DESIGN CONSIDERATION OF PILES AGAINST LATERAL SPREADING CAUSED BY LIQUEFACTION

The liquefaction is response of loose saturated sand to cyclic loading of earthquake in which the sand loses its strength as a result of excess pore water pressure and tendsto liquefy. Accordingly, there is a high potential for lateral movement of soil on slop and severe damage to structures in coastal ports during earthquake as reported around theworld [1]. Generally, excessive pore water pressure in vulnerable soils during earthquake has twofold unwanted effects on structures as: • lateral and vertical strength reduction of soil• additional lateral load due to the lateral spreading/movement of soils on slope In this study, the flexural mode of failure in marine piled-structure, as one of the most important cases of maritime structures is investigate and local strengthening of vertical piles in a real case is examined. Upper and lower band of lateral strength of soil is considered to adoptstrengthening length of piles.