Descargue el texto completo en el repositorio institucional del Massachusetts Institute of Technology: http://hdl.handle.net/1721.1/111038

Descargue el texto completo en el repositorio institucional del Massachusetts Institute of Technology: http://hdl.handle.net/1721.1/111040

Underground structures serve as means of carrying out essential activities in a modern society; therefore, their proper seismic performance is important in the mitigation of the risk of disasters. This work addresses the seismic effects on underground structures in highly seismic areas such as the coast of Perú. The software FLAC was used to perform dynamic analyses of underground structures with rectangular section, using free-field type boundary conditions, accounting for the nonlinear inelastic behavior of the soil, under seven earthquakes matched to the same target spectrum. The analyses were carried out for different earthquake intensities, varying the soil characteristics (homogeneous or stratified) and the geometry of the structure. The results show that when the structure is placed in a homogeneous soil the forces and displacements have only small variations. However, when it is...

The estimation of the maximum design responses according to the current Peruvian technical standard NTE E.030 is carried out considering seismic action as unidirectional. The design spectral acceleration parameters are based on Ground Motion Models which use the geometric mean of the EW and NS earthquake components to define the horizontal component of acceleration, which is always less than the maximum component; hence they are on the unsafe side. Furthermore, even with the correct seismic intensity, the simultaneous action of both components may result in larger demands than those computed by considering only one component at a time. Buildings that would be most affected would be those with torsional irregularity. In this article the most used definitions of horizontal seismic component have been revised, comparing seismic records of events from subduction sources. Then, using both rec...

The social, economic, and environmental consequences of the failure of an arch dam make it essential to evaluate its dynamic response to mitigate the risk of a disaster. Since the slenderness and flexibility of these dams tend to increase the fluid-structure interaction during an earthquake, this work compares the dynamic response of a hypothetical arch dam in the Marañón river, in northern Perú, for both full and empty-reservoir conditions. Three formulations were used to estimate the hydrodynamic pressures: Westergaard’s added mass, Eulerian and Lagrangian. The comparisons were performed for earthquakes of distinct seismogenic sources, previously matched to a uniform hazard spectrum with a return period of 10000 years. The finite element method was used to derive the seismic demands of the dam-reservoir-foundation system in COMSOL Multiphysics software, carrying out time-history a...

This paper aims to study the efficiency of energy dissipators, both fluid viscous and hysteretic, to improve the seismic responses of buildings. To quantify the ability of energy dissipators to reduce seismic responses, a series of time history analyzes were carried out on simplified models of buildings. Said simplified models consist of masses and springs with linear and elastic behavior whose properties are obtained from a shear beam model, joined by link elements with non-linear behavior to simulate energy dissipators. The main study parameters that were considered are the fundamental period of the structure without seismic control devices and the objective reduction factor. Likewise, a procedure is proposed for the dimensioning of the hysteretic dampers that will be incorporated into a building. On the other hand, the main building of the Lima airport was used as a case study, for wh...