Open Collections

Liquefaction induced deformations of earth structures

University of British Columbia

Liquefaction-induced ground displacements resulting from earthquake shaking are a major cause of damage to earth structures comprising of or underlain by loose saturated sands. A number of dams have failed due to liquefaction-induced deformations. Examples of these are the failures of eleven tailings dams in Chile during the March 1965 earthquake and the Mochikoshi tailings dams in Japan due to the 1978 earthquake. A number of other dams have undergone large deformations but have not failed in as much as the impounded water was not released. The classic example of this was the near failure of the Lower San Fernando dam due to the 1971 earthquake. A liquefaction induced flow slide occurred on the upstream side removing the crest of the dam and leaving only about 1.5 m freeboard. Of more interest from the analytical point of view was the behaviour of the Upper San Fernando dam in which the crest of this dam moved about 1.5 m due to earthquake induced liquefaction. Of equal importance are the ground failures due to liquefaction-induced lateral spreading. It occurs on gently sloping grounds and sometimes on almost flat grounds, but usually occurs over a very wide area. Although this type of earthquake-induced ground movement does not involve a flow failure where the static shear stresses exceed the residual strength of soils, it is potentially damaging and it has caused over one hundred million US dollars worth of damage in United States alone since the 1964 Alaska earthquake. The prediction of earthquake induced displacements of earth dams involving soils whose properties change markedly during cyclic loading is a difficult problem. The difficulty mainly arises from modeling the stress-strain relations of soils, particularly when pore pressure rise and liquefaction occur. The strains required to trigger liquefaction are generally small (

Thesis/Dissertation

application/pdf

2009-06-04

For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.

http://hdl.handle.net/2429/8787

Civil Engineering

University of British Columbia

UBCV

DSpace