Influence of lateral cyclic loading on the piled-raft foundation embedded in layered soil

The work includes an experimental analysis was performed to determine the impact of several variables on the behavior of laterally loaded piled raft model (2×2) having a ratio of length to diameter (L/D=40) and a diameter spacing (S / D) ratio of 3, 5 and 7 at frequency (0.2) Hz embedded in layered soil. The results are submitted as load-deflection curves and bending moment profiles. The effects of degree of saturation, number of cycles, level of cyclic loads, and the location of piles in a row are studied in this work. The results illustrated that increasing degree of saturation for clay soil (mid-layer) decreasing the lateral resistance of this model by about (25%, 31%, and 39%) for S/D=3, 5, and 7 respectively and bending moment by about (7%, 15%, and 17%) for S/D=3, 5, and 7 respectively. The piles in the front rows resist the soil with its full capacity, while in the trailing rows (i.e back) the shadowing effect tends to cause a reduction in soil resistance. The results clarified that maximum bending moment for trailing row less than the leading row by about 7%. The presence of vertical loads lead to an improvement in the lateral resistance of the model with dry clay soil about (28%, 26% and 12%) for S/D=3, 5, and7 respectively, whereas the increase in the horizontal resistance of the model with partially saturated clay soil about (40%, 45%, and 44%) for S/D=3, 5, and 7 respectively, compared with the absence of vertical loads.