The Zizhi Tunnel connects Zijin Port Road at one end and Zhipu Road at the other. Near Xixi Paradise, the tunnel intersects with underground cables. "If we couldn't provide the precise location of the cables, construction couldn't proceed," said Ren Guangzhen, a dedicated maintenance worker at the Hangzhou Power Supply Company's Transmission Operation and Maintenance Department. He explained that they solved the detection problem using a self-developed new technology. This technology allows for zero-error precise location of underground cables without excavating cable ducts. This innovative invention by the Hangzhou Power Supply Company is a leader in the pipeline detection industry and has obtained national invention and utility model patents.
"We open the manholes at both ends of the jacking pipe, and a parabola runs through the ground. Then we insert a plastic tube through a pre-drilled hole. Inside the tube is a detection instrument. By dragging the tube multiple times within the cable conduit, the carbon rod inside the instrument stores the X and Y coordinates of each point. Connecting the carbon rod to specialized equipment, the data from these locations is exported, allowing us to simulate the entire pipeline path and create a four-dimensional graphic with very high accuracy," Ren Guangzhen explained. "It's like performing a gastroscopy; the location of the cable is immediately apparent."
Currently, through the application of this project, Hangzhou Power Supply Company has identified the precise locations of 164 trenchless cable pipelines and established a "four-dimensional" information file for each pipeline segment. This accurately displays the route of 124.75 kilometers of 35-220 kV underground cables, directly saving nearly 50 million yuan annually. This data can also be provided to related projects in the future to ensure that construction accurately avoids underground cables.
