The phenomenon of liquefaction in the foundation of the Persian Gulf dams using numerical modeling

The phenomenon of liquefaction in the fondation of the persian gulf dams using numericol modeling.Liquefaction is an important geotechnical phenomenon that causes severe structural damages during earthquake. This phenomenon usually takes place in saturated loose sandy soils under static/dynamic conditions. Interaction of solid and fluid phases during cyclic loading causes the pore water pressure builds up thus the effective stresses in the solid phases decrease. This leads to the reduction of the shear strength of the soil.The dams founded on loose sand deposits, are susceptible for liquefaction and damage. Liquefactionoccurrence in the dam foundation causes failure of dam or large permanent deformation in dam body.In this research, static and cyclic behavior of soils is analyzed by modeling of a two-phase medium considering interaction between its phases. Biot’s modified theory is employed for modeling saturated soil behavior. Analysis is carried out by applying dynamic loading of recorded earthquakes. Densification model is used for modeling liquefaction. In this research, PISA finite element software is modified and its capabilities are increased to do dynamic analysis as well as liquefaction modeling. Several static and dynamic problems are analyzed in order to verify the program’s formulation. Program’s results are compared with analytical solutions and/or other software’s results. In order to demonstrate the capability of the modified PISA for liquefaction modeling, results of a centrifuge experiment of VELACS project is used; and the obtained results from the program are compared with the experimental results and other numerical simulations’ output. Another centrifuge test was analyzed for demonstrating the modified PISA capability in the modeling of liquefaction occurrence in dam foundation. Numerical modeling results were compared with experimental and another numerical modeling results. Comparison showed that the PISA can capture the main features of liquefaction in dam foundation.

کلیدواژه ها:

ravangraei ، pisa ،