Transcript No Slide Title

IWM 2000
Turku,
Finland
Pasi Korkeakoski
17.7.2015
1
45 Delegates
North-Amerika
27 %
Asia
16 %
Finland
24 %
Europe
33 %
Pasi Korkeakoski
17.7.2015
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Session 1 Application Areas
Findings:
•Fields of applications of micropile
• underpinning
• settlement control
• uplift securing
• slope and embankment stabilisation
• alternating compression and tension loads,
• combination of micro pile installation with jet grouting
• reinforced soil
• new foundations
• Use of micropiles is concentrating to projects where use of traditional
piling methods are technical very difficult or risky.
Gaps:
• Use of micropiles in "normal" piling projects is still too expensive.
• Load test standardisation
Pasi Korkeakoski
17.7.2015
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Session 2 Classification and Definition of Micropile Type
Findings:
•Definition and classifications can be based on
• Installation method
• Material
• Dimension and cross-sectional shape
• Geotechnical bearing properties (base, shaft,…)
• "Additional treatment" (grouting
•Classification systems of Micropiles
• FHWA  drilled and grouted small diameter piles
• European CEN-standards  small diameter piles
•Typical features of micropile
• Small diameter
• High bearing capacity compared to cross-section
• Minimum soil displacement even with displacement piles
• Often low head room and restricted access conditions
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Session 3 Design
Some research results:
• Micropile groups and networks under earthquake loading
• Micropiles under cyclic loading
• Bearing capacity of impact driven micropiles
• Behaviour of corrosion protection of micropiles
Precise research issues and challenges:
• Full-scale loading test (test standards)
• Beneficial network/interlocking effect not established
• Effects of raked piles still not clear
The aim is develop DESIGN MANUALS and STANDARDS and get
better ANALYTICAL APPROACH-PROGRAMS for Micropiles especially
under Earthquake loading and Cyclic loading.
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Session 4 Execution
Micropile practice in Japan, America and Europe was well presented
Many countries has ready Design and Implementation Manuals or at
least they are under construction.
In Europe has tried to harmonise individual national standards to
global European standards. Standardisation is very demanding and
takes a lot of time, because many things are totally different in each
country, such as:
• soil condition
• used pile types and techniques
• design, execution, monitoring culture
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Session 5 Monitoring and Control
•Capacity testing methods for conventional driven large
diameter piling appear applicable for micropiles, driven or
grouted
•The importance of environmental awareness (avoiding
pollution due to drilling flush and grouting spillage.
•The importance of ground water monitoring
•The importance of monitoring and testing was emphasised
through the session and future efforts should be done with
diligence and full enthusiasm.
THE NEED OF STANDARDISATION OF LOAD TEST
PROCEDURES BECAME WELL ESTABLISHED.
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Session 6 Case Histories
"We have great construction information, but not so
great geotechnical information".
It was stated that we need three important things:
• (a) a broad and detailed database of different
construction technology and equipment, correlated to
micropile performance data,
•(b) well-documented and well-instrumented load tests
to FAILURE!, and
•(c) data on performance of different micropiles under
various field applications. All of these should be
available in an accessible repository!
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