Effects of Physical Properties Mechanical State on the      Deformation of Porous Sediments
{'Code': '06030204', 'Directorate': {'LongName': 'Directorate For Geosciences'}, 'Division': {'LongName': 'Division Of Earth Sciences'}}
{'SignBlockName': 'Michael A. Mayhew'}
The mechanical behavior of porous sediments is important for               the understanding of deformation in accretionary prisms, subsiding              and spreading basins, and other settings in which "soft"                        sediments are subjected to tectonic or gravitational stresses.                  Unfortunately the relationships among physical properties,                      mechanical state, and structural fabric for these sediments are                 very poorly known, which has impeded the development of                         quantitative geomechanical models.  A series of mechanical tests                have been made moderately porous (20-40%) silty clays (both                     natural and artificially consolidated) that will allow us to                    correlate the physical properties and mechanical state of these                 sediments with the structural fabrics produced during deformation.              We investigated strength surface for laboratory consolidated                    sediments, as depicted in a 3-dimensional space of effective mean               stress, differential stress, and void ratio, at mean stresses                   typical of geologic conditions in accretionary prisms.  For                     natural sediments from basinal sequences we measured in-situ                    strength and analyze the failure fabrics produced during bedding                parallel shortening.  For the study of naturally deformed                       sediments we have several samples from DSDP sites in the Nankai                 accretionary prism.  Structural fabric analyses included optical                microscopy for measurement of the overall and internal geometries               of the failure zones, microprobe studies for porosity variations,               and x-ray pole figure goniometry for fabric anisotropy and strain.
{'FirstName': 'Daniel', 'LastName': 'Karig', 'EmailAddress': None, 'StartDate': '05/01/1988', 'EndDate': None, 'RoleCode': 'Principal Investigator'}
{'Name': 'Cornell University', 'CityName': 'Ithaca', 'ZipCode': '148502820', 'PhoneNumber': '6072555014', 'StreetAddress': '373 Pine Tree Road', 'CountryName': 'United States', 'StateName': 'New York', 'StateCode': 'NY'}
{'Code': '1574', 'Text': 'GEOPHYSICS'}
{'url': 'https://www.nsf.gov/awardsearch/download?DownloadFileName=1987&All=true', 'xml': '8720754.xml'}