Including Imperfections within the Displacement-based Koiter Methodology

The Koiter methodology is a reduced-order model that can predict the initial post-buckling characteristics of structures. Incorporating the Koiter approach within finite element simulations resulted in challenges. These included mesh sensitive initial post-buckling coefficients, computationally expensive high-order derivatives, and phenomena...

Mathematical modelling of the mechanical response of geosynthetic-reinforced and pile-supported embankments

Piled foundations are commonly employed to reduce settlements in artificial earth embankments founded on soft soil strata. To limit the number of piles and, consequently, construction costs, popular is the use of geosynthetic reinforcements laid at the embankment base. Nowadays, the complex interaction between geosynthetics, piles and soil is...

Raising the bar in seismic design: cost–benefit analysis of alternative design methodologies and earthquake-resistant technologies

The severe socio-economic impact of recent earthquakes has represented a tough reality check, further confirming the mismatch between society expectations and reality of seismic performance of modern buildings. Life-safety code-compliant design criteria are not enough when dealing with new structures. To raise the bar in terms of structural...

A New Strategy for Mitigating Pipeline Uplift in Liquefied Soils

Seismic-induced liquefaction is one of the main hazards for pipelines buried in saturated granular materials. When soil is partially or completely fluidized, a lifeline, although installed in superficial trenches in which the coarse backfill soil usually is compacted, may experience a sudden uplift and damages. To reduce pipeline uplift and...

Displacement-based formulation of Koiter's method: Application to multi-modal post-buckling finite element analysis of plates

Koiter's asymptotic method enables the calculation and deep understanding of the initial post-buckling behaviour of thin-walled structures. For the single-mode asymptotic analysis, Budiansky (1974) presented a clear and general formulation for Koiter's method, based on the expansion of the total potential energy function. The formulation from...

Displacement-based verification of unreinforced masonry walls acting out-of-plane within a structural system

The out-of-plane behavior of unreinforced masonry walls subjected to lateral loading is a complex structural problem. This thesis focuses on the stability of URM walls in a building system under seismic loads that are comparable to those found in the Groningen scenario. The investigation is carried out by addressing both the physical and the...