Table of contents:

How To Build A Foundation On Heaving Soil - 2
How To Build A Foundation On Heaving Soil - 2

Video: How To Build A Foundation On Heaving Soil - 2

Video: How To Build A Foundation On Heaving Soil - 2
Video: Foundation frost heaving 2024, March
Anonim

About the dangers of heaving soils - how to protect summer cottages from this harmful phenomenon

To the beginning

Figure 7
Figure 7

The same problem can be solved in another way. So, as shown in figure 7. Here the heaving forces do not act on the base of the foundation. This is achieved by the fact that the support is located below the level of soil freezing. However, there remains the danger of pressure on the foundation of the lateral grip forces. How to get rid of them can be seen in Figure 8. In this case, the lateral adhesion force is practically equal to the load created by the weight of the building, since there is non-porous soil around the foundation (in this case, coarse sand).

Figure 8
Figure 8

To reduce the action of lateral adhesion forces on the foundation, its side walls are coated with greases. A layer of grease isolates the foundation from the soil, and the heaving effect does not occur. The treated surface must be covered with a thick plastic wrap, isoplast, roofing material. And this coating is securely fixed to the foundation. Otherwise, the grease will mix with the soil, and then, as they say, start all over again. Care should also be taken to ensure that the grease does not absorb into the foundation material. For this, the walls of the foundation must be painted with waterproof enamels before applying the lubricant.

Figure 9
Figure 9

It should be noted that after the foundation supports have been installed, they must not be left unloaded, as they may move under the action of lateral adhesion forces. In an extreme case, around the foundation it is necessary to arrange a reliable heat-insulating coating of sawdust, slag, expanded clay and other materials that can protect the soil from freezing. To avoid the action of lateral adhesion forces, a shallow foundation must not be built on a frozen base.

But what to do if cracks or distortions still appear in the house or building? How can these destructive forces from swelling of the soil eliminate or at least slow down their action? The first step is to install reliable metal tightening strips or corners on the cracks (Figure 9). This is often very helpful.

Figure 10
Figure 10

I have been observing a multi-storey residential building with cracks in the walls for several years. It is on them that the tightening strips are installed. And I must say that over the years the cracks have not widened at all. The installation of the tie strips is perhaps the most radical attempt to prevent the walls and foundations from collapsing. Other measures mainly serve to weaken the effect of heaving forces as much as possible.

You can, for example, pour soil around the house (Figure 10). Or dig a ditch around the house 1.2-1.5 meters wide and up to 0.8 meters deep and replace the heaving soil with gravel or coarse sand (Figure 11). Practice proves that such a replacement can reduce the freezing depth to 40 centimeters.

In addition, it is possible to lay an insulating gasket about two meters wide from a mixture of slag and coarse sand to a depth of 20-40 centimeters (Figure 12). The layer of this mixture should be at least 20 centimeters, and it is laid on top of the same gravel and coarse sand 20-30 centimeters thick. It turns out, as it were, strengthening the lower layer with the upper one. This allows to reduce the freezing depth by 0.5-0.7 meters.

Figure 11
Figure 11

It is even desirable to build around the house a so-called "vegetable" protection against deep freezing of the soil. To do this, the thickest layer of turf is laid around the house and bushes are planted. They will retain and accumulate snow around them, thereby forming a thermal cushion, which significantly reduces the depth of soil freezing in comparison with snow-free areas.

Just remember that you cannot shovel snow from the house in winter. Except, of course, the tracks to it. They are small enough, and therefore do not have a significant effect on the freezing of the surrounding soil.

Drainage ditches are very useful for lowering the groundwater. They are dug out on both sides of the house in the direction of the general lowering of the site. Or they are sent to drainage wells, which are located as far from the house as possible. Sections of asbestos-cement pipes or other available drainage materials are laid at the bottom of the ditches. For example, various construction waste, broken bricks, rubble, small stones. After that, the ditch is covered with earth.

Figure 12
Figure 12

Of course, the most reliable of all is a properly arranged, buried foundation, laid below the level of freezing of the soil. This is a very reliable foundation that can withstand almost any deformation movement of the soil. However, its device is associated with a large amount of work, and, consequently, with a high cost. That is not always affordable for a summer resident.

But in any case, when constructing a foundation in heaving soils, both a sound technical solution and its impeccable practical implementation are required. Only then will it be possible to avoid the destructive phenomena associated with the deformation of the swollen soil.

Therefore, when starting construction on heaving soil, one must always remember this.

Alexander Nosov, jack of all trades

Recommended: