As he wrote in the article on geology, in difficult cases one has to consider more than one version of the foundations. If there is a landslide slope, heterogeneous soils, geological anomalies – there can be very different foundations, different options for the location of the house and its architecture (with or without a basement) – and ultimately different options for the cost. Each time it is very interesting to find a solution in all these cases, but today it’s about a site on a slope.
When it comes to the slopes, the forums say that it’s better not to build there, but in the news we hear about destruction, we see how the slopes slide, dragging houses, roads and trees. Is it all scary?
Fortunately, such disasters, as a rule, do not occur, because the probability of a slope sliding down is taken into account in the project. How this is done, I will tell you further, but now let’s start with what is a landslide process.
It occurs where there are special, landslide soils – and then, when they stop. These are loess (or loess-like sandy loam / loam), which sharply lose their strength when soaking: porous, they shrink when soaked, and the slope starts to move.
How to find out about this risk? Geologists do the drilling of wells under the building site of a future home, and several more wells along the slope, below and above the house. Having obtained soil samples, they recognize their properties and depths (as a rule, there are several of them, and they are arranged in layers).
Then they do the calculation, which shows where the curve of the potential slope slip.
And here it is already possible, firstly, to design the foundation (pile or plain, but to make a house with a basement), knowing the structure of the soil and their properties, and secondly, you can move the house to a safe place to get away from this potential slip curve , (and at the same time from unnecessarily expensive foundations or from the basement).
As this happens, let’s look at a specific example.
Given: plot on a slope, the Severn project. Geology shows the heterogeneity of soils (one of them – landslide), different depth of occurrence.
Four options are possible:
1. Pile through the landslide soil
2. make a subbasement under the basement floor –
