1 Full Scale Crash Test on a Group of Piles in Clay Mojdeh Asadollahi Pajouh 1 , Jean-Louis Briaud 2 , Dean Alberson 3, Dusty Arrington 4 , Alireza Mirdamadi 5 1 Ph.D. Candidate Zachry Dept. of Civil Engineering, Texas A&M University, College Station Texas, USA. Email: mojdeh84@tamu.edu 2 Professor, Zachry Dept. of Civil Engineering, Texas A&M University, College Station, Texas, USA. 3 Assistant Agency Director, Texas A&M Transportation Institute, Texas A&M University System, College Station Texas, USA. 4 Associate Transportation Researcher, Texas A&M Transportation Institute, Texas A&M University System, College Station Texas, USA. 5 Ph.D Zachry Dept. of Civil Engineering, Texas A&M University, College Station Texas, USA. ABSTRACT: This paper presents a full scale test on a pile group as part of a study on the lateral behavior of groups of piles subjected to impact loads. In recent years, pile groups have been installed as an efficient system to protect structures such as bridge piers, offshore platforms and significant buildings against extreme horizontal loads from ships or vehicles. There has been a crucial need to design such impact resisting structures embedded in soils. One of the most effective tools to understand the soil behavior during impacts is a full scale crash test. These tests are rare as they are expensive and difficult to run. This paper presents part of a comprehensive study on a group of four piles embedded 2 meters in hard clay, connected together with two beams, and designed to arrest a 2300 kg pickup truck with an approaching velocity of 100 km/h. In order to monitor the behavior of the piles and beams, the instrumentation included accelerometers on the truck, strain gages on the piles and high speed cameras for displacement. Such full scale tests can provide valuable data for calibration of analytical or numerical models. The details of the full scale test along with the measured response are presented. INTRODUCTION In recent years, the increasing number of vehicle crashes and associated concerns of tragic damage and loss of human life has attracted attention and emphasized the need for efficient impact resisting structures. One of the most widely used structures to shield bridge piers, berthing foundations and significant facilities is a group of piles directly embedded in the soil. In order to ensure a safe, practical and efficient design of these barriers, it is critical to understand the impact mechanism, the soil and pile behavior under impact loading, and the contributing factors to the barrier resistance. There are numerous studies available in literature addressing soil-pile interaction under dynamic loading either analytically or numerically (Wu & Fin , 1997; Brown & Bollman, 1996; El Naggar & Novak, 1996).A major part of these studies investigate the dynamic behavior of soil-pile systems through experiments (Brown, Morrison, & Resse, 1988; McVay, Zhang, Molnit, & Lai, 1998). To date however there are very few tests concerning impact loading on a group of piles. 1132 IFCEE 2015 © ASCE 2015 IFCEE 2015 Downloaded from ascelibrary.org by TEXAS A&M UNIVERSITY on 06/10/15. Copyright ASCE. For personal use only; all rights reserved.