METHOD OF REPAIR OF SAGGING AND WASHED-OUT SECTIONS OF UNDERGROUND PIPE LINE Russian patent published in 2003 - IPC

FIELD: construction engineering; repair of underground pipe lines. SUBSTANCE: section of pipe line to be repaired is opened , trench under it is deepened and supporting and water retentive cofferdams are formed. Trench is filled with water, cofferdams are cut off, pipe line is overloaded and covered with soil. Digging the trench is started from ends of sections forming pits under pipe line which are filled with filling material and trench is carried out to bed portion. Then, water retentive cofferdams are formed for bounding bed portion of section and water discharge hose is dug out to discharge water beyond bed portion and repair of pipe line insulation is performed, after which water retentive cofferdams are cut off and overloads are installed. Simultaneously, supporting cofferdams are cut off and bed is restored; then, trench is finally filled. EFFECT: enhanced reliability. 2 cl, 4 dwg