عنوان مقاله [English]
Superstructures may subject to lateral load like earthquake, wind, wave impact and ship ducking. In these cases engineers prefer to apply piles or pile groups. The exact predictions of the load-deflection response of pile groups under lateral loading always have been a big challenge for engineers due to a lot of parameters involved. These parameters include soil relative density, type of soil and its classification, water table elevation, length and diameter of pile, type of load, rigidity of pile and pile cap and etc. In this study some experimental tests were performed to investigate the effect of cross section shape of pile on lateral resistance of pile group. In consideration of amount of material used to construct pile for optimum design, four different cross section shapes of piles with the same surface area were used. The cross section shapes of piles involved H pile, end closed pipe, square, and fin pile. Different condition such as pile arrangement, pile spacing and soil relative density for different cross section shapes of piles were assessed. A poorly graded sandy soil was used. The lateral load was applied on pile groups by using a 2.5KN capacity jack and the deflection of pile cap was measured by a dial gage with accuracy of 0.01mm. Results revealed that the ratios of lateral resistance of fin pile, square pile and H pile groups to that of pipe pile group were 1.39, 1.19, and 0.85, respectively. By increasing number of piles in group the average lateral load per pile in pile group reduced for all pile shapes. Also by increasing pile spacing from 3Dp to 6Dp, the lateral resistance of each pile in group and also group efficiency of all pile shapes increased significantly. Although, by increasing soil relative density the lateral resistance of pile groups increased, the group efficiency reduced to 50%.