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.
Influence of stratified soil on seismic response of pile supported buildingIJARIIT
In the last few decades, it has been perceived that Soil Structure Interaction (SSI) changed the reaction attributes of
a structural system due to huge and firm nature of structure and frequently, soil softness. In the current study, to depict the
influence of soil structure interaction on the seismic response of a structure due to earthquake loading, a 5 storied (G+4)
simple square building supported on pile foundation resting on stratified soil was selected. The building sections were
modelled and analysed for different configurations (i.e., with and without slab and infill) using finite element method
SAP2000. The deformations under seismic loading in the structure and piles by incorporating the effect of soil-structure
interaction and fixed base condition were extracted, compared and discussed. Impact of variety of the parameters on different
soil conditions like variation in soil profile and number of soil layers, influence of slab and infill are considered for which the
buildings are modelled by alternate approaches, namely, (1) bare frame with fixed supports, (2) frames including slab and
infill with support accounting for soil-flexibility. The results indicate that the roof displacement varies significantly for
different soil layer combinations if included the soil structure interaction compared to that of fixed base analysis. Thus
considering the effect of SSI is essential. The horizontal displacement of the structure is maximum for a bare frame with slab
when compared to bare frame and infill frame. When infill wall is added to the structure, the horizontal displacement is
decreased due to the stiffness of the infill wall.
Effect of soil structure interaction on high rise r.c regular frame structur...eSAT Journals
Abstract Reinforced concrete building structure consist of horizontal member (beam & slab) and vertical members (columns & walls), and supported by foundation. The structure is subjected to loads of self-weight, live load, wind load and earthquake load etc. The structural strength of slab and the brick walls is not normally considered in the analysis of the structure Generally the foundation support is assumed as either hinged or fixed support, while foundations transmit the load to the soil medium which undergoes a settlement (vertical) depending on the loads from the structure and characteristics of the soil medium, causing the additional forces in structure. However, this effect is normally neglected in the structural analysis due to its complicated analysis. An attempt is made to analyze the structure considering the foundation soil settlement as define like soil medium by spring. The structure is analyzed for various seismic zones of India. (II, III, IV,&V), sub grade modulus of soil (Gs) from 12000kN/m3 to 60,000kN/m3.The results of the above analysis are used to study the effect of soil – structure interaction on horizontal displacement ‘훿x’ at each floor, and vertical displacement ‘훿y’ at the supports of a building. From the study, it is observed that the maximum percentage of variation in x- trans is 337 percentage with respect to fixed support condition at sub grade modulus of 12,000 kN /m2/m at seismic zone V and the maximum percentage of variation in y- trans is 1420 percentage with respect to fixed support at sub grade modulus 12,000 kN/m2/m at seismic zone V. From pilot study, concluded that effect of soil – structure interaction has to consider especially for lower sub grade modulus of soil at higher seismic intensities. KeyWords: Soil structure interaction (SSI), R.C.frame, Seismic load, High rise buildings etc…
UNDERSTANDING THE PERFORMANCE OF DEEP MIXED COLUMN IMPROVED SOILS - A REVIEWIAEME Publication
The essence of ground improvement is to enhance the engineering properties of weak soils to provide stability and sufficient bearing capacity for construction and other engineering purposes. Deep soil mixing is one method that has been widely employed for this purpose due to the
environmental nature and efficiency of this method. In deep soil mixing, the amount of binder to be mixed with the weak soil depends on the initial moisture content of the surrounding soil. Several researchers have reported on this method of soil improvement through laboratory experiments, in situ testing and numerical modelling.
Effect of Soil Flexibility on Analysis and Design of BuildingIJERA Editor
Generally in the analysis and design of multi-story building frame it is assumed that the base is fixed but in actual the structure is ultimately supported on soil which is flexible in nature. This flexibility of soil may vary due to load-settlement characteristics of soil, variation in soil strata below the foundation level, seasonal variation of soil property etc. The flexible nature of soil causes differential settlement between foundations on application of loads which in turn redistribute the structural forces as well as design. The present paper attempts to acknowledge the effect of soil flexibility in analysis and design of structure. A G+7 4-bay by 4-bay RCC residential building frame supported on sandy soil and situated in seismic zone V as per IS: 1893(part 1)-2002 is analysed usingStaad pro software. Initially the building frame is modelled and analysed assuming fixed base and support reactions are determined for different load cases. The foundation sizes for different supports are calculated by using Staad foundation software. The fixed support is replaced by a spring of equivalent foundation stiffness to perform flexible base analysis. In flexible support analysis the maximum total settlement and differential settlement between footings is found to be 44.19 mm and 8.14 mm respectively which is neglected in conventional analysis. The variation in values of settlement is more critical in case of seismic loading. Soil flexibility causes significant variation in values of support moment compared to vertical support reaction. The flexibility of soil also affects the forces in beams and columns. The requirement of steel reinforcement is reduced by nearly 7% in flexible support system compared to fixed base. The study shows that the soil flexibility redistributed the structural forces and affects the analysis and design of structure. In present study analysis and design of structure assuming flexible base is found to be more accurate and economical.
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…
Influence of stratified soil on seismic response of pile supported buildingIJARIIT
In the last few decades, it has been perceived that Soil Structure Interaction (SSI) changed the reaction attributes of
a structural system due to huge and firm nature of structure and frequently, soil softness. In the current study, to depict the
influence of soil structure interaction on the seismic response of a structure due to earthquake loading, a 5 storied (G+4)
simple square building supported on pile foundation resting on stratified soil was selected. The building sections were
modelled and analysed for different configurations (i.e., with and without slab and infill) using finite element method
SAP2000. The deformations under seismic loading in the structure and piles by incorporating the effect of soil-structure
interaction and fixed base condition were extracted, compared and discussed. Impact of variety of the parameters on different
soil conditions like variation in soil profile and number of soil layers, influence of slab and infill are considered for which the
buildings are modelled by alternate approaches, namely, (1) bare frame with fixed supports, (2) frames including slab and
infill with support accounting for soil-flexibility. The results indicate that the roof displacement varies significantly for
different soil layer combinations if included the soil structure interaction compared to that of fixed base analysis. Thus
considering the effect of SSI is essential. The horizontal displacement of the structure is maximum for a bare frame with slab
when compared to bare frame and infill frame. When infill wall is added to the structure, the horizontal displacement is
decreased due to the stiffness of the infill wall.
Effect of soil structure interaction on high rise r.c regular frame structur...eSAT Journals
Abstract Reinforced concrete building structure consist of horizontal member (beam & slab) and vertical members (columns & walls), and supported by foundation. The structure is subjected to loads of self-weight, live load, wind load and earthquake load etc. The structural strength of slab and the brick walls is not normally considered in the analysis of the structure Generally the foundation support is assumed as either hinged or fixed support, while foundations transmit the load to the soil medium which undergoes a settlement (vertical) depending on the loads from the structure and characteristics of the soil medium, causing the additional forces in structure. However, this effect is normally neglected in the structural analysis due to its complicated analysis. An attempt is made to analyze the structure considering the foundation soil settlement as define like soil medium by spring. The structure is analyzed for various seismic zones of India. (II, III, IV,&V), sub grade modulus of soil (Gs) from 12000kN/m3 to 60,000kN/m3.The results of the above analysis are used to study the effect of soil – structure interaction on horizontal displacement ‘훿x’ at each floor, and vertical displacement ‘훿y’ at the supports of a building. From the study, it is observed that the maximum percentage of variation in x- trans is 337 percentage with respect to fixed support condition at sub grade modulus of 12,000 kN /m2/m at seismic zone V and the maximum percentage of variation in y- trans is 1420 percentage with respect to fixed support at sub grade modulus 12,000 kN/m2/m at seismic zone V. From pilot study, concluded that effect of soil – structure interaction has to consider especially for lower sub grade modulus of soil at higher seismic intensities. KeyWords: Soil structure interaction (SSI), R.C.frame, Seismic load, High rise buildings etc…
UNDERSTANDING THE PERFORMANCE OF DEEP MIXED COLUMN IMPROVED SOILS - A REVIEWIAEME Publication
The essence of ground improvement is to enhance the engineering properties of weak soils to provide stability and sufficient bearing capacity for construction and other engineering purposes. Deep soil mixing is one method that has been widely employed for this purpose due to the
environmental nature and efficiency of this method. In deep soil mixing, the amount of binder to be mixed with the weak soil depends on the initial moisture content of the surrounding soil. Several researchers have reported on this method of soil improvement through laboratory experiments, in situ testing and numerical modelling.
Effect of Soil Flexibility on Analysis and Design of BuildingIJERA Editor
Generally in the analysis and design of multi-story building frame it is assumed that the base is fixed but in actual the structure is ultimately supported on soil which is flexible in nature. This flexibility of soil may vary due to load-settlement characteristics of soil, variation in soil strata below the foundation level, seasonal variation of soil property etc. The flexible nature of soil causes differential settlement between foundations on application of loads which in turn redistribute the structural forces as well as design. The present paper attempts to acknowledge the effect of soil flexibility in analysis and design of structure. A G+7 4-bay by 4-bay RCC residential building frame supported on sandy soil and situated in seismic zone V as per IS: 1893(part 1)-2002 is analysed usingStaad pro software. Initially the building frame is modelled and analysed assuming fixed base and support reactions are determined for different load cases. The foundation sizes for different supports are calculated by using Staad foundation software. The fixed support is replaced by a spring of equivalent foundation stiffness to perform flexible base analysis. In flexible support analysis the maximum total settlement and differential settlement between footings is found to be 44.19 mm and 8.14 mm respectively which is neglected in conventional analysis. The variation in values of settlement is more critical in case of seismic loading. Soil flexibility causes significant variation in values of support moment compared to vertical support reaction. The flexibility of soil also affects the forces in beams and columns. The requirement of steel reinforcement is reduced by nearly 7% in flexible support system compared to fixed base. The study shows that the soil flexibility redistributed the structural forces and affects the analysis and design of structure. In present study analysis and design of structure assuming flexible base is found to be more accurate and economical.
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…
EFFECT OF SOIL INTERACTION ON 3×3 BUILDING FRAME EMBEDDED IN MULTILAYERED SOILIAEME Publication
Objectives: To study the
multilayered soil. Methods/Analysis:the pile foundation is analyzed in ANSYS. The effect about soilstructure interface on thedisplacement of columns in theconnected by means of thoseobtained on or after thesoilstructural analysis and theconservative
method of analysis. Soil non-linearity inside the horizontaldirection is performed by means of Pcurves. Findings: These curves are developed using Matlock and API(American PetroleumInstitute) equations. And the results shows that the values obtained from SSI for bending moment,
shear force and deflection are more than that of without SSI.
interaction on a building frame embedded in multilayered soil
types of piles and number of bays andout for the differenttypes of soils using ANSYS
A review on: The influence of soil conditions on the seismic forces in RC bui...IJERA Editor
This study focuses on a review of the influence of soil conditions on the seismic forces in RC buildings. The aim of this study is to gain understanding the effect of the local site conditions on the seismic forces in building. The study helps in creating awareness about the importance of the local site conditions, such as proximity to the source of earthquakes (faults) and the local geological and topographical features in the earthquake resistant design of buildings. The current Indian code of practice for seismic analysis IS 1893:2002, specifies seismic zones to consider different levels of intensity of ground shaking, There are also maps of the principal tectonic features and lithological formations. This paper shows the soil condition effects studied by the various researchers.
A NUMERICAL STUDY ON INTERFERENCE EFFECTS OF CLOSELY SPACED STRIP FOOTINGS ON...IAEME Publication
Foundations of structures often need to be placed close to meet the architectural as well as the functional requirements. In such cases, the combined action of footings is different from a single footing. It causes interference of the stress zones. In the present study, the interference effects of two closely spaced strip footings on the surface of cohesive and cohesionless soils are being investigated. Parametric studies are done for two footings by varying the spacing between the footings and the width of the footings. The results are presented in terms of efficiency factors. In the first case, both the footings are loaded simultaneously up to failure. In the second case, one of the footings representing an already existing foundation is loaded with half of the estimated failure load of isolated footing and adjacent footing loaded up to failure. The effect of interference is observed to be particularly significant in terms of the settlement. Effect of shear keys placed beneath the footings, at different locations beneath the footing and the interference of such footings is also studied in case of stiff clay. It is found that the presence of shear keys has a significant effect on the interference between the footings, compared to without the shear keys, especially in reducing the tilt of foundations.
Finite element analysis of frame with soil structure interactioneSAT Journals
Abstract
For the analysis of a building frame, the columns at the foundation level are considered as fixed. But in real condition it is not the case. While considering soil in the analysis of building frame 100% fixity may not be ensured. Because of the settlement and rotation of foundation, shear force and bending moment in superstructure get altered. This effect is called as “Soil Structure Interaction” Present work is to study behavior of bare frame & in-filled frame having soil beneath. In these cases three types of soils are considered, soft, medium stiff and hard. Also in-filled panel is of brick masonry only. Various cases frames are studied. The following are the cases:
1] Analysis of bare frame with soil.2] Analysis of In-filled frame with Soil.3] Analysis of Bare frame without Soil.4] Analysis of In-filled frame without Soil Frame with different combinations mentioned above (with/without infill panel, with/without soil) is analyzed by using ANSYS 14.5. These results are comprised with SSI and without SSI.
Keywords: Soil Structure Interaction, In-Filled Frame, Bare Frame.
SEISMIC REACTION OF BUILDING FRAME UNDER VARIOUS ZONES CONSIDERING FLEXIBLE A...IAEME Publication
Objectives: To find seismic reaction of building frame under various zones considering flexible and rigid supports. Methods/Analysis: If a structure is subjected to an earthquake excitation, it interacts with the foundation and soil, and the ground motion is varied. That means, the movement of the whole ground structure system is under the influence of soil type also by the type of structure. As the seismic waves transfer from the ground which consist of alteration in soil properties and performs according to soil’s respective properties differently. In this study, different soil strata are taken and corresponding vertical and lateral displacement are determined with G+4 in zones II, III, IV and V. A G+4 building is modeled in STAAD. Pro for different types of soils such as hard, medium and soft. Findings: The work consist the calculations of vertical and lateral support reactions for soil types in various seismic zones and the comparison of Rigid and Flexible supports is obtained. Applications: Effect of seismic reaction of building frame under various zones considering flexible and rigid supports concept can be extended to different types of buildings and number of bays and storeyes can be increasd further the analysis can be carried out for the different types of zones using STAAD - PRO.
STUDY OF SUITABLE FOUNDATION IN SEISMIC ZONE III CONSIDERING SSIIAEME Publication
Objective: The objective of the paper is the study of maximumshear forces and bendingmoments of soil interaction of different types of foundations.made to study the effect of soil structure interaction of a multiisolated foundation and strip foundation systems resting on clay soil. The building was
analyzed by equivalent static method using STAAD Prosoftware for building with rigid base.ANSYS 12.0 is used for analyzing the building for effect of soifoundation and strip foundation.resting on earthquakeprone region, the soil structure interaction must be considered inanalysis. Foundation is a part of structure in whichis found that by considering the soil structure interaction the shear force and bending momentsof strip foundation are very less than isolated foundation.
DYNAMIC ANALYSIS OF SOIL STRUCTURE INTERACTION (SSI) USING ANFIS MODEL WITH O...IAEME Publication
One of the real difficulties for structural engineers is design and construction of
structures with satisfactory performance under dynamic loading conditions actuated
by strong wind or seismic tremors. SSI is a major problem in the construction process,
which may alter the dynamic characteristics of the structural response altogether. The
SSI system has two characteristic differences from the general structural dynamic
system which are the unbounded nature as well as the non-direct characteristics of the
soil medium. This study considering the SSI impacts in dynamic impacts of concrete
moment opposing building frames resisting on Soil Pile Structure (SPS) is additionally
anticipated. In SSI modeling, for diminishing the complexity and enhance the
prediction accuracy, Adaptive Neuro Fuzzy Inference System (ANFIS) model with
Opposition Based BAT Algorithm (OBAT) is proposed. It is demonstrated that the
proposed model can foresee the dynamic response of the soil-structure system with
great accuracy in much less time contrasted and the current strategies.
The Effect of Structure -Soil Interaction on Eccentrically Loaded FrameIJERD Editor
The interaction among structures, their foundations and the soil medium below the foundations alter
the actual behaviour of the structure considerably than what is obtained from the consideration of the structure
alone. Thus, a reasonably accurate model for the soil–foundation–structure interaction system with
computational validity, efficiency and accuracy is needed in improved design of important structures. The
framed structures are normally analyzed with their bases considered to be either completely rigid or hinged.
However, the foundation resting on deformable soils also undergoes deformation depending on the relative
rigidities of the foundation, superstructure and soil. Interactive analysis is, therefore, necessary for the accurate
assessment of the response of the superstructure.
VARIATION OF SEISMIC RESPONSE OF MID-RISE RC BUILDINGS DUE TO SOIL STRUCTURE ...IAEME Publication
The seismic design of RC buildings requires determining the expected base shear, lateral drift at each story level and internal forces of the structural elements. In the analysis, it is common for the structural engineers to consider a fixed base structure which means that the foundations and the underlying soil are assumed to be infinitely rigid. This assumption is not proper since the underlying soil in the near field often consists of soft soil layers that possess different properties and may behave nonlinearly leading to drastic variation of the seismic motion before hitting the structure foundation. In addition, the mutual interaction between the structure, its foundation and the underlying soil during the vibrations can substantially alter the structure response. This response variation depends on the structure characteristics, the soil properties and the nature of the seismic excitation. Consequently, an accurate assessment of inertial forces and displacements in structures requires a rational treatment of soil structure interaction (SSI) effects.
Effect of foundation flexibility on dynamic behaviour of asymmetric building ...eSAT Journals
Abstract In general the seismic design of building frame structures the designers will consider only the results of fixed base condition the effect of flexibility is ignored. In post-earthquake study the framed structure reveals that the interaction of soil and foundation plays an important role in damage of the building frame structures. In this regard a literature survey has been done on frame structures supported on various foundations such as isolated, combined, raft & pile foundations. To examine the literature revels the few investigations were done on asymmetric building frame structure is supported on isolated footing. So in this paper is an attempt to the study of dynamic behavior of asymmetric building frame structure is supported on isolated footings. The modeling and analysis is done by using “finite element method software” SAP2000 VERSION 14, by considering the different soil conditions, (soft, medium, hard) different soil parameters (passion’s ratio, young’s modulus, dynamic shear modulus) different height ratio’s, different span ratio’s & fixed base conditions. The response of the building frame structure is obtained in terms of fundamental natural period, lateral displacement and seismic base shear. Keywords: Soil structure interaction, Fundamental natural period, Base shear, Lateral displacement….
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
EFFECT OF SOIL INTERACTION ON 3×3 BUILDING FRAME EMBEDDED IN MULTILAYERED SOILIAEME Publication
Objectives: To study the
multilayered soil. Methods/Analysis:the pile foundation is analyzed in ANSYS. The effect about soilstructure interface on thedisplacement of columns in theconnected by means of thoseobtained on or after thesoilstructural analysis and theconservative
method of analysis. Soil non-linearity inside the horizontaldirection is performed by means of Pcurves. Findings: These curves are developed using Matlock and API(American PetroleumInstitute) equations. And the results shows that the values obtained from SSI for bending moment,
shear force and deflection are more than that of without SSI.
interaction on a building frame embedded in multilayered soil
types of piles and number of bays andout for the differenttypes of soils using ANSYS
A review on: The influence of soil conditions on the seismic forces in RC bui...IJERA Editor
This study focuses on a review of the influence of soil conditions on the seismic forces in RC buildings. The aim of this study is to gain understanding the effect of the local site conditions on the seismic forces in building. The study helps in creating awareness about the importance of the local site conditions, such as proximity to the source of earthquakes (faults) and the local geological and topographical features in the earthquake resistant design of buildings. The current Indian code of practice for seismic analysis IS 1893:2002, specifies seismic zones to consider different levels of intensity of ground shaking, There are also maps of the principal tectonic features and lithological formations. This paper shows the soil condition effects studied by the various researchers.
A NUMERICAL STUDY ON INTERFERENCE EFFECTS OF CLOSELY SPACED STRIP FOOTINGS ON...IAEME Publication
Foundations of structures often need to be placed close to meet the architectural as well as the functional requirements. In such cases, the combined action of footings is different from a single footing. It causes interference of the stress zones. In the present study, the interference effects of two closely spaced strip footings on the surface of cohesive and cohesionless soils are being investigated. Parametric studies are done for two footings by varying the spacing between the footings and the width of the footings. The results are presented in terms of efficiency factors. In the first case, both the footings are loaded simultaneously up to failure. In the second case, one of the footings representing an already existing foundation is loaded with half of the estimated failure load of isolated footing and adjacent footing loaded up to failure. The effect of interference is observed to be particularly significant in terms of the settlement. Effect of shear keys placed beneath the footings, at different locations beneath the footing and the interference of such footings is also studied in case of stiff clay. It is found that the presence of shear keys has a significant effect on the interference between the footings, compared to without the shear keys, especially in reducing the tilt of foundations.
Finite element analysis of frame with soil structure interactioneSAT Journals
Abstract
For the analysis of a building frame, the columns at the foundation level are considered as fixed. But in real condition it is not the case. While considering soil in the analysis of building frame 100% fixity may not be ensured. Because of the settlement and rotation of foundation, shear force and bending moment in superstructure get altered. This effect is called as “Soil Structure Interaction” Present work is to study behavior of bare frame & in-filled frame having soil beneath. In these cases three types of soils are considered, soft, medium stiff and hard. Also in-filled panel is of brick masonry only. Various cases frames are studied. The following are the cases:
1] Analysis of bare frame with soil.2] Analysis of In-filled frame with Soil.3] Analysis of Bare frame without Soil.4] Analysis of In-filled frame without Soil Frame with different combinations mentioned above (with/without infill panel, with/without soil) is analyzed by using ANSYS 14.5. These results are comprised with SSI and without SSI.
Keywords: Soil Structure Interaction, In-Filled Frame, Bare Frame.
SEISMIC REACTION OF BUILDING FRAME UNDER VARIOUS ZONES CONSIDERING FLEXIBLE A...IAEME Publication
Objectives: To find seismic reaction of building frame under various zones considering flexible and rigid supports. Methods/Analysis: If a structure is subjected to an earthquake excitation, it interacts with the foundation and soil, and the ground motion is varied. That means, the movement of the whole ground structure system is under the influence of soil type also by the type of structure. As the seismic waves transfer from the ground which consist of alteration in soil properties and performs according to soil’s respective properties differently. In this study, different soil strata are taken and corresponding vertical and lateral displacement are determined with G+4 in zones II, III, IV and V. A G+4 building is modeled in STAAD. Pro for different types of soils such as hard, medium and soft. Findings: The work consist the calculations of vertical and lateral support reactions for soil types in various seismic zones and the comparison of Rigid and Flexible supports is obtained. Applications: Effect of seismic reaction of building frame under various zones considering flexible and rigid supports concept can be extended to different types of buildings and number of bays and storeyes can be increasd further the analysis can be carried out for the different types of zones using STAAD - PRO.
STUDY OF SUITABLE FOUNDATION IN SEISMIC ZONE III CONSIDERING SSIIAEME Publication
Objective: The objective of the paper is the study of maximumshear forces and bendingmoments of soil interaction of different types of foundations.made to study the effect of soil structure interaction of a multiisolated foundation and strip foundation systems resting on clay soil. The building was
analyzed by equivalent static method using STAAD Prosoftware for building with rigid base.ANSYS 12.0 is used for analyzing the building for effect of soifoundation and strip foundation.resting on earthquakeprone region, the soil structure interaction must be considered inanalysis. Foundation is a part of structure in whichis found that by considering the soil structure interaction the shear force and bending momentsof strip foundation are very less than isolated foundation.
DYNAMIC ANALYSIS OF SOIL STRUCTURE INTERACTION (SSI) USING ANFIS MODEL WITH O...IAEME Publication
One of the real difficulties for structural engineers is design and construction of
structures with satisfactory performance under dynamic loading conditions actuated
by strong wind or seismic tremors. SSI is a major problem in the construction process,
which may alter the dynamic characteristics of the structural response altogether. The
SSI system has two characteristic differences from the general structural dynamic
system which are the unbounded nature as well as the non-direct characteristics of the
soil medium. This study considering the SSI impacts in dynamic impacts of concrete
moment opposing building frames resisting on Soil Pile Structure (SPS) is additionally
anticipated. In SSI modeling, for diminishing the complexity and enhance the
prediction accuracy, Adaptive Neuro Fuzzy Inference System (ANFIS) model with
Opposition Based BAT Algorithm (OBAT) is proposed. It is demonstrated that the
proposed model can foresee the dynamic response of the soil-structure system with
great accuracy in much less time contrasted and the current strategies.
The Effect of Structure -Soil Interaction on Eccentrically Loaded FrameIJERD Editor
The interaction among structures, their foundations and the soil medium below the foundations alter
the actual behaviour of the structure considerably than what is obtained from the consideration of the structure
alone. Thus, a reasonably accurate model for the soil–foundation–structure interaction system with
computational validity, efficiency and accuracy is needed in improved design of important structures. The
framed structures are normally analyzed with their bases considered to be either completely rigid or hinged.
However, the foundation resting on deformable soils also undergoes deformation depending on the relative
rigidities of the foundation, superstructure and soil. Interactive analysis is, therefore, necessary for the accurate
assessment of the response of the superstructure.
VARIATION OF SEISMIC RESPONSE OF MID-RISE RC BUILDINGS DUE TO SOIL STRUCTURE ...IAEME Publication
The seismic design of RC buildings requires determining the expected base shear, lateral drift at each story level and internal forces of the structural elements. In the analysis, it is common for the structural engineers to consider a fixed base structure which means that the foundations and the underlying soil are assumed to be infinitely rigid. This assumption is not proper since the underlying soil in the near field often consists of soft soil layers that possess different properties and may behave nonlinearly leading to drastic variation of the seismic motion before hitting the structure foundation. In addition, the mutual interaction between the structure, its foundation and the underlying soil during the vibrations can substantially alter the structure response. This response variation depends on the structure characteristics, the soil properties and the nature of the seismic excitation. Consequently, an accurate assessment of inertial forces and displacements in structures requires a rational treatment of soil structure interaction (SSI) effects.
Effect of foundation flexibility on dynamic behaviour of asymmetric building ...eSAT Journals
Abstract In general the seismic design of building frame structures the designers will consider only the results of fixed base condition the effect of flexibility is ignored. In post-earthquake study the framed structure reveals that the interaction of soil and foundation plays an important role in damage of the building frame structures. In this regard a literature survey has been done on frame structures supported on various foundations such as isolated, combined, raft & pile foundations. To examine the literature revels the few investigations were done on asymmetric building frame structure is supported on isolated footing. So in this paper is an attempt to the study of dynamic behavior of asymmetric building frame structure is supported on isolated footings. The modeling and analysis is done by using “finite element method software” SAP2000 VERSION 14, by considering the different soil conditions, (soft, medium, hard) different soil parameters (passion’s ratio, young’s modulus, dynamic shear modulus) different height ratio’s, different span ratio’s & fixed base conditions. The response of the building frame structure is obtained in terms of fundamental natural period, lateral displacement and seismic base shear. Keywords: Soil structure interaction, Fundamental natural period, Base shear, Lateral displacement….
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Dynamic Analysis of Multi-Storeyed Frame-Shear Wall Building Considering SSIIJERA Editor
The structural system of a high-rise building often has a more pronounced effect than a low rise building on the
total building cost and the architecture aspect of building. Shear walls are lateral load resisting structural
systems which provide stability to structures from lateral loads like wind and seismic Loads. The design of multi
storey building is to have good lateral load resisting System along with gravity load system for safety of
occupant and for better performance of structure even in most adverse condition. The main scope of this project
is to apply class room knowledge in the real world by designing a multi-storied residential building. Shear walls
are more efficient in resisting lateral loads in multi storied buildings. Steel and reinforced concrete shear walls
are kept in major positions of multi storied buildings which are made in consideration of seismic forces and
wind forces. To solve this purpose shear walls are a very powerful structural elements, if used judiciously can
reduce deflections and stresses to a very great extent. Our project contains a brief description of building with
shear wall and without shear wall thoroughly discussed structural analysis of a building to explain the
application of shear wall. The design analysis of the multi storied building in our project is done through
STAAD-PRO, most popular structural engineering software. It is featured with some ultimate power tool,
analysis and design facilities which make it more users friendly.
Soil Structure Interaction Analysis of Multi Storey Building Frame for Seismi...ijtsrd
Presently a day the human life and the climate have often been jeopardized by the characteristic perils like seismic tremor, torrent, flood, twister and avalanches. As an outcome of which the human culture and the countrys economy get hampered following the event of a catastrophic event. In agricultural nations like India, where the populace is huge and is expanding step by step, the social and financial components power individuals to live in weak territories, because of which the impacts of these cataclysmic events are disastrous. Among every one of these dangers, liquefaction of soil can be brought up as one of the most appalling seismic perils. Consequently assessment of liquefaction helplessness is a significant part of geotechnical designing. Soil structure connection impact in the examination and plan of RC outline structures is progressively perceived yet not infiltrated to the grass root level attributable to different complexities included. It is settled reality that the dirt structure collaboration impact significantly impact the plan of multi story structures exposed to parallel seismic burdens. In this examination we are performing seismic appraisal utilizing Analytical apparatus SAP2000 over a midrise building outline where we will give sidelong load to zone V 0.36 to decide soil structure communication for parallel burdens, for this investigation a midrise even structure of G 7 storey is considered. Shristee Saxena | Prof. Juhi Nigam "Soil Structure Interaction Analysis of Multi Storey Building Frame for Seismic Load using SAP2000" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-6 , October 2020, URL: https://www.ijtsrd.com/papers/ijtsrd33689.pdf Paper Url: https://www.ijtsrd.com/engineering/civil-engineering/33689/soil-structure-interaction-analysis-of-multi-storey-building-frame-for-seismic-load-using-sap2000/shristee-saxena
Seismic Analysis of Irregular Building Frames with Soil Structure Interactionijtsrd
Seismic response of structure is extremely complex because of non linear behaviour soil during earth quakes. Seismic design of structure is generally carried out assuming fixed based ignoring the flexibility of soil. The purpose of the study is to describe and investigate different approaches of considering soil flexibility in the soil structure interaction SSI with regard to response in the super structure. In the present work, to illustrate the effect of soil – stricture interaction on the seismic response of frame structure, irregular frame 15 storey having consider with based supported as fixed with an without considering the soil structure interaction. Building are model in SAP 2000. Three type of soil i.e. hard, medium hard, soft soil are used to in SSI – study. the soil is model as spring model or elastic continuum FEM , and stiffness is calculated by using the gerorge gazettes equation. The effect of SSI on various structural parameter i.e. natural time period, based shear, roof displacement, are studed and discuss. The main objective in using this earthquake was, to find out of the structure when heat by long duration and see the how the response of modified, when the soil effect are taken into considerate. Sumit S. Chaudhari | M. R. Nikhar | V. A. Kalmegh "Seismic Analysis of Irregular Building Frames with Soil Structure Interaction" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-1 , December 2020, URL: https://www.ijtsrd.com/papers/ijtsrd38125.pdf Paper URL : https://www.ijtsrd.com/engineering/structural-engineering/38125/seismic-analysis-of-irregular-building-frames-with-soil-structure-interaction/sumit-s-chaudhari
Effect of vertical discontinuity of columns in r.c frames subjected to differ...eSAT Journals
Abstract Majority of structural systems are designed with various levels of irregularities in accordance with architectural requirements in order to produce aesthetic buildings. Irregular structures come into being due to discontinuity in mass, stiffness and strength in elevation and due to asymmetric geometrical conCharturation on plane. One of the irregularities in elevation is discontinuity of columns. In the present study, effects of the structural irregularity which is produced by the discontinuity of a columns in RC space frames subjected to different wind loads was investigated. Investigation was carried out for R.C space frames, with and without vertical discontinuity of columns for G+5, G+10 & G+15 storeys, assumed to be located in different wind zones in India. Both regular and irregular structures were analysed using STAADPro. From the study, it was concluded that frames without vertical discontinuity of the columns having more stiffness when compared to frames with vertical discontinuity of columns. Keywords: Structural irregularity, Vertical discontinuity, Discontinuity of columns, Wind loads.
Study on Tall Structure for Hilly and Plane Surface under Seismic and Wind Lo...ijtsrd
There are various previous studies done for proper planning and good construction practices of multistoried buildings on sloping ground in particular, which lead to irregularities in plan and elevation of the buildings. Analysis and design of space building frame for seismic loading and wind pressure is very essential these days because of the construction of high rise buildings. It is also necessary to construct an economical and more durable structure. The current work examines the structural behavior of reinforced concrete columns, beam, and footing in sloping geometry. In this study a G 8 storey RCC building is analyzed on varying sloping angles i.e., 0o or plane surface and Hilly Surface 15o . The seismic forces and wind pressure are considered simultaneously as per IS 1893 2002 and IS 875 PART 3 respectively. The whole structure is analysis on software STAAD Pro v8i. The effect of Hilly ground on building performance during earthquake and wind pressure is observed. Seismic analysis has been done using Linear Static method. Analysis is done to evaluate the effect of sloping grounds on structural forces and displacement. In horizontal and vertical reaction, beam, shear force, and bending in lateral displacement in the column, axial force and columns, the moment of bending is critically analyzed to measure the effects of plane and hilly ground. It has been observed that the small height paving columns attract more forces, because their stiffness has increased significantly, which, in turn increases the bending moment and shear force. Thus, the section of these columns should be designed for modified forces due to the effect of hilly ground. Akanksha Deshmukh | Pratiksha Malviya "Study on Tall Structure for Hilly and Plane Surface under Seismic & Wind Load Conditions using STAAD ProV8i Software" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd25288.pdfPaper URL: https://www.ijtsrd.com/engineering/civil-engineering/25288/study-on-tall-structure-for-hilly-and-plane-surface-under-seismic-and-wind-load-conditions-using-staad-prov8i-software/akanksha-deshmukh
Comparative study on multistoried building using linear and non linear analysisIJARIIT
The effect of infill walls on the building is generally neglected in the analysis. In fact, an infill wall contributes to the
lateral strength and stiffness of the structure. Seismic response analysis of multi storey building frame with infill was done by
modeling the infill wall as an equivalent diagonal strut. For the equivalent diagonal strut, the thickness is taken equal to the
thickness of the wall and width of the strut as per “Equivalent strut method”. The comparison of seismic responses is done for
the multi-storied buildings with infill as equivalent diagonal strut using linear and non-linear analysis. ETABS software is used
for the present study.
“ Study of Sesmic Analysis of Masonry Wall Structure”IJERA Editor
Earthquakes are natural trouble under which disasters are mainly caused by damage or collapse of the structure and other man-made structures. When an earthquake occurs natural period of vibration is more on heavy loaded building and less in light loaded building. If the building is light weighted, i.e. steel is less then economy of structure is also achieved. Hence it is necessary to find out natural/fundamental time period when mass changes with different type of brick masonry and concrete masonry.This is necessary because IS 1893:2002 does not incorporate the effect of mass in a formula which they have mentioned for brick masonary structure. Thedesign will also analyze with ETAB software.
International Journal of Engineering Research and DevelopmentIJERD Editor
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Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
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Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
2. 1261WANG JIAQI, JIN WENBIAO, GUO HUA, WANG XINYUE AND LIU JUNLIANG
International Journal of Earth Sciences and Engineering
ISSN 0974-5904, Vol. 08, No. 03, June, 2015, pp. 1260-1263
3. Numerical Analysis
3D models were created to simulate both symmetrical
and unsymmetrical buildings. The dimensions for
foundation were determined by considering maximum
support reaction of 2700 KN, obtained with fixed
support condition. Foundations were first assigned with
fixed supports to represent the hard strata and analyzed.
In order to simulate soil structure interaction effects,
support conditions were changed to ‘Compression only
spring’ type. The dimension for foundation, obtained for
cohesive soil condition with safe bearing capacity of
200 kN/m2
was 3m x 3m. Similar value for cohesion-
less soil with safe bearing capacity of 350 KN/m2
was
2.1m x 2.1m. The safe bearing capacity was as per
Ramamrutham 2013 [5]. The subgrade modulus
considered was 60000 KN/m2
/m for cohesive soil and
235000 KN/m2
/m for cohesion-less soil as provided in
Arora 2011[6].
The buildings are subjected to load cases as dead load,
live load, seismic load and combination of load cases
with 1.2 times dead load, 1.5 times of live load and
seismic load. Dead load case includes the self-weight,
member load of 19 KN/m for floor beams and 5.4KN/m
for roof beams, floor load of 3.75 KN/m2
on all floors.
Live load of 5KN/m2
was considered for all floors
except for the roof with load intensity 1.5 KN/m2
.
3.1. Time History Analysis
3D models of the buildings with above mentioned
specifications were subjected to time history excitation
which was defined in time history definition. External
earthquake data was input as a basic data for analysis,
with damping of 0.05 as specified by IS 1893-2002 [9].
Analysis was carried out for fixed support condition and
repeated for different soil types by changing the support
conditions.
4. Results and Discussion
Improper planning and design of buildings is one among
the reason for its failure. Present study focuses on forces
and stresses developed in buildings due to seismic
loading and different types of failures to be considered
while designing earthquake resistant buildings.
4.1. Joint Displacements
Joint displacement for unsymmetrical building found on
cohesion-less soil was more as shown in the Figures 2.
Percentage increase in displacement is 13.8% compared
to cohesive soil and 68.6% compared to hard strata.
Similar increase in the value is only about 6.5% and
56.3% respectively, for symmetrical building.
4.2. Forces in beams
Comparisons of beam end forces are as shown in Figure
3. Unsymmetrical building found on cohesion less soil
gave more values. The percentage increase was 42.2%
more than that for cohesive soil and 98.6% more than
that for fixed support condition respectively.
4.3. Stresses in beams
Similar results were noticed for stresses in beams as
shown in Figure 4. Unsymmetrical building found on
cohesion less soil is more vulnerable showing an
increase in percentage of 78.2% in case of cohesive soil
and 98.9% in case of fixed support, compared to
symmetric building.
Comparison of result shows that soil condition and
unsymmetric in building plan, affects the stability of the
building. Cohesion-less soil leads to more deflection
and sway for the buildings.
4.4. Time based Displacement
Magnitude of displacement at different time interval is
as shown in Figure 5. Unsymmetrical building in
cohesion less soil is more vulnerable showing
percentage increase of 46.7% compared to symmetrical
building on similar soil.
4.5. Sway Pattern
Sway pattern of the buildings are as shown in Figure 6.
The un-symmetrical buildings have twisting or torsional
effect, when subjected to lateral seismic forces and
vulnerability is more in case of such buildings found in
cohesion-less soil.
5. Conclusion
Time History analysis of both symmetrical and un-
symmetrical buildings founded on different soil is
carried out considering soil-structure effect. Un-
symmetrical buildings were highly affected compared to
symmetric building. The following conclusions were
arrived
Percentage increase for joint displacement for
unsymmetrical building found on cohesion-less soil
was 13.8% and 68.6%, compared to cohesive soil
and hard strata.
Beam end forces are enhanced by 42.2% and
98.6%, compared to cohesive and hard strata.
Beam stresses are increased by 78.2% and
98.9%,compared to cohesive soil and fixed support
condition
Time based results also show similar increment of
46.7% for displacement, compared to symmetrical
building.
Sway in unsymmetrical building is accompanied by
twisting or torsional effect due to mass irregularity.
The effect is again reinforced due to cohesion less
soil.
3. 1262 Experimental Study on Ammonia Nitrogen Absorption Performance of Zeolite Powder
International Journal of Earth Sciences and Engineering
ISSN 0974-5904, Vol. 08, No. 03, June, 2015, pp. 1260-1263
The time based joint displacements, beam end forces
and beam stresses shows enhanced values for un-
symmetrical buildings found in cohesion less soil. It is
concluded that un-symmetrical buildings should be
constructed with symmetrical shear walls for preventing
twisting effect. For buildings to be constructed on soft
soil the soil must be stabilized and design of foundation
should be carried out accordingly.
Acknowledgement
Support and guidance provided by Shanmugha Arts,
Science, and Technology & Research Academy is
gratefully acknowledged.
References
[1] K.S. Sivakumaran, “Seismic Analysis of Mono-
symmetric multi-storey building including
foundation interaction”, Computers & Structures,
Vol. 36, Issue No. 1, pp. 99-107, 1990.
[2] B. Neelima, B. Pandu Ranga Rao, P. Kodanda
Rama Rao and S.R.K.Reddy, “Earthquake
Response of Structures under Different Soil
Conditions”, International Journal of Engineering
Research & Technology, Vol. 1, Issue No. 7, 2012.
[3] J.A. Pires, “Stochastic seismic response analysis of
soft soil sites”, Nuclear Engineering and Design,
Vol. 160, Issue No. 3, pp. 363-377, 1996.
[4] Naida Ademovic, Mustafa Harasnica and Daniel V.
Oliveira, “Pushover analysis and failure pattern of
typical masonry residential building in Bosnia and
Herzegovina”, Engineering Structures, Vol. 50, pp.
13-29, 2013.
[5] S. Ramamrutham and S. Narayan, Design of
Reinforced Concrete Structures (Revised
Seventeenth Edition), Dhanpat Rai Publishing
Company (P) LTD, 2013.
[6] K. R. Arora, Soil Mechanics and Foundation
Engineering, Standard Publishers Distributors,
2011.
[7] Hendramawat A Safarizkia, S.A. Kristiawanb, and
A. Basuki, “Evaluation of the Use of Steel Bracing
to Improve Seismic Performance of Reinforced
Concrete Building”, Procedia Engineering, Vol. 54,
pp. 447 – 456, 2013.
[8] R. M. Jenifer Priyanka, N. Anand, Dr. S. Justin,
“Studies on Soil Structure Interaction of Multi
Storeyed Buildings with Rigid and Flexible
Foundation”, International Journal of Emerging
Technology and Advanced Engineering, Vol. 2,
Issue No. 12, 2012.
[9] IS 1893 (Part 1)-2002: Indian Standard Criteria for
Earthquake Resistant Design of Structures, Part 1–
General Provisions and Building (Fifth Revision),
Bureau of Indian Standards, New Delhi.
[10]IS 456 – 2000: Indian standard code of practice for
general structural use of plain and reinforced
concrete, New Delhi.
(a) Symmetrical building
(b) Un-Symmetrical building
Figure 1: Plan of the buildings
Figure 2: Comparison of joint displacements
4. 1263WANG JIAQI, JIN WENBIAO, GUO HUA, WANG XINYUE AND LIU JUNLIANG
International Journal of Earth Sciences and Engineering
ISSN 0974-5904, Vol. 08, No. 03, June, 2015, pp. 1260-1263
(3a) Fixed Support
(3b) Cohesion soil
(3c) Cohesion-less soil
Figure 3: Comparison of Beam End Forces
Figure 4: Comparison of Beam Stress
(5a) Symmetrical buiding
(5b)Un-Symmetrical building
Figure 5: Time vs Displacement graph for buidings in
cohesion-less soil