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Geotechnical Design

Scope of Services

 

The Geotechnical Unit is responsible for providing recommendations for the design and construction of bridge foundations, retaining walls, sheet piles, spillways, roadway embankments, geosynthetic reinforcement systems, and earth dams for the statewide DOTD system. Other responsibilities include determining pile lengths, performing embankment stability analysis, predicting embankment settlements, performing wave equation analyses for pile driving, designing sheet piles, and producing other geotechnical-related designs.

 

Field monitoring data is obtained from the Pile Driving Analyzer and recommendations are based on pile stresses, pile integrity, and pile capacity.  These field monitoring services are provided to DOTD's Construction and Maintenance sections.

 

Pile and Drilled Shaft load tests are analyzed and recommendations for pile/shaft order lengths are provided to our Construction section. 

 

Consultant Contracts

 

Some of DOTD's geotechnical design and exploration work is conducted under retainer contracts managed by the Geotechnical Unit. Consultants may perform geotechnical investigations consisting of soil borings, laboratory testing, optional cone penetrometer test (CPT) soundings, soil classification, and a Geotechnical Data Report (GDR). 

Geotechnical Exploration Services

Geotechnical exploration services to be provided shall include, but are not limited to:

  • Performing field reconnaissance (including obtaining all rights of entry, utility locations, access, etc.)
  • Obtaining and coordinating traffic control
  • Mobilization/demobilization of all equipment necessary to perform the work
  • Performing deep borings, CPT soundings, and shallow subgrade soil survey borings
  • Performing Thin-Walled Tube Sampling of Soils (ASTM D1587) and Standard Penetration Tests and Split-Barrel
  • Sampling of Soils (ASTM D1586)
  • Reporting water table readings
  • Sealing boreholes in accordance with all applicable regulations
  • Reporting surveyed latitude and longitude and natural ground elevation of boring locations surveyed by a
  • Professional Land Surveyor licensed in Louisiana
  • Performing relevant laboratory testing
  • Classifying soils according to the visual-manual method (field/extrusion logs), Unified Soil Classification System (deep/bridge borings), and AASHTO classification system (soil subgrade survey borings)
  • Drafting soil boring logs
  • Digital submittal of all test data in the LADOTD’s standard format
  • Submittal of Geotechnical Data Reports