Geotechnical Considerations Introduction Field Exploration Techniques Borings and Drilling Methods • Soil-Sampling Methods • Rock Coring • In Situ Testing • Downhole Geophysical Logging • Test Pits and Trenches • Geophysical Survey Techniques • Groundwater Measurement 30 Defining Site Investigation Requirements Choice of Exploration Methods and Consideration of Local Practice • Exploration Depths • Numbers of Explorations • The Risk of Inadequate Site Characterization. | Chai J. McNeilan . Geotechnical Considerations. Bridge Engineering Handbook. Ed. Wai-Fah Chen and Lian Duan Boca Raton CRC Press 2000 30 Geotechnical Considerations Thomas W. McNeilan Fugro West Inc. James Chai California Department of Transportation Introduction Field Exploration Techniques Borings and Drilling Methods Soil-Sampling Methods Rock Coring In Situ Testing Downhole Geophysical Logging Test Pits and Trenches Geophysical Survey Techniques Groundwater Measurement Defining Site Investigation Requirements Choice of Exploration Methods and Consideration of Local Practice Exploration Depths Numbers of Explorations The Risk of Inadequate Site Characterization Development of Laboratory Testing Program Purpose of Testing Program Types and Uses of Tests Data Presentation and Site Characterization Site Characterization Report Factual Data Presentation Description of Subsurface Conditions and Stratigraphy Definition of Soil Properties Geotechnical Recommendations Application of Computerized Databases Introduction A complete geotechnical study of a site will 1 determine the subsurface stratigraphy and stratigraphic relationships and their variability 2 define the physical properties of the earth materials and 3 evaluate the data generated and formulate solutions to the project-specific and site-specific geotechnical issues. Geotechnical issues that can affect a project can be broadly grouped as follows Foundation Issues Including the determination of the strength stability and deformations of the subsurface materials under the loads imposed by the structure foundations in and beneath slopes and cuts or surrounding the subsurface elements of the structure. Earth Pressure Issues Including the loads and pressures imposed by the earth materials on foundations and against supporting structures or loads and pressures created by seismic or other external forces. 2000 by CRC Press LLC Construction and Constructibility Considerations .
