Geology and Civil Engineering

• Every branch of civil engineering interacts with the earth's surface.
• Works designed by civil engineers are either supported by or located within the earth's crust.
• The practice of civil engineering involves design, control, and construction direction.
• Geology studies the composition and arrangement of the earth's crust.
• Many civil engineers in the early 19th century, when engineering was less specialized, were also active geologists.
• William Smith is an outstanding example of these pioneering civil engineer/geologists.
• Robert Stephenson combined geological study with early railway construction and other well-known engineering figures.
• Geology is typically included as a basic subject in civil engineering courses.
• Geology provides a service by applying its findings to specific engineering problems.

Training in Geology

• Geologic training for civil engineers should be general, covering principles and the interrelation of various geology branches.
• Focus should be on physical geology, structural geology, and petrology.
• Field experience is crucially important.
• A geologic and topographic survey camp would be ideal.
• Geologic training should have a study of geologic lessons from real engineering scenarios.
• Geology is widely recognized as essential to civil engineering.

Practical Experience

• Knowledge derived from wide experience is not common.
• The knowledge is intuitive and more than just observational.
• Understanding what lies beneath the ground can help engineers direct exploratory work.
• The work of Dr. C.P. Berkley on the Catskill Aqueduct in NYC is a great example of geology's use.
• The geologic investigations for the Mersey River tunnels in Liverpool, England, by Prof. P.G.H. Boswell are a similar example.
• Engineering geologists are often consultants; having a geologist on the board is a North American tradition.

Geologist and Civil Engineering Work

• Geologists find out about new exposures made by the engineers in charge of the work.
• Civil engineers must have training in geology.
• Geologists advise civil engineers and work with the engineers responsible for the work
• Cooperation is needed between civil engineers, engineering geologists, practical builders, and scientists.
• Geologists analyze conditions, while engineers determine how to change existing conditions to suit a plan.
• Geologists cite problems and suggest troubles; engineers solve problems and overcome troubles.
• The engineer has the final responsibility for project decisions, and the engineer is guided by information from the geologist.

The Pattern of Civil Engineering

• Civil engineers study the site, conduct geological investigations, and gather detailed data.
• Geologic reports and topographic studies are critical for understanding design and construction conditions.
• Reconnaissance surveys and exploratory investigations (boreholes, pits) provide information for design and estimates.
• Knowledge of subsurface conditions and construction materials shape the planning.
• Engineers prepare plans and specs for bidding or administration.
• Geologic insights improve the accuracy of contract documents for engineers and contractors.
• Proper classification of excavation materials (earth, softrock, hard rock) is critical to prevent disputes.
• Ambiguous term like "hardpan" should be avoided to maintain clarity and prevent legal issues.

Key Terms for Excavation

• Hard Rock: Requires drilling and blasting.
• Weak Rock: Blocky, removable without blasting.
• Earth/Soft Rock: Weathered rock, clay, sand, gravel - manageable with simple tools.
• Soil: Unconsolidated natural materials.
• Weak Rock: Rock of low compressive strength.
• Rock: Solid bedrock, either place or excavated.

Construction Operations

• Every construction activity (excavation, foundation work) interacts geological features.
• Geological investigations are essential for effective planning for engineers and contractors

Monitoring

• Constant observation and documentation of geological conditions during construction are crucial.
• Regular updates ensure assumptions align with actual conditions and enable design/construction method adjustments.

Practical Value of Geologic Records

• Helps design validation: adapting designs to reflect actual site conditions.
• Confirms construction suitability: the appropriateness of plans and equipment.
• Serves as a reference for future projects or dispute resolution

Consequence of Poor Geologic Records

• Inadequate records can lead to costly resurveys or maintenance delays

Maintenance

• Civil Engineering structures and surrounding ground must be inspected and maintained for safety and functionality.

• Inspections should focus on:

  • Building Piers: Checking for scouring around the foundation.
  • Dams: Monitoring for erosion of foundation beds caused by leaks

• Geologic features play a vital role in maintenance that should be considered during inspections.

• Regular inspections are essential for man-made structures and their foundations' long-term stability.