معين خراشادي زاده

Different case studies have shown that liquefaction-induced lateral spreading caused significant damage to many important structures supported on pile foundations after major earthquakes. This study involved a comprehensive series of shaking table tests to eva‎luate the behavior of a single pile and a group of 2x2 circular piles with free and fixed heads when subjected to lateral spreading caused by liquefaction in sandy soil on an inclined slope. Additionally, the study aimed to compare the response of these pile groups in the presence of three distinct types of protection piles. Protection piles included circular piles upstream, finned piles downstream, and circular piles upstream. Instrumentation was implemented to record accelerations, excess pore water pressures, displacements of the piles' head and cap, and piles' bending moments. The results from the instrumentation showed that using finned protection piles with the same cross-sectional area as circular piles had a superior performance in disrupting soil flow, and reduced the lateral force exerted on the main piles by about 24-50%. Additionally, the results showed that non-protected free-headed piles could withstand a greater maximum bending moment compared to fixed-headed piles. It was observed that the reduction in bending moments was more significant in free-headed piles when protection piles were present compared to fixed piles. When finned piles were used as protection piles, the bending moments of the front and rear piles were reduced by approximately 31% and 21%, respectively, under restricted pile head conditions. Meanwhile, under free head conditions, the bending moments were reduced by about 34% and 42%. Furthermore, the modification factors of the recommended lateral pressure distribution along a pile, according to the Japanese Road Association (JRA) design code, were determined for the protected and non-protected free and fixed-headed pile groups of the current study. It was found that this modification factor (CL) was highly dependent on the location of piles in a group, pile head conditions, and the presence of protection piles in lateral spreading analysis.

گسترش جانبي , روانگرايي , شمع‌هاي محافظ , ميز لرزه , شمع‌هاي داراي باله , گروه شمع

Lateral spreading , protection piles , shaking table , finned pile , liquefaction , Group Pile

Moein Khorashadizadeh

Alireza Saeedi Azizkandi