analysis and the condition of critical hydraulic gradients is verified.•Step 3 concerns deformation assessment and stability analysis. Computations are carried out for selected cross-sections of the dam. At this stage transient coupled problem of deformation and groundwater flow is considered. Stability is assessed with the use of shear strength reduction technique.The proposed approach enables verification of all relevant conditions of limit states. Furthermore, it has been developed in such a way as to enable computationally efficient analysis of considered phenomena. The method constitutes a general framework of design procedure. It can be easily adapted to conform any standard requirements, e.g., by taking adequate values of partial safety factors. Moreover, design solutions can be optimized through parametric analyzes.

Probabilistic Analyses of a Post-Grouted Anchor–Soil Bond Friction Performance Considering the Geological Origin and the SPT-N Tendency with Depth

This paper presents a probabilistic study of anchor–soil bond stress performance in a post-grouted anchor wall. The variability of geotechnical shear strength parameters will be described by a probability density function (PDF) and as a linear and squared shear strength function with depth based on widely available standard penetration test (SPT) data on two geologies (mudflows and residual soils). Monte Carlo simulation was carried out to evaluate the mean and standard deviation of ultimate anchor strength. The study allows the factor of safety (FS) to be determined to achieve a target probability of failure (pf). The first analyses consist of a probabilistic analysis without considering the shear strength varying with depth (SSVD), while the second one includes SSVD. Probabilistic analyses (without SSVD) show that a reduction of the pf depends only on the design FS. The probabilistic SSVD analyses showed that the N-value at the surface (N0), and the function gradient (ρ) had an important influence on the anchor pf. It is shown that the use of an overall FS can be considered as a high-risk design for soils with a high N0 variability and low ρ. Therefore, the target pf shows that the top anchors are the most critical, so higher FS values are required (FS > 2.5), especially for mudflow soils.