Field Exploration, Testing, and Instrumentation

Samples tell you about a few points, and field work tells you about the site. This chapter covers how subsurface conditions are explored, tested, and monitored. It starts with the general requirements of a field investigation, the initial investigation, and guidelines for detailed explorations.

It then covers presentation of geotechnical information, geophysical methods, soil borings and test pits, and sampling. Penetration resistance tests, including the standard penetration test, groundwater measurements, in situ measurement of soil and rock properties, field instrumentation, and soil profile development complete the chapter. It is useful to the engineer who writes the exploration scope, the driller who carries it out, and the contractor who needs to understand what the report does and does not say.

In this chapter

• Overviewpage 186
• General Requirements of Field Investigationspage 186
• Initial Field Investigationspage 188
• Guidelines for Detailed Explorationspage 190
  • General Scope of Program
  • Investigation Steps
  • Field Boring Procedures
  • Roadway Soil Surveys
  • Structures
  • Borrow Areas
  • Retention Ponds
• Presentation of Geotechnical Informationpage 199
  • Roadway Soil Survey
  • Structures Investigation
  • Final or Supplementary Report
  • Signing and Sealing
  • Plan and Specification Review
  • Unwanted
• Geophysical Methodspage 210
• Soil Borings and Test Pitspage 214
  • Soil Borings
  • Test Pits
  • Test Trenches
• Samplingpage 216
  • Disturbed and Undisturbed Sampling
  • Types of Soil Sampling
  • General Requirements for Sampling Program
  • Undisturbed Samples from Test Pits
  • Rock Cores
  • Sampling of Disintegrated Rock Transition Zones
  • Offshore Sampling
• Penetration Resistance Testspage 222
  • Standard Penetration Test (SPT)
  • Cone Penetrometer Test (CPT)
  • Dynamic Cone Penetrometer Test
  • Dilatometer Test (DMT)
  • Pressuremeter Test (PMT)
  • Plate Bearing Test
  • Field Vane Test
  • Pocket Penetrometer
  • Torvane Shear Device
  • Percolation Test
• Groundwater Measurementspage 253
  • Piezometers
  • Typical Installation
  • Piezometer Types
  • Multiple Installations
  • Measurements
  • Sources of Error
• Measurement of Soil and Rock Properties in situpage 258
  • In-Place Density
  • Detection of Combustible Gases
• Field Instrumentationpage 260
  • Inclinometers (Slope Indicators)
  • Settlement Indicators
  • Tiltmeters
  • Monitoring Wells
  • Vibration Monitoring
  • Special Instrumentation
• Soil Profile Developmentpage 262