Presentation from Master of Science thesis defense (Evaluation of Rapid Impact Compaction for Transportation Infrastructure Applications; July 15, 2011)

1. IOWA STATE UNIVERSITY
Civil, Construction & Environmental Engineering
Peter Becker
Graduate Research Assistant
Master of science thesis defense
15 July 2011
Dream it, Design it, Build it. www.ccee.engineering.iastate.edu

2. Transportation Research Board and the
Strategic Highway Research Program 2
(SHRP2)
Mr. Ed O’Malley and GeoStructures, Inc.
Drs. David White, Jeramy Ashlock, and Charles
Jahren
Mr. Ed O’Malley and GeoStructures, Inc.
Earthworks engineering research center
(EERC) and the Institute for Transportation
(InTrans)

3. 1 Introduction
2 Rapid impact compaction (RIC)
3 Current state of practice for commercial
construction applications
4 Test methods
5 Materials
6 Results and analysis
7 Assessment of RIC for transportation
applications
8 Conclusions and recommendations

4. Transportation agencies seldom utilize
geoconstruction technologies due to different
“obstacles”
Rapid impact compaction (RIC) has potential
for transportation infrastructure projects but
has yet to be used

5. • no simple design/analysis procedure;
• no established performance criteria;
• no easy-to-use-tools to select technology;
• no long-term performance data;
• environmental impacts;
• performance uncertainty; and
• no accessible case histories (Berg et al., 2008)

6. Goal of Research:
Evaluate RIC for civil engineering applications in
transportation sector
Research Objectives:
1. develop expanded RIC knowledge base from
contractors;
2. present detailed case history of RIC project; and
3. assess applicability of
design, QC/QA, specification procedures.

8. Reported RIC Projects in USA:

9. Design/Analysis:
Qualitative procedure
Construction and QC/QA:
Follows square impact point spacing
Compaction at each impact point concludes after
different criteria:
QA performed by SPT

10. Commercial project case
histories:
 RIC performance
 Example: Reading, PA (I)
• Misc. debris fill; sand
• 6.5 m (21 ft) compaction depth
• pre-RIC SPT-N60 = 10 (loose DR)
• post-RIC SPT-N60= 28 (medium DR)

11. Vibrations:

12. Vibrations:
90% confident
Safe Working Distances
(Siskind et al., 1980):
•Plaster: 19.0 m (62.3 ft)
•Dry wall: 14.5 m (47.6 ft)
•All other: 7.2 m (23.6 ft)

13. Cost:
•Mobilization cost:
$37,000
•Unit cost:
$9.7 per SF ($0.90 per SF

14. Material Characterization:
Grain size analysis (ASTM D422-63)
Field moisture content (ASTM D2216-10)
Minimum dry unit weight (ASTM D4254-83)
Maximum dry unit weight (ASTM D4253-83)
Standard proctor (ASTM D698-00)
Drained direct Shear (ASTM D3080-04)
• Material consolidated to presumed RIC dynamic
loading
Scanning electron microscopy (SEM)

15. Dynamic penetration index (DPI) to Relative
Density (DR) correlation:
Specimen
batched at
field moisture 7.18 kPa (150 psf)
content surcharge is
Specimen is placed on
placed in relative compacted
density mold, specimen
compacted for DCP test
predetermined conducted on
time duration; compacted
relative density specimen,
computed repeated twice

16. Springfield Fill:
Highly variable granular material
(sand, silt, gravel, misc. debris)
Classifications: SM (USCS);
A-2-4(0) (AASHTO)
Compactibility: 1.545
(Assumed GS = 2.7)

17. Hard Pack:
 Well-graded mixture of crushed
brick, stone, sand, reclaimed
asphalt, concrete, etc.
 Classifications: SM (USCS);
A-1-b (AASHTO)
 Compactibility: 0.891
(Assumed GS = 2.7)
ρd,min = 19.50 kN/m3
ρd,min = 15.79 kN/m3

18. Case History (Springfield, MA):
 Background
• Office building
• Poor subsurface conditions
• Improve foundation with
RIC to avoid
deep foundations
o Required SPT-N60 = 15 to
4.6 m (15 ft depth)
Boring FW-511

19. RIC Program
•2 660 m2 (28 600 SF) area
•Lasted 3 weeks

20. RIC Results
• SPT testing (no split spoon sampling)
o Compaction depth: 5.6 m (18.5 ft)
o Post-RIC average SPT-N60: 35 (pre-RIC of 15)
Borings
•FW-511 (pre-RIC) Average for pre-
•RIC-6 (post-RIC) and post RIC

21. DCP Testing:
Before compaction
trial

22. After Compaction Trial
DCP 1 (0 m from crater center)

23. After Compaction Trial

24. DPI to DR Correlation:
 Hard Pack  Springfield Fill
Confinement correction
Liao and Whitman Skempton
(1986) (1986)

25. Application of correlations to Field Data:
Pre-RIC profile Post-RIC profile
(0 m from crater center)

26. Spatially analyzed relative density profile
[Liao and Whitman (1986) correction]:

28. Sequence 1; pass 1
Sequence 2; pass 2
Spatial analysis of QC data:
Sequence 3; pass 3

29. SHRP2 R02
• Phase 1
o Identification of geoconstruction technologies
applicable to transportation infrastructure
• Phase 2
o Development of selection guidance system
o Comprehensive Technology Summary (CTS)
o Task 10 Assessment of Design Methods and QC/QA
Procedures
o Task 12 Assessment of Existing Specifications

30. CTS
• Summary of basic
function, advantages, disadvantages, etc.
• Potential transportation infrastructure
applications

31. Task 10
• Design method
o Direct measurement of improvement depth following
construction
• QC/QA procedures
o QC procedures
 Process control, equipment performance (data acquisition
system)
o QA procedures
 Bearing capacity, predicted settlement, liquefaction
susceptibility (in situ penetration tests)
o Currently flawed

32. Task 12
• One specification available (commercial
specification)
o Performance-related specification
o Requires improvement before application to
transportation projects

33. Obstacle Mitigation Measure from Proposed Future
this Research Mitigation Measures
Lack of Simple, Design procedures for RIC Develop design charts for
comprehensive, and within the commercial degree of compaction;
nonproprietary design sector have been reported develop model for
procedure estimating compaction
depth
Lack of established QC/QA procedures for RIC Develop QC/QA guidelines
engineering parameters within the commercial from correlations to QC
and/or performance sector have been reported data, design charts, etc.
criteria
Lack of easy-to-use tools for Establishment of selection Update as needed
selecting technology guidance system
Lack of long-term Performance data, although Construct controlled test
performance data short-term, from sections for long-term
commercial RIC projects monitoring
have been reported
Environmental impacts (i.e., Vibration data from different Update as needed
vibrations) RIC projects has been
presented
Performance uncertainty Performance data from Construct controlled test
commercial projects have sections for long-term
been reported monitoring
Lack of accessible case Multiple commercial sector Implement field
histories RIC case histories have demonstration studies on
been provided transportation projects

34. Thank you for your attention!
Are there any questions?