Concrete piles suitable as foundation pillars

Abstract

This invention relates to foundation work of structures in a very cold district, especially to a method of preventing the upward movement of foundation pillars in weak ground in which concrete piles are required as foundation pillars. Concrete piles are driven to a permanent frozen stratum passing through a weak stratum which repeats freeze and melt conditions according to the atmospheric change and the like, and then the concrete piles themselves are cooled artificially or by utilizing the ultra-low temperature of the permanent frozen stratum during the period of refreeze of the weak stratum in order to make frozen parts in the weak stratum around each concrete pile. Therefore, the upward movement of the weak stratum due to its cubic expansion during the period of freeze is done with slide around the boundary between the frozen part and the other part of the weak stratum, and thereby the concrete piles are not directly affected by pulling force due to the cubic expansion of the weak stratum and the upward movement of the concrete piles is prevented. Furthermore, the present invention relates to concrete piles suitable as foundation pillars in a very cold district characterized in respectively having a cooling unit which is set at the time of producing each concrete pile and used to make a frozen part in the weak stratum.