Detection of Sedimentation Conditions in the Huangxiao River Box Culvert in Wuhan

Release time:

2026-03-23 17:19

Full-water pipeline inspection has long been a challenging task in drainage pipeline inspection operations. Traditional sonar-based inspection methods are characterized by relatively cumbersome workflows, low inspection efficiency, and significantly longer overall inspection times compared with TV inspection, placing a considerable burden on inspection contractors. The development of an autonomous underwater vehicle capable of carrying a sonar transducer and maneuvering freely in water would represent a disruptive improvement over conventional sonar inspection practices.
The RSM-SNR (C) Pipeline Dynamic Sonar Inspection System (Blue Whale No. 1) is a purpose-built device developed by Zhongyan Technology to address the challenging issue of high-water-level inspections in the pipeline inspection market. The primary R&D objective was to overcome the low efficiency and high operational complexity associated with conventional sonar-based inspection methods. To date, this system has been successfully launched and deployed in numerous domestic pipeline inspection projects, earning widespread acclaim from users. Below are several real-world field cases demonstrating the Blue Whale No. 1’s performance in practical applications.

Testing Equipment: RSM-SNR (C) Pipeline Dynamic Acoustic Sonar Inspection System
Box culvert dimensions: 6800 mm × 5800 mm

Project Overview
The primary objective of this inspection is to evaluate the effectiveness of desilting work carried out by the construction contractor on the box culvert. Dynamic sonar is used to acquire contour data at regular intervals, enabling an assessment of the remaining sediment thickness inside the culvert. As the Huangxiao River box culvert serves as the main sewage trunk line for the Hankou area of Wuhan, its closure entails high costs and significant technical challenges; therefore, the client has requested that data collection be completed without sealing the culvert. At the site, the water level is essentially at full capacity, preventing entry of all-terrain robots, and the flow velocity exceeds 0.2 m/s.

Solution
Based on the owner’s requirements and the actual site conditions, we have decided to use the RSM-SNR(C) pipeline dynamic sonar inspection system to inspect the box culvert. This equipment is equipped with a sonar transducer that enables it to perform various maneuvers in water, including ascending, descending, advancing, retreating, turning left, turning right, and maintaining a fixed depth while hovering. The device features a built-in high-precision electronic compass and depth sensor, allowing it to continuously acquire its orientation and attitude in the water. In addition, the system is outfitted with high-brightness front lighting and a camera capable of 4K ultra-high-definition video recording, which helps operators locate the pipe openings in fully flooded manholes.

Data analysis
On-site operators used a powered sonar system to advance more than 200 meters upstream from the lifting well, reaching the boundary of this contract section. The sonar signals acquired are shown below. Thanks to the submersible’s excellent propulsion and attitude-control capabilities, the sonar transducer successfully captured contour data for nearly all of the boundaries of this fully flooded box culvert. Subsequent analysis revealed that the residual sediment on the culvert invert in this segment does not exceed 40 mm, thereby meeting the Employer’s requirements.