A question about civil engineering – related to the material of backfill soil
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This post was last edited by Lai Lai on 2009-7-31 at 16:34. For on-site construction, a small building needs to be built; the foundation is not very deep, about 2 meters. However, there is a fire water pipe beneath the foundation, buried at a depth of 3.4 meters. Since the soil in the trench is not compact enough after backfilling, what should be done? Is a special type of backfill soil required?
The backfill soil in the trench must be compacted in layers every 30–50 centimeters, not to mention that there is a foundation on top as well. The only options are to use water to sink it, or to excavate part of the backfill soil and replace it with sand mix or gravel; the density must be over 90%.
You have a small structure with low loads, and there’s also a 1.4-meter layer of soil on top; so it’s not a big problem. You can use a cover plate or stone masonry for coverage, but be careful since there are fire hoses above – can’t you just use something that isn’t placed directly on top of those hoses?
The fire protection pipes beneath the foundation are buried at a depth of 3.4 meters; it is possible to construct the foundation in such a way as to go over these pipes, and the trench beneath the foundation should be backfilled with soil in layers while compacting it to reduce settlement of the foundation! !