1, with different functions: pits are generally used to store food and articles. Manholes are used in bends, branches, drops and other places of drainage pipelines, which is convenient for inspection and dredging of used wells.
2. Different locations: pits usually refer to cellars, which means basements. The manhole is a sewer manhole in the middle of the road, also called skylight.
? Extended data:
In cities, all public water supply, sewage pipes, telephone lines and optical fiber networks may be connected through underground passages under inspection wells. Manhole is its exit to the ground and is covered by manhole cover. Underground pipelines are mostly straight. When steering is needed, a manhole is arranged at the steering position, so that the straight pipeline is not easy to be blocked and the pipeline is easy to install. In addition, in order to facilitate work and safety, a manhole will be set in the middle of a certain length of pipeline to facilitate access to the pipeline.
In sewage engineering, manholes with different designs can have different functions, such as degrading manholes and dividing manholes. Degraded manholes are manholes where water enters the bottom of manholes from high places and consumes kinetic energy, which can reduce the kinetic energy of water and is suitable for draining water from high places to low places. Sand-separating manhole is a manhole whose bottom sinks to collect garbage.
Reference details: Baidu Encyclopedia -CMC