This concerns a new build in a gap site, surrounded by 1970s houses with basements; none of these had pile foundations or similar.
The soil expert for the building company (developer) has now completed their work and presents the following results.
According to the soil report:
During the ground investigation, a highly organic layer of floodplain clay and mud with very low load-bearing capacity was found between 0.90 - 2.80 m (3.0 - 9.2 ft) below ground level. Because of these soils being prone to settlement, additional measures are necessary for the foundation (such as pile foundations with bored piles or deep foundations with concrete shaft rings).
Ground/stratified water: Water strike at 2.70 - 2.80 m (8.9 - 9.2 ft) below ground level, measured after drilling completion at 1.60 - 1.70 m (5.2 - 5.6 ft) below ground level (pressurized). Groundwater is possible in sandy and gravelly layers depending on precipitation.
Groundwater level (GWL): 0.40 m (1.3 ft) below ground level [-0.78 m relative].
Seepage water: After heavy rainfall events, full saturation of soil pores up to ground level is possible (pore water saturation), resulting in puddle formation.
Soil profile:
1. From surface to 0.30 m (1.0 ft) below ground level: Topsoil, sand, silty - weakly silty, slightly humic.
Consistency/structure: loose to partly medium dense. Color: dark brown - brown-grey - dark grey - brown.
2. From 0.30 m to 0.90 - 1.00 m (3.0 ft) below ground level: Cover sediments, sand, strongly silty - silty.
3. From 0.90 - 1.00 m to 2.70 - 2.80 m (3.0 - 9.2 ft) below ground level: Floodplain clay/mud, silt, sandy - slightly sandy, slightly clayey, organic.
General characteristics: Layers 2 and 3 are highly organic (decomposed wood and plant remains with musty odor).
4. From 2.80 m to 5.00 m (9.2 - 16.4 ft) below ground level: Fluviatile sediments, sand, weakly silty, weakly gravelly, in core sample 1 from 4.60 m (15.1 ft).
General characteristics: Sand, strongly silty.
Question: Pile foundations would not only be costly but also much more complex due to pressure probing (15 m to 20 m [49 - 66 ft]), aerial survey proving freedom from utility lines and unexploded ordnance, monitoring, etc. Is there an alternative solution here?
Thank you in advance!
The soil expert for the building company (developer) has now completed their work and presents the following results.
According to the soil report:
During the ground investigation, a highly organic layer of floodplain clay and mud with very low load-bearing capacity was found between 0.90 - 2.80 m (3.0 - 9.2 ft) below ground level. Because of these soils being prone to settlement, additional measures are necessary for the foundation (such as pile foundations with bored piles or deep foundations with concrete shaft rings).
Ground/stratified water: Water strike at 2.70 - 2.80 m (8.9 - 9.2 ft) below ground level, measured after drilling completion at 1.60 - 1.70 m (5.2 - 5.6 ft) below ground level (pressurized). Groundwater is possible in sandy and gravelly layers depending on precipitation.
Groundwater level (GWL): 0.40 m (1.3 ft) below ground level [-0.78 m relative].
Seepage water: After heavy rainfall events, full saturation of soil pores up to ground level is possible (pore water saturation), resulting in puddle formation.
Soil profile:
1. From surface to 0.30 m (1.0 ft) below ground level: Topsoil, sand, silty - weakly silty, slightly humic.
Consistency/structure: loose to partly medium dense. Color: dark brown - brown-grey - dark grey - brown.
2. From 0.30 m to 0.90 - 1.00 m (3.0 ft) below ground level: Cover sediments, sand, strongly silty - silty.
3. From 0.90 - 1.00 m to 2.70 - 2.80 m (3.0 - 9.2 ft) below ground level: Floodplain clay/mud, silt, sandy - slightly sandy, slightly clayey, organic.
General characteristics: Layers 2 and 3 are highly organic (decomposed wood and plant remains with musty odor).
4. From 2.80 m to 5.00 m (9.2 - 16.4 ft) below ground level: Fluviatile sediments, sand, weakly silty, weakly gravelly, in core sample 1 from 4.60 m (15.1 ft).
General characteristics: Sand, strongly silty.
Question: Pile foundations would not only be costly but also much more complex due to pressure probing (15 m to 20 m [49 - 66 ft]), aerial survey proving freedom from utility lines and unexploded ordnance, monitoring, etc. Is there an alternative solution here?
Thank you in advance!
michert schrieb:
What type of building was the assessment based on? A house with or without a basement?The house is planned without a basement. A waterproof concrete basement here costs about 60,000€ (approximately $64,000), which is not economically viable.
lisaa11 schrieb:
In the neighborhood, there are exclusively houses from the 1970s with basements; none of them have pile foundations or similar.How were they founded instead – assuming your plot is not the only one located above a layer of poor soil – to build their houses (with basements)?Lumpi_LE schrieb:
Or build a wooden house, that weighs almost nothing..Even facts can change; the energy-saving regulations have also affected construction methods that were once lighter in weight.https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/
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