The manhole cover is the wall leading to the top of the entrance and exit of the underground facility. In order to meet the requirements of daily maintenance, inspection wells are set up at road turns. The inspection well can not only withstand the high-speed and large flow of traffic vehicles, but also prevent vehicles, pedestrians and foreign objects from entering, ensuring the normal operation of equipment maintenance. At present, nearly 80,000 street lampshades in Changsha are basically square manhole covers. After years of observation, combined with operation and maintenance experience, it has been discovered that the traditional square manhole design has many drawbacks. With the continuous development of science and technology, urban road lighting facilities have also been continuously improved and innovated, and it is urgent to break the original design concept.

Comparison of square manhole cover and round manhole cover

Except that the round manhole cover in the maintenance space is smaller than the square manhole cover, the round manhole cover has the following advantages compared with the square manhole cover:

(1) The round manhole cover has fewer corners and is more beautiful than the square manhole cover.

(2) The stress balance of the round manhole cover can prevent noise and sound.

(3) The stress of the circular manhole cover is even, and its bearing capacity is higher than that of the square manhole cover. The circular manhole cover is not easy to tilt, which can better protect the safety of pedestrians and vehicles.

(4) The performance of the round well cover is better than that of the square well cover. Vehicles and pedestrians pass the street light manhole cover at any time. Each diameter passing through the center of the round hole cover has the same length. No matter how large the tilt, the diameter of the manhole cover will be slightly larger than the diameter of the wellhead below, and the manhole cover will not fall into the wellhead.