Shake Table Study on the Efficiency of Seismic Base Isolation Using Natural Stone Pebbles

Abstract

The results of a shake table study of the efficiency of a seismic base isolation using a layer of natural stone pebbles are presented. Models of stiff and medium-stiff buildings were tested. Case studies were conducted with the foundation of model on the rigid base and on four different layers of pebbles (thin and thick layer with small and large pebbles). Four different horizontal accelerograms were applied, and the characteristic displacements, accelerations, and strains were measured. Strains/stresses of the tested models remained in the elastic area. It was concluded that the effectiveness of the stone pebble layer under the foundation, i.e., the reduction in the seismic forces and stresses in the structure compared to the classical solution of foundation, significantly depends on the type of the applied excitation and depends relatively little on the layer thickness and pebble fraction. The results of the study showed that a layer of pebbles can significantly reduce the peak acceleration and strains/stresses of the model, with acceptable displacements. Further research is expected to confirm the effectiveness of this low-cost and low-tech seismic base isolation and to pave the way to its practical application.

Geotechnical Seismic Isolation System Based on Sliding Mechanism Using Stone Pebble Layer: Shake‐Table Experiments

“…Previous research [27] has suggested that a natural stone pebble layer below the foundation can significantly reduce strain/stresses of stiff and medium-stiff building models under earthquake load. Namely, depending on the type of applied excitation and some other parameters, compared to the rigid base case, a pebble layer reduced the strain/stress in the MSB model from 28% to 53% and in the MSSB model from 8% to 47%.…”

“…Banović et al [27] performed an experimental shaketable study to investigate the possibility of using a layer of natural stone pebbles below the foundation for seismic base isolation of buildings. Models of stiff and medium-stiff buildings were tested with the model on different layers of pebbles and on the rigid base with the possibility of foundation uplifting.…”

“…However, firm conclusions require further research. e base isolation concept in [27] can be categorised as a "Geotechnical Seismic Isolation (GSI) system," as defined initially by Tsang [28] and also adopted by Brunet et al [29] and Forcellini [30]. Namely, the dissipation of earthquake energy and the reduction of earthquake forces on the building in this concept are dominated by the sliding mechanism of the foundation on seismic isolation and between pebbles sublayers.…”

“…is paper presents the results of a further research segment related to the concept of seismic base isolation using a layer of natural stone pebbles below the foundation presented in [27]. Namely, the research results of six different parameters related to the effectiveness of the adopted aseismic layer are presented.…”

Application of Pebbles for Geotechnical Seismic Isolation (GSI): Experimental Parametric Study

“…The topic of this research is to investigate the possibility of using stone pebbles (ASL-1) and pebbles with geosynthetics to enhance the sliding performance (ASL-2) as suitable materials for the GSI system [58][59][60][61][62][63][64][65]. The price of such seismic isolation is low, and construction is quick and easy.…”