behaviour o f soft storey rc fra med building under...

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International Journal of Civil Engineering and Technology (IJCIET) Volume 8, Issue 4, April 2017, pp. 265–277 Article ID: IJCIET_08_04_033 Available online at http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=8&IType=4 ISSN Print: 0976-6308 and ISSN Online: 0976-6316 © IAEME Publication Scopus Indexed

BEHAVIOUR OF SOFT STOREY RC FRAMED BUILDING UNDER SEISMIC LOADING

B. Lalitha Chandrahas PG Student, K L University, Department of Civil Engineering,

Vaddeswaram, Andhra Pradesh, India

P. Polu Raju Associate Professor, K L University, Department of Civil Engineering,

Vaddeswaram, Andhra Pradesh, India

ABSTRACT Indian urbanization has led to increase in demand for construction of commercial

floors, parking facilities in the lower stories of building. The location of open storey at different levels in a building is most vulnerable to seismic forces which may lead to either partial damage or collapse of the building above that floor. The conventional design methods are not accountable for such failures in past earthquakes. In this article attempts are made to explain the factors that impact the soft storey failure in a building. Pushover analysis has been carried out for a G+9 multistoried building to study the soft storey effect at different floor levels using SAP 2000 software. The behavior of RC framed building with soft storey under seismic loading has been observed in terms of hinge formation patterns, total lateral drift, storey shear, overturning moment, and time period for considered structure. It is observed that infill wall has significant effect in the stiffness and lateral resistance of frame.

Key words: Soft storey, Hinge formation, Infill wall, Storey Drift, SAP 2000. Cite this Article: B. Lalitha Chandrahas and P. Polu Raju, Behaviour of Soft Storey RC Framed Building Under Seismic Loading. International Journal of Civil Engineering and Technology, 8(4), 2017, pp. 265–277. http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=8&IType=4

1. INTRODUCTION A soft storey is one in which the lateral stiffness is less than 70 percent of that in the storey above or less than 80 percent of average stiffness of three storeys above as shown in Fig. 1 [1]. In urban locations, many of the moment resisting frames inmulti-storey buildings are constructed with an adopted open storey in order to accommodate parking facilities, office receptions and other large open areas for multiple purposes and are considered as unavoidable features.

The open floor consists of a little or no infill walls so it has less frame-infill interaction and may significantly decreases both stiffness and strength of the floor. Such multi-storey reinforced concrete buildings are often called buildings with soft storey, which fails during

B. Lalitha Chandrahas and P. Polu Raju


seismic lateral loads. In this paper, the performance and behaviour of multi storey RC building with soft storey at different levels is analysed.

The soft storey failure during earthquake occurs due to the following factors: Presence of wide openings in bottom storey like offices, shops and hotels which may not

present in upper storeys.

Slender column in the particular storey.

Lower storey weakens first, creates the weak storey and leads to the collapse of structures. Behaviour of structure with and without infill walls is entirely different. During the

earthquake the infill walls contribute 80% to structural strength and 85%to stiffness of the structure. The relative increase in impact of earthquake force is small when compared to the increase in strength of masonry infill [2]. The presence of infill walls in upper storeys, the stiffness is generally higher compared to lower storey. The storeys with infill walls act as a single block and move together increasing lateral displacement of building in soft storey. In such buildings the upper storeys above soft storey, swing like an inverted pendulum during earth quake shakes. During earth quake amount of earthquake force increases with increase in mass. As mass increases inertia force increasing and as inertia force increases lateral loads on the structure increases. The bricks and concrete blocks are treated as non-structural members and their stiffness and strength contribution is neglected during earthquake resistance design. However, the effect of such structural elements under seismic action has been proved to have a considerable effect on building, by increasing both structural stiffness and strength when compared to bare frame (without infill walls) building [2].The significant evidences from damage in RC buildings with soft storey, which located in active seismic zones showed that many buildings failed at soft storey leads to potential economic loss. During a strong earthquake motion a building is subjected to a large storey shear, deflections and inter-storey drift which causes the instability of structure. It is observed that damage is due to local stress concentration accompanied by large plastic deformations at ends of columns, i.e. (when a hinge is formed there is a redistribution of forces causing the increase in number of hinges leading to the formation of soft-storey mechanism) creates weak storey and cause failure of columns. Such failure mechanism is called column sway mechanism or soft storey mechanism [3].

1.1. Infill Walls

Modelling of infills is classified into two types; they are macro modelling and micro modelling [4, 5]. In macro modelling infill walls are simulated as equivalent single strut or multi-struts whichever is more suitable for the study. Some past papers suggested that single strut model is incapable for detailed analysis like infill structures interactions [5, 6].To obtain an accurate and detailed analysis report micro modelling method can be used. The micro modelling analysis is carried out using FEM which can precisely predict the infill walls interaction with structure. FEM is very complex and time consuming process, due to this reason the macro modelling process can be used. In addition, the macro modelling process is widely acceptable and preferable method for high rise structures. In this study single strut model is used in place of masonry infill wall, representing the stiffness and structural strength [7, 8, and 9].

1.2. Push Overloading It is acknowledged that compared to other types of analysis the time-history analysis is more accurate method of analysis. However, pushover analysis is most preferable and accepted method because of its conceptuality and computational simplicity. Also, it gives capacity

Behaviour of Soft Storey RC Framed Building Under Seismic Loading


spectrum along with performance point during seismic performance based analysis of structures. Using pushover analysis can be determine the capacity of the structure. If the performance point lies within the collapsible range, the structure performs well during earth quake. In pushover analysis, prescribed loading is applied incrementally until the structure reaches its limiting state. Push over analysis is also called as non-linear static. The static approximation in non-linear static analysis indicates the vertical distribution of lateral modes that captures the material nonlinearity of an existing structure and by monotonically increasing those loads until peak response of structure is obtained [10].

Factors effecting static lateral load using mode superposition method are: Seismic demand of structure based on base shear vs. roof displacement.

The maximum ductility capacity and rotation of members.

Plastic hinge distribution for ultimate load at each step of loading.

Distribution of localized damage at ultimate load condition.

1.3. Description of Hinges Generally plastic hinges will form at the ends of beams and columns under earthquake loading. Studying the formation of hinges helps in describing the structural behavior. It is observed that the user-define hinges perform well in capturing the hinging mechanism in structural model when compared to default hinges. In beams, plastic hinges are formed due to uni-axial bending moments but in columns plastic hinges are formed due to both axial loads and biaxial bending moments. Different hinges are applied to both columns and beams separately. In SAP 2000, Flexural default hinges (M3) and shear hinges (V2) were assigned to beams at two ends. The interacting (P-M2-M3) a coupled frame hinges property was also assigned for all the columns at upper and lower ends.M3 hinge is used to simulate the plastic hinge caused by uni-axial moment as user defined hinges to beams and similarly in columns, PMM hinges are used to simulate the plastic hinge due to axial load and biaxial bending moments. Masonry infill walls were modeled as equivalent diagonal strut using two nodded beam element. Moments at both ends of the strut are released to prevent the transfer of bending moment [11].

1.4. Lateral Load Patterns Lateral load pattern represents the inertia force distribution under seismic design. As the severity of earthquake changes with duration of earthquake, the distribution of inertia force also changes (i.e., based on inelastic deformation) [1, 11].None of the single load pattern is sufficient to determine the variation in local demand in a design based earthquake. So two lateral load patterns are taken and blended to find the inertia force distribution using pushover load case.

The methods for mode blending are: Inverted triangular lateral load pattern is calculated by using base shear method with

fundamental modes.

The design lateral load pattern is calculated using SAP2000 by including higher mode effects.

2. BACKGROUND In 1969, Fintel and Khan [12] introduced the concept of soft storey, however during the 1930s, some other researchers focused on some aspects of an open or soft first storey. In 1997 Uniform Building Code (UBC) [12] and several other codes [13, 14] defined the soft storey as the floor of about 70% less stiff than the floor above it. Habibullah and Stephen [15]



explained about dynamic and static analysis of the multi-storied building, which also include P-Delta effect (the generation of second order overturning moment because of lateral movement of mass in a deformed state is known as P-Delta effect). Along with direct displacement method they considered P-Delta effect for both static and dynamic analysis. Chopra et al. [16] conducted the extensive study on dynamic analysis along with nonlinear response analysis with different rules of mode combination. He commented that, peak estimation of storey shear of building with widely spread natural frequencies is appreciably accurate using SRSS rule. Vamvatsikos and Cornell [17] concluded that Incremental Dynamic Analysis (IDA) is more useful tool for seismic engineering because, it considers both ductility and demand capacity of a structure. Shome and Cornell et al. [18] studied on collapse state seismic demand analysis and concluded that nonlinear time history analysis is a most accurate method for seismic demand computation. Ghosh and Fanella [19, 20] showed a step by step complete dynamic design procedure and explained detailed static and dynamic computation method using Equivalent Lateral Force (ELF). It was concluded that, in general 3 modes are sufficient for most buildings having moderate height. It was commented that modal dynamic analysis method gives fairly accurate results so it is mandatory for every analysis. Jain et al. [21] explained about damage of RC structure during past Bhuj earth Quake using push over analysis and showed seismic inadequacies of code methods. The pattern of failure indicates lack in seismic ductile detailing and structural irregularity which results in poor structural performance under seismic loads. Chandrasekaran et al. [22] showed the plan irregularity effect on seismic vulnerability of moment resisting frame structures (MRFS). The author given more importance to effect of re-entrant corners of MRFS on its seismic vulnerability of A/L ration reneging 0.15 to 0.2. The study was conducted on configuration of buildings and base shear values were analysed along the considered direction of the earthquake. Surya and Agarwal [23] indicates that as Drift value ratio increases the frequency drops by 40-50%. It is because of widening of cracks and decrease of stiffness. They also added that in undamaged state strain energy dissipates though intermolecular friction (elastic viscose damping) which is constant for certain material but if strain energy exceeds beyond minimum limit structure changes its way of dissipation of energy through cracks and increases its damping ratio

Table 1 Building Modal Details

Structure SMRF

No of Stories G+9 Storey Height 3m Bays in x and y directions 5 Type of Soil Medium soil Seismic Zone V Importance factor 1 Response Reduction Factor, R 5 (SMRF)



Table 2 Material Properties

Material Property

Grade of Concrete M25 Grade of Steel Fe415 Member Properties

Beam in longitudinal x-direction, size 0.3m × 0.6m

Beam in transverse y-direction, size 0.3m × 0.6m

Column Size 0.6m × 0.6m Thickness of Slab 125mm

Table 3 Loading Details for Design

Live or imposed load 3.5 kN/m2 (According to IS 875-1987 (part:2)[24]

Floor finishes loading 1.75 kN/m2(According to IS 875- 1987 (part:2) [24]

Wall load on beams 19 kN/m(According to IS 875- 1987 (part:2) [24]

Equivalent lateral loads According to IS 1893:2002(part:1) [1]

Figure 3 Equivalent diagonal compressive strut model (Genidy et al., 1959)



3D Modal Plan

Figure 2 Modelling of Masonry- Infill Walls

3. DESCRIPTION OF BUILDING MODEL In this study a typical reinforced concrete (RC) framed building is designed according to the Indian code. A building model with 5 bays each of 3m is considered in both X and Y directions and each floor height is 3m as shown in Fig. 2. The building was modelled as moment-resisting frame having soft storeys at base, third storey, fifth storey, seventh, and ninth storey. A symmetric building is considered in both X and Y directions to avoid torsion effect [25, 26]. Table 1 shows the building model details such like number of stories, each storey height and type of soil etc. Material properties and cross sectional details of structural elements are shown in Table 2. Loading details for the design was shown in Table 3. SAP 2000 17is well-known software package used for developing the model. Moreover, the SAP 2000 is used for both static and dynamic analysis as per Indian codes. Hysterious loop is considered to study the amount of energy dissipated for both elastic and in-elastic design of a structure. The energy dissipated for in-elastic design is higher than the elastic design so, to make design safer and efficient. The study of inelastic behaviour of structure is preferred. On comparing the energy curves the performance based design methods are more superior to the elastic design method for its optimum utilization of structural capacity. There are two proposed methods in simulating the behaviour of masonry-infill walls, the micro model method (Morbiducci [5]) and macro model method (Polyakov [8]).Though micro model method is producing best results in understanding the local and global responses, it is rarely used because of its complex, computational nature and simulation difficulty. Macro modelling is widely used method but the disadvantage in equivalent diagonal strut method (macro modelling method) is in its inaccurate modelling of openings. However, effect of opening can be created using less number of struts in less infills storeys (Asteris 2003, Puglisi and Uzcategui 2008)[6]. In the present study Infill wall is modelled as equivalent diagonal compression strut of suitable width based on empirical equation Eq.(1). The strut is modelled using two noded frame or beam elements. Transfer of bending moments from structural member to masonry wall was prevented by specifying the moment releases at both the ends of strut. Shear hinges were provided to beams and axial moment interaction hinges to columns. The thickness and modulus of elasticity of the strut are equivalent to the



existing infill panel. The thickness of the strut can be written in terms of the column height between centrelines of beams and the length of the panel using Eq. (1).

in f0 .410 .1 75( ) r

co la h Eq. (1)

The diagonal length of infill panel can be calculated as shown in Eq. (2).

2 2inf inf inf( ) ( )r L h Eq. (2)

The coefficient λi which is used to compute the width of infill strut and can be calculated as a function of infill panel height hinge, modules of elasticity of frame material Efe. Similarly the material of infill is simulated using its modules as Eme. The column has a moment of inertia Icol, the length of infill panel length is taken as Linf and thickness tinf as shown in Eq. (3). Fig. 3 shows, Equivalent diagonal compressive strut model.

1 / 4

in f

i n f

s in 24

m ei

fe c o l

E tE I h

Eq. (3)

Eq.1 represents the effective width of strut, Eq. 2 represents diagonal length of strut and Eq.3 represents material constant.

Table 4 Maximum joint displacements along X-direction

Storey No BF(m) GF(m) 3rd(m) 5th(m) 7th(m) 9th(m) Full(m)

0 0 0 0 0 0 0 0

1 0.048193 0.055784 0.00306 0.003407 0.003316 0.004228 0.006065

2 0.097341 0.060998 0.007283 0.007109 0.006913 0.011092 0.012369

3 0.134273 0.06474 0.069744 0.010476 0.010189 0.017606 0.018088

4 0.159886 0.068209 0.073818 0.014035 0.01316 0.023457 0.02323

5 0.175617 0.071374 0.076872 0.076881 0.015817 0.028663 0.027794

6 0.184456 0.074275 0.079696 0.080052 0.018409 0.033214 0.031798

7 0.191308 0.076905 0.082254 0.082615 0.025065 0.03714 0.035301

8 0.19735 0.079256 0.084539 0.084893 0.027108 0.04071 0.038394

9 0.202768 0.081327 0.086546 0.086876 0.028691 0.044996 0.041071

10 0.207622 0.083132 0.088292 0.08858 0.029998 0.047654 0.043351



Figure 4 Maximum Joint displacements along X-direction BF, bare frame; GF, ground floor; 3rd, third floor; 5th, fifth floor; 7th, seventh floor; 9th,

ninth floor; FULL, full strut model;

Figure 5 Comparative Study of Time Periods

Figure 6 Comparative study of Cyclic Frequency

0123456789

1011

0 0.05 0.1 0.15 0.2 0.25

Stor

ey N

o.

Drift(m)

BF GF3RD 5TH7TH 9THFULL

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

1 2 3 4 5 6 7 8 9 10 11 12

Tim

e Pe

riod(

sec)

Modal Step number push over load case

full struct 9th floor7th floor5th floor3rd floorground floorbare frame

0

5

10

15

20

25

1 2 3 4 5 6 7 8 9 10 11 12

Freq

uenc

y(C

ycle

s/Se

c)

Modal Step number in push over load case

Full struct9th floor7th floor5th floor3rd floorground floorBare frame



Figure 7 Variation of Base shear with type of Structure

Bare Frame Ground floor Soft story 3rd Floor Soft story 5th Floor Soft Story

Elastic state

Immediate Occupancy Life Safety

Collapse Prevention Ultimate Capacity

Residual strength

Complete Collapse

7th Floor Soft story 9th Floor Soft Story Complete Infill walls Nature of Hinges as Per Push Over loading Case with colour coding

Figure 8 Hinge formations for different Structures

5233.818

6748.1327400.466

8254.848738.361 8601.294 8792.707

Bare frame Ground Floor 3rd Floor 5th Floor 7th floor 9th Floor Full struct

Base Shear (kN)



4. RESULTS AND DISCUSSIONS Drift is defined as lateral displacement and inter storey drift is the difference between the roof and floor displacements of that storey in a building if it normalized with height of the storey it is known as Drift ratio. Drift ratio is maximum at middle floor levels It can be observed on considering infill action there is a significant reduction in the drift values but at the location of soft-storey , storey drift value exceed the allowable limit. This can be seen in values of Table.4 and Fig. 4.

By comparing the plotted curves for infill frame with soft storey, it was observed that all curves show similar trend at starting stage and start to deviate with significant increase in displacement from the location of soft storey as shown in Fig. 4. The sudden increase in peak displacement is due to absence of masonry infill action at the soft storey level. It is worth noting that the soft storey does not affect the obtained displacement value of storeys located below it. The presence of soft storey at the base or at any other level generally decreases the amount of shear force that transferred to the next floor. The Storey displacement values of the bare frame model is very high when compared to the infill wall model. The frequency of structure decreases as time period increases due to the development and widening of cracks. If the structural displacement increase beyond the yield point displacement the stiffness of structure decreases due to the formation of cracks therefore stain energy dissipated is quantified and changes the damping ratio of the model. As damping ratio changes it changes the period and frequency of the model [23]. From the above discussion we can conclude that as the Drift ratio increases the frequency decreases.

The state of stress in infill masonry is different along the height (infill action of masonry wall is different at different storey height) as the column and beams in upper floors try to transfer certain amount of force to the infill by strut action as we move to the upper floors the weight above the storey reduces and the amount of force transferred to strut also reduces. So, infill action of walls in top floors is very less when compared to below floors. Form the plot, as long as the location of soft storey is below the middle floor level maximum lateral drift is height, if the soft storey height above middle floor the maximum lateral drift values decreases. It can be seen in the maximum storey displacement values of 7th& 9th soft-storey. As the soft storey moves up in a building diaphragm drift decreases.

In structural system vibrational properties like Natural frequency (ω), Time Period and mode –shapes (φ) has a considerable impact over the failure patterns of structure [27].The bare frame model give a higher time period value, compared to the other structural models in analysis. From the data it can conclude that there is a significant effect of in fill walls on the time period and frequency of the structure. Therefore bare frame analysis of structure will not give accurate values and it over estimates the drift, displacement and Time period values.

As the time period, frequency and drift values depends on the weight (force) and modules of elasticity (which impacts stiffness of a material) of the structure on reducing the weight of the infill material, it can be reduce drift values of the structure There is significant increase in base shear as the location of soft-storey varies along the height as observed from Fig.7 Stress concentration increases at the location of soft storey during earthquakes because of sudden reduction of stiffness (location soft storey) which increase concentration of the stress in columns. The columns in the soft storey floor reach plastic state even though other storey columns are still in elastic state. This is caused due to ignoring the stiffness contribution of infill wall in the analysis and design. As soft-storey fails, it leads to total collapse of structure even though other floors of the structure are in elastic state. On observing Hinge formation patterns as shown in Fig.8. As the push over load steps increases the number of hinges forming also increase showing the locations where stiffness is reducing plastic hinge rotation is concentrated at the top and bottom ends of the columns and it represents typical failure



mechanism of soft-storey frames. Maximum yielding of material in columns and beams occur in soft storey due to concentration of stress. So if a column fails it causes partial failure or sometimes complete collapse of structure whereas if beam fails the failure is localized and gets distributed to other structural components. By adopting strong column weak beam concept we can localize the failure mode As the location soft-storey shifts to upper floors the yielding of material is less so lower intensity hinges are formed after maximum number of steps in push over analysis. The parameters that impacts the poor performance of the structure during earth quakes are type of reinforcement, % of reinforcement, ductile detailing of reinforcement and confinement of reinforcement etc., it is observed that effect of concrete grade and steel grade has no significance in failure modes as modules of elasticity is independent of grade of cement and steel. Formation of hinges in a structure determines the load transfer mechanism, extent of damage and amount of rehabilitation work it requires. As the force is directly proportional to the stiffness, on increasing stiffness in members of floors, load it can resist also increases so stiffness of the structure is to be increased.

Stiffness ratio of the structure is important factor for successful strengthening of building with soft storey. Some possible solutions for soft storey problem is increase stiffness of columns by providing lateral stiffeners (braces of stiffeners), shear walls, or by providing a solid lift inner core [28].After Bhuj earth quake Indian seismic code IS: 1893(part1)-2002 suggested that forces in beams and column in open storey buildings is approximated by multiplying the bare frame design forces with a multiplication factor 2.5 under the action of earth quake loads so that the column and beams can be designed to the new design force values [1, 29, and30].

5. CONCLUSIONS From the soft storey analysis the following conclusions are drawn:

There is significant effect of infill walls in the stiffness and lateral resistance of frame. The uneven distribution of in fills should be regular to avoid soft storey formation.

As the location of soft storey shifts to upper floors the maximum lateral drift value decreases. In case of unavoidable conditions, soft storey should be provided in upper floor levels above middle floor heights to decrease the impact of soft-story.

In order to prevent the soft-story collapse of the structure. The maximum lateral drift values of the story should be limited and the stiffness of the column should be increased.

REFERENCES [1] IS 1893-2002 (Part-1), “Criteria for Earthquake resistant design of structures”, General

provisions and buildings, Bureau of Indian Standards, New Delhi.

[2] H.S.Lee and S.W.Woo, “Effect of masonry infills on seismic performance of A 3 story R.C frame with non-seismic detailing”, Earthquake Eng., Struct, Dyn, vol.31,pp-353-378,2002.

[3] C. Repapis, C.Zeris, and E. Vintzileou, (2008) “Evaluation of the seismic performance of existing RC Building”, A case study for regular and irregular building”, Journal of Engineering, 10:3, p.p. 429-452.

[4] J.Asteris, I.P. Giannopoulos, and C. Z. Chrysoustomou, (2012) “Modelling of in filled frames with openings”, the open construction and building technology journal, 6, supplementary (1-M6), pp.81-91.

[5] R. Morbiducci, “Non-linear parameters of models for masonry”, International Journal of Solids and Structures, Vol.40 (15), 4071-4090, 2003



[6] T.Paulay and M.J.N. Priestley, “Seismic Design of concrete and Masonry Buildings”, John Wiley &Sons Inc., New York, USA, 1992

[7] B.S. Smith, “Lateral stiffness of in filled Frames”, Journal of Structural Division, and Proc. of ASCE, 114, 1962.183-199.

[8] S. Polyakov, “On the interaction between masonry filler walls and enclosing frame when loading in plane of the wall”, Translation in earthquake engineers, earthquake engineering, Earthquake engineering research institute, San Francisco, 36-42(1960)

[9] Applied Technology Council (ATC-40), “Seismic Evaluation and Retrofit of Concrete Buildings”, Vol. 1 and 2, Redwood City, California, 1996.

[10] H. Shashikumar and Sayed Ahamed Raza, “Capacity based modal dynamic analysis with soft story and masonry core wall as infill” International Journal of modern Engineering Research(IJMER) Vol.5(6), June 2015, ISSN:2249-6645.

[11] SAP 2000 manual, “Three Dimensional Static and Dynamic Analysis and Design ofBuilding”, 2000 IBC, ASCE 7-98, and ACI 318-99” ISBN: 58001-112-8, June 2013.

[12] M. Fintel and F. Khan, “Shock-absorbing soft storey concept for multi-storey earthquake structures", ACI Journal, Vol. 66, pp. 381-390, 1969.

[13] UBC, “Uniform Building Code”, International Conference of Building 1997.

[14] IBC, “International Building Code”, USA: International Code Council Inc., 2009.

[15] A. Habibullah and S. Pyle, “Practical three dimensional non-linear static pushover analysis”, Structures Magazine, winter, 1998.

[16] A.K. Chopra and R. K. A. Goel “Model push over analysis procedure to estimate seismic demand for buildings: theory and preliminary evaluation”, Pacific Earthquake Engineering Research Centre, Collage of Engineering University of Berkeley, Berkeley; 2001.

[17] D. Vamvatsikos and C.A. Cornell “Incremental Dynamic Analysis and Its Application to Performance-Based Earth quake engineering”, 12th European Conference on Earthquake Engineering Paper Reference-479.

[18] N. Shome and C.A. Cornell, Stranford University, “Structural Seismic Demand Analysis” 8thACSE Speciality Conference on Pubabilistic Mechanics and Structural Reliability, PMC2000-119.

[19] S.K.Ghosh and D.A. Fanella “Seismic and Wind Design of Concrete Building” (2000 IBC, ASCE 7-98,and ACI 318-99” ISBN: 58001-112-8. June 2013.

[20] W. W. El- Dakhankhni, M. Elgaaly, and J.F. Abel, “A six-strut model for Non-linear Dynamic analysis of steel in filled Frames”, International Journal of Structural Stability and Dynamics, 2(3), 2002, 335-353..

[21] S.K. Jain, K. Mitra, Manish, and M. Shah (2010) “Seismic Evaluation of RC-Frame Building in India Earth quake” A Proposed Rapid Visual Screening Procedure for Seismic Evaluation of RC-Frame Buildings in India. Earthquake Spectra: August 2010, Vol. 26, No. 3, pp. 709-729.

[22] S. Chandrasekaran, U.K. Tripathi, and M. Srivastava, “Study of plan irregularity effect on seismic vulnerability of MRFS” Conference on shock & Impact loads on Structures, 2003, pp.125-136.

[23] V.V.S .Surya Kumar Dadi and Pankaj Agarwal “Updating the nonlinear analytical modelling of soft story RC framed building models based on cyclic test results” Springer Science and Business Media Bull Earthquake Engineering(2013) 11:1493-1515.



[24] IS: 875 (part 1and 2) -1987Code of practice for design loads (other than earthquake) for buildings and structures.

[25] S. Ahamed and J.G. Kori, “Performance Based Seismic Analysis of an Unsymmetrical Building Using Pushover Analysis”, International Journal of Engineering Research, vol. 1, no .2, pp.100-110, 2013.

[26] C.Athanassiadou, “Seismic Performance of RC Panel Frames Irregular in Elevation” Engineering Structures, vol. 30, pp.1250-1261.

[27] P.S.Dande and P.B.Kondag (2013) “Influence of Provision of Soft story in RC framed building for earthquake resistance design”. International Journal of Engineering Research applications 3(2):461-468.

[28] A. Kadid and A. Boumrkik, “Pushover Analysis of Reinforced Concert Frame Structure”, Asian Journal of Civil engineering, vol.9 no.1, pp. 75-83, 2008.

[29] Federal Emergency Management Agency (FEMA-356), “Pre standard and Commentary for the Seismic Rehabilitation of Buildings”, Washington DC, U.S.A., 2000.

[30] “Seismic Response of Moment Resisting Frame with Open Ground Story Designed as per code Provisions RC building” Architecture Research, pp.20-26, 2012.

[31] Prerna Nautiyal, Saurabh Singh and Geeta Batham. A Comparative Study of the Effect of Infill Walls on Seismic Performance of Reinforced Concrete Buildings. International Journal of Civil Engineering and Technology, 4(4), 2013, pp. 208–218

[32] Dr. Suchita Hirde and Ms. Dhanshri Bhoite. Effect of Modeling of Infill Walls on Performance of Multi Story RC Building. International Journal of Civil Engineering and Technology, 4(4), 2013, pp. 243–250

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