青岛亚行贷款的热网输配工程项目，设计蒸汽干线的约11．4Km，大多为架空，少数为地沟敷设．在埕口路段近60m、300℃、820的管线，原设计为地沟敷设，但该地段是汽车进出的主干线，紧靠铁路干线，地下水位高，地沟深度要达5m以上。地沟的加固处理、施工、防水难度很大，经研究 The heat network transmission and distribution project of Qingdao ADB’s loan, the design of steam trunks about 11.4Km, mostly overhead, a few for the laying of the trench. The pipelines in the near 60m, 300°C, and 820 pipelines are originally designed for laying trenches. However, this section is the trunk line for vehicles entering and exiting. It is close to the main line of the railway. The groundwater level is high and the depth of the trench is more than 5m. The trench treatment, construction and waterproofing are very difficult.