Geotechnical Engineering

Geotechnical engineering focuses on the behavior of earth materials.  It is important for all civil engineering projects, but also has applications for other engineering disciplines concerned with construction on the surface or within the ground.  Geotechnical engineering uses principles of soil and rock mechanics to investigate subsurface conditions and materials, determine the physical and chemical properties of these materials, and assess risks posed by the conditions observed.  Ultimately every structure rests upon the earth and the natural complexities of the site geology can have serious impacts on the cost, usability, and safety of structures.

Geotechnical investigations are most commonly performed for the design and construction of above ground structures such as buildings, bridges, and retaining walls; however, they are also frequently performed for large earthwork projects such as tunnels, dikes, reservoirs, etc.  While not commonly considered, geotechnical investigations have benefits to even small civil utility projects by providing the contractor with information regarding subsurface soil and ground water conditions.  This information can often help to reduce the potential for change orders and unforeseen conditions during construction which result in increased cost and project delays.

TD&H Engineering works closely with the Owner and their design team to develop a scope of work for the field investigation and laboratory testing which considers the individual project needs, client budget, project schedule, and other factors.  The number and type of borings or excavations and analysis methods can vary from project to project and is balance between the amount of geologic information obtained and the project constraints.

Our engineers are also experienced in evaluating the need for specialized investigation methods or monitoring equipment which can be required on some more remote or difficult projects.  Our internal abilities include the following:

• Cone Penetration Testing (CPT)
• Monitoring Well Installation and Testing
• Slope Inclinometer Installation and Monitoring
• Field Resistivity Testing
• Variety of Software Packages for deep foundations, slope stability, retaining wall design, etc.
• Advanced geotechnical testing including direct shear, consolidation, swell, and unconfined compression.

All samples collected during our investigations are analyzed in our AASHTO and Corp of Engineers accredited Materials Testing Laboratory.  This allows our engineers to carefully monitor the geotechnical and laboratory scheduled and distribute information as needed to avoid delays to other portions of the project team.  Our goal is to work closely with the design teams to help ensure the successful completion of each and every project while considering the limitations or complexities that may result from the local geologic conditions.