Design and Construction of Jing River Horizontal Opposite-directional Drilling Crossing Project of Second West to East Gas Pipeline

The Jing River crossing in Jingyang County as a bottleneck engineering of the Second West to East Gas Pipeline Project is the completed long-distance horizontal opposite-directional drilling crossing with the biggest pipeline diameter in China,which has the overall length of 1 040 m and two parallel crossing steel pipelines,namely a main D 1 219 mm × 27.5 mm gas pipeline and a D 114 mm × 6.5 mm optical fiber cable casing.The crossing engineering encountered the complex geological layers of pebble,sand and powdery clay.The combinatorial construction scheme,i.e.large excavation of deep foundation pit for burying pipeline + long-distance temping casing + horizontal opposite-directional drilling crossing,was adopted,and many technical innovations were made.This HHD crossing engineering provides reference for design and construction of similar projects at home and abroad.