— Both, natural and man-made slopes formed for various purposes may cause numerous permanent problems in engineering applications. Therefore, it is important to know composition and mechanical behavior of soil environment leading to geotechnical problems on slope surfaces. The risk analyzes of natural and artificial slopes, realized detailed, can lead to reliable results. Based on those results, it is possible to produce optimal technical solutions with respect to an acceptable risk level. The researches on these subjects give new opportunities to improve the existing knowledge by reviewing them. The main aim of this study is objectively to evaluate the parameters caused slope stability problems. In this regard, the parameters of slope angle, internal friction angle and cohesion of soil, and groundwater level, which are main risk factors for a slope, and should contribute to raise awareness about this issue, were investigated. Keywords— Factor of safety, risk factors, slope stability.
An On-Situ Study of Stability Analysis on Slopes Using Undrained Shear Streng...IOSR Journals
The slope stability problems in residual soil are receiving increasing attention in recent years. The
stability of slope is one of the important criteria where consider worldwide for a wide range of engineering
projects. The rainfall seems to be the most common cause for landslide in residual soil slope. After a period of
continuous rainfall, soil becomes saturated and a wetting front is developed because of infiltration of rainwater
into the ground and into the slope surface respectively. The objective of the paper is to find threshold slope
based on undrained shear strength parameters.
Integrated Methodology for the Seismic Design of Reinforced Embankments with ...IRJET Journal
This document presents an integrated methodology for the seismic design of reinforced soil embankments with berms (slopes with stepped terraces). The methodology is based on limit analysis and the quasi-static approach. It accounts for seismic loading conditions and considers cohesionless soils that deform plastically according to the Coulomb failure criterion. A software application was designed to implement this methodology for seismic design. It allows the user to define seismic hazard and design reinforced slopes based on potential failure planes. The results are compared to conventional methods and finite element analysis. Continuous slopes are also compared to slopes with berms, highlighting the advantages of composite geometries for high embankments.
Soil sheet pile interaction part i a review of theories and design methodsIAEME Publication
This document summarizes theories and modeling methods for studying the interaction between soil and sheet pile walls. It discusses the complex nonlinear behavior of soil-sheet pile interaction and reviews various modeling approaches used to analyze it, including the Mohr-Coulomb and cap models. It also reviews conventional design theories for sheet piles, such as the Coulomb and Rankine theories. The document emphasizes the importance of numerical analysis tools like the finite element method in accurately modeling the interaction between soil and sheet piles.
STRESSES BELOW EXISTING STRUCTURES DURING TUNNEL EXCAVATION USING TUNNEL BORI...ijiert bestjournal
The Finite element (FE) analysis include the response of structures t o horizontal & vertical dynamic forces and consider all site characteristics,such as soils and geologic conditions. The induced stresses under the foundation of adjacent buildings during newly constructed underground tunnel through TBM,were investigated in this study. Results of this study were examined to find out whether the amount of variations in forces and stresses are in the allowable ranges or not. In this paper,soil parameters used for the study are based on the existing Delhi Metro tunnel site. Using these soils parameters,tunnel excavation through TBM has been modelled in PLAXIS Tunnel - 3D and the adjacent structures have also been included in the model.
The document summarizes a study that used electrical resistivity methods to characterize a landfill site in Ilorin, Nigeria. 2D resistivity surveys were conducted along four profiles using a Wenner-Schlumberger array. The results identified low resistivity zones below 17-36 ohm-m, indicating contaminant leachate plumes up to 40 m deep. A three-layer geo-electric model was observed. The topographic data showed the site sloped northward. Profile 1 located near settlements showed contaminants drifting north, potentially impacting groundwater sources.
A comparison on slope stability analysis of aydoghmoosh earth damdgjd
1. The document compares slope stability analysis of the Aydoghmoosh Earth Dam in Iran using limit equilibrium methods, finite element analysis, and finite difference methods.
2. Safety factors calculated using the simplified Bishop method and finite element analysis were similar at 1.494 and 1.596, respectively.
3. The finite difference method produced a safety factor of 1.79, around 12% higher than the finite element method. This is because the finite element method accounts for elasticity modulus in its calculations.
Numerical simulation of laterally loaded pileDr. Naveen BP
This document presents a finite element model simulation of a lateral load test on a 1m diameter bored pile embedded in residual soils. The pile and soil were modeled in PLAXIS 2D, with the soil represented by a Mohr-Coulomb model and the pile as a beam element. The model results showed good agreement with load-displacement curves from the field test. However, the field test was unable to apply loads high enough to reach design code displacement limits due to limitations of test equipment for large piles in residual soils. The numerical model can simulate larger displacements to evaluate pile behavior under higher loads.
Stability analysis of earth dam by geostudio softwareiaemedu
The document summarizes a study on the stability analysis of an existing 21m high earth dam in India called Bhimdi earth dam. The study analyzed the stability of the dam by changing parameters like berm width and the position of filter drains using GeoStudio software. The factors of safety were computed for various scenarios and compared to the existing design. Strengthening the dam with anchors and nails also increased the factors of safety. Changing the berm width from 5m to 3m decreased the factor of safety from 2.43 to 2.25 on the downstream side. On the upstream side, a narrower berm width and adding anchors and nails also increased the factors of safety.
An On-Situ Study of Stability Analysis on Slopes Using Undrained Shear Streng...IOSR Journals
The slope stability problems in residual soil are receiving increasing attention in recent years. The
stability of slope is one of the important criteria where consider worldwide for a wide range of engineering
projects. The rainfall seems to be the most common cause for landslide in residual soil slope. After a period of
continuous rainfall, soil becomes saturated and a wetting front is developed because of infiltration of rainwater
into the ground and into the slope surface respectively. The objective of the paper is to find threshold slope
based on undrained shear strength parameters.
Integrated Methodology for the Seismic Design of Reinforced Embankments with ...IRJET Journal
This document presents an integrated methodology for the seismic design of reinforced soil embankments with berms (slopes with stepped terraces). The methodology is based on limit analysis and the quasi-static approach. It accounts for seismic loading conditions and considers cohesionless soils that deform plastically according to the Coulomb failure criterion. A software application was designed to implement this methodology for seismic design. It allows the user to define seismic hazard and design reinforced slopes based on potential failure planes. The results are compared to conventional methods and finite element analysis. Continuous slopes are also compared to slopes with berms, highlighting the advantages of composite geometries for high embankments.
Soil sheet pile interaction part i a review of theories and design methodsIAEME Publication
This document summarizes theories and modeling methods for studying the interaction between soil and sheet pile walls. It discusses the complex nonlinear behavior of soil-sheet pile interaction and reviews various modeling approaches used to analyze it, including the Mohr-Coulomb and cap models. It also reviews conventional design theories for sheet piles, such as the Coulomb and Rankine theories. The document emphasizes the importance of numerical analysis tools like the finite element method in accurately modeling the interaction between soil and sheet piles.
STRESSES BELOW EXISTING STRUCTURES DURING TUNNEL EXCAVATION USING TUNNEL BORI...ijiert bestjournal
The Finite element (FE) analysis include the response of structures t o horizontal & vertical dynamic forces and consider all site characteristics,such as soils and geologic conditions. The induced stresses under the foundation of adjacent buildings during newly constructed underground tunnel through TBM,were investigated in this study. Results of this study were examined to find out whether the amount of variations in forces and stresses are in the allowable ranges or not. In this paper,soil parameters used for the study are based on the existing Delhi Metro tunnel site. Using these soils parameters,tunnel excavation through TBM has been modelled in PLAXIS Tunnel - 3D and the adjacent structures have also been included in the model.
The document summarizes a study that used electrical resistivity methods to characterize a landfill site in Ilorin, Nigeria. 2D resistivity surveys were conducted along four profiles using a Wenner-Schlumberger array. The results identified low resistivity zones below 17-36 ohm-m, indicating contaminant leachate plumes up to 40 m deep. A three-layer geo-electric model was observed. The topographic data showed the site sloped northward. Profile 1 located near settlements showed contaminants drifting north, potentially impacting groundwater sources.
A comparison on slope stability analysis of aydoghmoosh earth damdgjd
1. The document compares slope stability analysis of the Aydoghmoosh Earth Dam in Iran using limit equilibrium methods, finite element analysis, and finite difference methods.
2. Safety factors calculated using the simplified Bishop method and finite element analysis were similar at 1.494 and 1.596, respectively.
3. The finite difference method produced a safety factor of 1.79, around 12% higher than the finite element method. This is because the finite element method accounts for elasticity modulus in its calculations.
Numerical simulation of laterally loaded pileDr. Naveen BP
This document presents a finite element model simulation of a lateral load test on a 1m diameter bored pile embedded in residual soils. The pile and soil were modeled in PLAXIS 2D, with the soil represented by a Mohr-Coulomb model and the pile as a beam element. The model results showed good agreement with load-displacement curves from the field test. However, the field test was unable to apply loads high enough to reach design code displacement limits due to limitations of test equipment for large piles in residual soils. The numerical model can simulate larger displacements to evaluate pile behavior under higher loads.
Stability analysis of earth dam by geostudio softwareiaemedu
The document summarizes a study on the stability analysis of an existing 21m high earth dam in India called Bhimdi earth dam. The study analyzed the stability of the dam by changing parameters like berm width and the position of filter drains using GeoStudio software. The factors of safety were computed for various scenarios and compared to the existing design. Strengthening the dam with anchors and nails also increased the factors of safety. Changing the berm width from 5m to 3m decreased the factor of safety from 2.43 to 2.25 on the downstream side. On the upstream side, a narrower berm width and adding anchors and nails also increased the factors of safety.
IRJET- Seismic Evaluation of Symmetric and Asymmetric Buildings by Pushover a...IRJET Journal
This document summarizes a study that analyzes the seismic performance of symmetric and asymmetric buildings using pushover analysis and time history analysis. Three new reinforced concrete buildings of different shapes (C-shaped, L-shaped, and square) with 14 stories were modeled. The models included bare frame, soft-story, and infilled wall configurations. Nonlinear static (pushover) analysis and dynamic (time history and response spectrum) analyses were performed to evaluate lateral displacements, story drifts, base shear, and other response parameters. Results showed that irregularly shaped and bare frame buildings experienced greater displacements and drifts compared to symmetric buildings and buildings with infill walls. Buildings with infill walls also had higher base shear values
Behavior of piles and pile groups under lateral loadjain_abhishek
This document presents methods for analyzing and designing piles subjected to lateral loads. It reviews rational methods that use the equations of mechanics to model soil-structure interaction, including the methods of Broms and Poulos. Soil response is modeled using nonlinear p-y curves representing the relationship between lateral soil resistance (p) and pile deflection (y). The document provides recommendations for developing p-y curves for different soil types, including soft clay, stiff clay, sand, and rock. It also describes methods for solving the differential equation that governs lateral pile behavior, including the difference equation method. The document concludes with a discussion of structurally designing piles to resist lateral loads.
This document analyzes and discusses the connection designs of precast load bearing walls in multi-story buildings subjected to seismic and wind loads. It presents the modeling and analysis of a G+11 story precast concrete shear wall structure using ETABS software. The effects of various seismic zones and wind speeds on structural responses like out-of-plane moments, axial forces, shear forces, base shear, story drift, and tensile forces in the shear walls are extracted and plotted. Maximum values of these responses at different story levels are compared for different seismic zones and wind speeds. Finally, the effect of seismic zone and wind zone on the structural behavior is summarized in tabular form.
This document discusses the optimal design of machinery shallow foundations on clay soils. It aims to minimize foundation cost by using foundation mass as the objective function, while ensuring high technical quality through 10 functional constraints related to soil mechanics and vibrations. These constraints control factors like foundation dimensions, bearing capacity, settlement, and maximum vibration amplitude. The approach uses MATLAB optimization to determine the optimal design that best satisfies the objective function and constraints.
Stability analysis and simulated hydrologic response of some vulnerable slope...iosrjce
Hillslope geometry, material properties, and hydraulic heterogeneities complicate slope stability
models. To reduce uncertainties in the determination of Factor of Safety, parameters obtained at in-situ stress
levels using ASTM standards were used in two slope stability models to identify and classify some vulnerable
slopes in northern and southern parts of Nigeria.Steady-state and peak strength parameters were applied
separately in an infinite slope analysis simulating the variation of slope attributes with degree of saturation. The
application yielded FS that were consistent with instability, and accurately predicted the characteristics of
slopes in which failure was likely. While rainfall was a common trigger, the probability of failure was higher
on slopes > 38o
in the northern part of the country underlain by igneous and metamorphic rocks. Contrastingly,
slopes with angles > 25o were predicted to be at risk in the southern part underlain by semi-consolidated
sandstones. These predictions are in good agreement with field and reported cases of mass movements in the
two regions. Using another stability method based on Bishop Model to correlate and validate the findings, the
research observed that the slopes were sensitive to moisture with considerable drop in FS as saturation
gradually increased. The study discovered that about 80 % saturation was enough to induce instability and that
beyond this threshold failure occurred when the slopes became marginally stable (FS ≤ 1). This threshold value
and the decline in FS with rise in saturation have important implications for rainfall-induced landslides on the
hilly areas of Nigeria.
Finite element analysis of underground metro tunnelsIAEME Publication
This document summarizes a study that performed finite element analysis of underground metro tunnels in Bangalore, India. It analyzed the tunnels' response to gravity, hydrostatic pressure, and blast-induced pressures from a hypothetical terror attack. The analysis used ANSYS to model the twin-tunnel system and surrounding soil, validating the results against theoretical solutions. It studied stresses, deformations, and effects on neighboring tunnels over time from a simulated pressure wave. The analysis also compared responses of different tunnel shapes and support systems under these loads.
EFFECT OF CONCENTRATED ECCENTRIC LOAD IN LONGITUDINAL DIRECTION OF RECTANGULA...IAEME Publication
Objectives: To study the effect of Relative Rigidity of soil interaction behaviour on the rectangular plates.Methods: Analysis was done for a rectangular footing subjected to the eccentric concentrated load in the longitudinal direction up to the middle one third of its longer span dimension, the loss of contact phenomena was analyzed by the finite element method using ANSYS 12.0 software and the Critical Relative Rigidity (CRR) values i.e. the relative rigidity (RR) at which the soil medium just starts experiencing loss of contact with the footing were obtained for various L/B (1.2 to 2.0) ratios up to the two way distribution. Findings: With the increase in the eccentricity of concentrated load the CRR values were decreased and as the L/B ratio increases, the CRR values increased. Improvements: Effect of Relative Rigidity of soil interaction behaviour concept can be extended to different types of plates like square, circular, and loss of contact phenomena should be analysed.
Model Study of Slope Stability in Open Pit by Numerical Modeling Using the Fi...CrimsonPublishersAMMS
Model Study of Slope Stability in Open Pit by Numerical Modeling Using the Finite Element Method by Saadoun Abderrazak in Aspects in Mining & Mineral Science
Effect of free surface boundary and wall flexibility in seismic design of liq...eSAT Journals
1) The document analyzes the effect of fluid-structure interaction on the modal characteristics of cylindrical steel water tanks with and without considering the free surface effect of the liquid.
2) Finite element models of shallow and tall tanks were created in ANSYS and modal analysis was performed considering different conditions such as with and without liquid sloshing.
3) The effect of liquid mass on the convective and impulsive modes was observed to decrease the natural frequencies more for the impulsive modes due to greater participation of the liquid mass. Flexibility of the tank wall was also found to increase the slosh frequencies.
This document is a project proposal to evaluate the impact of climate change on asphalt roads in Khyber Pakhtunkhwa province. The proposal was submitted by three students and supervised by an assistant professor. The objectives are to analyze temperature changes in the region, determine the impact on asphalt roads, and predict how temperatures may change climate change scenarios for roads by 2026. The methodology will include collecting 15 years of temperature data, analyzing average monthly temperatures over time, and using statistical tests like Mann-Kendall trend test to identify temperature trends and changes. The study aims to help transportation planning and safety measures by researching problems deteriorating asphalt roads.
1) The document presents an optimization of a 3D geometrical soil model for analyzing multiple square footings on sand using finite element modeling.
2) A fixed meshing pattern was adopted with the 3D soil model discretized into triangular elements. Multiple footing configurations were analyzed for different spacing between footings.
3) The optimized 3D geometrical soil model dimensions were found to be X=19B, Y=Z=15B, where B is the footing width. This model provided comparable results for ultimate bearing capacity and settlement to other studies.
Optimization of 3 d geometrical soil model for multiple footing resting on sandeSAT Journals
Abstract The study of ultimate bearing capacity (UBC) for a group of two or more footings had been made by investigators for the effect of interference of footings by various means, which is not considered in the conventional theories of bearing capacity. The Finite Element Method (FEM) initiated with 2D/3D modelling is being used for such complex problem. In the present study 3D geometrical soil models were developed and tested with multiple footing on cohesion-less soil using 3D FEM simulation software. This paper highlights optimized 3D geometrical soil model for multiple footing on sand. The meshing parameters, soil model size observed to be influencing the displacement and stresses to great extent. Keywords: FEM, geometrical soil model, interference, multiple footings.
#02080327-27-Time History Analysis of Sym and Unsym building (1)Vishruth Jain
1) Time history analysis was conducted on symmetric and unsymmetric 4-story buildings with different soil conditions, including fixed supports, cohesive soil, and cohesionless soil.
2) The analysis found that unsymmetric buildings on cohesionless soil experienced the greatest displacements, forces, and stresses in structural members. Displacements increased up to 68.6% compared to other conditions.
3) Beam end forces increased up to 98.6% for unsymmetric buildings on cohesionless soil compared to other conditions. Stresses in beams also increased up to 98.9% under this condition.
Soil sheet pile interaction part ii numerical analysis and simulationIAEME Publication
This document summarizes a study that uses numerical analysis to investigate the interaction between soil and an embedded sheet pile wall. Finite element modeling was used to analyze sheet pile walls embedded in both homogeneous and heterogeneous soil strata. The results showed variations between theoretical conventional design approaches and the numerical analysis results for both anchored and cantilevered sheet pile walls. Specifically, the numerical analysis showed cases where deformation was overestimated by up to 31.28% when assuming homogeneous soil compared to modeling heterogeneous soil layers. Additional numerical modeling analyzed replacing steel reinforcement with carbon fiber reinforced polymer in concrete sheet piles installed in corrosive shoreline environments. This modeling showed little variation in horizontal deformation between conventional steel and CFRP reinforcement.
Soil structure interaction effect on dynamic behavior of 3 d building frames ...eSAT Journals
Abstract The soil flexibility effect is generally not considered in seismic design of building frames and the design is done based on results of dynamic analysis taking fixed base condition. Flexibility effect of soil causes lengthening of lateral natural period due to overall reduction in lateral stiffness of the structure. Such lengthening lateral natural period (T) may considerably vary the seismic response of building frames resting on raft foundation. Hence it is necessary to unite the flexibility of soil on which the foundation rests during analysis such study being termed as soil structure interaction (SSI). In the present study the dynamic behavior of building frames over raft footing under seismic forces uniting soil structure interaction is considered. The analysis is carried out using FEM software SAP2000 *Ver14. For the interaction analysis of space frame, foundation and soil are considered as parts of a single compatible unit and soil is idealized using the soil models for analysis. The soil system below a raft footing is replaced by providing a true soil model (continuum model). In continuum model, soil is considered as homogeneous, isotropic, elastic of half space for which dynamic shear modulus and Poisson’s ratio are the inputs. Influence of number of parameters such as number of storey’s, soil types and height ratio for seismic zone-V is considered in present study. Building responses are considered for bare frame with and without accounting for soil flexibility. The responses in terms of lateral natural period and seismic base shear, lateral displacement (story drift), with and without soil flexibility is compared to evaluate the contribution of soil flexibility on building frames. Keywords: soil structure interaction, natural period, base shear, max. lateral displacement and raft footing etc…
Investigation into the effects of delamination parameters of the layered compoIAEME Publication
The document investigates the effects of delamination parameters on layered composite plates subjected to close proximity blast loads. A finite element analysis is conducted to model various delamination scenarios, including position within the plate thickness, delamination area ratio, and explosive charge weight. The analysis finds that the presence of delamination within composite plates decreases their protective capacity against explosive charges. Graphical results are presented showing the effects of different delamination positions, charge masses, and delamination area ratios on the plate response.
SLOPE STABILITY ANALYSIS USING GeoStudio AND PLAXIS 2D SOFTWARE: A COMPARATIV...IRJET Journal
This document presents a comparative study of slope stability analysis using GeoStudio and PLAXIS 2D software. The study focuses on analyzing a slope in the Thodupuzha-Cheruthoni road in Kerala, India that is prone to landslides. Laboratory tests are conducted to determine the soil properties at the site. Numerical models are developed using GeoStudio and PLAXIS to analyze seepage patterns and slope stability. The factor of safety results from both software are compared to identify any differences in their accuracy and efficiency for seepage and slope stability analysis of road embankments. The findings of this study can help determine the most appropriate software for analyzing slope stability and maintaining safe slopes for roads.
SLOPE STABILITY ANALYSIS USING GeoStudio AND PLAXIS 2D SOFTWARE: A COMPARATIV...IRJET Journal
This document presents a comparative study of slope stability analysis using GeoStudio and PLAXIS 2D software. The study focuses on analyzing a slope in the Thodupuzha-Cheruthoni road in Kerala, India that is prone to landslides. Laboratory tests are conducted to determine the soil properties at the site. Numerical models are developed using GeoStudio and PLAXIS to analyze seepage patterns and slope stability. The factor of safety results from both software are compared to identify any differences in their accuracy and efficiency for seepage and slope stability analysis of road embankments. The findings of this study can help determine the most appropriate software for analyzing slope stability and maintaining safe slopes for roads.
Predicting Resilient Modulus of Clayey Subgrade Soils by Means of Cone Penetr...Pouyan Fakharian
Resilient modulus (Mr) of subgrade soils is considered as one of the most important factors for designing flexible pavements using empirical methods as well as mechanistic-empirical methods. The resilient modulus is commonly measured by a dynamic triaxial loading test, which is complex and expensive. In this research, back-propagation artificial neural network method has been employed to model the resilient modulus of clayey subgrade soils based on the results of the cone penetration test. The prediction of the resilient modulus of clayey subgrade soil can be possible through the developed neural network based on the parameters of the cone tip resistance (qc), sleeve friction (fs), moisture content (w), and dry density (γd). The results of the present study show that the coefficients of determination (R2) for training and testing sets are 0.9837 and 0.9757, respectively. According to the sensitivity analysis results, the moisture content is the least important parameter to predict the resilient modulus of clayey subgrade soils, while the importance of other parameters is almost the same. In this study, the effect of different parameters on the resilient modulus of clayey subgrade soil was evaluated using parametric analysis and it was found that with increasing the cone tip resistance (qc), the sleeve friction (fs) and the dry density (γd) and also with decreasing the moisture content (w) of soils, the resilient modulus of clayey subgrade soils increases.
This document discusses several applications of slope stability analysis using the finite element method. It begins by introducing slope stability analysis and some traditional limit equilibrium methods. It then discusses two main advantages of the finite element method: it does not require assumptions about the failure surface shape or location, and it can model complex geometries and soil properties. The document presents several examples of applying the finite element method to analyze slope stability under various conditions, including accounting for drainage, brittle soil behavior, and engineering interventions. It compares results to traditional methods and notes the additional data on stresses, strains, and progressive failure that finite element analysis can provide.
The objective of this project is to calculate the factor of safety of a complex slope situation. The stress distribution zones are also shown in the project. The probability of slope failure can be shown using FLAC3D software.
IRJET- Soil Mass Movement with Recent Deluge in Kerala as BackdropIRJET Journal
This document discusses soil mass movement in Kerala, India following severe flooding in July 2018. Laboratory tests were conducted on soil samples from an affected site, including sieve analysis, direct shear testing, and specific gravity tests. Slope stability analysis was performed using the Swedish circle method and PLAXIS software. The analyses found a safety factor of 8.163 without anchors and 8.445 with anchors installed. The study concluded that poor construction practices and soil deterioration from prolonged flooding contributed to failures. Anchors were recommended to stabilize slopes and prevent further landslides in severely affected areas.
IRJET- Seismic Evaluation of Symmetric and Asymmetric Buildings by Pushover a...IRJET Journal
This document summarizes a study that analyzes the seismic performance of symmetric and asymmetric buildings using pushover analysis and time history analysis. Three new reinforced concrete buildings of different shapes (C-shaped, L-shaped, and square) with 14 stories were modeled. The models included bare frame, soft-story, and infilled wall configurations. Nonlinear static (pushover) analysis and dynamic (time history and response spectrum) analyses were performed to evaluate lateral displacements, story drifts, base shear, and other response parameters. Results showed that irregularly shaped and bare frame buildings experienced greater displacements and drifts compared to symmetric buildings and buildings with infill walls. Buildings with infill walls also had higher base shear values
Behavior of piles and pile groups under lateral loadjain_abhishek
This document presents methods for analyzing and designing piles subjected to lateral loads. It reviews rational methods that use the equations of mechanics to model soil-structure interaction, including the methods of Broms and Poulos. Soil response is modeled using nonlinear p-y curves representing the relationship between lateral soil resistance (p) and pile deflection (y). The document provides recommendations for developing p-y curves for different soil types, including soft clay, stiff clay, sand, and rock. It also describes methods for solving the differential equation that governs lateral pile behavior, including the difference equation method. The document concludes with a discussion of structurally designing piles to resist lateral loads.
This document analyzes and discusses the connection designs of precast load bearing walls in multi-story buildings subjected to seismic and wind loads. It presents the modeling and analysis of a G+11 story precast concrete shear wall structure using ETABS software. The effects of various seismic zones and wind speeds on structural responses like out-of-plane moments, axial forces, shear forces, base shear, story drift, and tensile forces in the shear walls are extracted and plotted. Maximum values of these responses at different story levels are compared for different seismic zones and wind speeds. Finally, the effect of seismic zone and wind zone on the structural behavior is summarized in tabular form.
This document discusses the optimal design of machinery shallow foundations on clay soils. It aims to minimize foundation cost by using foundation mass as the objective function, while ensuring high technical quality through 10 functional constraints related to soil mechanics and vibrations. These constraints control factors like foundation dimensions, bearing capacity, settlement, and maximum vibration amplitude. The approach uses MATLAB optimization to determine the optimal design that best satisfies the objective function and constraints.
Stability analysis and simulated hydrologic response of some vulnerable slope...iosrjce
Hillslope geometry, material properties, and hydraulic heterogeneities complicate slope stability
models. To reduce uncertainties in the determination of Factor of Safety, parameters obtained at in-situ stress
levels using ASTM standards were used in two slope stability models to identify and classify some vulnerable
slopes in northern and southern parts of Nigeria.Steady-state and peak strength parameters were applied
separately in an infinite slope analysis simulating the variation of slope attributes with degree of saturation. The
application yielded FS that were consistent with instability, and accurately predicted the characteristics of
slopes in which failure was likely. While rainfall was a common trigger, the probability of failure was higher
on slopes > 38o
in the northern part of the country underlain by igneous and metamorphic rocks. Contrastingly,
slopes with angles > 25o were predicted to be at risk in the southern part underlain by semi-consolidated
sandstones. These predictions are in good agreement with field and reported cases of mass movements in the
two regions. Using another stability method based on Bishop Model to correlate and validate the findings, the
research observed that the slopes were sensitive to moisture with considerable drop in FS as saturation
gradually increased. The study discovered that about 80 % saturation was enough to induce instability and that
beyond this threshold failure occurred when the slopes became marginally stable (FS ≤ 1). This threshold value
and the decline in FS with rise in saturation have important implications for rainfall-induced landslides on the
hilly areas of Nigeria.
Finite element analysis of underground metro tunnelsIAEME Publication
This document summarizes a study that performed finite element analysis of underground metro tunnels in Bangalore, India. It analyzed the tunnels' response to gravity, hydrostatic pressure, and blast-induced pressures from a hypothetical terror attack. The analysis used ANSYS to model the twin-tunnel system and surrounding soil, validating the results against theoretical solutions. It studied stresses, deformations, and effects on neighboring tunnels over time from a simulated pressure wave. The analysis also compared responses of different tunnel shapes and support systems under these loads.
EFFECT OF CONCENTRATED ECCENTRIC LOAD IN LONGITUDINAL DIRECTION OF RECTANGULA...IAEME Publication
Objectives: To study the effect of Relative Rigidity of soil interaction behaviour on the rectangular plates.Methods: Analysis was done for a rectangular footing subjected to the eccentric concentrated load in the longitudinal direction up to the middle one third of its longer span dimension, the loss of contact phenomena was analyzed by the finite element method using ANSYS 12.0 software and the Critical Relative Rigidity (CRR) values i.e. the relative rigidity (RR) at which the soil medium just starts experiencing loss of contact with the footing were obtained for various L/B (1.2 to 2.0) ratios up to the two way distribution. Findings: With the increase in the eccentricity of concentrated load the CRR values were decreased and as the L/B ratio increases, the CRR values increased. Improvements: Effect of Relative Rigidity of soil interaction behaviour concept can be extended to different types of plates like square, circular, and loss of contact phenomena should be analysed.
Model Study of Slope Stability in Open Pit by Numerical Modeling Using the Fi...CrimsonPublishersAMMS
Model Study of Slope Stability in Open Pit by Numerical Modeling Using the Finite Element Method by Saadoun Abderrazak in Aspects in Mining & Mineral Science
Effect of free surface boundary and wall flexibility in seismic design of liq...eSAT Journals
1) The document analyzes the effect of fluid-structure interaction on the modal characteristics of cylindrical steel water tanks with and without considering the free surface effect of the liquid.
2) Finite element models of shallow and tall tanks were created in ANSYS and modal analysis was performed considering different conditions such as with and without liquid sloshing.
3) The effect of liquid mass on the convective and impulsive modes was observed to decrease the natural frequencies more for the impulsive modes due to greater participation of the liquid mass. Flexibility of the tank wall was also found to increase the slosh frequencies.
This document is a project proposal to evaluate the impact of climate change on asphalt roads in Khyber Pakhtunkhwa province. The proposal was submitted by three students and supervised by an assistant professor. The objectives are to analyze temperature changes in the region, determine the impact on asphalt roads, and predict how temperatures may change climate change scenarios for roads by 2026. The methodology will include collecting 15 years of temperature data, analyzing average monthly temperatures over time, and using statistical tests like Mann-Kendall trend test to identify temperature trends and changes. The study aims to help transportation planning and safety measures by researching problems deteriorating asphalt roads.
1) The document presents an optimization of a 3D geometrical soil model for analyzing multiple square footings on sand using finite element modeling.
2) A fixed meshing pattern was adopted with the 3D soil model discretized into triangular elements. Multiple footing configurations were analyzed for different spacing between footings.
3) The optimized 3D geometrical soil model dimensions were found to be X=19B, Y=Z=15B, where B is the footing width. This model provided comparable results for ultimate bearing capacity and settlement to other studies.
Optimization of 3 d geometrical soil model for multiple footing resting on sandeSAT Journals
Abstract The study of ultimate bearing capacity (UBC) for a group of two or more footings had been made by investigators for the effect of interference of footings by various means, which is not considered in the conventional theories of bearing capacity. The Finite Element Method (FEM) initiated with 2D/3D modelling is being used for such complex problem. In the present study 3D geometrical soil models were developed and tested with multiple footing on cohesion-less soil using 3D FEM simulation software. This paper highlights optimized 3D geometrical soil model for multiple footing on sand. The meshing parameters, soil model size observed to be influencing the displacement and stresses to great extent. Keywords: FEM, geometrical soil model, interference, multiple footings.
#02080327-27-Time History Analysis of Sym and Unsym building (1)Vishruth Jain
1) Time history analysis was conducted on symmetric and unsymmetric 4-story buildings with different soil conditions, including fixed supports, cohesive soil, and cohesionless soil.
2) The analysis found that unsymmetric buildings on cohesionless soil experienced the greatest displacements, forces, and stresses in structural members. Displacements increased up to 68.6% compared to other conditions.
3) Beam end forces increased up to 98.6% for unsymmetric buildings on cohesionless soil compared to other conditions. Stresses in beams also increased up to 98.9% under this condition.
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Determining Important Grade of Environmental Risk Factors at Slopes
1. International Journal of Engineering Research & Science (IJOER) ISSN: [2395-6992] [Vol-4, Issue-4, April- 2018]
Page | 24
Determining Important Grade of Environmental Risk Factors at
Slopes
Baki Bagriacik1
, Hakan Guneyli2
, Suleyman Karahan3
1
Department of Civil Engineering, Cukurova University, TURKEY
2,3
Department of Geology Engineering, Cukurova University, TURKEY
Abstract— Both, natural and man-made slopes formed for various purposes may cause numerous permanent problems in
engineering applications. Therefore, it is important to know composition and mechanical behavior of soil environment
leading to geotechnical problems on slope surfaces. The risk analyzes of natural and artificial slopes, realized detailed, can
lead to reliable results. Based on those results, it is possible to produce optimal technical solutions with respect to an
acceptable risk level. The researches on these subjects give new opportunities to improve the existing knowledge by
reviewing them. The main aim of this study is objectively to evaluate the parameters caused slope stability problems. In this
regard, the parameters of slope angle, internal friction angle and cohesion of soil, and groundwater level, which are main
risk factors for a slope, and should contribute to raise awareness about this issue, were investigated.
Keywords— Factor of safety, risk factors, slope stability.
I. INTRODUCTION
Surfaces that are oriented horizontally at a certain angle are defined as slopes. If angle of earth surface is great enough, soil
moves downward due to gravity. Thus, slope loses its stability and this event caused an environmental risk situation. In order
to assess the environmental risk of slopes, it is necessary to know the safety factor of natural slopes, on which are frequently
encountered in the natural ear surface, excavation slopes and slopes compacted as controlled against landslide. The all factors
affecting displacements need to be considered for a slope, which the environmental risk ratio (slope safety) will be
determined. The safety of soil structure is often defined by a parameter called the safety factor (the environmental risk
factor). This parameter can be described as the ratio of strength of soil to the load applied to it. Since this is a mathematical
term, which represents the stability of the structure examined, this ratio varies based on the shear strength and stresses
examined in the slope stability. A number of safety factor (environmental risk factor) definitions are available in engineering
literature. The safety factor is a ratio of resistive forces along the sea surface to the shear forces; of the existing shear strength
of soil along the potential shear surface to the mean shear stresses; and is a factor that the shear strength parameters decrease
to maintain slope at limit equilibrium condition along a specific shear surface. For complete stability of a soil depending on
these descriptions mentioned above, the safety factor F is defined as:
SF=available shear strength/shear stress required for equilibrium
It is stated that the minimum value of the safety factor given as a basic formula above should be 1.0 on a sliding surface not
only for fail but also for stable condition. In following years, lots of studies on both analyzes of slope and their movement
characteristics were conducted (Bishop [1]; Spencer [2]; Spencer [3]; Maksimovic [4]; Ching and Fredlund [5]; Fredlund [6];
Brinkgreve and Bakker [7]; Duncan [8]; Griffiths and Lane [9]; Cheng [10]; Hammah and diğ. [11]; Cheng and Lansivaara
[12]). The main objective of many studies in the literature on slopes is to obtain economical and safe solutions to avoid an
environmental risk (an adequate safety factor value) in ground structure, excavations and fills. The slope-based
environmental risk studies on this subject cover a detailed investigation of the environment, material on the environment and
economical parameters. In recent years, slope stability analysis has gained importance due to rapid population growth,
increase of motorways based on technological development, dams, and deep and large excavation.
The finite element method was developed for stress analysis of aircraft bodies in 1956 and has later been started to use in
solution of engineering problems in the following years. This method has been developed rapidly over the years, and used in
many engineering applications. Numerical analyzes are effective mathematical methods used to solve complex engineering
problems. The finite element method the most commonly utilized among the numerical analysis methods is one of the
mathematical methods. In this method, the engineering problems can be solved by dividing the continuous environment into
various geometric subspaces called the finite element. The finite element method is a numerical analysis technique widely
used in many engineering applications both for research and in design (Köksal, [13]).Since the stress analysis in soil mass is
approximation in conventional slope stability analysis, calculation has some difficulties for different loading conditions and
2. International Journal of Engineering Research & Science (IJOER) ISSN: [2395-6992] [Vol-4, Issue-4, April- 2018]
Page | 25
geometries. The finite element method has increasingly been used in slope stability analysis with the spread of computer use
in engineering as well as in all areas. The advantage of finite element approach over the other conventional limit equilibrium
methods is that there is no need for an assumption for the location and shape of slide (shear) surface, and properties and
orientations of the slices. The finite element method as with two or three dimensions can be applied to all types of failure
mechanism in complex slope geometries and conditions of various soil boundary and loading. It is possible to obtain the
knowledge of material structure behavior in close to present conditions, and of accurately stress and replacements in soil.
Moreover, the method can be used easily in long and short stability analyzes, and in conditions of slope reinforcement by
materials such as geotextile or soil nail, and availability of ground water.
II. MATERIAL AND METHOD
In this study, numerical analysis by using finite element method (Plaxis 2D) [14]were carried out in order to investigate the
effect of parameters of cohesion, internal friction angle, slope angle and groundwater level on the slope failure mechanism in
sloped areas. Therefore, two-dimensional analyses using finite element method were performed by considering plane strain
state. The finite element model used in analyzes is presented in Figure 1.
FIGURE 1. THE MODEL OF FINITE ELEMENT USED IN THE ANALYZES
In this context, MC (Mohr-Coulomb) soil model, which can model elasto-full (complete) plastic soil behavior and is widely
available in the literature, was selected. MC model contains five different parameters of elasticity modulus (E), Poisson ratio
(v), cohesion (c), internal friction angle () and dilation angle (ψ). In addition, advanced parameters such as Eincrement and
cincrement are also included in the model. The analyzes were carried out by choosing the most fine mesh selected from the
five different mesh types in Plaxis 2D software.
III. FINDINGS AND DISCUSSION
In the study, the results of analyzes using the finite element method to determine the effect of the parameters such as slope
angle, internal friction angle and cohesion of soil, and groundwater level on the safety factor (environmental risk factor) of a
slope are presented below.
3.1 Influence of Slope Angle
Analyzes performed by the finite element method were also conducted to investigate the effect of slope angle change on the
safety factor of a slope. Internal friction angle (=350), unite weight (γ=17.2 kN/m3
), cohesion (c=0.01 kN/m2
), elasticity
modulus (E=24000 kN/m2
), poisson ratio (v=0.20) as constant parameters, and slope angle (β) values ranging from 300 to
400 as variable parameter were selected in the calculations. The determined results of the safety factors (environmental risk
factors) vs. the slope angle values are seen in Figure 2 and Table 1.
TABLE 1
THE VALUES OF THE SAFETY FACTORS
Slope Angle, Safety Factor
Model 1. =30 1.270
Model 2. =32 1.192
Model 3. =35 1.022
Model 4. =40 0.914
3. International Journal of Engineering Research & Science (IJOER) ISSN: [2395-6992] [Vol-4, Issue-4, April- 2018]
Page | 26
FIGURE 2. THE VALUES OF THE SAFETY FACTORS FOR SLOPE ANGLE
As a result, it was determined that the safety against landslide (failure) decreases due to the increase of slope angle, and
obtained a strong (R=0.98) relationship between the slope angle and the safety factor. The data from the analyzes by the
finite element method indicate that an increase in slope angle of 100 causes an decreases in the safety factor as per 28%, and
thus it has been emphasized analytically that the slope angle change is very important parameter in terms of the slope
stability.
3.2 Influence of Internal Friction Angle
Analyzes based on the finite element method were also carried out in order to evaluate the effect of internal friction angle
change on the safety factor of a slope. The soil model parameters used in the analyzes were selected as constant values of
slope angle (β=300
), unite weight (γ=17.2 kN/m3
), cohesion (c=0.01 kN/m2
), elasticity modulus (E=ranging from 22000 to
28000 kN/m2
), poisson ratio (v=0.20), and as the variable parameter of internal friction angle () values ranging from 300
to
430
. The results obtained from these analyzes are seen in Figure 3 and Table 2.
FIGURE 3. THE VALUES OF THE SAFETY FACTORS FOR FRICTION ANGLE
TABLE 2
THE VALUES OF THE SAFETY FACTORS FOR FRICTION ANGLE
Friction Angle, Elasticity modulus Safety Factor
Model 1. =30 22000 kN/m2
1.044
Model 2. =35 24000 kN/m2
1.270
Model 3. =40 26000 kN/m2
1.529
Model 4. =43 28000 kN/m2
1.711
0.80
0.85
0.90
0.95
1.00
1.05
1.10
1.15
1.20
1.25
1.30
25 30 35 40 45
SafetyFactors,SF
Slope Angle, (o)
0.8
0.9
1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
25 30 35 40 45
SafetyFactor,SF
Friction Angle, (o)
4. International Journal of Engineering Research & Science (IJOER) ISSN: [2395-6992] [Vol-4, Issue-4, April- 2018]
Page | 27
The results from the analyzes by the finite element method indicate that the increase of internal friction angle increases the
safety against sliding (failure) of slope, and the relationship between the internal friction angle and the safety factor has a
strong (R=0.99) correlation coefficient. It was also found that an increase in internal friction angle of 430
at a constant slope
angle leads an increase in the safety factor as per 39%. On the other hand, the degree of importance of internal friction angle
for slope stability analyzes was revealed as well.
3.3 Influence of Cohesion
Analyzes made using the finite element method were conducted to assess the effect of cohesion change on the safety factor of
a slope, as well. Internal friction angle (Φ=10), slope angle (β=320
), unite weight (γ=17.2 kN/m3
), elasticity modulus
(E=24000 kN/m2
), poisson ratio (v=0.20) as constant parameters, and cohesion values ranging from 0.500 to 1.500 kN/m2
as
variable parameter were selected in the calculations. The determined safety factor (environmental risk factor) values
depending on cohesion values of a soil are shown in Figure 4 and Table 3.
TABLE 3
THE VALUES OF THE SAFETY FACTORS FOR COHESION
Finite Element Method, c (kN/m2
) Safety Factor
c=0.500 0.624
c=0.625 0.764
c=0.750 0.901
c=0.780 0.932
c=0.820 0.976
c=0.850 1.006
c=0.875 1.036
c=1.000 1.173
c=1.125 1.312
c=1.250 1.720
c=1.500 2.200
FIGURE 4. THE VALUES OF THE SAFETY FACTORS FOR COHESION
As a result of the analyzes, it was exhibited that the safety factor increases depending on increasing of cohesion of soil, and
was acquired a strong (R=0.98) relationship between the cohesion and the safety factor. The data from the analyzes by the
finite element method point out that an increase in cohesion value of 1 kN/m2
leads an enhancement in the safety factor as
per 72%. Moreover, it was revealed from the analyzes that how cohesion of soil forming slope affected stability of slope.
3.4 Influence of Groundwater Level
Analyzes performed by the finite element method were also conducted to investigate the effect of groundwater level change
on the safety factor of a slope. Internal friction angle (=10), slope angle (β=320
), and unite weight (γ=17.2kN/m3
), cohesion
(c=0.85kN/m2
), elasticity modulus (E=24000 kN/m2
), poisson ratio (v=0.20) as constant parameters, and groundwater level
0.00
0.50
1.00
1.50
2.00
2.50
0 0.5 1 1.5 2
SafetyFactor,SF
Cohesion, c (kN/m2)
5. International Journal of Engineering Research & Science (IJOER) ISSN: [2395-6992] [Vol-4, Issue-4, April- 2018]
Page | 28
values ranging from 0 to 0.45 m as variable parameter were selected in the calculations. The determined results of the safety
factors (environmental risk factors) vs. the groundwater level values are seen in Figure 5 and Table 4.
TABLE 4
THE VALUES OF THE SAFETY FACTORS FOR WATER GROUND LEVEL
Water Ground Level (m) Safety Factor
0 1.006
0.05 1.002
0.10 1.000
0.15 1.000
0.20 1.044
0.25 1.134
0.30 1.275
0.35 1.492
0.40 1.822
0.45 2.312
FIGURE 4. THE VALUES OF THE SAFETY FACTORS FOR WATER GROUND LEVEL
There is an asymptotic negative relationship with a strong correlation coefficient between the groundwater level and the
safety factor according to the analyzes. While a significant change in safety factor does not occur at depth of the groundwater
level from 0 to 0.2m, the deepening of groundwater level from 0.2m leads to an increase in the safety factor at much larger
values.
IV. CONCLUSION
Series of numerical analysis by using finite element method (Plaxis 2D) [14] were performed to investigate the effect of a
change of cohesion, internal friction angle, slope angle and groundwater level on the safety factor of slope failures. From the
data and assessments presented in this paper the following conclusions can be drawn:
Based on increasing of slope angle, the safety of slope against landslide (failure of slope) decreases. An increasing in the
slope angle of range from 30 to 400 leads to an average 28% reduction in the safety factor.
It was determined that the safety of slope against to failure decreases depending on the increment of the internal friction
angle. An increase of the internal friction angle ranging from 300
to 430
causes an increment in the safety factor as per 39%.
The enhancement of cohesion value of soil forming a slope causes significantly the safety of slope against to failure. An
increase of the cohesion ranging from 0.500 to 1.500 kN/m2 leads to an increment in the safety factor as per 72%.
In case of lowering groundwater level from top of the slope, there is no significant change in safety factors up to a certain
depth (0.20 m from the top of slope), and distinct changes in safety factor occur from 0.2 meter by deepening the ground
0
0.5
1
1.5
2
2.5
0 0.1 0.2 0.3 0.4 0.5
SafetyFactor,SF
Water Ground Level, WGL, (m)
6. International Journal of Engineering Research & Science (IJOER) ISSN: [2395-6992] [Vol-4, Issue-4, April- 2018]
Page | 29
water level. The relationship between the safety factor and the groundwater level has an asymptotic with strong correlation
coefficient.
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