Carrying capacity — Sensitivity

Load capacity is defined as the extent to which a soil is insensitive to setting (sacks of the ground level) as a result of overloading, e.g. increase in build-up, shallow-based buildings, sandways for roads and dike bodies. Upper load results in compaction of the clay/peat package, which causes the soil to be compressed and the ground level decreases. Settlement is actually a factor in subsidence. The term ‘setting’ is used in this factsheet in relation to carrying capacity. Thus, the less sensitive an area for setting is due to overload, the more loadable the subsoil is there, and therefore relatively more suitable for the construction of buildings and constructions. The good building lands are stable sandy soils with a lot of carrying capacity for constructions. Slack soils with low carrying capacity, which are sensitive to settlement and in which (not well-founded) constructions can sink away, contain a lot of clay and peat. Susceptible soils lie mainly in the west of the Netherlands, west of the higher sandy soils, in Friesland and parts of Overijssel and the Zuiderzee polders. The subsurface is weak. The more peat in the subsurface, the weaker the ground. When allocating funds from the Municipal Fund, this is called “bad land”. According to the legal definition, the substrate is ‘bad’ if in the upper 8 meters there is a connected package of clay and/or peat of at least 5 meters thick. But in practice, subsidences can also occur on thinner or deeper clay and peat layers. For example, pile foundations are used to derive capacity from deeper sand layers. Carrying capacity is shown in maps in different ways. Examples of this include: • Setting sensitivity card for overload • Minimum foundation depth pile foundations • Good/Bad land map (for Gemeentefonds) • Suitability for traditional construction • Suitability underground construction The last two are maps composed of maps of different properties of the substrate. The suitability for traditional constructions (buildings made of stone or concrete with a foundation on steel or piles, and infrastructure (roads, sewerage) without pile foundation) is composed, for example, of the building sensitivity map and the map of minimum foundation depths. Underground construction is an additional factor in groundwater pressure.