Experimental Assessment of Seismic Pile-Soil Interaction

Abstract

Physical modeling has long been established as a powerful tool for studying seismic pile-soil-superstructure interaction. This chapter presents a series of 1-g shaking table tests aiming at clarifying fundamental aspects of kinematic and inertial interaction effects on pile-supported systems. Pile models in layered sand deposits were built in the laboratory and subjected to a wide set of earthquake motions. The piles were densely instrumented with accelerometers and strain

1-g Experimental investigation of bi-layer soil response and kinematic pile bending

“…In this paper, small scale model shaking table tests, carried out at the BLADE Laboratory in University of Bristol within the framework of the Seismic Engineering Research Infrastructures for European Synergies (SERIES) project [46,47], are presented and discussed. Tests were performed on both single and grouped piles embedded in a two-layer soil profile.…”

Soil–pile–structure interaction: experimental outcomes from shaking table tests

“…While data from instrumented piles under buildings of different vibrational characteristics subjected to actual earthquake motions would be ideal, such data are rare due to high cost and the unpredictable nature of earthquake occurrence. Therefore, well-controlled laboratory investigations on pile models alongside with analytical and numerical simulations are pivotal for understanding the seismic response of structures on both single piles and pile groups [22][23][24][25][26][27][28][29].The scope of the present work is to examine the complex soil-pile-structure interaction (SPSI) problem by discussing in a detailed manner a large set of experimental results from high-quality shaking table tests carried out on pile models. The experimental program was performed at the Bristol Laboratory for Advanced Dynamics Engineering (BLADE), within the Framework of the Seismic Engineering Research Infrastructures for European Synergies (SERIES), which was funded by the 7th Programme of the European Commission.Experimental tests were carried out on different pile group configurations, with and without pile caps and/or superstructures, subjected to both horizontal and vertical dynamic shaking.…”

“…While data from instrumented piles under buildings of different vibrational characteristics subjected to actual earthquake motions would be ideal, such data are rare due to high cost and the unpredictable nature of earthquake occurrence. Therefore, well-controlled laboratory investigations on pile models alongside with analytical and numerical simulations are pivotal for understanding the seismic response of structures on both single piles and pile groups [22][23][24][25][26][27][28][29].…”

Characterisation of shear wave velocity profiles of non-uniform bi-layer soil deposits: Analytical evaluation and experimental validation

“…[9]), but it is obtained from the lateral equilibrium of a soil column featuring the same layering and inhomogeneity characteristics. The proposed closed-form solution is validated through comparisons of numerical analyses performed with the analytically predicted shear wave velocity profiles, against experimental results from high-quality shaking table tests carried out within the framework of the SERIES project PILESI [14]. In this project, the free field response of a bi-layer Leighton Buzzard sand deposit subject to dynamic excitations has been thoroughly investigated on the shaking table at BLADE laboratory of University of Bristol (UK), and relevant numerical simulations were performed.…”

“…Nevertheless, this paper only focuses on the free field response of the bi-layer deposit, looking at the response of accelerometers located in a vertical array, at sufficient distance from both the piles and the boundaries of the equivalent shear beam container, to avoid interaction effects on soil response. The response of the whole system has been analysed in other studies[14,[16][17][18][19].The bi-layer deposit in the examined configuration consisted of a 0.44m thick layer of dense sand, overlaid by a0.36m thick layer of loose sand. To achieve a proper stiffness contrast between the top and bottom layers, two different types of dry sands (Sr= 0) were utilised: the bottom layer was a mix of Leighton Buzzard (LB) Sand Fractions B and E (85% and 15% respectively), pluviated through a 12mm diameter nozzle to achieve a high mass density (2 = 1780 kg/m 3 ); the top layer was made of LB Fraction E Sand, deposited through a 40mm diameter nozzle to achieve a lower mass density (1 = 1390 kg/m 3 ).…”