Performannce Base Analysis of Multy Storied Building

In India multistoried buildings are widely designed with the method suggested by Indian Standard IS1893: Part-1:2016, Criteria for the Earthquake resistance design of the structures: General Provision and Buildings for the calculation of equivalent horizontal load generated during earthquake. Response Spectrum method is widely used for the multistoried buildings with base shear scaled to get the equal value as calculated with the time period obtained by the empirical formula of time period of the buildings. The approach of the dynamic analysis is basically a linear approach. In this scenario we are totally relying on ductility of the structure. The concept for performing the Pushover Analysis is to analyze a structure with non linear approach and to find the behavior of structure beyond its ductile limit. Pushover analysis can help to demonstrate how progressive failure in building really occurs and to identify the mode of final failure of the buildings. Pushover analysis is commonly used to evaluate the seismic capacity of existing structures and appears in several recent guidelines for retrofit seismic design. It can also be useful for performance-based design of new buildings that rely on ductility or redundancies to resist earthquake forces. So basically Pushover analysis is non linear approach to estimate the strength capacity of the structure beyond Limit State. In this analysis we can predicts the weak areas in the building and keeping track of the sequence of damages of each and every member in the building/structure, thus can be performed for existing structure and also for performance base design, similarly for progressive collapse analysis. The approach is easy to understand, when we designed or analyze a moment resisting frame as per IS 1893:2016 by Response Spectrum method with response spectrum method with the response reduction factor 5 i.e. R=5, we are basically designing the structure with 1/5th horizontal load (calculated with the empirical formula given in IS 1893:2016), the rest 4/5th load is basically taken care by the ductile behavior of the building. The ductile detailing suggested by the 13920:2016 will resist the full impact of seismic load without collapse. The distribution and impact of the full horizontal load can be analyzed with the non linear approach, and pushover analysis is one of them. METHODLOGY: A pushover analysis is performed by subjecting a structure to a monotonically increasing pattern of lateral loads, representing the inertial forces which would be experienced by the structure when subjected to ground shaking. Under incrementally increasing loads various structural elements may yield sequentially. Consequently, at each event, the structure experiences a loss in stiffness. Using a pushover analysis, a characteristic non linear force displacement relationship can be determined. Key elements of the pushover analysis 1) Definition of plastic hinges, it includes hinges for uncoupled moment, hinges for uncoupled axial load, hinges for uncoupled shear force, hinges for coupled axial force and hinges for biaxial bending moment. 2) Definition for control node, the node used to monitor the displacement of the structures. Pushover curve is obtained from the displacement verses base shear. 3) Developing the pushover curve which includes the elevation of the forces distribution 4) Estimation of the displacement demand. 5) Evaluation of performance level for the structure

Damage capacity on RC structures using performance based analysis

Performance based analysis is conducted on a structure to know the performance of building under severe earthquake loads with limited and well-distributed damage. To do this analysis a non-linear static analysis called pushover analysis had conducted on the structure. In this paper, an RC building with both 5 storey and 10 storey is designed for both gravity loads and earthquake resistant loads using SAP2000 software. Analysis is done in both X and Y direction to get a damage curve (pushover curve). By studying the damage curve, the results that obtained are earthquake resistant designed building had more strength when compared to gravity load designed building and it is better to consider earthquake in building design , because gravity loads alone cannot give the adequate results.

COMPARATIVE STUDY OF PERFORMANCE BASED BEHAVIOUR OF MOMENT RESISTING FRAMES WITH STRUCTURAL SHEAR WALLS, CONCENTRIC BRACED FRAMES & BUCKLE RESISTING BRACED FRAMES

Performance evaluation and design of civil facilities against earthquakes is a challenge to engineers because of the large uncertainty in the seismic demand and capacity of structures. The purpose of the study is to perform comparative analytical investigation of performance-based behavior between Moment Resisting Frames with Structural shear Walls, Concentric Braced Frames & Buckle Resisting Braced Frames of a concrete structure by using ETABS-2017 software. The comparative analytical evaluation of the study will be based on the parameters such as displacement, inter-story drift, pushover curve and life expectancy level. The purpose of the study is to obtain a structural system which is more efficient, reliable and strong in its nature and strength.

Seismic Fragility Analysis of Poorly Built Timber Buildings in Yangon Slum Areas

In Yangon and the suburbs of Myanmar, timber-framed buildings are the popular choice of construction for residential purposes. Nearly 8% of the total population in Yangon live in the slums and slum-like areas where the dwellings are predominantly made of non-durable materials. Wood, jungle wood, and bamboo are used as the framework and corrugated galvanized iron sheets as walling and sheathing material. The seismic-resistance capacity of timber buildings in slum areas has never been approved based on experimental evidence. Therefore, this study aims to conduct a seismic fragility analysis for poorly built timber buildings by providing a suitable method through numerical and experimental approaches. Pull-over loading tests were conducted on selected buildings to assess their loading-displacement capacity. Further, numerical modeling was done using the Wallstat simulation tool, which is based on the discrete element method. The pushover curve was validated with the curve from the pull-over load test. Once the numerical model was confirmed, dynamic analysis was conducted for different peak ground acceleration (PGA) (g) values until the complete numerical collapse of the building. Three building configurations with three ranges of variable material properties were considered in this study. A primary damage state started at the low PGA value of 0.05 g, and it can be confirmed that the timber buildings that were studied, are vulnerable to earthquakes. The results based on qualitative analysis were accumulated to obtain the damage state matrix, which was then used to obtain the fragility curves.

A Model for In-Plane Capacity of Multi-Leaf Stone Masonry Walls

Masonry walls with distinct layers, known as multi-leaf masonry walls, are prevalent in many regions of the world including ancient architecture in Europe and new construction in the Himalayan region of South Asia. This paper presents a model for determining the capacity of multi-leaf stone masonry wall from its physical and mechanical parameters. For the study, a “Standard Wall” with typical properties of a multi-leaf stone masonry wall is defined and the capacity of the stone masonry wall is studied varying different physical and mechanical parameters of the wall to explore an analytical model that can represent the capacity of multi-leaf stone masonry. 300 models of multi-leaf stone masonry panels are analysed in ANSYS, and the capacity and displacement parameters are extracted by bilinearization of the pushover curve. As a result, a mathematical model between the capacity of a multi-leaf stone masonry wall and physical and mechanical properties is established.

Nonlinear Behavior of Building with Varying Percentages of Slab Opening

The work describes about irregular plan geometric forms that are more in metro cities. Irregularities are not avoidable in construction of buildings. In present scenario many buildings have irregular configurations both in elevation and plan. Now a day’s openings in the floors are common for many reasons like stair cases, lighting architectural etc. The present study focuses on the behavior of 10 storey reinforced concrete buildings under seismic zone-v, the plan dimensions is taken as 28 m x 28 m. The plan irregularities such as openings in slab with varying percentages is taken in this study. Study is done on various plan configuration buildings and the action of structural diaphragm on its performance during earthquake is studied. Pushover analysis is performed by using ETABS software, for present work five models are studied 1) building without opening in slab 2) plan irregular building with 10% opening in slab 3) plan irregular building with 20% opening in slab 4) plan irregular building with 30% opening in slab 5) plan irregular building with 40% opening in slab. Output from software consisting of Pushover curve and hinge formation results of all five models which are presented. Plan irregularity find better structural system solution such as in 20% opening shows better base shear.

Performance of Outrigger System by Non-Linear Static Method

High rise building structures are highly affected by lateral loads and wind forces. To enhance lateral force outrigger systems are developed, which are one of the most popular and efficient, because they are easier to build and they provides good lateral stiffness. With the rise of building height, deep beam become concrete walls at least of one story height. Axial shortening effect between core and perimeter structure has to be considered.In the present work 20 story reinforced concrete structure has taken with outrigger walls attached from core to the outer perimeter column. By changing the different position of outrigger level are kept for analysis.The building without and with outrigger are compared with bareframe. These are different building models analysed (a) Bare frame of twenty story building (b) Bare frame with core shear wall building (c) Outrigger system at top of building (d) Outrigger system at top & 0.75 Height of building (e) Outrigger system at top & 0.50 Height of building (f) Outrigger system at top & 0.25 Height of building. Non-linear static analysis results were compared. The analytical methods used in the work are pushover method. In this work, various parameters like pushover curve, displacement vs base force, story displacement, hinges formation are obtained for all the models.Outrigger at optimum level at 0.5 Height gives better results in both displacements and base force. To sustain peak lateral loads these systems are provided half of the height. These study gives has inelastic behaviour of structure.

A Nonlinear Static Research on A G+5 Storey Existing RC Structure Under Seismic Loading

A six-story reinforced concrete structure area to a seismic hazard can be analyzed; as soon as the member has yielded, the plastic hinge will likely be used to symbolize the mode of failure in the beams and columns. The pushover analysis is carried out on constructing utilizing an identical static process from ETABS-2016 and IS 1893-2016. The analysis is regulated through efficiency-situated warmness engineering legal guidelines, even as an inelastic structural evaluation is combined with seismic hazard to calculate the expected seismic performance of the structure. The building's basis shear v / s roof strain curve referred to as the pushover curve is an enormous consequence of pushover evaluation; nonlinear dynamic evaluation is carried out in both respects (X & Y). Default hinge facets to be had in precise packages are built-in for every member in step with FEMA-440(Federal Emergency management agency) and ATC-40(applied technology Council) for every member.

PENGARUH SETBACK PADA BANGUNAN DENGAN SOFT STORY TERHADAP KINERJA STRUKTUR AKIBAT BEBAN GEMPA

Pembangunan konstruksi teknik sipil mengalami perkembangan yang sangat pesat seiring dengan berkembangnya zaman sehingga menuntut kita lebih kreatif dalam perancangan struktur baik dalam bentuk bangunan beraturan maupun tidak beraturan yaitu, bangunan setback dan bangunan soft story. Di Indonesia, tantangan yang dihadapi dalam kontruksi gedung bertingkat adalah adanya resiko akibat gempa. Salah satu metode untuk menganalisis beban gempa adalah analisis pushover. Analisis pushover merupakan prosedur analisis untuk mengetahui perilaku keruntuhan suatu bangunan terhadap gempa. Penelitian dilakukan untuk mengetahui seberapa besar pengaruh setback dan soft story yaitu bangunan tanpa dinding pengisi pada lantai dasar terhadap kinerja struktur akibat beban gempa berdasarkan hasil kurva pushover. Stuktur bangunan dimodelkan sebagai portal 2 dimensi yang tanpa adanya dinding pengisi pada lantai dasar yaitu terdiri dari 4 model rangka penuh, setback1, setback2, dan setback3. Hasil analisis dalam penelitian ini menunjukkan bahwa kontribusi dinding pengisi yang terbuat dari dinding bata mempengaruhi kekakuan lateral struktur, serta dengan dikuranginya setback pada struktur bangunan mengakibatkan nilai kekakuan semakin kecil sehingga nilai daktilitas semakin besar. Pada struktur gedung rangka penuh dan setback1 lunak kondisi bangunan sudah mengalami rusak parah atau runtuh saat terjadi gempa kuatdikarenakan terbentuknya sendi plastis pada kolom lantai pertama. Kata Kunci : Analisis Pushover, Dinding Pengisi, Setback, Soft Story ABSTRACT The construction of civil engineering construction has developed very rapidly along with the development of the era so it demands that we are more creative in the design of structures both in the form of irregular and irregular buildings ie, setback building and soft story building. In Indonesia, the challenge faced in the construction of multi-storey building is the risk caused by the earthquake. One method to analyze earthquake loads is pushover analysis. Pushover analysis is an analytical procedure to determine the collapse behavior of a building against earthquake. The research was conducted to find out how big the effect of setback and soft story that is building without wall filler on the ground floor to the structure performance due to earthquake load based on the result of pushover curve. The structure of the building is modeled as a 2-dimensional portal without the filler wall on the ground floor consisting of 4 full frame models, setback1, setback2, and setback 3. The results of the analysis in this study indicate that the contribution of wall filler made of brick walls affect the lateral stiffness of the structure, as well as with the reduced setback on the structure of the building resulting in smaller stiffness value so that the greater the ductility value. In full skeletal structure and soft setback1 the condition of the building has been severely damaged or collapsed during a strong earthquake due to the formation of plastic joints in the first floor column. Keywords: Pushover Analysis, Setback, Soft Story, Wall Filler