METHOD FOR IMPROVING EXCAVATED EARTH AND SAND IN EARTH PRESSURE SHIELD TUNNELING METHOD

摘要

PURPOSE: To effectively utilize removed earth by adding a predetermined amount of polymeric improving material to excavated earth and sands containing highly water-absorbable polymer, and removing water from the highly water-absorbable polymer to contract the polymer, thereby discharging the earth and sands. ;CONSTITUTION: Highly water-absorbable polymer is added to excavated earth and sands in a chamber 1a of an excavation machine 1, which earth and sands are discharged by means of a screw conveyor 2. The excavated earth and sands are sent to an improving device 3, where cationic polymeric improving material having plug ions, anionic one having minus ions, neutral nonionic one are added to the earth and sands in the ratio of 2-6kg of the polymeric improving material per m³ earth and sands. And water is removed from the highly water-absorbable polymer which has absorbed water and has been expanded to contract or eliminate the polymer so that the excavated earth and sands can be handled as general surplus soil, not as industrial waste. By this method, excavated earth can be utilized as filling material.;COPYRIGHT: (C)1995,JPO