Analysis of Multistory Buildings With Stub Column In Different Seismic Zones In India – A Review

Construction of building requires proper planning and management. Buildings are subjected to various loads such as dead load, live load, wind load and seismic load. Seismic load has extreme adverse effect on building so it is necessary to perform seismic analysis. This paper explains about the response of building when it is subjected to seismic load, this response can be shown by story drift and base shear. Behavior of buildings with stub columns is analyzed and the results are compared with buildings without stub columns. Seismic analysis has been performed on (G+7) buildings located in seismic zones 2,3,4&5 using ETABS software. Analysis has been performed according to IS 1893:PartI (2002).The storey drift and design base shear are evaluated and compared. Pushover analysis was performed and the results were compared.

Review on “Comparative study of flat slab structure and conventional slab structure”

For the drawing engineers, selection of the type of the structure for a specific purpose is very important, as multistory buildings are becoming necessary, as construction for living style with increases in requirement of space. The lack of space is forcing us to raise the height of structures possible to unbend maximum number of people. This paper aims to effort on seismic response of unappetizing slab RCC structure for the various height and plan, moreover aims to compare policies of unappetizing slab towers with old conventional 2-way slab system for different zones like zone II, zone III, zone IV, zone V in respect with maximum BM, story shear, base shear, and story drift, by the help of analysis soft wares like ETABS.

Stable Lead Isotopic Ratios as Indicator of Urban Geochemical Processes

The study is aimed to apply the Pb isotope fingerprinting technique for tracing pollution of urban surface deposited sediment (USDS). USDS reflect changes in the geochemical conditions occurring in the environment. USDS samples were collected in residential areas with multistory buildings in Russian cities: Magnitogorsk, Nizhny Tagil, Tyumen, Ufa, and Chelyabinsk. Elements concentrations and stable Pb isotopic ratios were measured in the samples. The reconstruction of the initial geochemical baseline (IGB) relationship between potentially harmful element (PHE) Pb and conservative lithogenic element (CE) Fe was carried out for USDS sample populations in the cities. The IGB reconstruction divided USDS sample populations into the groups of ‘polluted’ and ‘unpolluted’ with Pb samples. Analysis of elements concentrations and Pb isotope ratios in the groups of USDS samples showed different trends in altering geochemical conditions for metals in the surveyed cities. The USDS is characterized by a decrease in the isotope ratios of 206Pb/204Pb and 208Pb/204Pb as a result of soil pollution by vehicles during the period of using leaded gasoline.

Out-of-Plane Flexure of Masonry Panels with External Thermal Insulation

The combined seismic and energy retrofit of existing aged buildings represents a topic of importance for the building stock. The current study investigates the out-of-plane performance of a specific type of thermo-insulation scheme with panels attached on the external facades of multistory buildings. The investigation was carried out through flexure tests of prototype masonry specimens. From the comparison of their flexural performance, with or without thermo-insulating attachments, the influence of thermal insulation on the out-of-plane behavior of clay brick masonry is demonstrated. It was found that when the thermo-insulating attachment is in tension from such out-of-plane flexure of the masonry facade it performs in a satisfactory way and gives an increased flexural capacity for the assembly. The thermal insulating panels, although partially debonded from the masonry substrate at a limit-state, do not collapse, even when the masonry panel develops large flexural cracks. This is due to the presence of the used plastic anchors. When the thermo-insulating panel is subjected to compression during such an out-of-plane flexure the resulting increase in the out-of-plane load bearing capacity is relatively small. Based on these observations it can be concluded that such thermo-insulating panels may also lead to a less vulnerable seismic performance than that of the same masonry panel without this type of thermo-insulating attachment. This was also confirmed when the in-plane behavior was considered from a separate investigation already published. The employed numerical modeling was successful in simulating the most important aspects of the out-of-plane response of the tested masonry wallets with or without thermo-insulating attachments. The good agreement with observed performance as well as the general nature of this numerical simulation confirms its validity for further use.

Predicting approximate seismic responses in multistory buildings from real-time earthquake source information, for earthquake early warning applications

Regional earthquake early warning (EEW) alerts and related risk-mitigation actions are often triggered when the expected value of a ground-motion intensity measure (IM), computed from real-time magnitude and source location estimates, exceeds a predefined critical IM threshold. However, the shaking experienced in mid- to high-rise buildings may be significantly different from that on the ground, which could lead to sub-optimal decision-making (i.e., increased occurrences of false and missed EEW alarms) with the aforementioned strategy. This study facilitates an important advancement in EEW decision-support, by developing empirical models that directly relate earthquake source parameters to resulting approximate responses in multistory buildings. The proposed models can leverage real-time earthquake information provided by a regional EEW system, to provide rapid predictions of structure-specific engineering demand parameters that can be used to more accurately determine whether or not an alert is triggered. We use a simplified continuum building model consisting of a flexural/shear beam combination and vary its parameters to capture a wide range of deformation modes in different building types. We analyse the approximate responses for the building model variations, using Italian accelerometric data and corresponding source parameter information from 54 earthquakes. The resulting empirical prediction equations are incorporated in a real-time Bayesian framework that can be used for building-specific EEW applications, such as (1) early warning of floor-shaking sensed by occupants; and (2) elevator control. Finally, we demonstrate the improvement in EEW alert accuracy that can be achieved using the proposed models.