Reduction in Stiffness of Cohesionless Soil Due to          Earthquake Loading
{'Code': '07030000', 'Directorate': {'Abbreviation': 'ENG', 'LongName': 'Directorate For Engineering'}, 'Division': {'Abbreviation': 'CMMI', 'LongName': 'Div Of Civil, Mechanical, & Manufact Inn'}}
{'SignBlockName': 'Clifford J. Astill', 'PO_EMAI': None, 'PO_PHON': None}
Cohesionless soils exhibit a loss of stiffness and strength when                subjected to earthquake or explosive loading, followed by a gradual             recovery as confining pressures and/or cementitious bonds redevelop. If         the soil experiences further shock loading during this period of reduced        stiffness, the soil experiences large shearing strains, and may liquefy.        However, quantitative measures of this behavior are not available.                                                                                              This research program is a laboratory and field investigation to observe        the changes in soil stiffness as a function of the soil's properties,           stress history, and magnitude  of disturbance, in order to determine the        increased risks associated with secondary disturbances.                                                                                                         The laboratory phase of the program uses two types of resonant column           apparatus to monitor  soil stiffness: a Hardin-type device modified for         impulse loading, and a recently-developed resonant column-torsional             shear device. The former apparatus can generate high pressure, short-           duration impulse loads typical of explosions, while the latter device           will simulate earthquake-type ground motions. Stiffness losses following        detonation of conventional explosives will be monitored during the field        testing. Subsurface dynamic pore pressures and ground motions will be           measured and related to the changes in the soil stiffness as determined         by cross-hole shear tests.
{'FirstName': 'Roman', 'LastName': 'Hryciw', 'PI_MID_INIT': 'D', 'PI_SUFX_NAME': None, 'PI_FULL_NAME': 'Roman D Hryciw', 'EmailAddress': 'romanh@umich.edu', 'NSF_ID': '000223272', 'StartDate': '09/01/1987', 'EndDate': None, 'RoleCode': 'Principal Investigator'}
{'Name': 'Regents of the University of Michigan - Ann Arbor', 'CityName': 'ANN ARBOR', 'ZipCode': '481091079', 'PhoneNumber': '7347636438', 'StreetAddress': '1109 GEDDES AVE, SUITE 3300', 'StreetAddress2': None, 'CountryName': 'United States', 'StateName': 'Michigan', 'StateCode': 'MI', 'CONGRESSDISTRICT': '06', 'CONGRESS_DISTRICT_ORG': 'MI06', 'ORG_UEI_NUM': 'GNJ7BBP73WE9', 'ORG_LGL_BUS_NAME': 'REGENTS OF THE UNIVERSITY OF MICHIGAN', 'ORG_PRNT_UEI_NUM': None}
{'Name': None, 'CityName': None, 'StateCode': None, 'ZipCode': None, 'StreetAddress': None, 'CountryCode': None, 'CountryName': None, 'StateName': None, 'CountryFlag': None, 'CONGRESSDISTRICT': None, 'CONGRESS_DISTRICT_PERF': '""'}
{'Code': '1496', 'Text': 'GEOTECHNICAL II'}
{'url': 'https://www.nsf.gov/awardsearch/download?DownloadFileName=1987&All=true', 'xml': '8708747.xml'}