EMERGENCY SEALANT FOR PREVENTING WATER FROM GETTING INTO SEAL TAILS OF TUNNELLING MACHINES

摘要

The invention concerns novel sealant reactive with water or an aqueous fluid encountered around tunnelling machines, said reactivity being observed by a change in consistence and volume of the sealant in situ (when contacted with water or aqueous fluid) which forms a compact, flexible and homogeneous plug, countering the advance of water and exhibiting characteristics comparable to that of a sealant for seal tails of tunnelling machines. Said reactive sealant comprises at least a majority hydrophobic base, a water soluble gelling agent and an agent reacting in the presence of water and capable, after reaction with said gelling or thickening agent, of providing the product with efficient consistency for producing waterproofness. The invention also concerns a preventive waterproofing method, preferably in urgent or emergency situations, for a tunnelling machine, which consists in injecting said novel sealant into the zone where waterproof properties have been lost, or at least part of said zone. Waterproof properties are restored within a few seconds and the tunnelling machine can proceed forwards.