How to install the manhole cover to adapt to the height of the road

Theoretically, the whole sand well structure can be built as a whole, rather than being divided into two stages for installation, and with detailed calculations of the longitudinal settlement and the plane of the road surface intersection, it is possible to place and install the well cover frame and accurately level and settle it, but in actual operation, it is not always possible to accurately predict the slope and horizontal angle of the well cover to be placed later. This situation is not uncommon, so the installation of sand well covers is generally still divided into two stages:

(1) The first stage:

The lower part of the sand well (about horizontal with the base). Then it is placed in the open sand well and a rigid cover is placed on it on which the asphalt material of the road surface is constructed.

(II) Second Stage:

The asphalt material and brickwork around the rigid cover are normally adjusted to the final surface level of the road by adjusting the well cover and frame. Finally, the well cover and frame are installed in the position shown in the sketch below.