Abstract

The main objective of the project is Vulnerability Assessment of Port buildings in different port regions along west coast of India. It includes development of earthquake scenario and fragility curves, which describes in detail the effects and consequences of a hypothetical earthquake at that region. In this paper the plan, elevation and design details of the port building near the Pipavav port is mentioned. For performance evaluation, a 3-dimensional model of the structure was generated. Analysis and design is performed on the structure. Pushover analysis is done for each earthquake data, and the graph is plotted for displacement vs load and displacement vs stiffness. Hence stiffness degradation for each earthquake data for its maximum displacement is determined and fragility curve is developed for the port building. A 3-dimensional model of the structure was modeled in STAAD.Pro and seismic base shear is calculated for the structure using the IScode 1893 (Part1:2002) and the linear time history analysis is carried out on the structure.

Abstract

Analysis and design of high-rise buildings for lateral load such as wind load and earthquake are the major issues which are playing significant role in recent decades .This paper describes a recent application of the computational fluid dynamics technique for wind analysis. Conventional wind analysis suggests wind tunnel experiment for arriving at the wind forces for a given structural form. As a case study a regural 38-story high-rise building (Jamieson place, Calgary Canada) made of concrete with shear wall ,built in downtown Calgary 2010 is selected. It is assumed that the building is located in highly seismic area. The design objective was to develop most cost-effective structural system while meeting building functionality goals and adhering to code requirement. The main structural design issues considered in this building are reviewed: Static analysis, Dynamic Analysis, Wind Analysis and Stability Analysis. Initial static and dynamic analysis is conducted in SAP and later wind analysis is conducted in Ansys as opposed to wind tunnel experiments. The building model is modeled in Ansys workbench and then the mesh file is imported to Ansys CFX for CFD simulation and analysis. After CFD analysis the wind forces on the building model are extracted in Ansys CFX-Post and imported to the structural model in SAP 2000 for the structural analysis.

Abstract

Presently India is home for about 1.2 billion people. This suggests that about 300 million houses are necessary to house them. According to National Housing Policy 2007 (NUHHP, 2007), the housing shortage is estimated to be about 25 million. And according to 2001 Census (Census 2001), Indian urban population constitutes 27.8%. However, it is increasing at an alarming rate of 4% per year. Further, population in India is distributed unevenly with minimum of 50 persons per km2 in some districts and upto 14000 persons per km2 in some other districts. Rural districts have upto 100 houses per km2 , towns 1000-1500 houses per km2 , cities 1500-2500 houses per km2 and urban centres and metros have as high as 7000 houses per km2. In addition, there is a great shift of population from rural to urban areas thus increasing the densities of population in urban areas. The number and proportion of cities with a population of one million or more has grown significantly in recent decades. From 12 in 1981 with 26.8% share of the total population, the number of million-plus cities has increased to 35 in 2001 with 37% share of the total urban population. On the other hand the dominant materials of choice for building were

Abstract

Bhuj earthquake of 26 January 2001 caused 14,000 casualties. Main reason for such huge casualties is low earthquake awareness and poor construction practices. Based on the technology advancement and knowledge gained after earthquake occurrences, the seismic code is usually revised. Last revision of IS 1893 (Criteria for earthquake resistant design of structures) was done in 2002 after a long gap of about 18 years. Some new clauses were included and some old provisions were updated. Assuming that concerned authorities will take enough steps for code compliance and the structures that are being constructed are earthquake resistant. In this light, what will happen to the safety of precode revision structures? These structures carry major percentage of vulnerable structure stock. Even if we have a very good disaster response system, it is impossible to reduce earthquake damage without considering the safety of precode revision structures. In this regard, a comprehensive study of seismic risk assessment of Gujarat is necessary. As a pilot study, government of Gujarat selected Gandhidham and Adipur cities in Kachchh district. Rapid Visual Screening (RVS) was conducted on 16000 buildings in Gandhidham and Adipur cities. Though, there are varied construction practices, about 26% of buildings were predominantly RCC type and 74% of masonry structure were found. RVS score of these structures reveal that in general buildings are of low quality and further evaluation and strengthening of buildings is recommended. The procedure adopted in this study is threetier method, i.e., Tier 1. Rapid Visual Screening, Tier 2. Preliminary assessment and Tier 3. Detailed assessment

Abstract

Disaster Demand for electricity in urban areas is increasing world over, because electricity is the prime lifeline support. Due to increase in fossil fuel prices coupled with concerns related to global warming, demand for nuclear energy is increasing. Around 30 countries are now using nuclear energy for production of electricity. However, its share in electricity production is varying from country to country. In some countries it is only 3% and in some countries it is around 50%. In light of March 2011 nuclear energy are reviewing the safety of their reactors against natural disasters. In this regard, authors proposed to study the current and projected nuclear energy demand for electricity supply in urban areas of India on one hand and scenario of seismic hazard and risk on the other hand.

Abstract

Building construction in India has been on rise since last two decades. More recently construction of tall buildings ranging from 30 to 50 stories have been proposed in many cities. For these buildings, wind analysis is as important as earthquake analysis, since in taller buildings, wind loads are dominant than earthquake loads at greater heights. In India, wind analysis is done according to IS 875 (Part III)-1987 (here after IS 875). But this code doesn’t provide sufficient information analysis of different structural forms. Quite often, engineers generally rely wind tunnel experiments to understand the behaviour. However, for arriving at the best orientation several tests have to be conducted which is tedious job. In the paper a necessity to adopt a different approach such as wind tunnel experiments and CFD simulation is proposed. Case study on wind analysis of Y-shaped tall building is illustrated using Ansys CFX and SAP 2000.

Abstract

Pipeline generally extends over long distances traversing through wide variety of different soils, geological conditions and regions with different seismicity. Majority of the past works in the area of pipeline subjected to fault motion is restricted in several ways. There were many analytical models developed in the past for pipeline fault crossing, however, they are of limited usage, for example analytical model developed for pipeline fault crossing can be useful for strike slip fault crossing only. Likewise incorporating the large geometric changes in analytical study is a tricky task; however pipeline subjected to the fault motion itself is a phenomenon of large geometric changes. Especially when pipeline subjected to compression, where in addition to material deformation it also undergoes general as well as local buckling with bending, contradictorily past work mostly assumed that pipeline is under tension. With day by day increasing capacity of computation and advancement in numerical modeling, one can find more facts for pipeline subjected fault motions including cases of pipe under compression as well. In this paper, past work is reviewed for pipeline subjected to large fault motion. A three dimensional FE based numerical model is suggested to carry out pipeline performance of buried pipeline subjected to fault motion. A proposed model includes material nonlinearity, as well as effect of the large geometric changes. For this purpose, three dimensional FE program is developed in MATLAB. Displacement controlled Arc-length technique is implemented to solve the nonlinear behavior. To reduce the computation time of analysis here parallelization tool kit of MATLAB is utilized.

Abstract

Heritage structures bears a valuable testimony of ancient cultural heritage of any country. Among these structures statues, iconic emblems plays significant role. In the proposed to study the vulnerability of monolithic statues to earthquake ground motions. Initially we used the equations developed by Housner for studying the dynamics of rigid blocks. Parametric study was conducted to study the inuence of size of the block and input parameters such as amplitude and frequency on the behaviour of the block. The study was extended to generate safe surface for the block of given dimensions. This surface gives the information that with any combination of parameters such as amplitude of vibration, frequency of vibration and duration of vibration, if the point lies outside the surface then block overturns otherwise it is safe. To verify the above formulation we selected four statues, viz, Gomateswara statue, Christ the Redeemer, Statue of Liberty, Guinyin Statue for case study. Initially all the statues were idealized like rigid blocks and later safe surfaces were developed for each statue. Since each statue is having different dimensions, surfaces were are also of different nature. Later, eighteen earthquake records were selected and strong ground motion parameters were estimated. Finally every statue was tested for the safety during the earthquake events. It was found that as the height of the statue is increasing its vulnerability is increasing. However, for all the given ground motions, none of the statue overturned.

Abstract

Many countries have become victims of terrorism on a large scale. Bombs have exploded in and around buildings in many countries causing civilian causalities and structural damage. A bomb explosion with in or around a building can have catastrophic effects, damaging and destroying internal or external portions of the building. Bomb damage to buildings depends on the type and layout of the structure, material used, range of the located explosive device and the charge weight. The impact from the blast causes debris, fire and smoke and hence can result in injury and death of occupants. Escape of the occupants and protection of the valuable documents, equipments, property is possible only when there is minimum damage to structures. This may be achieved by designing the building structures for blast loading. This attempt gives basic idea to all the consultants in estimating the blast loads over the building structures.

Abstract

The amplification of ground motion is being observed during major earthquake events all over the world and is highly dependent on the local geological, topography and geotechnical conditions. In view of this there is a great need to study the local site effects in a seismically active region. In this paper, the numerical modeling of infinite media is carried out by using transmitting boundary condition. Wave interaction with different kinds of boundaries like fixed and viscous boundary is discussed. The heterogeneities in the soil media are taken into account by considering the soft clay and the rock inside the half-space. Peak ground acceleration at the surface is plotted and local amplification of soils is studied by giving Elcentro ground motion as input at the bed rock for both the cases. In the half-space where clay is present, PGA is amplified by a factor of 2.5 with respect to input. More energy is concentrated in the half-space where clay is present. In the half-space where rock is present the area adjacent to the rock is getting amplified as energy is concentrated around the rock.