According to the elevation of casing. According to the public information query, the elevation of the pile casing is drilled from the ground during pile construction, and the steel pile casing is built in after the orifice is slightly higher than the design elevation. When installing the pile casing, take out the soil sample at the lower part of the pile casing, and then pour cement slurry into the pile casing to make the pile body. At this time, after pouring to the design elevation, the mud will be squeezed upward and the liners will not be lifted upward.