Effect of soil plug removal on the load-carrying capacity of symmetric and non-symmetric pile groups

• Published in: Ships and offshore structures Vol. 15; no. 9; pp. 911 - 933
• Main Authors: Fattah, Mohammed Y., Salim, Nahla M., Al-Gharrawi, Asaad M.B.
• Format: Journal Article
• Language: English
• Published: Cambridge Taylor & Francis 20.10.2020; Taylor & Francis Ltd
• Subjects: Bearing strength; Carrying capacity; Components; Friction; Gauges; group; Internal friction; Length; Load carrying capacity; Pile groups; Piles; Pipe pile; plug; Reduction; Relative density; Removal; sand; Shear strength; Skin; Skin friction; Soil; Soil density; Soils; Strain gauges; Tests
• ISSN: 1744-5302; 1754-212X
• DOI: 10.1080/17445302.2019.1694298

This study comprises experimental tests that consist of 138 tests that are divided as follows: 36 tests for single pile, 36 tests for pile group (2 × 1), 36 tests for pile group (2 × 2) and 30 tests for pile group (2 × 3). All tubular piles are tested in poorly graded sand. Different parameters are considered such as the method of installation, relative density, removal of soil plug with respect to length of plug and pile length-to-diameter ratio. Strain gauges are used to separate skin friction with two components of shear resistance and end bearing. It was concluded that the removal of soil plug from piles (single or group) will cause a reduction in single and group capacities due to the elimination of two components, internal friction and the confining in end-bearing zone. The maximum reduction occurs in the dense state of soil with 61.5% and 83% for single and group of piles, respectively.