ENV 206 Full (Portuguese Version)

THE EXTENSION OF THE N2 METHOD TO ASYMMETRIC BUILDINGS

Pushover procedure for seismic analysis of buiIdings

Optimal seismic performance-based design of reinforced concrete buildings using nonlinear pushover analysis

A modal pushover analysis procedure to estimate seismic demands for unsymmetric-plan buildings

SUMMARY
Based on structural dynamics theory, the modal pushover analysis (MPA) procedure retains the conceptual simplicity of current procedures with invariant force distribution, now common in structural engineering practice. The MPA procedure for estimating seismic demands is extended to unsymmetric-plan buildings. In the MPA procedure, the seismic demand due to individual terms in the modal expansion of the effective earthquake forces is determined by non-linear static analysis using the inertia force distribution for each mode, which for unsymmetric buildings includes two lateral forces and torque at each floor level. These ‘modal’ demands due to the first few terms of the modal expansion are then combined by the CQC rule to obtain an estimate of the total seismic demand for inelastic systems. When applied to elastic systems, the MPA procedure is equivalent to standard response spectrum analysis (RSA). The MPA estimates of seismic demand for torsionally-stiff and torsionally-flexible unsymmetric systems are shown to be similarly accurate as they are for the symmetric building; however, the results deteriorate for a torsionally-similarly-stiff unsymmetric-plan system and the ground motion considered because (a) elastic modes are strongly coupled, and (b) roof displacement is underestimated by the CQC modal combination rule (which would also limit accuracy of RSA for linearly elastic systems).
KEY WORDS: modal pushover analysis; unsymmetric-plan building; seismic demands

Adapting earthquake actions in Eurocode 8 for performance-based seismic design

SUMMARY
Performance-based seismic design (PBSD) can be considered as the coupling of expected levels of ground motion with desired levels of structural performance, with the objective of achieving greater control over earthquake-induced losses. Eurocode 8 (EC8) already envisages two design levels of motion, for no collapse and damage limitation performance targets, anchored to recommended return periods of 475 and 95 years, respectively. For PBSD the earthquake actions need to be presented in ways that are appropriate to the estimation of inelastic displacements, since these provide an effective control on damage at different limit states. The adequacy of current earthquake actions in EC8 are reviewed from this perspective and areas requiring additional development are identifed. The implications of these representations of the seismic loads, in terms of mapping and zonation, are discussed. The current practice of deffining the loading levels on the basis of the pre-selected return periods is challenged, and ideas are discussed for calibrating the loading-performance levels for design on the basis of quantitative earthquake loss estimation. Copyright ? 2005 John Wiley & Sons, Ltd.
KEY WORDS: performance-based seismic design; earthquake actions; return periods; design levels; loss modelling; Eurocode 8

Practical Design of Steel Structures

Practical Design of Steel Structures presents practical design examples and calculations for a multi-bay, steel-framed industrial building under the actions of a variety of loads, including travelling crane loads, dead and imposed loads, and wind forces. For the first time, engineers and students alike can appreciate the complete design process through the analysis of the whole structure and the design of structural members. The calculations are clearly presented, employing a step-by-step approach stating the design philosophy, design considerations and clarifying the referred clauses of the code of practice.

However, before analysing the structure and the design of its structural elements, it is necessary to understand the theoretical background and how the structure behaves under the actions of various loads, based upon practical design and field experience. The author considers the structural arrangement with respect to selection and availability of construction material, the cost within the scheduled construction program and the overall budget. In addition he examines the buildability of the structure with regard to space restriction, method of construction and the geotechnical conditions of the site.

The essence of this book is the simplicity and clarity of approach in the complete analysis of the whole structure and the structural design of every member. Augmented by design sketches, this book will prove valuable to practising engineers in design offices and students on structures courses.

Manhattan Skyscrapers

Elastomer Bearing Design Spreadsheet

No install - Direct use

Spatial Water Management: Creating Local Support for Regional and National Planning Issues