Experimental study of the seismic response of a structure set amongst closely adjacent structures

Abstract

The influence of soil on the dynamic response of soil-structure systems is usually studied on a stand-alone (SA) structure, even though closely adjacent structures form the vast majority of the population, especially in large cities. When structures are closely adjacent to each other, the wavefield in the soil, generated by the vibration of the footings, produces a complex interaction between them. Scant attention, especially by physical experiments, has been paid to this interaction. This work addresses the seismic response of a single degree-of-freedom structure (structure of focus) considering the influence of one and two closely adjacent neighbours. Experiments were performed using a large laminar box filled with sand sitting on a shake table. Results from utilising four recorded ground motions from the 2010-2011 Canterbury earthquake sequence are analysed. The effect of adjacent structures on the acceleration and displacement of the top mass of each structure, as well as the uplift of the footings, are discussed. Changes in the fundamental frequency due to the presence of neighbouring structures are identified. The use of the SA system, without consideration of closely adjacent structures, may result in a significant error in the estimation of the response of the structure of focus. In general, acceleration, lateral displacement and uplift reduced in comparison with that of the corresponding SA case. A footing settlement mechanism, resulting from uplift of the system that reflects the influence of adjacent structures, is also revealed.

Experimental evaluation of the role of slenderness in seismic behaviour of bridges with rockable footing

“…Their result showed that the flexibility of the support has different influences on the top displacements and accelerations of tanks depending on the slenderness. Barrios et al 23 demonstrated the significance of slenderness and supporting soil in the interaction between closely adjacent structures. Through shake table experiments, Qin and Chouw 24 revealed the important role of footing mass in controlling the amplitude of rocking.…”

Seismic Structure‐Soil‐Structure Interaction between inelastic structures

“…Experimental methods (centrifuge tests [27][28][29][30][31] and shaking table test [32][33][34][35][36][37] ) represent an important validation point for numerical models and provide preliminary estimates of the effects of complex interaction problems. The disadvantages of the experimental methods are that they are technically challenging to undertake and pose several difficulties in achieving appropriate scaling of the soil strains and inertial forces.…”

Effect of pier height and support flexibility on seismic response of bridges including poundings

“…However, the authors also pointed out that having soil support could lead to larger footing rotations and create permanent footing settlements that impair structural stability. Recently, Barrios et al (2021a) performed shake-table experiments on a rockable structure with the influence of surroundings. The result showed that the response of a stand-alone structure is not the same as the structure of focus with adjacent structures.…”