Settlement and Deformation Pattern of Modeled Wooden Piles in Clay

Abstract

This paper presents the results of laboratory experimental investigation on settlement and deformation pattern of modeled wooden square and circular piles in clay. The modeled piles were sawn, sharpened and carved from strong wood obtained from Minsk, Belarus. The configurations of circular section consist of 20mm and 200mm for diameter and length respectively. The square section is 20 x 20 mm, with a length of 200 mm. Single pile as well as pile groups of 2x2 (4 piles) with centre to centre spacing (a) = 4d, and 3x3 (9 piles) with centre to centre (a) = 3d, were driven into clearly marked layered clay soils differentiated by moisture and density of w = 20%, γ = 17 kN/m3 for the weak; w = 10%, γ = 19 kN/m3 for the strong), and a third layer of reinforced weak soil having reinforcing bars placed in it. The tests were conducted in a specially designed testing equipment/tank. The loadings were applied at the rates of 0.01, 0.05, 0.1 and 1mm/min. The modeled piles were subjected to axial compressive loads and the effect on the settlement of the soils in the inter-pile spacing, as well as those under and around the piles were evaluated. Pile displacement increased linearly with the applied loads. The pile axial capacity increases with the loading rate. The initial settlements of square piles are generally higher than in circular piles, but the latter gives higher over-all settlement than the former. Lateral deformations decrease with increase in distance from the pile, and outward radial deformations around the pile decrease down-wards along the pile depth.