In Situ Determination of Soil Modulus and Damping as a Function of Level of Strain (NEES-2006-0163)

<p><strong>Title</strong>: In Situ Determination of Soil Modulus and Damping as a Function of Level of Strain (NEES-2006-0163)</p> <p><strong>Year Of Curation: </strong>2011</p> <p><strong>Description: </strong>In this study, the new field technique is developed to evaluate the linear and nonlinear shear moduli of soils. This method involves: (1) applying static vertical loads near surface of a soil, (2) applying dynamic horizontal loads to generate elastic waves within the soil mass, and (3) measuring the response of the soil mass beneath the loaded area using the embedded instrumentation. Both static and dynamic loads are applied using the mobile vibroseis, called Thumper (small-capacity vibroseis) and T-Rex (large-capacity vibroseis), of nees@UTexas. As a source of wave propagation the circular concrete footing is utilized. Before constructing the concrete footing velocity transducers (geophones), are embedded beneath the proposed footing location to monitor the propagation of waves. On the concrete footing the static loads are applied in different amplitude levels and these static loads provide different confining states of stress in the instrumented soil mass. At a certain level of static load, a set of dynamic loads is applied from the small-strain to large-strain levels. Applying horizontal dynamic loads in the small-strain range generates shear wave propagation in the small-strain range and the measurements of this shear wave propagation allow us to obtain the linear modulus of soil. In the same manner the horizontal dynamic loads in the medium- to large-strain ranges generate shear wave propagation in the medium- to large-strain ranges and the measurements of those wave propagation allow us to obtain the nonlinear shear modulus. The set of dynamic loads (from small- to large-strain ranges) is applied at each of the different static load levels. Therefore, the variations of G values with strain amplitude are able to be determined with different confining states of stress in the field.</p> <p><strong>Award: </strong>http://www.nsf.gov/awardsearch/showAward?AWD_ID=0421275</p> <p><strong>PIs & CoPIs: </strong>Giovanna Biscontin</p> <p><strong>Dates: </strong>August 01, 2005 - September 30, 2009</p> <p><strong>Organizations: </strong>Texas A & M University, TX, United States, University of Texas at Austin, TX, United States</p> <p><strong>Facilities: </strong>Texas A & M University, TX, United States,  University of Texas at Austin, TX, United States</p> <p><strong>Sponsor: </strong>NSF - 0421275</p> <p><strong>Keywords: </strong>Soil Modulus, Damping,Strain, Vibroseis, Shear Modulus</p> <p><strong>Publications: </strong></p> <nb:citations></nb:citations>