pile driving problems and solutions by dr. malek smadi of geotill
TRANSCRIPT
Pile Driving Problems and
Solutions
ASCE Indiana State Section 2014 Annual Meeting
4/15/2013
Malek Smadi, Ph.D., P.E.
Principal Engineer - GEOTILL - Fishers, Indiana
[email protected] - www.geotill.com
CONTENTS
1. Objectives
2. Piles With Blow Count Above Minimum Pile Penetration Requirements.
3. Piles Driving Significantly Deeper Than Estimated.
4. Abrupt Change or Decrease in Blow Counts for Bearing Piles.
5. Lateral Movement of Previously Installed Piles When Driving New Piles.
6. Piles Driving Out of Alignment.
7. Pile Obstructions at Depth.
8. Pile damage
9. Steel Pile Head Deforms
10. Higher Blow Count than Expected.
11. Lower Blow Count than Expected.
13. Case Histories
a. NFS RR Over SR 331
b. SR 13 Over Elkhart River
c. CR 150 East
d. I80/94 over S.R. 912
e. U.S. 12 over Grand
Calumet River
Objective
Improve
understanding of
driven pile design and
construction.
Understand the
importance of
geotechnical
investigations, design,
and the plans and
specifications.
Educate constructors
and designers about
common issues so
that good foundation
construction practices
are followed.
To achieve quality
assurance.
Keys to Success
Subsurface investigation
Design Considerations
Knowledge of construction techniques
Design for constructability and reliability
Appropriate specifications
Quality assurance
Subsurface Investigations
The best practice to reduce the risk of
construction problems is early recognition of
geotechnical problems during design stage and
designing accordingly.
Perform an adequate subsurface investigation
in advance of final design.
SPT- Errors & Omissions
Overburden effect
Improper seating of sampler at bottom of
hole
Inadequate cleaning of loose material at
the bottom of hole
Balance hydrostatic pressures inside and
outside the borehole.
Operator Errors
Dilatant soils causes
Subsurface Investigations
Hammer classification chart
Hammer classification chart
Hand Held Pile Driver
Minimum Pile Penetration Requirements
Check if driving system is matched to the pile
If no obvious problems are found, dynamic
measurements should be made to determine if
it is driving system or soil behavior related
Driving system problems could include pre-
ignition, low hammer efficiency, or soft cushion
Soil problems could include higher soil strength
than anticipated, temporarily increased soil
resistance with later relaxation (required
restrike to check), large soil quakes, or high
soil damping
Piles Driving Significantly Deeper Than Estimated
Soil resistance at the time of driving could be
lower than anticipated or driving system
performance is better than anticipated
Perform restrike tests after an appropriate
waiting period to evaluate soil strength change
If the ultimate capacity based on restrike blow
count is still low, check drive system
performance and restrike capacity with
dynamic measurements
Contact the structural engineer/designer for
recommended change
I-465 & I-65 Bridge Indianapolis
Blow Count Significantly Lower than Expected
Review soil borings
If soil borings do not indicate soft
layers, pile may be damaged
below grade
If the pile was spliced, re-evaluate
splice detail and field procedures
for possible splice failure
Recent INDOT Splices
Abrupt Change or Decrease in Blow Counts for Bearing
Piles
If borings do not indicate weathered profile above
bedrock/bearing layer, then pile toe damage is likely
For piles that allow internal inspection, reflect light to
the pile toe and tape the length inside the pile for
indications of toe damage
For piles that cannot be internally inspected,
dynamic measurements could be made to evaluate
problem or pile extraction could be considered
Failed Piles I-69 over Hurricane Creek
Lateral Movement of Previously Installed Piles When
Driving New Piles
Pile movements likely due to
soil displacement from adjacent
pile driving
Possible solutions include:
Re-driving of installed piles
Change in sequence of pile
installation
Predrilling of pile locations to
reduce ground movements
Lateral pile movements could
also result from adjacent slope
failure
County Road 150 East
Lateral Movement of Previously Installed Piles When
Driving New Piles
Lateral pile
movements
could also
result from
adjacent slope
failure
Toll Road I-90 adjacent to Calumet River
Piles Driving Out of Alignment
Piles may be moving out
of alignment tolerance due
to hammer-pile alignment
control or due to soil
conditions
If due to poor hammer-pile
alignment control, a pile
gate, template or fixed
lead system may improve
the ability to maintain
alignment tolerance
Soil conditions such as
near surface obstructions
or steeply sloping bedrock
having minimal
overburden material may
prevent tolerance from
being met
Pile Obstructions at Depth
If deep obstructions are
encountered contact the
engineer for remedial
design
Ultimate capacity of piles
hitting obstructions
should be reduced based
upon pile damage
potential and soil matrix
support characteristics
Additional piles may be
necessary
Steel Pile Head Deforms
Check helmet
size/shape
Check steel strength
Check evenness of
the pile head
determine pile head
stress. If calculated
stress is high, reduce
hammer energy
(stroke) for low blow
counts; for high blow
counts, different
hammer or pile type
may be required
NFS RR Over SR 331
Pay Attention to Scour Depth
Verifying High Capacity Piles with Large Diameter
54-inch Pipe Piles with welded shoes
Verifying High Capacity Piles with Large Diameter
Pile driving to install 8-ft-diameter test pile at Stony Creek Bridge
Verifying High Capacity Piles with Large Diameter
Verifying High Capacity Piles with Large Diameter
For pier 6, which is northern pier for the
main truss on Milton-Madison, the
contractor proposed to 36" diameter by 7/8"
thick steel open pipe pile
Due the size of pile and loading, it was
requested from the contractor to perform
static load test or statnamic test instead of
PDA
Milton-Madison Bridge
Questions ? Dr. Malek Smadi, P.E.
Principal Engineer - GEOTILL Fishers, Indiana
[email protected] www.geotill.com