Classification of piles based on the results of low strain pile integrity tests – Case studies of selected piles in Lagos and Port-Harcourt, Nigeria

Abstract

This paper presents the performance of low strain pile integrity test (LSPIT) based on data collected from selected piles in Lagos and Port-Harcourt industrial cities of Nigeria. Two types of piles were considered in this paper, namely bored piles (BP) and auger cast-in-place piles (ACIP). A brief review of LSPIT was carried out and the case studies were introduced. Wireless pile integrity tester (PIT-W) manufactured by Pile Dynamics Incorporation was applied for data collection and analysis. Basically, seven major categories of LSPIT can be introduced based on velocity curves reflection. These categories of piles are well detailed in the result section as AA, AB, ABx, PFx, PDx, IVx and IR. The classification above improves existing ones because information is available on precise pile length at which, soundness and defects of pile can be detected. Results obtained from case studies indicated that tested piles were primarily of the AA, AB, PFx and PDx categories/type. The study areas were chosen because most of the industrial application of piles in Nigeria can be found in these two cities. Summarily, all tested BP were structurally sound, about 78% of the all tested piles (BPs and ACIPs) were reported to be structurally sound, while 22% have impedance changes indicating slight soil intrusion, negligible voids within concrete mass without severe effect on the structural soundness of piles and they were typically ACIPs. The term ‘anomaly’ in this paper is used to describe piles with slight positive reflection for small necking, voids, cracks, etc.