steel safety bollards
The embedded depth of the casing shall meet the design requirements, and the embedded depth shall meet the following requirements:
1. When the casing is buried in dry land or shallow water, for the impervious bottom layer, the burial depth should be 1.0-1.5 times the outer diameter of the casing, but not less than 1.0m; for the permeable bottom layer such as sand and silt, the buried depth is the same as above, but It is advisable to replace with impermeable soil to not less than 0.5m below the edge of the protective tube, and the replacement diameter should exceed the diameter of the protective tube by 0.5-1.0m.
2. In deep water and riverbed soft soil and thick silt layer, the bottom edge of the protective tube should go deep into the impermeable layer; if there is no impermeable layer, it should enter 0.5-1.0m into the large gravel and pebble layer.
3. For riverbeds affected by scouring, the bottom edge of the protective tube should enter not less than 1.0m below the general scour line. For riverbeds seriously affected by local scour, the bottom edge of the protective tube should enter not less than 1.0m below the local scour line.
4. In seasonally frozen soil areas, the bottom edge of the protective tube should penetrate not less than 0.5m into the unfrozen soil layer below the freezing line; in permafrost areas, the bottom edge of the protective tube should penetrate into the permafrost layer no less than 0.5 m. 0.5m.
5. In dry land or when the water depth is less than 3m and there is no weak soil layer at the bottom of the island, the casing can be buried by open-cut method, and the clay soil filled at the bottom and surrounding of the casing must be compacted in layers.
6. When the cylinder body is less than 3m, and the silt and soft soil at the bottom of the island are not thick, the open-cut burying method can be used; When the hammer sinks, the plane position, vertical inclination and connection quality of the casing should be strictly controlled.
7. In the waters where the water depth is greater than 3m, the protective casing should be assisted by the working platform and guide frame, and the methods of vibration, hammering, water jetting, etc. should be used to sink.
8. The top surface of the casing should be 2m higher than the construction water level or groundwater level, and 0.5m higher than the construction ground, and its height should still meet the requirements for the height of the mud surface in the hole.
9. For the protective tube set in place, the allowable deviation of the top surface is 50mm, and the allowable deviation of the inclination is 1%.
Post time: Feb-08-2022