|PDH Online Course Description||PDH Units/
Learning Units (Hours)
John Huang, Ph.D., PE and John Poullain, PE
This four hour online course discusses guidelines and criteria for laboratory testing of rock and the interpretation of rock properties. Basic concepts of rock behavior and the selection of appropriate tests for the design of structures and foundations in or on rock are considered. Frequently used rock tests include those used to establish index properties, determine strength, permeability and durability of rock. Index property tests range from moisture content, specific gravity to unit weight and strength tests include the unconfined and triaxial compressive, tensile and direct shear tests. Durability tests include the slake durability index for wetting and drying and tests of rock freezing / thawing. Also considered is quality assurance for laboratory testing which includes the storage, handling and selection of specimen samples. The AASHTO and ASTM designations for the most frequently used laboratory tests are provided.
The design of building foundations, cuts, fills and slopes requires an understanding of rock strength and characteristics and consideration of problem types of rock and how rock masses behave under imposed loads. Laboratory tests and in-situ field-testing provide the information required to evaluate the subgrade rock conditions and to determine measures to take for proposed construction and construction activities. These criteria and guidelines are important so the appropriate tests are selected especially since the laboratory tests can be expensive but not nearly as expensive in case of a project failure.
The existing subgrade may have poor strength or instability due to excess clay, expansive clays, silts, fine sands, discontinuities, limestone sinkholes, bentonitic shales or high watertables. Existing rock properties such as voids must be known to protect against potential settlement from the design bearing capacities. There are problem rocks such as tailings and shales, which have structures that will crumble when exposed to air or water and when saturated are greatly reduced in strength. Such rock masses may expand in volume due to stress and deformation and the hydraulic integrity is altered and permeability increased. Some other soils, which contain clays such as bentonite, can expand and increase in volume when exposed to 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.