Seismic Evaluation Of Buildings Research Articles

Damage State of Non-Engineered Residential Buildings Owing to Earthquakes: A Case Study in Pacitan Regency, Indonesia

Abstract The Pacitan Regency of Indonesia is located in an area of high seismic activities. Regrettably, field surveys held in Pacitan Regency, Indonesia have revealed the prevalence of low-income housing structures that do not meet the engineering standards and are vulnerable to damage during earthquakes. The seismic evaluation of these buildings is urgently required. This study proposes realistic damage state limit values for the seismic damage evaluation of non-engineered buildings. For this purpose, an incremental dynamic analysis was conducted on a sample of non-engineered buildings in Pacitan to evaluate their probable seismic damage. As a result, curves showing the dynamic pushover responses of buildings to various input earthquakes were plotted. These curves were then summarized as three-linear curves, providing a single value for the average response of the structure. Based on this simplified curve, a more realistic damage-state limit for non-engineered structures are proposed. The damage levels of slight (DS1), moderate (DS2), extensive (DS3), and complete (DS4) were determined using the drift ratio at the linear elastic limit, midway point between the linear elastic and yield limits, yield state, and 80% rupture limit, respectively.

Using Digital Twin Technology to Overcome Challenges in Civil Engineering and Construction: A Review

The purpose of this review article is to address the existing knowledge gap by presenting an extensive overview of the diverse uses of digital technology (DT) in the fields of construction and civil engineering. Additionally, it seeks to demonstrate how DT can effectively mitigate the challenges faced by the sector. A comprehensive review is conducted by collating insights from recent research papers across the globe and providing a holistic, time-efficient, and tailored understanding of the Digital Twin Technology in Civil Engineering and Construction. The review spanned critical areas including infrastructure construction, structural health monitoring, energy efficiency in buildings, seismic evaluation of buildings, safety of heritage buildings, and the diverse applications of digital twins in construction design, monitoring and management. This study acts as a thorough guide for experts, providing them with a consolidated source of knowledge. With the construction industry's complicated difficulties, understanding how digital twins might provide solutions is crucial. Professionals can use this technology to assure not only efficiency but also sustainability, which is becoming increasingly important in today's environment.

Development and Verification of the Capacity Curve for Two Dimensional Reinforced Concrete Moment-Resisting Frames System under Earthquake Loading

Pushover analysis is an efficient method for the seismic evaluation of buildings under severe earthquakes. This paper aims to develop and verify the pushover analysis methodology for reinforced concrete frames. This technique depends on a nonlinear representation of the structure by using SAP2000 software. The properties of plastic hinges will be defined by generating the moment-curvature analysis for all the frame sections (beams and columns). The verification of the technique above was compared with the previous study for two-dimensional frames (4-and 7-story frames). The former study leaned on automatic identification of positive and negative moments, where the concrete sections and steel reinforcement quantities the source of these moments. The comparison of the results between the two methodologies was carried out in terms of capacity curves. The results of the conducted comparison highlighted essential points. It was included the potential differences between default and user-defined hinge properties in modeling. The effect of the plastic hinge length and the transverse of shear reinforcement on the capacity curves was also observed. Accordingly, it can be considered that the current methodology in this paper more logistic in the representation of two and three-dimensional structures.

Seismic Evaluation of Buildings using Adaptive Force-Based Multimode Pushover Analysis

The conventional pushover method has 2 major drawbacks, it cannot account for the higher mode effect and do not consider the change in lateral load pattern when the structure reaches its inelastic phase. To overcome those limitations, in this research will present the Adaptive Force-Based Multimode Pushover Analysis (AFMP) method, in this method the higher mode effect, and the change in lateral load pattern have already been considered. This research will compare the result of evaluation using triangular and uniform load pattern with the AFMP load pattern using 1, 2, and 3 modal pairs towards its effects on non linier seismic behaviour of a building with the first mode being not dominant. The analysis resulted that using the AFMP method yields to a higher seismic response on the upper floors, caused by the higher being considered in the analysis. The triangular load pattern, resulted in smaller seismic response on all stories than the AFMP method, while the uniform load pattern tends to overestimate the response on the lower floors. Based on the performance criteria of FEMA 356, the conventional pushover resulted in Life safety performance level, while the AFMP also resulted in Life safety performance level.

Spectrum-based pushover analysis for estimating seismic demand of tall buildings

A quick and accurate estimate of the seismic demand of tall buildings is one of the important issues in the seismic evaluation of buildings. Nonlinear response time history analysis method (NLRHA) is considered as the most accurate and rigorous method, but the computation requirement of NLRHA for tall buildings can be complex and very time-consuming. Whereas the conventional pushover procedure is not capable of reasonably estimating seismic demand of mid and high rise-buildings, due to the oversimplification of conventional pushover approaches and the complexity of seismic performance of buildings. In this paper, a quick, yet effective, method of analysis, named as a spectrum-based pushover analysis (SPA) method, is proposed to estimate the seismic demand of tall buildings. In the SPA procedure, the very complex and complicated dynamic coupling effect of modes of the nonlinear seismic performance of a building is simplified, and the consecutive pushover technique is adopted to consider the simplified coupling effect. Comparison of the results obtained from NLRHA, the modal pushover analysis method, the consecutive modal pushover analysis method and the proposed SPA method is made. It is seen that the SPA method predicted the seismic demand of buildings well, including the inter-storey drift ratio and hinge plastic rotation, which are very close to those of NLRHA. Owing to its accuracy, effectiveness, and spectrum-based calculation procedure, the proposed SPA procedure is considered to be a very promising tool for predicting the seismic demand of tall buildings.

Seismic Evaluation of Buildings with Plan Irregularity

With the application of modern technologies in Civil Engineering, construction of high rise buildings with irregular plan configuration is increasing very quickly. Multi-story buildings are prone to lateral loads from wind or earthquake, which necessitates the need of seismic studies. Buildings can be designed to reduce these lateral loads by many methods; which is why the action of structural diaphragms have to be studied. Several studies have shown the effect of plan configuration on base shear, displacement and story drift, torsional buckling. The lateral stiffness of the building frame affects the maximum displacement of the structure due to earthquake. Study is done on various plan configuration buildings and the action of structural diaphragm on its performance during earthquake is studied.

A Static Nonlinear Procedure for the Evaluation of the Elastic Buckling of Anchored Steel Tanks Due to Earthquakes

Ground-supported steel tanks experienced extensive damage in past earthquakes. The failure of tanks in earthquakes may cause severe environmental damage and economic losses. This study deals with the evaluation of the elastic buckling of above-ground steel tanks anchored to the foundation due to seismic shaking. The proposed nonlinear static procedure is based on the capacity spectrum method (CSM) utilized for the seismic evaluation of buildings. Different from the standard CSM, the results are not the base shear and the maximum displacement of a characteristic point of the structure but the minimum value of the horizontal peak ground acceleration (PGA) that produces buckling in the tank shell. Three detailed finite element models of tank-liquid systems with height to diameter ratios H/D of 0.40, 0.63, and 0.95 are used to verify the methodology. The 1997 UBC design spectrum and response spectra of records of the 1986 El Salvador and 1966 Parkfield earthquakes are used as seismic demand. The estimates of the PGA for the occurrence of first elastic buckling obtained with the proposed nonlinear static procedure were quite accurate compared with those calculated with more elaborate dynamic buckling studies. For all the cases considered, the proposed methodology yielded slightly smaller values of the critical PGA for the first elastic buckling compared to the dynamic buckling results.

Response To: B. Maison's Discussion of “Evaluation of Modal and FEMA Pushover Analyses: SAC Buildings”

The authors agree with the discusser that even improved pushover analysis procedures can be inaccurate for buildings deforming far into the inelastic range—in the region of negative post-yield stiffness with significant degradation of lateral capacity. However, estimates of seismic demands obtained by MPA were much better than from FEMA force distribution over a wide range of responses—from essentially elastic response of Boston buildings to strongly inelastic response of Los Angeles buildings. For a wide range of buildings and ground motions, MPA estimates of seismic demands were accurate enough relative to the results of nonlinear RHA to be useful in the seismic evaluation of buildings. The potential and limitations of every approximate analysis procedure, including the NSP used in current practice and MPA, should be documented so that the procedure is not used outside its range of applicability. This was one of the objectives of our paper. Because MPA is based on structural dynamics theory, it offers three theoretical advantages. First, when applied to elastic systems it is equivalent to standard response spectrum analysis (RSA) (Chopra and Goel 2002, 2004) available in commercial software used by the profession. Second, although modal pushover analysis theory is strictly not valid for inelastic systems, the fact that elastic modes are coupled only weakly in the response of inelastic systems to modal inertia forces (Chopra and Goel 2002, 2004) permitted development of MPA, an approximate procedure. Third, the theory and concepts underlying MPA are extendable to unsymmetric-plan buildings (Chopra and Goel 2004). Contrary to the discusser’s interpretation of MPA as ‘‘an intricate ten-step procedure,’’ MPA retains the conceptual simplicity of current NSP with invariant force distribution, now common in structural engineering practice. Because higher-mode pushover analyses are similar to the first-mode analysis, MPA is conceptually no more difficult than procedures now standard in structural engineering practice. Because pushover analyses for the first two or three modal force distributions are typically sufficient in MPA, it requires computational effort that is comparable to the FEMA-356 procedure,

Nonlinear procedures for seismic evaluation of buildings

Nonlinear procedures for seismic evaluation of buildings