IWM 2000 Turku, Finland Pasi Korkeakoski 11.11.2018

Pasi Korkeakoski 11.11.2018

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 11.11.2018

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 Pasi Korkeakoski 11.11.2018

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. Pasi Korkeakoski 11.11.2018

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 Pasi Korkeakoski 11.11.2018

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. Pasi Korkeakoski 11.11.2018

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! Pasi Korkeakoski 11.11.2018