The document discusses subsurface investigation and geotechnical evaluation methods. It describes designing investigation programs, common investigation methods like conventional soil borings, cone penetration testing, and test pits. It also covers reviewing investigation logs, classifying soil, determining engineering properties, and completing geotechnical evaluations. The presentation provides guidance on using different techniques to understand soil and site conditions for engineering design.

1. Atlantic Testing Laboratories
Subsurface Investigation
and
Geotechnical Evaluation
NYSCHSA
January 22, 2013

2. Topics
 Designing a Subsurface Investigation Program
 Subsurface Investigation Methodologies
 Subsurface Investigation Log Review
 CPT Log Review
 Soil Classifications
 Engineering Properties of Soil
 Geotechnical Evaluation

3. Designing a Subsurface Investigation
 Determining the Number of Soil Borings
 Former NYS Building Code
 The Building Code of NYS 2002 (based on IBC 2000)
 As a Rule of Thumb – 1 Boring for every 2,500 to 5,000 s.f.
of building footprint

4. Seismic Site Classification
Determination
 Code does not require a 100 foot boring
 Calculate the average soil properties in the
top 100 feet. (either soil shear wave velocity,
Standard Penetration resistance, of soil
undrained shear strength)
 Section 1615.1.1 allows the register design
professional to assume based on knowledge
of local geology

5. Seismic Site Classification
Determination
 Use table 1615.1.1 to determine Seismic Site
Classification (class A, B, C, D, E, or F)
 Obtain the maximum considered earthquake ground
motion of 0.2 sec spectral response (Ss)
 Obtain the maximum considered earthquake ground
motion of 1 sec spectral response (S1)

6. Seismic Site Classification
Determination
 Can be obtained from the maps in the code,
the CD prepared by ICC, or USGS web page
 Adjust Ss and S1 based on coefficients
presented in Tables 1615.1.2(1) and
1615.1.2(2)

7. Seismic Site Classification
Determination
 Central New York sites typically fall into site
class B, C, or D
 Glacial till and/or bedrock is often found at
shallow depths.
 Exception is Onondaga Lake area, bedrock
and/or glacial till in excess of 300 feet

8. Subsurface Investigation
Methodologies
 ConventionalSoil Borings
 Cone Penetration
Testing (CPT)
 Geoprobe
 Test Pits

9. Conventional Drilling
 Hollow Stem Augers
 Flush Joint Casing
 Split Spoon Sampling
 Undisturbed Samples
 Bedrock Coring

10. Hollow Stem Augers
 Auger Flights around a center sampling tube
 Size refers to diameter of
sampling tube
 Advantages
 Quick
 More Economical
 Water not necessary
 Ability to collect bulk samples

11. Flush Joint Casing
 Can be Driven or Spun-in the ground
 Advantages
 Can be advanced through
cobbles and boulder
 Can be advanced to depths
of around 300 feet
 Provides a stable hole for
special testing such as
permeability testing

12. Split Spoon Sampling
 In accordance with ASTM D 1586
 Sample for soil classification and future
laboratory testing
 Retained in sealed glass jars

13. Undisturbed Samples
 In accordance with ASTM D 1587
 Obtained from cohesive soils
 Returned to the laboratory for
multiple analyses
 Provides accurate representation
of in-situ conditions

14. Bedrock Coring
 In accordance with ASTM D 2113
 Double tubed core barrel with a diamond
cutting shoe
 Samples are returned for classification, RQD
determination, and laboratory analysis

16. Cone Penetration Testing
 Pushes a “cone” with
electronic sensors
 In accordance with ASTM D
3441
 Determines:
 Tip resistance
 Side friction
 Pore water pressure
 Seismic shear wave
velocity

17. Cone Penetration Testing
 Advantages
 Rapid: Can advance 200 to 400 feet per day
 Accurately determines to Seismic Site Classification
 Replicates pile driving
 Useful in cohesive and sand soils

18. Cone Penetration Testing
 Disadvantages
 Not able to be pushed in dense soils or bedrock
 No sample recovered, soil classifications relies on
soil properties
 Requires a large drill rig for reaction weight

19. Typical CPT Log

20. Cone Penetration Testing

21. Geoprobe
Data: Environmental
Sampling, Soil
Classification, Bedrock
Profile, and Groundwater
Elevation

22. Geoprobe

23. Test Pits
Advantages
 Good for fill sites
 Groundwater
information
 Collect bulk samples
Disadvantages
 Limited depth
 Cannot determine
Seismic Site
Classification

24. Subsurface Investigation Log
Review
 Contain a wealth of information
 Soil types
 Soil consistency
 Groundwater information

29. Soil Classification
 Several Systems Used
 Burmister
 Unified Soil Classification System
 NYSDOT
 USDA

30. Burmister Soil Classification
 Visual-manual procedure
 Performed by the drillers in the field
 Soil classification verified in the laboratory

31. Burmister Soil Classification
BOULDERS: > 12” Particle Size
COBBLES: 3” – 12” Particle Size
GRAVEL: Course: 3” - 1” Sieve Size
Medium: 1” – ½” Sieve Size
Fine: ½” - #4 Sieve Size
SAND: Course: #4 - #10 Sieve Size
Medium: #10 - #40 Sieve Size
Fine: #40 - #200 Sieve Size
SILT: #200 Sieve (0.074 mm) to 0.005 mm
CLAY: <0.005 mm Particle Size

32. Unified Soil Classification System
 In accordance with ASTM D 2487 and ASTM
D 2488
 ASTM D 2487 - laboratory analysis
 ASTM D 2488 - visual manual procedure
performed in laboratory

33. Unified Soil Classification

34. Engineering Properties of Soil
 Natural Moisture Content
 Atterberg Limits
 Liquid Limit
 Plastic Limit
 Plasticity Index
 Shear Strength
 Internal Friction Angle
 Consolidation Potential

35. Soil Property Uses
 Bearing Capacity
 Lateral Earth Pressures
 Slope Stability
 Frost Heave Potential

36. Geotechnical Evaluation
 Geotechnical Report Contents
 Optional Services
 Site Visit

37. Thank You

38. Question & Answer
How deep can you
drill with hollow stem
augers?

39. Question & Answer
In what type of soil
conditions is a
Shelby Tube most
conducive?

40. Question & Answer
Does a 100 foot
boring need to be
drilled to determine
the seismic site
classification?

41. Question & Answer
True or False:
Determining the
groundwater
table is extremely
important.

42. Question & Answer
What type of soil parameter
does Cone Penetration
Testing (CPT) determine that
conventional soil borings can
not?

43. Thank You