Ultimate soil pressures for piles subjected to lateral soil movements

A series of laboratory model tests in soft clay was conducted to investigate the behavior of coupled piles subjected to lateral soil movements ("passive" piles). and to determine the ultimate soil pressure acting on the pile shaft. Two piles in a row (center-to-center "joining" line being perpendicular to the direction of the applied soil movements) and in a line (center-to-center "joining" line being in the direction of the applied soil movements) were considered. The ultimate soil pressures along the pile shaft for two piles in a row and in a line with pile spacings of three and five times the pile width (B = 20 mm) were lower than those for single passive piles. Group effects still existed even with a pile spacing of 5 B for coupled piles in a row and in a line, Group factors decrease as pile spacing decreases for piles in a row. The test results also indicated that different distributions of limiting soil pressures along the pile shaft were developed for the single and coupled passive piles.