Incremental dynamic analyses are conducted for a suite of low-and mid-rise reinforced-concrete special moment-resisting frame buildings. Buildings non-conforming and conforming to the strong-column weak-beam (SCWB) design criterion are considered. These buildings are designed for the two most severe seismic zones in India (i.e., zone IV and zone V) following the provisions of Indian Standards. It is observed that buildings non-conforming to the SCWB design criterion lead to an undesirable column failure collapse mechanism. Although yielding of columns cannot be avoided, even for buildings conforming to a SCWB ratio of 1.4, the observed collapse mechanism changes to a beam failure mechanism. This change in collapse mechanism leads to a significant increase in the building's global ductility capacity, and thereby in collapse capacity. The fragility analysis study of the considered buildings suggests that considering the SCWB design criterion leads to a significant reduction in collapse probability, particularly in the case of mid-rise buildings.

Structural optimization seeks the selection of design variables to achieve within the limit (constraints) placed on the structural behaviour, geometry or other factors; its goal of optimality defined by the objective function for specified loading conditions. The three basic features design variables, objective function and constraints contrive to form the design problem. There are several mathematical techniques to solve such problems. The polynomial optimization technique is a recently evolved procedure which is concerned with finding the minimum of a polynomial objective function subjected to constraints. A structural design problem has been formulated in this manner which enables minimum cost design to be derived rapidly and simply. A paper deals with the application of Polynomial optimization technique to R.C.C. beam-member design problem. In the present study this technique is used to determine the minimum cost of reinforced concrete members by considering several design variables such as breadth, depth, area of reinforcing steel etc. Since it is difficult for the designer in the office to become familiar with the mathematical computation required, further attempt is made to represent the resulting optimum design expressions in the form of “Nomograms” which will facilitate the work in the design office.

The present scenario in India, particularly in metro cities has restricted the horizontal growth, which led to the vertical growth for building construction. Today, fast track construction is a rapidly growing economy, brings rising costs and therefore time saving in construction can compensate significant proportions of the overall construction cost.This paper presents a study on, time and cost wise feasibility of steel framed composite floor building. A case study considered for this work is 10 storied multilevel cars parking building. A major feature of this building is post-tensioned composite steel beams having span of 16 m. Considering same plan, floor area, floor to floor height and loading conditions, this existing building is designed and constructed by other two ways viz. precast concrete frame with precast concrete floor and steel frame with precast concrete floor. While designing the above structure with precast concrete frame with precast concrete floor, one additional column is introduced in between 16m span lengths to the overall plan to suit the design criterion.The Microsoft Project-2003 used for time scheduling and the optimum time required at different stages of all these three buildings are calculated. The total cost of each structure is calculated as material and construction costs of each structural element only. The results shows that steel frame with composite deck floor saves 55.3% construction time than precast frame with precast concrete floor and 14.3% compared to steel frame with precast concrete floor. However, this required extra 23.10% of direct cost and 12.99% of net cost for precast frame with precast concrete floor while 0.52% and -2.34% for steel frame with precast concrete floor.

No abstract

The concept of prestressing steel structures has only recently been widely considered, despite a long and successful history of prestressing concrete members. Several analytical studies of prestressed steel plate girder were reported in the literature, but much of that work was not studied with reference to different parameters like tendon profile, eccentricity, partial span to full span ratio, prestressing force, load carrying capacity etc. associated with prestressing. This paper examines analytically a comparative study of various tendon configurations and prestressing parameters on over all analysis and design of prestressed steel plate girder. The output from the computer Program for analysis and design of steel plate girder prestressed with different tendon configurations are compared among each other. As a Case-study, a prototype model of Prestressed Steel Testing Frame with straight tendon has been designed, constructed and tested in the laboratory for its safe load carrying capacity and maximum deflection.