Abstract

In the recent past there is increased interest in detection and extraction of buildings using object based approaches on given high to very high resolution imagery. In this paper, we introduce a new unsupervised approach to detect buildings from the very high resolution (VHR) multispectral satellite image. Independent component analysis (ICA) followed by Otsu thresholding is used for extraction of multicoloured buildings of diversified size and shape. QuickBird imageof Legaspi city has been used to analyze the technique and detection results obtained from three subset images indicate average detection percentage of 84.35 % along with 38.19 % branch factor value. Object-level evaluation results give 72.48% for fully detected buildings count

Abstract

Many countries have their own building codes-of-practice for earthquake resistant design of structures. These codes provide conventional approach to earthquake resistant design of buildings with sufficient strength, stiffness and inelastic deformation capacity to withstand a given level of earthquake generated force. Under a given earthquake, the level of damage to a structure is greatly influenced by nonlinear capacity of its members. Even when the nonlinear capacities are same, the overall damage is critically influenced by the structure’s shape, size and geometry.This paper presents the research on the influence of aspect ratio on overall damage of the structure subjected to earthquake loading. In this paper a numerical study is carried out for 3 benchmark structures, with an aspect ratio (height to widthratio) of 3, 1 and 0.3, to define failure pattern in nonlinear state. Nonlinear static pushover analysis is performed to understand the capacity of structure and expended energy based damage assessment is used to estimate the damage. The results are compared in terms of damage, displacement and plastic hinge pattern

Abstract

n present scenario buildings with floating columns are of typical feature in the modern multistorey construction practices in urban India. Such types of constructions are highly undesirable in building built in seismically active areas. This paper studies the analysis of a G+5 storey normal building and a G+5 storey floating column building for external lateral forces. The analysis is done by the use of SAP 2000. This paper also studies the variation of the both structures by applying the intensities of the past earthquakes i.e., applying the ground motions to the both structures, from that displacement time history values are compared. This study is to find whether the structure is safe or unsafe with floating column when built in seismically active areas and also to find floating column building is economical or uneconomical.

Abstract

The 7.8 M earthquake occurred in south east Iran on 16 April 2013 at 10: 44: 20 UTC. This earthquake was the most massive earthquake in last 50 years, with tremors felt across Pakistan, Oman and UAE. According to BHRC (Iranian Building and Housing Research Center) report, this event was recorded by 33 digital accelerographs in Iran Strong Ground Motion Network. The peak acceleration was recorded in Sabz Gazz seismic station. This study presents simulation of near-field ground motions of the 2013 Iran earthquake. For this purpose, five seismic stations are selected to simulate ground motions using semi-empirical approach. Hamzehloo and Mahood (2012) attenuation relationship for south east Iran is used to obtain acceleration waveformenvelope function. Acomparison is done on characteristics of observed and simulated ground motions. The simulated results are satisfactory at many of the seismic stations. It is concluded that higher frequencies (2-10 Hz) of simulated ground motions match with observed ground motions.

Abstract

The term natural hazard implies a natural phenomenon which may cause direct damage, injury, or harm to those in its path (Selby, 1993). In India, natural disasters majorly relates to its climatic conditions. For example disasters like droughts, flash floods, cyclones, avalanches, landslides by rains etc are the cause of massive loss of life and property. On the other side earthquakes also causes a major threat to the nation, where seismically triggered landslides are one among the many types of hazards. This hazard has greatly increased because of the expansion of commercial and residential development in to earthquake-prone slope side locations. Most moderate and large earthquakes produce ground motions that can trip Landslides, which poses a double threat to those living in these risk areas. This study mainly focuses on the threat assessment of buildings located on slopes prevalent to earthquake hazard and to develop a Slope Hazard Zonation Map for an area of interest. Keywords: Natural hazards, Earthquake risk, Landslides, Threat map.

Abstract

Capture the mechanical behaviour of RC frame systems subjected to Lateral loading and estimating the damage state of structure are still changing tasks in civil engineering

Abstract

Crustal deformation in vertical direction is higher at convergent plate marg other plate margins. Even though there are three types of convergent plate mar continental-continental plate, oceanic-continental plate and oceani considers only the interaction between oceanic plate and continental plate lithospheric mantle to understand the topography effect on continental plate. T element models are developed and analyzed using commercially availabl Contact properties are defined between plates so that effect of friction is calc an elasto-visco rheology and analysis is carried for 30000 years. The mo nclination angles leading to subduction or collision effects the length of vertic Also, increasing the coefficient of friction decreases the vertical deforma amount of subsidence. This study concludes inclination angle and coefficient role for the development of higher topographic regions at convergent plate mar asupuleti and Pradeep Kumar Ramancharla. This is an open access article distributed un use, distribution, and reproduction in any medium, provided the original work is properl evolved to be one of the most aining the behaviour of rigid the earth’s surface leading to Convergent, Divergent and dynamic evolution of the, 1965). One of the nteraction leading to different re found where tectonic plates te boundaries comprise both At subduction zones geological suggest that convergence is plate (oceanic plate) r oceanic plate). At collisional plates are both continental in the other carries a magmatic. In simple the continental ion) normally follows the convergent forces of lateral Turcotte and Schubert, bservations show that vertical surface near convergent …

Abstract

Improperly designed brick masonry walls cause undesirable effects under seismic loading in both brick masonry in-filled reinforced concrete (RC) frames and masonry load bearing wall structures. Doors and windows (openings) are unavoidable components in brick masonry in-filled RC structures and masonry load bearing wall structures because of its functional and ventilation requirements. The presence of openings in brick masonry walls reduces the lateral stiffness and strength of the wall in both RC and load bearing structures, which changes the actual behavior of structure. If these openings are located in the restricted zones like areas within middle two thirds of a wall wall, then the wall needs to be strengthened by providing necessary horizontal/vertical (bands) structural elements such as lintel or lintel bands around them. Lack of such structural elements may cause the structure to undergo severe damage during the earthquake event. In this paper, two case studies,(a) the presence of openings in infill wall with or without lintel and lintel band (b) the presence of openings in load bearing wall with or without lintel and lintel band is studied, to know the nonlinear response of brick masonry in-filled RC frame and load bearing wall under seismic loading. To understand the behaviour of the infilled frames and load bearing wall, a two dimensional (2D) infilled frame and load bearing wall is modeled and analyzed using a tool based on Applied Element Method (AEM). Nonlinear static pushover (SPO) is performed to estimate capacity of the models.

Abstract

Nuclear power plant is one of the largest source of producing electricity in India after thermal, hydroelectric and renewable sources of electricity. As of 2013, India has 21 nuclear reactors in operation in 6 nuclear power plants, having an installed capacity of 5780 MW and producing a total of 30, 293 GWh of electricity while six other reactors are under construction and are expected to generate an additional 6,100 MW. After 2011 Fukushima earthquake in Japan, safety of nuclear reactors has become a major concern. For assessing safety it is utmost important to have information on expected earthquake events. In case of lack of sufficient information, artificial ground motions may be generated by using geological features and faults information. This study presents simulation of near field generated ground motions of Rawatbhata nuclear power plant. For this purpose, three faults nearer to the power plant have been selected to the generate ground motions using semi-empirical approach. It is observed that as the source (M) of the earthquake increases, the amplitude of the ground motion, duration and energy content increases. Similarly, the spectral accelerations also increase due to all three active faults.

Abstract

The process of crustal deformation depends on the type of tectonic plate interactions viz. convergent, divergent and transform. For all the three cases, the topography effect is different. However, higher elevations and huge compressions are measured at convergent plate margins. Past observations reveal that these margins are very much prone to great earthquakes especially at the locations where oceanic plate is subducting underneath a continental plate. For the purpose of understanding horizontal and vertical displacement profiles on both the plates, a study considering the interaction between oceanic and continental plate which are resting on lithosphere mantle is carried out. Two dimensional finite element models were developed and analyzed using commercially available software ABAQUS. Contact properties are defined between plates so that effect of friction is calculated. All plates have an elastic rheology and slip is allowed at the interfaces. The models demonstrate that inclination angles leading to subduction or collision affects the length of vertical and horizontal displacements. Also, increasing the coefficient of friction decreases the vertical deformation but increases the amount of subsidence. This study concludes that the inclination angle and coefficient of friction plays a vital role for the development of varied crustal deformations at convergent plate margins.