Upshots of pin piles retrofitting for existing structures

Abstract

The heterogeneity of soil is an advantage as well as a disadvantage at the same time. The well graded soil possesses more density and stability then uniformly graded soil, but at same time because of uneven distribution of soil underneath the foundation soil may behave differently to different soil conditions. The soil beneath the foundation cannot be accessed directly therefore methods like pin piles came into the picture. The piles having diameter less than 300 mm are termed as pin piles. Under this portion of study the gain in strength by soil under the foundation of existing structure was noted down by an experimental method. The structure and subsequent conditions were simulated in the laboratory. The quantity and spacing of pin pile are interrelated. In the analysis the pin piles are inserted in the periphery of the existing footing in one line and footing size remains constant throughout the experiments, therefore the more spacing means less number of pin piles and vice versa. The distance between pin piles is termed as pitch length as measured from center to center.The distance from the outermost edge of footing is termed as edge distance also taken as variable. The experiments were designed in MiniTab 9.0 for suitable combinations of variables. The settlement of soil at 25 mm was considered a failure and optimized quantity and spacing of pin piles were determined. The positive effects of pin piles were observed when inserted in the periphery of existing footing.