PURIFYING METHOD OF UNDERGROUND SOIL

摘要

PROBLEM TO BE SOLVED: To provide a purifying method of contaminated underground soil by supplying iron powder directly as a soil purifying agent to the contaminated soil at a layer lower than an underground structure while keeping the existing underground structure as it is at a site of the contaminated soil and by dispersing the iron powder in the earth near the contaminated soil by agitating and mixing. SOLUTION: In the purifying method of contaminated underground soil below a level which cannot be drug by a multi-axis drilling machine composed of an usual earth auger. An upper layer ground is drilled and crushed soil is discharged by a rotary casing driver engineering method, and a lower part in a drilled hole for soil discharging is further excavated by using a multi-axis auger. Excavation, agitating and mixing are simultaneously executed while pouring the iron powder from each axis end of the multi-axis auger. By repeating these operations, a large number of continuous soil layers blended with the iron powder are formed in parallel at a proper depth where contaminated underground soil exists.