GC Method - Glass reinforced Insituform Liners for Large Diameter Structures

摘要

The lining of large and non circular conduits with cured in place liners is often limited by the thickness of the polyester liner necessary to withstand hydrostatic buckling due to ground water pressure. Iida Kensetsu have developed and refined a method for strengthening critical areas of an Insituform cured in place pipe liner by positioning glass reinforced plastic panels at critical sections of the host pipe which bond effectively to the inverted polyester impregnated lining tube during curing of the resin. This process, now patented in Japan, is recognised as an improvement of the original Insituform Process~(TM). By positioning the reinforcing panels at zones of the liner subject to the highest buckling forces the installer can utilise a composite of lesser overall thickness than would be required from a regular polyester liner. The use of reinforcing panels in the composite liner can enhance project feasibility in large and irregular shaped pipelines such as box culverts and ovoids. The design principles involving detailed structural analysis were determined through a programme of work undertaken at Kyushu University. These principles and the variety of experience gained lining of more than some fifty box culverts in Japan are described in the paper. Amongst the projects detailed is the 2,5m X 2,5m River Onga sluice lined in Kyushu in March 1999 which is thought to be the largest CIPP lining undertaken in recent years.