METHOD OF RE-USING SLURRY IN GROUND IMPROVING CONSTRUCTION WORK

摘要

A method of re-using a slurry, which is discharged at the time of ground improving construction work, as a grout (hardening material). The method comprises adding a magnetically permeable substance to the hardening material to be injected; measuring a physical quantity indicative or magnetic permeability of the hardening material to which said substance is added; calculating the quantity of the hardening material from said measured physical quantity; recovering slurry discharged when executing the ground improving construction work; calculating the quantity of the recovered hardening material after measuring the above-defined physical quantity in recovered slurry; calculating the difference in quantity between the injected hardening material required for ground improvement and the recovered hardening material; and injecting the hardening material in a quantity corresponding to said difference. With the measurement of the physical quantity of the substance contained in the recovered slurry and indicative of magnetic permeability, the quantity of the hardening material recovered and a quantity thereof to be added are calculated. In this way, the quantity of the hardening material recovered is calculated at the same time as the recovery of slurry and, therefore, the quantity of the hardening material to be injected additionally can be controlled in real time.