NEESpiles

NEESR-SG: Study of Pile Foundations Subjected to Liquefaction-Induced Lateral Spreading

Tests 3m and LG-0

The NEESPiles project will involve the laminar box filled with saturated sand at a relative density of 40-50%. The first test denoted by LG-1 involves a level ground deposit subjected to shaking. These initial experiments are to be subjected to gradually increasing acceleration shaking leading to gradual increase in pore pressure (and slow development of peak shear strains) rather than rapid rise on pore pressures, to allow the FEM/DEM modelers to assess the model predictive capabilities and make refinements as necessary.

Experiment Setup

The 1g shaking tests will be conducted in UB-NEES laboratory using 2.75m wide x 5.0m long x 6.2m high laminar box. The box is made up of 24 aluminum laminates which are I-sections having 0.3m deep and 0.25 m wide. Each laminate is supported by a number of heavy-duty ball bearings mounted on laminate webs. A gap of approximately 5mm is allowed between the laminates in order to have relative laminate movements only on bearings with little friction. The base of the box is a steel bridge supported on ball bearings over a machined steel plate placed on the strong floor of the UB-NEES laboratory, and a steel interface plates that are used to connect two dynamic actuatuors to the base of the laminar box.

Updates

NEESPile Nugget

November 16, 2006 as a part of the NEESPiles project sponsored by the NSF a level-ground liquefaction test will be conducted using the laminar box. In this test the laminar box is filled with saturated loose sand up to a height of approximately 17 feet, and subjected to a sinusoidal 1-D ground motion at the base with a peak horizontal acceleration of about 0.3g. The soil is instrumented with a dense array of piezometers,MEMS accelerometers (shapeaccel array), and potentiometers (for measurement of lateral displacements of the box, and vertical settlement of the ground surafce during and after shaking).

Liquefaction Test LG-0 on 11/16/06 was a success. Post-test activities are in progress. Future liquefaction tests involving sloping ground and piles will be announced in March 2007.

Sponsor

This project is supported by the George E. Brown, Jr. Network for Earthquake Engineering Simulation program of the National Science Foundation under award number CMS-0529995.









SEESL - Structural Engineering and Earthquake Simulation Laboratory
212 Ketter Hall, Buffalo, NY 14260, USA
phone. +1(716)645-3019       fax. +1(716)645-3733