Real Estate Management Strategy and Underpinning Indications Timing

Real Estate Management Strategy and Underpinning • Indications • Timing • Methods of underpinning 21. 9. 2003 IWM 2003 Seattle Jouko Lehtonen

Need of underpinning • • Existing foundations on wooden piles Settlements Potential risks of decayed wooden piles Cracking of superstructures 21. 9. 2003 IWM 2003 Seattle Jouko Lehtonen

Economy of underpinning • Earlier stage in renovation construction (i) => less settlements (ii) bigger collection of potential underpinning methods and less problems in superstructures => less costs • Later working => financing can be done later • Optimal date for underpinning? 21. 9. 2003 IWM 2003 Seattle Jouko Lehtonen

Methods of underpinning in very soft soils • Jet grouting – Applicable only up to 10 m column length • Micropiling – Applicable to any pile length – Various pile types up to foundation conditions • Impact driven micropiles – Conventional driving against the pile head – Side Grip Piling • Jacked micropiles – Conventional pushing against the pile head – Side Grip Installation • Drilled micropiles – DTH – Top Hammer Installation » Conventional driving against the pile head » Side Grip Installation? 21. 9. 2003 IWM 2003 Seattle Jouko Lehtonen

Micropiling method has impact to the building and use of it • Settlements during construction • Noise • Timing – Some methods are available only in the earlier stages of the potential underpinning time 21. 9. 2003 IWM 2003 Seattle Jouko Lehtonen

Decision to underpin • Today: no policy to follow => decisions made by chance or by accident • Tomorrow? – Tools for strategic planning – Collection of underpinning methods => decisions will be made based on good understanding on the problems and challenges => less costs, less damages in superstructures => more business to the micropile industry => win-win 21. 9. 2003 IWM 2003 Seattle Jouko Lehtonen