Clay soil is often referred to as “heavy soil.” In agriculture, clay soil can present a significant challenge mainly due to poor soil drainage. Clay soil also tends to compact and crumble into clumps when cultivated, trampled, or worked when wet.
Clay has tiny particles with tiny pore spaces or micropores. Because there are more pore spaces, clay loam has an overall larger total pore space than sandy soil, so the soil absorbs and retains more water. This makes it poorly aerated and poorly drained. Even when the soil dries, the delicate texture of its particles causes them to stick together or form clods. This makes it very difficult to work, hence the term “heavy soil.” The term “heavy” or “light” refers to the level of ease with which it can be worked and does not indicate its weight.
Clay soil that becomes too compacted may require a long time to restore to a good soil structure, as the inherent moist quality of clay soil requires the addition of large amounts of organic matter such as green plant materials, animal droppings, leaf mold, and compost to improve its structure.
The clay soil treatment Texas with lime for civil engineering has gained particular prominence in recent decades. In contact with clayey soil, lime clay soil treatment Texas produces a drying effect, a process of ion exchange and a pozzolanic reaction that manifests itself in a reduction of moisture; modification of its granulometry, microstructure, and porosity; an increase of permeability; reduction of plasticity; elimination of swelling; modification of compaction characteristics; increase of consistency and long-term resistance with less deformability and increase of resistance to erosion. A series of critical factors condition these improvements:
- Clay content and its mineralogy
- The presence of organic matter and soluble sulfates
- Soil plasticity
- Type and form of lime application
- Compaction moisture
- Ripening and curing period as well as temperature
- The presence of water and its flow and the formation of ice
Once the soil has been stabilized, you should reach for the most robust substrate that appears to be under 196 inches (you must confirm its strength). If you lay a foundation on the level of expansive clays, you may have many problems in the future.
The most solid foundation is to make spread footings under the walls at a depth that reaches about 12 to 16 inches below the clay layer, making trenches 71 feet deep by about 16/20 inches wide (or at least 4 inches wider than the walls). This running “shaft” works only in compression so that you can make a cyclopean foundation of stone and hydraulic lime. This foundation will go perimetrically under all the walls.
Another option would be to make a shallow strip footing and make punctual shafts that reach 71 every 120 feet approximately, but then you have to reinforce those struts with bamboo. So they may end up rising a little due to the effect of the expansive clays. This solution is simpler and cheaper than the previous one because there is less foundation volume, but not as safe.