An investigation to seismic induced soil pressures on relatively rigid structures with deep embedment

Abstract

<p>Design of earthquake-resistant structures has been an important area in both research and engineering practice for decades. Realistic determination of seismic loading on structures is one of the governing design criteria for design of new buildings or evaluation of existing structures. For the nuclear industry, the performance of structures is extremely important owing to public safety concerns.</p> <p>This report explores the methodologies used to calculate seismic-induced soil pressure applied onto partially embedded structures. A critical review was performed on different methods developed in the past, which includes simplified analytical approaches based on either yielding wall theory or rigid wall theory and detailed dynamic analysis with the consideration of soil-structure interaction effects. Assumptions, range for appropriate application, and corresponding shortcomings of these methods are identified. Several critical issues that have significant impact on the soil-structural response but are not sufficiently taken into account in most existing models, are identified. These include embedment effects, interface boundary conditions and material nonlinearity. Following the review, a detailed seismic analysis using the finite element method is carried out to explore the effects of embedment effects, interface boundary conditions and material nonlinearity on seismic earth pressure. A simplified CANDU 6 reactor building excited by an artificial strong ground motion is used in this analysis. The seismic earth pressures obtained from this detailed seismic analyses under various conditions are then compared with the simplified approaches to evaluate their accuracy.</p>