1. Wedge backfill
2. The distance is not less than 1.5 m from material to two sides of corrugated culvert pipe.
3. Paving material on both sides symmetrically at same time.
4. Vertical construction process that can from the center to both sides of the culvert, but also from both sides to the center of the culvert.
5. Unsymmetrical backfill would cause the pipe body irregular distortion, easy to cause an accident and collapse.
6. The pipe body would present regular deformation when layered symmetric backfill. After the termination of filling soil, the pipe body would repristinate original state.
Steel corrugated culvert is also called the corrugated pipe culvert, it is to point to lay buried culvert under the condition of road and railway use thread bellows. It is made of corrugated sheet metal rolls made of corrugated iron or with makings to circular corrugated pipe, widely used in highway, railway culvert, tong road, bridge, tunnel, temporary retaining wall of roadway supporting service road, drainage pipe and all kinds of mine and other projects. Productions are fabricated according to customer's request or the drawings requirement. These pipes are very adaptable to various environment.