scholarly journals Study on Dynamic analysis of Diagrid and Outrigger Structures Subjected to Seismic and Wind Load

Author(s):  
Sharath Kumar N

A Comparative study of G+30 story regular, diagrid, outrigger structure is presented. A square shaped floor plan of 18 m × 18m size was considered. ETABS 2016 was used in modeling and analysis of structural members. All structural members were designed as per IS 456:2000, load combinations such as dead load, live load, earthquake and wind loads were considered for analysis and design of the structure. Later Regular, Diagrid and outrigger structural systems were compared; the key results like Base shear, story displacement and story drift are obtained. It is found that diagrid system is efficient in resisting seismic loads and outrigger system is found efficient in resisting wind loads.

Author(s):  
Latha M S

Water tank is a container used for the storing of liquids and they are classified based on shape and location. The overhead tank is an important and it is very common public utility structure. The study predicts the analysis and design of the rectangular and circular overhead water tank using ETABS software. The water tank is modeled and analyzed by using dynamic analysis to resist lateral loads and design is made using working stress method manually. Dead load, live load, wind load and seismic loads are applied based on IS codes. The behavior of structure for the parameters like Story drift, displacement, stiffness, deflection, storey shear, base shear, area of steel and hoop tension for circular and rectangular water tank are studied and then comparison of the results is made between circular and rectangular overhead water tank. By this study we say that the circular water tank is suitable for larger capacity and rectangular is suitable for smaller capacity and it is economical for larger capacity.


In the present study, modeling and analysis of a three-lane three-span box bridge has been carried out by using finite element software STAAD pro.v8i. The study has been execute to find the effect of skew angle on all bride slabs (top slab, bottom slab, outer walls, inner walls) under various loads (dead load, live load, surfacing load, earth pressure, temperature and live load surcharge) and their combinations using IRC 6:2016. Skew angles taken for study ranges from 00 to 700 with an interval of 100 . Parameters that are mainly examined are longitudinal moments, transverse moments, torsional moments, shear forces and displacements. It has been observed that with the increase of skew angle all the parameters increases with the increase of skew angles in all slabs.


2003 ◽  
Vol 30 (2) ◽  
pp. 429-439 ◽  
Author(s):  
F M Bartlett ◽  
H P Hong ◽  
W Zhou

The 2005 edition of the National Building Code of Canada (NBCC) will adopt a companion-action format for load combinations and specify wind and snow loads based on their 50 year return period values. This paper summarizes statistics for dead load, live load due to use and occupancy, snow load, and wind load that have been adopted for calibration, and a companion paper presents the calibration itself. A new survey of typical construction tolerances indicates that statistics for dead load widely adopted for building code calibration are adequate unless the dead load is dominated by thin, cast-in-place concrete toppings. Unique statistics for live load due to use and occupancy are derived that pertain specifically to the live load reduction factor equation used in the NBCC. Statistics for snow and wind loads are normalized using the 50 year values that will be specified in the 2005 NBCC. New statistics are determined for the factors that transform wind speeds and ground snow depths into wind and snow loads on structures.Key words: buildings, code calibration, companion action, dead loads, live loads, load combinations, load factors, reliability, safety, snow loads, wind loads.


Author(s):  
Abdul Wasey Abdul Wahab ◽  
Dr. P. B. Ullagaddi

When the multi-storied buildings are constructed a suitable care should be taken while designing, as they are subjected to lateral forces. The behaviour of multi-story building depends upon either in plan or in vertical direction i.e, elevation, is considered as one of the main causes of failure during earthquakes. Thus irregular structures, especially the structures which are located in seismic zones are required a special attention during analysis and design of structure. In this study Plan irregular (C-shaped building) is considered to carry out study. Bracing system is installed to provide strength against lateral loading and the behaviour of the structure in terms of base shear, story drift, stiffness and the lateral displacements are observed. Three different types of bracings X, V and Diagonal are installed in the structure. Total 4 models are analysed for 7 story height level, 4 Models are computed to determine the performance of the structure. One MRF and three models with different bracing system. And the best suitable bracing system for this study. The method used for this study is response spectrum method, to perform dynamic analysis of the structure.


2003 ◽  
Vol 30 (2) ◽  
pp. 440-448 ◽  
Author(s):  
F M Bartlett ◽  
H P Hong ◽  
W Zhou

The 2005 edition of the National Building Code of Canada (NBCC) will adopt a companion-action format for load combinations and specify wind and snow loads based on their 50 year return period values. This paper presents the calibration of these factors, based on statistics for dead load, live load due to use and occupancy, snow load, and wind load, which are summarized in a companion paper. A target reliability index of approximately 3 for a design life of 50 years was adopted for consistency with the 1995 NBCC. The load combinations and load factors for strength and stability checks recommended for the 2005 NBCC were based on preliminary values from reliability analysis that were subsequently revised slightly to address major inconsistencies with past practice. The recommended load combinations and factors generally give factored load effects similar to those in the 1995 NBCC, but are up to 10% more severe for the combination of dead load plus snow load and are generally less severe for the combination of dead load, snow load, and live load due to use and occupancy. Load factors less than one are recommended for checking serviceability limit states involving specified snow and wind loads. Importance factors for various classifications of structure are also presented. Revisions to the commentaries of the NBCC are recommended that will provide guidance on dead load allowances for architectural and mechanical superimposed dead loads and cast-in-place cover slabs and toppings.Key words: buildings, code calibration, companion action, dead loads, live loads, load combinations, load factors, reliability, safety, snow loads, wind loads.


Author(s):  
Siddhesh Bisane

Abstract: Structural analysis is the science of determining the effects of different loads on structures. Structural stability and stiffness are a main concern in any high-rise structures. Shear walls are structural members that are mainly responsible for resisting lateral loads predominant on structures. They are mainly responsible to increase the stiffness, reduce story drift and displacement. In order to have a comprehensive understanding about the contribution of shear wall, following research is carried out. This research involves comparing two G+16 structures; one without a shear wall and one with it. The structure has 4 bays of 3m each along X direction and Z direction. In this, we will see how shear wall resists lateral sway and reduces story drift and increases stiffness. As the height increases, the shear wall absorbs more lateral load than the frame. The software to be used for analysis is STAADPro. Keywords: STAADPro, Stiffness, storey displacement, storey drift.


2002 ◽  
Vol 124 (3) ◽  
pp. 132-138 ◽  
Author(s):  
Bernt J. Leira ◽  
Tore Holma˚s ◽  
Kjell Herfjord

Analysis and design of deep-water riser arrays requires that both collision frequency and resulting stresses in the pipes are addressed. Within a probabilistic context, the joint modeling of the current magnitude and surface floater motions must be taken into account. The present paper gives an outline of the general analysis setup, and response statistics obtained as a result of time domain simulations are described. Utilization of the analysis is also discussed in relation to estimation of extreme response and fatigue lifetime. As an example of application, a specific Spar buoy riser configuration at a water depth of 900m is considered.


Buildings ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 162 ◽  
Author(s):  
Cristiano Loss ◽  
Stefano Pacchioli ◽  
Andrea Polastri ◽  
Daniele Casagrande ◽  
Luca Pozza ◽  
...  

Changes to building codes that enable use of materials such as cross-laminated timber (CLT) in mid- and high-rise construction are facilitating sustainable urban development in various parts of the world. Keys to this are the transition to multi-performance-based design approaches along with fewer limitations on heights or the number of storeys in superstructures constructed from combustible materials. Architects and engineers have increased freedom to apply new design and construction concepts and methods, as well as to combine timber with other structural materials. They also have started to develop wall arrangements that optimise interior space layouts and take advantage of the unique characteristics of CLT. This paper discusses the seismic response of multi-story buildings braced with a CLT core and perimeter shear walls anchored to foundations and floor platforms using modern high-capacity angle brackets and hold-downs, or X-Rad connectors. Linear dynamic finite element (FE) models of seismic responses of superstructures of various heights are presented, based on experimentally determined characteristics of wall anchor connections. Particular attention is given to fundamental vibration periods, base shear and uplift forces on walls, as well as inter-story drift. Discussion of FE model results focuses on structural engineering implications and advantages of using CLT to create shear walls, with emphasis on how choice of wall anchoring connections impacts the possible number of storeys and configurations of superstructures. Employing CLT shear walls with X-Rad or other types of high capacity anchoring connections makes possible the creation of building superstructures having eight and potentially more storeys even in high seismicity regions. However, it is important to emphasise that proper selection of suitable arrangements of shear walls for CLT buildings depends on accurate representation of the semi-rigid behaviors of anchoring connections. The linear dynamic analyses presented here demonstrates the need during engineering seismic design practices to avoid use of FE or other design models which do not explicitly incorporate connection flexibilities while estimating parameters like fundamental periods, base shear and uplift forces, as well as inter-story drift.


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