Experimental investigation of seismic damage identification using PCA-compressed frequency response functions and neural networks

https://accedacris.ulpgc.es/jspui/bitstream/10553/16238/3/Padron_Dynamic_Structure.pdf

Dynamic structure soil structure interaction between nearby piled buildings under seismic excitation by bem-fem model

Experimental investigation on reinforced concrete interior beam–column joints rehabilitated by ferrocement jackets

This paper presents the experimental results obtained from the testing of nine 1:3 scale square-shaped column specimens. Characteristics of the specimens are low-lateral confinement, low-to-moderate shear span, and high-axial load. Detailing of the transverse reinforcement includes both 90° and 135° hooks. Specimens with low-shear span failed under shear in a brittle manner. Flexural failures were observed in specimens with moderate shear span and having a lateral confinement ratio of 0.003. Lateral confinement has significant influence on the ultimate drift, of which an increase from 0.001 to 0.003 could increase the ultimate drift capacity by up to 100%. Seismic performance of columns with low-to-moderate shear span may not be accurately reflected by the ductility factor. Better representation is provided by the ultimate drift ratio, and can be estimated by an empirical equation. The use of 90° hooks in detailing the transverse reinforcement leads to a 40% reduction on the ultimate drift capacity. Guidelines are also given to estimate the corresponding reduction on the ductility factor.

Drift Capacity of Rectangular Reinforced Concrete Columns with Low Lateral Confinement and High-Axial Load

https://accedacris.ulpgc.es/jspui/bitstream/10553/16153/4/Dynamic_analysis_by_a_BEM_FEM_model.pdf

Dynamic analysis of piled foundations in stratified soils by a BEM-FEM model

A continuum model for the interaction analysis of a fully coupled soil–pile–structure system under seismic excitation is presented in this paper. Only horizontal shaking induced by harmonic SH waves is considered so that the soil–pile–structure system is under anti-plane deformation. The soil mass, pile and superstructure were all considered as elastic with hysteretic damping, while geometrically both pile and structures were simplified as a beam model. Buildings of various heights in Hong Kong designed to resist wind load were analysed using the present model. It was discovered that the acceleration of the piled-structures at ground level can, in general, be larger than that of a free-field shaking of the soil site, depending on the excitation frequency. For typical piled-structures in Hong Kong, the amplification factor of shaking at the ground level does not show simple trends with the number of storeys of the superstructure, the thickness and the stiffness of soil, and the stiffness of the superstructure if number of storeys is fixed. The effect of pile stiffness on the amplification factor of shaking is, however, insignificant. Thus, simply increasing the pile size or the superstructure stiffness does not necessarily improve the seismic resistance of the soil–pile–structure system; on the contrary, it may lead to excessive amplification of shaking for the whole system. Copyright © 2003 John Wiley & Sons, Ltd.

Soil–pile–structure interaction under SH wave excitation

Progress in earthquake resistant design of buildings in Hong Kong

Publisher Summary This chapter examines the seismic capacity of rectangular reinforced concrete columns having non-seismic detailing. Six column specimens in 1:3 scales are tested under cycles of lateral load. The column specimens were characterized by high axial load, low lateral confinement ratio, and low to moderate shear span ratio. An ultimate drift ratio is introduced to quantify the seismic capacity. Poor performances are observed on column specimens with low shear span when subjected to cyclic lateral loads. Four column specimens failed under shear, and flexural failures were observed in the other two column specimens with lateral confinement ratio at 0.003 and moderate shear span. An increase in the axial load ratio within the range 0.4–0.65 resulted in a reduction in the lateral load-carrying capacity by about 10% and a reduction in the ultimate drift capacity by about 30%. Lateral confinement has significant influence on the ultimate drift, of which an increase from 0.001 to 0.003 could raise the ultimate drift capacity by up to 100%. At low to moderate shear span, contributions of shear and bond slip to the deformation must be considered. However, deformation outside the plastic region could be neglected for a column with low shear span ratio.

Siu Shu Eddie Lam

Papers

Drift Capacity of Rectangular Reinforced Concrete Columns with Low Lateral Confinement and High-Axial Load

Soil–pile–structure interaction under SH wave excitation

Progress in earthquake resistant design of buildings in Hong Kong

Behavior of rectangular columns with low lateral confinement ratio

Ultimate drift ratio of rectangular reinforced concrete column in Hong Kong