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Dissipative steel structures for seismic up-grading of long-bay masonry buildings
Published in Federico M. Mazzolani, Stessa 2003, 2018
F.M. Mazzolani, A. Mandara, S. Froncillo
The use of passive energy control and dissipation techniques may represent an effective alternative to conventional strengthening operations in the seismic up-grading of existing buildings. This has been widely experienced in many applications carried out in the last years, including buildings belonging to the historical or monumental field (Mazzolani & Mandara 1994, Croci et al. 2000, Indirli 2000). According to this approach, the seismic performance can be enhanced either by fitting the construction with adequate energy dissipation capability and/or by reducing the amount of earthquake energy transferred to the structure. In such a way, not only an increase of the maximum earthquake magnitude tolerable by the structure is achieved, but also a limitation of conventional strengthening interventions, which turns to be very useful when buildings possess monumental features. For this reason, these innovative techniques are looked up with great interest in the restoration of historical buildings, where a demand for more effective seismic protection solutions is deeply felt today.
Performance-Based Design
Published in Bungale S. Taranath, Tall Building Design, 2016
The PBD procedure starts with the definition of acceptable risk. Prior to inception of design work for a new or retrofitted building, discussion should be initiated between the design team and the owner’s representatives to explain the level of seismic performance that will be achieved by conformance to the code and other possible performance options that may be available. In this discussion, seismic performance refers to the extent of damage and loss that is likely to occur in earthquakes of differing magnitudes. This discussion focuses on ensuring that all parties understand that earthquake or damage-free performance is not possible and compromises must be made between seismic performance and cost. Acceptable risk refers to the extent and types of damage and loss that the building owners can tolerate. Clearly, avoidance of casualties is of the highest priority, but what are the priorities for issues such as damage to the building’s structure, nonstructural components, and systems and contents?
Earthquake activity
Published in F.G. Bell, Geological Hazards, 1999
The seismic performance of a building is influenced by its mass and stiffness; its ability to absorb energy (i.e. its damping capacity); its stability; and its structural geometry and continuity. As such, the earthquake resistance of a building depends on an optimum combination of strength and flexibility, since it has to absorb and resist the impact of earthquake waves. Buildings that have been constructed of several types of material may be vulnerable to earthquake shocks.
Seismic vulnerability and risk assessment at the urban scale using support vector machine and GIScience technology: a case study of the Lixia District in Jinan City, China
Published in Geomatics, Natural Hazards and Risk, 2023
Yaohui Liu, Xinyu Zhang, Wenyi Liu, Yu Lin, Fei Su, Jian Cui, Benyong Wei, Hao Cheng, Lutz Gross
The factors that may affect the seismic performance of buildings, such as the building structure, characteristics, quality, age, and preservation state, are considered. The building data required in this study include the type of structure, roof type, number of floors, period of construction, and preservation state (Riedel et al. 2014). According to the urban planning data from Lixia District and Jinan city, the building period was divided into four subperiods: 2002-present, 1982-2002, 1960-1981, and before 1960. According to the RISK-UE seismic assessment method, the number of floors was divided into three categories: low-rise buildings with two floors or less, moderate-rise buildings with three to five floors (including five floors), and high-rise buildings with more than six floors (Lestuzzi et al. 2016). The roof types were divided into two categories: flat roofs and sloped roofs. The effects of site factors and topography on seismic vulnerability were not considered in this study.
Displacement-Based Seismic Design Approach for Prestressed Precast Concrete Shear Walls and its Application
Published in Journal of Earthquake Engineering, 2018
The aim of performance-based seismic design is to improve structural engineering by providing engineers with the capability of designing structures to achieve different seismic performance levels. The performance target can be determined by the importance of the structure, the level of seismic intensity, and the requirements of the owners. The DDBD approach is a branch of performance-based design. The aim of the DDBD approach is to ensure the seismic performance of a structure within an expected target drift under a predefined level of earthquake intensity. The basic premise of the DDBD procedure is to convert the structure into an equivalent single-degree-of-freedom (SDOF) substitute structure. In previous studies, several efforts have been made to adapt the displacement-based design methodology for different types of structures including precast walls with additional dampers [Pennuci et al., 2009], eccentrically braced steel frames [O’Reilly et al., 2015], and buckling-restrained braced frames [Feng et al., 2016]. In designing the PPCW systems, Rahman and Sritharan [2006] investigated the implications involved with the application of a displacement-based and a force-based procedure for the precast shear wall systems. It was concluded that when both approaches achieved performance objectives, the displacement-based procedure results in a lower design base shear, which means a more reasonable design.
Efficiency and Cost-Benefit Analysis of Seismic Strengthening Techniques for Old Residential Buildings in Lisbon
Published in Journal of Earthquake Engineering, 2018
Rui Marques, Paula Lamego, Paulo B Lourenço, Maria L Sousa
The seismic performance of a building is a measure of its earthquake resistance capacity against the seismic load to which it may be subjected, for given limit states. This performance is evaluated in terms of a global indicator of the building response, normally the displacement, but also considering the damage occurrence concerning the limitation of losses. The procedure for seismic performance assessment adopted here is based on the N2 method by Fajfar [2000], which is specified in Eurocode 8—Part 1 [CEN, 2004]. Further, the damage occurrence is considered by performing a fragility analysis after computing the fragility curves of the buildings, in order to estimate the losses. The seismic performance assessment requires the computation of the capacity curves of the buildings and their conversion to capacity spectra (see Sec. 4.2), to next apply the N2 method. The calculation of the fragility curves of the buildings is made according to the HAZUS method [FEMA & NIBS, 2003], as presented below. In this work, by considering that, for both the local and global strengthening techniques, the main objective is to provide to the building a box-behavior, and the building top displacement is assumed to be the representative engineering demand parameter (EDP) for seismic assessment. The use of other criteria and EDPs is possible and may be considered in future studies, to assess the seismic performance at an element or story level. As an example, Diz et al. [2015] considered both the out-of-plane and in-plane local displacements and stresses as EDPs.