For brick masonry of cast iron manhole cover, its inner diameter or length * width, square and round (if it is constructed according to the actual sample) shall be determined according to the size of the well cover designed by the design institute, which can also be executed according to the corresponding standards. When building the well, it must be noted that the inner diameter of the wellhead should be consistent with the inner diameter of the well cover and grate, and the installed well cover should be flush with the road surface. After the well seat is cast and paved with concrete or asphalt, the cover shall be opened and cleaned in time to prevent mortar or asphalt from casting the inspection well cover and seat into a whole, so as not to affect the future opening.
During the installation of cement pavement manhole base, the 20cm thick ring beam cast with C25 concrete on the brick masonry of the wellhead shall be leveled, and the manhole base must be kept solid in all directions, flat and not loose. The 40cm wide concrete protective ring (or 20cm wide concrete protective ring, reinforced with steel bars, if it is a cement pavement) shall be cast on the manhole cover, and the maintenance period shall be more than 10 days.
In order to keep the appearance of the cover beautiful and the surface pattern and handwriting clear, during the construction of asphalt pavement, thin iron sheet shall be used to cover the manhole cover or waste oil shall be used to brush the cover to prevent asphalt oil from spraying on the manhole cover; During the construction of cement pavement, the manhole cover shall be covered with plastic film to prevent the cement mortar from contaminating the surface of the manhole cover and damaging the surface patterns and handwriting. The manhole cover surface can also be cleaned with water after the construction on the same day.
When installing the cast iron manhole cover on the asphalt pavement, attention must be paid to avoid the construction machinery directly rolling the manhole seat. When the pavement is cast as a whole, holes slightly larger than the manhole seat should be reserved on the pavement and placed after the asphalt pavement is completed. (The full concrete pavement shall be installed after the second stone is paved and compacted) Ensure the placement quality of the manhole cover to extend the service life.
