I – Structural cracks:
Cracks are the result of the link between your building and the soil which must be considered as a whole “construction”.
Your house (single storey) must restore its mechanical load to the soil, which can be averaged at 2.5 to 3.2 T / m2. So your foundations, the footings for a 100m2 house will transmit 300 tonnes to the soil, which is quite significant.
It should be understood that the mechanical resistance of the soil and its contact surface will limit, depending on its dimensioning, the repercussions of soil movements and therefore of structural cracks, or foundation cracks. In this case, for the standard 25m2 seat soles, a load of 12 T / m2 will be transmitted to the soil.
Of course the compression bulb (zone of influence) will have its impact, the nature of the soil will be important in the process and will impact the foundation cracks.
This being said, the mechanical structure of your sub-works (foundations as a whole) will have its importance: types of steels entering the foundation reinforcement cage, the choice of constructing a collaborating raft foundation etc.