Pushover Analysis for Plan Irregular Building Structures

Nonlinear static procedures (NSPs), also known as "pushover methods", represent the most used tool in the professional practice for assessment of seismic performance of building structures. Most of the methods subscribed by major seismic codes for seismic analysis of new or existing buildings have been originally defined for simple regular structures

Linear Chromatic Adaptation Transform Based on Delaunay Triangulation

Computer vision algorithms that use color information require color constant images to operate correctly. Color constancy of the images is usually achieved in two steps: first the illuminant is detected and then image is transformed with the chromatic adaptation transform ( CAT). Existing CAT methods use a single transformation matrix for all the colors of the input image. The method proposed in this paper requires multiple corresponding color pairs between source and target illuminants given by patches of the Macbeth color checker. It uses Delaunay triangulation to divide the color gamut of the input image into small triangles. Each color of the input image is associated with the triangle containing the color point and transformed with a full linear model associated with the triangle. Full linear model is used because diagonal models are known to be inaccurate if channel color matching functions do not have narrow peaks. Objective evaluation showed that the proposed method outperforms existing CAT methods by more than 21%; that is, it performs statistically significantly better than other existing methods.Ministry of Science of Republic of Slovenia, Program Computer Visio

Analysis in seismic provisions for buildings: past, present and future

The analysis of structures is a fundamental part of seismic design and assessment. It began more than a 100 years ago, when static analysis with lateral loads of about 10% of the weight of the structure was adopted in seismic regulations. For a long time seismic loads of this size remained in the majority of seismic codes worldwide. In the course of time, more advanced analysis procedures were implemented, taking into account the dynamics and nonlinear response of structures. In the future methods with explicit probabilistic considerations may be adopted as an option. In this paper, the development of seismic provisions as related to analysis is summarized, the present state is discussed, and possible further developments are envisaged

Seismic performance of existing RC framed buildings using pushover analysis method

The aim of this study is to present a methodology on the determination of the seismic performance of existing reinforced concrete (RC) structures subjected to earthquake effects. This paper focuses on the assessment of existing RC structures with a nonlinear analysis (pushover analysis) method. The research is presented with the case study of an existing RC structure. The investigations on this RC structure is done with the field surveys, lab studies and numerical analyses. The first stage of the study includes the assessment of the compliance between the architectural and structural design projects of the related structure. Necessary checks have been made whether the projects of the structure are consistent with its existing state. Secondly, on-site mechanical tests were conducted on the structural members, and laboratory tests were performed on the samples collected from the structure. In the last stage, the seismic performance of the structure was determined based on the three-dimensional finite element model prepared for the existing state of the structure. The analysis results are discussed considering the target performance level parameter. The results have shown the importance of designating the appropriate target performance level in the evaluation of the seismic performance of RC structures