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At present, seismic load evaluation for design of Indian buildings are carried out using Indian seismic code. In which, building Time period, Response Reduction factor and Importance factor alters design base shear majorly. Currently IS code defines Importance factor differently as “1” for general buildings and “1.5” for public buildings. This factor makes public buildings as heavier sections as it increases design base shear. However there are no evidence that, how this importance factor affects/alters/improves the seismic behavior of buildings. In this present study, four storey RC frames are designed with different importance factors. Pushover analyses are carried out to find its effects on over strength factor and response reduction factor.

Construction failure is always associated with non-fulfillment of the quality and technical specifications of the material that should be considered when the construction process has been done. STKIP ADZKIA Padang building is one of 4-story reinforced concrete (RC) building that has structural damage during construction phase. The beams of the building undergo large deflection and the cracks appear in the wall when the building was constructed up to 2nd floor. In this paper, building assessment was carried out to evaluate the performance of the existing building. The structure was analysed based on New Indonesian Seismic Code, SNI 03-1726-2012. The result shows that the building is not capable to resist the working loads. Furthermore, retrofitting of the building structure using V-inverted steel bracing was proposed. The analysis result shows that retrofitting of ​​the structure by installing the steel bracing on the RC frames in both X and Y directions increase the capacity of the building structure.

The damages observed during the earthquakes occurred in the last decades have clearly shown as the influence of infill panels on the seismic behaviour of Reinforced Concrete (RC) buildings should be taken into account; the global stiffness and the strength of the RC frames are significantly modified by the infills. In the present study the influence of infills in terms of shear forces has been analyzed by means of linear static analysis; a parametric study has been carried out to evaluate the behavior of infilled frames varying both modelling approach and the mechanical properties of the masonry infills. In terms of modelling approach the single and multi-strut models have been adopted; the Young modulus of masonry infills have been varied in the common range proposed in literature. The results show that multi-strut approach is able to predict both global and local behavior. In addition, the importance of the mechanical properties of masonry infills in the evaluation of the elastic period and shear force in the columns is underlined.

Previous studies indicated that the external prestressing tendons can effectively improve the deformability and bearing capacity of RC frames. However, how to utilize the external prestressing tendons to prevent the increase of deformation of the structure with catenary action in the process of collapse needs further study. Using an analytical method for the stress variations of external prestressing tendons based on structural deformation, the deflection and stress of beam-column sub-structureunder the failure of RC column during elastic and plastic stages are studied, the calculation of ultimate bearing capacity considering catenary action are also presented which provide a basis for collapse-resistant design of beam-column sub-structures.

In recent decades Performance Based Seismic Design (PBSD) is widely used for evaluation of the structural performance because of its capability and simplicity to estimate inelastic response of structure. On the other hand, some times in construction based on architectural decision, size of beams are being decreased. The aim of this attempt is to investigate the effect of beam size on structural behavior based on PBSD method using simple procedure. Capacity Spectrum Method (CSM) was implemented using set of RC frames (2, 4, 6, 8 and 10 story with three bays) and ETABS2000 to determine the weakness of the frames system due to their reduced beam size. The performance of the frames was measured at Life Safety damage control level.

Incorporating the probability of seismic hazard, expected annual earthquake loss with different collapse margin ratio (CMR) has been studied in this paper. Nonlinear simulation models of reinforced concrete (RC) frames were analyzed using incremental dynamic analysis (IDA) under continuous earthquake intensity. The analytic results from four examples of RC frames show that the expected annual loss has negative correlation with theCMRof the concerned structures, and seismic loss basically decreases with increasingCMRat given ground motion intensity. The proposed idea herein could be regarded as a promising improvement on the quantification of earthquake loss estimation by utilizingCMRof structures.

Masonry infills are commonly used in reinforced concrete (RC) frame structures. In this paper a separate finite element modelling method is proposed and used to study the lateral behaviour of single-storey one-bay masonry infilled frames with openings under monotonic horizontal loading. The interface friction model and the surface-based cohesive model are combined to simulate masonry interface and the interface between masonry wall and RC frame. Damage plastic model of material property is adapted to capture the brittle behaviour of concrete and bricks. Appropriate experimental data available from the literature are utilized to verify the model. The comparison between the numerical analysis and test results indicates that the proposed FE modelling method can predict the masonry infill wall’s crack patterns and the lateral strength and stiffness of the structure with window or door opening successfully.

Slope structure means a structure built on a slope in the mountainous region. The aim of this study is to study the influence of masonry infill on the seismic characteristics of RC frames on slope. First, the main results of the calibration analyses using the infill model introduced in the Part (I) of the paper are presented. Second, the performance of different reinforced concrete two bay-frames, bare and infilled, subjected to eight seismic motions were investigated. The results show that if the infill is built correctly in all storeys, it gives a significant contribution to the energy dissipation capacity by reducing the dissipation energy demands in frame elements and decreasing significantly the maximum displacements. Therefore the contribution of masonry is of great importance.

Buildings on the slope are widely used and have been increasing in mountainous city. The object of this study is to study the influence of masonry infill on the seismic characteristics of RC frames on slope. The concept of slope building is introduced, and the proposed infill model is presented. It is a single equivalent strut model with the compression and tension behavior. The proposed infill model uses the energy-based cyclic degradation law to simulate the deterioration of the infill during the seismic action. In the Part (II) of the paper, the infill model is calibrated, and the performance of different reinforced concrete two bay-frames, bare and infilled, subjected to eight seismic motions was investigated.

To optimize the design of RC frames with special-shaped columns, some special care should be given to the design of this type of structure. Designers should attach great importance to concept design by considering the structure as a whole to assimilate seismic energy. Ductility has to be guaranteed both for the structure and for the members. In high-rise buildings, frame-shear wall structure is preferred. Safety of L-shaped Corner columns is to be improved or otherwise cantilever beams can be designed to prevent progressive collapse.

Comparison of the vulnerabilities between former and current RC frame structures after the 2008 Wenchuan earthquake are performed in the paper. Two representative types of RC frame building in Wenchuan county town are studied by nonlinear finite element method (FEM). Probabilistic seismic demand models (PSDM) for RC frame structures is built to assess the safety levels of two representative RC frames in Wenchuan county town. The fragility curves for immediate occupancy (IO), significant damage (SD), and collapse prevention (CP) damage levels of the RC frame building are analyzed. The result indicates the safety levels of current RC frame building in Wenchuan district are well improved compared to the former RC frame building after the 2008 Wenchuan earthquake.

The in-plane seismic performance has been studied by many researchers all over the world, whereas few studies have been done on the out-of-plane behavior of the infilled RC frames. In this paper, a separate finite element model for simulating the out-of-plane failure mode and capacity of masonry-infilled RC frames is developed using 3-D elements with damage-plasticity material model and the surface-based contact cohesive interaction model simulating the interface between blocks. Comparison between the results of analysis and experiment indicates that the present model can successfully simulate the out-of-plane behavior of the structure.

A hysteretic model of conventional steel braces consisting of 18 parameters is proposed. This model is able to simulate the hysteretic behavior of conventional steel braces accurately. The collapse-prevention strengthening effect with steel braces for a typical reinforced concrete (RC) frame that was close to the epicenter and collapsed during the Great Wenchuan Earthquake is discussed via push-over analysis and collapse fragility analysis based on incremental dynamic analysis. The result could be referred to for the seismic collapse prevention design of RC frames.

To study the bearing capacity, ductile, energy dissipation capacity and failure mechanisms of RC frames which Strengthened with CFRP sheet and steel plate, three concrete frame specimens were subjected to the horizontal low cyclic loading. One was loaded up to the failure load, the others were strengthened with CFRP sheet and steel plate after loading to damage, and then were loaded up to the failure load. In terms of cracking load, yield load and ultimate load, the experimental results show that the improved degree of frame strengthened with steel plate is more than with CFRP sheet, on the other hand, regarding ductile and energy dissipation capacity, the improvement of frame strengthened with CFRP sheet is better than with steel plate.

Failure mechanism and fire resistance comparison of concrete-filled steel tube (CFST) frames, reinforced concrete (RC) frames and steel reinforced concrete (SRC) fames are proposed in this paper when their bearing capacity and rigidity at room temperature are similar. The result shows that the failure mode and failure mechanism of the 3 frame structures are much different, and the SRC frames have the maximum fire resistance.

In this paper, a new retrofit method, which is called “Hybrid Wall Technique”, is proposed for retrofitting soft-story RC frames. In the proposed technique, steel plates encase the boundary RC columns, and connect to additional steel plates at the bay of the frame with the help of high-strength bolts. After installation of steel plates and high-strength bolts, which are also used as formworks, the additional concrete is cast. Structural performance of the proposed metho­­­d is verified by experimental investigations conducted on one-bay one-story RC frames. One non-retrofitted frame and three frames retrofitted by thick or thin hybrid walls were evaluated experimentally.