### INFLUENCE OF A ROUND CAP ON THE BEARING CAPACITY OF A LATERALLY LOADED PILE

Pages 63 - 68

Foundations of laterally loaded single piles are widely used as part of power transmission lines, wind power stations, highway structures, etc. Ongoing pressure applied to a laterally loaded pile, particularly at the ground level, causes the soil deformation characterized by the bulging of the soil surface.

In the majority of cases, the deformation strength of a pile depends on the front-face soil resistance, Horizontal beams, ground caps or rigid plates are used to increase the pile resistance. An effective method of pressure reduction contemplates the use of a rigid round cap at the front-face or upper level of the soil.

In this paper, the authors analyse the data to examine how a round cap installed at the ground level impacts the bearing capacity of a single pile.

This research based on the methodology developed by the authors demonstrates that a laterally loaded pile, supported by a rigid cap at the ground level, is exposed to increased resistance due to the following factors, including the passive pressure along the cap side that creates an unloading effect for a horizontally-loaded pile. The cap acts as a vertical soil rebuff creating an additional resistance moment; the horizontal shear of the cap causes supplementary lateral resistance of a pile.

The following initial geometric and elastic material properties of the single pile are applied: total length = 5.0 meters (3.0 m above and 2.0 m below the ground surface); pile diameter = 40 centimeters; circle plates of various diameters = 60; 70; 80 and 100 cm and their thickness = 20 cm. A lateral load is applied at various heights, , of 0.2; 1.0; 2.0 and 3.0 meters above the ground level.

Elastic properties of the soil are assumed to be constant at each point below the surface of the ground, they are listed below: bulk modulus of soil E=20 MPa; Poisson's ratio μ=0,37; unit Weight γ=18,5 kN/m; cohesion =0,05 MPa; angle of internal friction φ=20°.

The data has proven that cap-covered piles are substantially more economical (over 40 %) in terms of materials consumption rate if compared to constant cross-section piles (cap-free or broadening piles), all other factors being equal.

DOI: 10.22227/1997-0935.2012.4.63 - 68

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