Ssi and Sssi Effects in Seismic Analysis of Twin Buildings: Discrete Model Concept

Abstract

This paper presents a numerical study of soil-structure interaction (SSI) and structure-soil-structure interaction (SSSI) effects on response of twin buildings during earthquake excitations. The buildings are modeled as shear buildings and the soil is simulated by a discrete model representing a visco-elastic half-space subjected to earthquake acceleration. Equation of motion of twin buildings with different conditions, fixed based (FB), SSI and SSSI, are developed via an analytical procedure and solved numerically. Buildings responses are evaluated for aforementioned three conditions considering various soil types and compared together. One must say that soil causes change in distribution of responses throughout the buildings while ignoring soil interaction may lead to detrimental effects on buildings. Anyway, interaction between twin buildings with SSSI condition slightly mitigates soil unfavorable effects compare to one building with SSI condition. In addition, it is found that influence of soil is very significant for soft to stiff soils whereas negligible for hard soils.

Vibration control of piled-structures through structure-soil-structure-interaction

“…Mulliken and Karabalis [5] evidenced large differences in the response of three adjacent buildings founded on rigid, surface foundations with respect to the single case, by defining a simple discrete model for predicting the dynamic interaction. Effects of both soil-structure interaction and structure-soil-structure interaction were investigated by Naserkhaki and Pourmohammad [6] on response of twin buildings during earthquake excitations. A recent review of the structure-soilstructure interaction problem can be found in Menglin et al [7].…”

Effect of Height Ratio and Mass Ratio on Structure—Soil—Structure Interaction of Two Structures Using Centrifugal Experiment

“…Mass ratio (ψ = mass adjacent /mass reference ) and height ratio (χ = h adjacent /h reference ) between adjacent and reference buildings are influential factors controlling SSSI phenomena [16][17][18]30,32]. In this study, to explore the effects of mass between adjacent buildings on SSSI phenomena, the mass of S1, the most massive structure, was pre-designed to be approximately 1.5 times larger than the mass of S2 and 15.3 times larger than that of S3.…”

“…Previous investigations have reported that significant changes of the near-field motion, due to the dynamic response of structures [14]. Such changes also affect the response of structures located nearby, this is called the structure-soil-structure interaction (SSSI) phenomenon [4,[15][16][17][18][19]. Therefore, it is essential in engineering practices to explore SSSI effects to avoid unexpected damage in structure when another structure is placed nearby, as SSSI effects are not considered in modern seismic design codes [20][21][22].…”

“…Some numerical or experimental studies have also been performed to find key factors controlling SSSI effects in a configuration group of two structures, including the distance between two foundations and the characteristics of an adjacent structure, such as relative mass, height, and natural frequency. Chen et al [17]; Ogut [30]; and Naserkhaki and Pourmohammad [18] have numerically demonstrated that a massive structure can have detrimental SSSI effects on a lighter structure. On the other hand, Alexander et al [16], Aldaikh et al [31], and Aldaikh et al [32] have used a discrete model and demonstrated that SSSI effects between two and three single-degree-of-freedom (SDOF) structures could be controlled by height or fixed-base frequency ratios between structures.…”

Structure-Soil-Structure Interaction between Underground Structure and Surface Structure

“…Moreover, Alexander et al [15] applied this method to study SSSI effect. After that, Naserkhaki and Pourmohammad [16] probed into the work of Mulliken et al [14].…”