Where is quick clay common in Canada?

Where is quick clay common in Canada?

In Canada, the clay is associated primarily with the Pleistocene-era Champlain Sea, in the modern Ottawa Valley, the St. Lawrence Valley, and the Saguenay River regions. Quick clay has been the underlying cause of many deadly landslides.

Why is Leda clay important in Ottawa?

Leda clay has a high-water content, which makes it highly compressible. Putting extra weight on it – such as the weight of a new home – has the potential to squeeze out some of the water, so that the clay compresses.

What caused the Rissa landslide?

The Case of the Rissa Landslide In April 1978, an earth fill was placed at the shore of the lake after excavations works were completed at a nearby barn. Suddenly, an 80-meter part of the shoreline slid into the lake as a result of the load applied by the earth fill.

Where is quick clay?

Quick clay is found below the marine level (the present elevation of where the sea level was at end of the last ice age) in Scandinavia. The Scandinavian peninsula (Norway and Sweden) was covered with an ice layer of about 3 000 meters (about 20 000 years ago).

Where is clay found in Ontario?

The principal clay areas are the former beds of glacial Lake Barlow – Ojibway, north of the height of land in northeastern Ontario, and glacial Lake Agassiz in north western Ontario.

What is Rissa landslide?

The famous 1978 quick-clay landslide at Rissa is the largest to have struck Norway in the last century. Of the 40 people caught in the landslide, one person died. The water waves that were generated by the landslide as it entered Lake Botnen, caused flooding and much damage in the village at the other side of the lake.

What are sensitive clays?

Clays may be described as sensitive when the undisturbed strength is greater than the disturbed (remoulded) strength, where the remoulded material can behave as a fluid (Geertsema and Torrance, 2005). Sensitivity is defined as the ratio of the undisturbed shear strength and the disturbed shear strength.

Can you build a house in clay soil?

Soil with good structure is more stable. Clay textures are often more stable than sand textures because they have better structure. However, a mix of particle sizes (and pore sizes) is best for engineering (just as it is best for growing crops).

What soil region is Ottawa in?

Sandy Soils
Sandy Soils (silty sand, gravel) Sand deposits in the Ottawa area are found in two main areas. First, in a large triangular patch extending across the Ottawa airport site and the lands to the south, and second, along beaches of old channels of the Ottawa River, such as Mer Bleu, an area southeast of the City.

What kind of failures can quick clays cause?

quick clay slides occur in marine clays that have an unstable structure. Disturbance of that structure can cause a massive reduction in strength, which then destabilises the slope allowing failure on even low slope angles.

What is clay sensitivity?

The degree of sensitivity of a clay is defined as the ratio of (compressive strength undisturbed) to (compressive strength remoulded), remoulding being carried out in such a manner as to avoid any change in water content.

How is marine clay formed?

When clay is deposited in the ocean, the presence of excess ions in seawater causes a loose, open structure of the clay particles to form, a process known as flocculation. Once stranded and dried by ancient changing ocean levels, this open framework means that such clay is open to water infiltration.