Seismic resiliency of new buildings has improved over the years due to improved seismic codes and design practices. However, vulnerability of seismically deficient older buildings, designed and built on the basis of older codes of practices, poses a significant threat to life safety and survivability of buildings. It is economically not feasible to retrofit the entire inventory of seismically deficient buildings. Therefore, there is need for a comprehensive plan to identify critical buildings and prioritize their retrofit and upgrading requirements. A risk‐based evaluation technique is proposed in this paper to quantify seismic assessment and develop a ranking scheme for reinforced concrete buildings. The seismic hazard, building vulnerability and consequence of failure are handled in hierarchical structures. Some of the input risk parameters, expressed as qualitative and quantitative quantifiers, are transformed into commensurable values. A knowledge‐based fuzzy rule base modelling is developed and verified through the use of 1994 Northridge Earthquake data on seismic damage of reinforced concrete buildings.
A reliable building vulnerability assessment is required for developing a risk‐based assessment and retrofit prioritization. Tesfamariam and Saatcioglu (2008) proposed a simple building vulnerability module where the building performance modifiers are in congruence with FEMA 154 . This paper is an extension of the building vulnerability assessment that include detailed performance modifier in congruence with FEMA 310 that is represented in a heuristic based hierarchical structure. Some of the input parameters are obtained through a walk down survey and are subject to vagueness uncertainty that is modelled through fuzzy set theory. A knowledge base fuzzy rule base modeling is developed and illustrated for reinforced concrete buildings damaged in the 1 May 2003 Bingöl, Turkey earthquake.
1 December 2014 in Journal of Performance of Constructed Facilities
Cross-laminated timber (CLT) products are gaining popularity in the North American market and are being used in midrise wood buildings, in particular, in shearwall applications. Shearwalls provide resistance to lateral loads such as wind and earthquake loads, and therefore it is important to gain a better understanding of the behavior of CLT shearwall systems during earthquake events. This paper is focused on the seismic performance of connections between CLT shearwall panels and the foundation. CLT panels are very stiff and energy dissipation is accomplished by the connections. A literature review on previous research work related to damage prediction and assessment for wood frame structures was performed. Furthermore, a test program was conducted to investigate the performance of CLT connections subjected to simulated earthquake loads. Two different brackets in combination with five types of fasteners were tested under monotonic and cyclic loading protocols. In total, 98 connection tests were conducted and the monotonic load-displacement curves and hysteretic loops were obtained. In this paper, an energy-based cumulative damage assessment model was calibrated with the CLT connection test data. Finally, a correlation between the damage index and physical damage is provided.
23 April 2014 in Journal of Earthquake Engineering
In this article, seismic vulnerability assessment is carried-out on a novel hybrid structure (steel moment resisting frame (SMRF) and cross laminated timber (CLT) infill panels). For the seismicity of Vancouver, Canada, a three-bay, 3-, 6-, and 9-story height SMRFs are designed for two ductility levels (ductile and limited ductility). To study the seismic vulnerability CLT infilled building, parametric analysis was performed by varying infill configuration (bare frame, one-bay infilled, two-bay infilled, and fully infilled). The structure is modeled in OpenSees and nonlinear dynamic analysis is performed. Peak inter-story drift demand and corresponding FEMA performance limits (capacity) values are used to compute the corresponding fragility curves. From the analyses, it can be seen that as more bays are infilled, the fundamental period and seismic vulnerability is reduced significantly. The results highlight that, within the performance-based earthquake engineering, different objectives can be met with varying the CLT configuration.
25 November 2023 in Reliability Engineering & System Safety