... board, drainage board) which is consisted with plastic net and per-meated geotextile both sides, can instead of ... the inside of the tunnel. Three-D Drainage Net Technical Data Technical Data experimental technique units Type ... StrengthISO10319KN/m28.030.0a,b,eExtensibilityISO10319%6060a,b,eDrainage Net physical property of Geotextile--------------------------HDPE------------- Material of Geotextile ...