Quote:
Originally Posted by e-clam9
Hi, I just wonder which way is more earthquake proof ? With caissons into the solid rock foundation, or without it (like Surrey) ? I wonder if BC has high standard on earthquake building code. Thanks.
|
Building on bedrock is the most solid basis. In an earthquake, bedrock typically moves less and so transfers less lateral load to a structure. It is also less likely to shift at a larger scale.
Structural Piles that go through the sedimentary layers to solid bedrock achieve the first of those two situations. But, if the layers above the bedrock shift, they can move the piles off plumb or off the bedrock.
Structural piles that work by way of friction in sedimentary layers could, depending upon their design and depth, lose their bearing capacity as the soil liquifies or vibrates, both of which would reduce the required friction.
All of these issues can be designed around, using everything from complex pile arrangements to the construction of void elements alongside or around piling which allow water to exit the soil and so reduce liquifaction. As to your question specifically, an engineer will be most happy with the situation in Surrey, ultimately you can say it is the safest . . . but technologically, it is just the easiest/cheapest.
Remember, for earthquake design, it is not always the goal to keep a structure perfectly protected. The priority is to have structures that do not fail catastrophically, killing occupants. Partial failures that allow the time needed for safe egress and the prevention of the spread of fire - for big earthquakes, these are the bottom line goals.
Prev
Linear Mode
