SOIL IMPROVING CONSTRUCTION METHOD

PROBLEM TO BE SOLVED: To place a hydrophobic strong columnar body in the weak ground by providing a process of forming a columnar hole in the weak ground, and a process of inserting a mixture of reaction delay lime and soil containing an organic colloidal particle solution, in the columnar hole. SOLUTION: A casing 1 is driven into the weak ground 2 by impact force to form a columnar hole 3. At this time, partial soil is carried onto the ground by driving the casing 1. On the ground, reaction retarded lime and weak soil are mixed and agitated by an agitator 4, and magnesium or the like is added to control reaction. During agitation, internal quick lime is exposed by friction or the like so as to generate hydration reaction with soil water. A mixture of this soil and reaction retarded quick lime is thrown into the columnar hole 3, and upon completion, rolling compaction is applied from the ground surface. Hydrophobic micro substance is therefore made into a more complete impermeable block. The casing 1 is pulled cut to form a columnar body 5 formed of the impermeable block. A strong pile not absorbing moisture can therefore be placed in the weak ground.