|PDH Online Course Description||PDH Units/
Learning Units (Hours)
John Huang, Ph.D., PE and John Poullain, PE
This three-hour online course discusses the guidelines and criteria employed in groundwater investigations. Basic concepts and methods used to determine subsurface conditions pertaining to groundwater levels, pore pressures and the permeability of subsurface materials are considered. Installation methods for observation wells and devices commonly used for sensing and measuring water levels in boreholes and observation wells are discussed. Permeability is measured in the field by a variety of tests, which include seepage, pressure or packer, pumping and aquifer, slug and the piezocone dissipation tests. Quality assurance for testing, obtaining measurements and logging subsurface data are considered. The AASHTO and ASTM designations for the commonly used tests are provided.
A ground water evaluation is part of the geotechnical investigations for most projects. The design for building foundations, excavation, fills and slopes require knowledge of the present groundwater conditions and potentials for groundwater seepage as well as other soil parameters including strength; soil characteristics, problem soils, and soil behavior under imposed loads. Determination of groundwater elevations and flow are required for construction and maintenance of earth dams, building excavations, foundations, air fields, roadways and detection of contaminant migration from hazardous waste fills and land fills. Groundwater investigations involve gathering data on groundwater levels and pressures and the permeability of the subsurface materials. These criteria and guidelines should be considered so the appropriate tests can be correctly performed. This is especially important since groundwater and permeability tests can be expensive but not nearly as expensive in case of project delays or failures. The limitations of the tests must be considered and planned for with an alternative or supplemental test.
The existing watertables, soil permeability and other soil properties must be known to achieve the design bearing capacities required to protect from settlement. There are problem soils such as loess, hydraulic fills and tailings, which have collapsing or low-density structures, and when saturated have large decreases in volume and loss of strength. Other problem soils, which contain clays such as bentonite, expand and increase in volume when exposed to water. There are also dispersive clays so named because the soil particles are not structurally sound and can easily disperse or detach and erode in still water.
This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of the course materials.
NY PE & PLS: You must choose courses that are technical in nature or related to matters of laws and ethics contributing to the health and welfare of the public. NY Board does not accept courses related to office management, risk management, leadership, marketing, accounting, financial planning, real estate, and basic CAD. Specific course topics that are on the borderline and are not acceptable by the NY Board have been noted under the course description on our website.