National University Rail Center Innovative Fully Precast Retaining Wall System For Highways and Railroads Maen Farhat, Momenur Rahman, Mustapha Ibrahim and Mohsen Issa, Univeristy of Illinois at Chicago Primary Grant Support: Utility Concrete Products (UCP) Totally Precast Concrete Counterfort Retaining Wall (TPCCRW) system is an innovative solution to the growing need to develop sustainable retaining wall systems. Satisfies code requirements for strength, serviceability, durability, and constructability. Consists of face panel and 3 counterforts fabricated as a single entity and assembled with the precast base slab. From each counterfort, 5 headed anchors were extended and grouted in the base slab. I.Perform experimental study on a 20 ft. high, 166 in. wide full scale prototype (TPCCRW): Identify the optimum methods and stages of fabrication and prepare an advanced instrumentation and monitoring system. Experimental testing by soil backfilling followed by applying load scenarios (4 different tests) reaching 200 kips by using hydraulic actuators. II. Conduct a Nonlinear Finite Element Analysis (NLFEA) using ANSYS package: The nonlinear analysis is carried out imitating the exact construction sequence of a retaining-wall backfills and surcharge loads. Problem Statement & Motivation Technical Approach Key Achievements Future Goals The anchors, being the most critical component, succeeded to maintain serviceability, and ultimate strength requirements per AASHTO LRFD. The wall deflection in the middle (H/2) did not exceed 0.2 in. The finite element model showed that the proposed wall exhibits sufficient rigidity against lateral deflection. Moreover, it is observed that the failure of TPCCRW is controlled by the ultimate failure of headed anchor located farthest from the face panel. A comprehensive design for the TPCCRW meeting the requirements of AASHTO LRFD was performed. TPCCRW was adopted by Illinois Tollway to be implemented in future projects on Interstate I-90. Experimental Investigation and NLFEA of the performance of the headed anchors when subjected to pullout load. Parametric study using the validated finite element model to investigate the performance of the wall under different conditions (i.e. different height, different number of anchors, etc…) Precast counterfort Retaining wall with wing walls Precast counterfort Retaining wall during assembly Experimental test setup showing the hydraulic actuators Anchors extended from each counterfort Finite element modeling for the wall system Finite element modeling for anchors as they are extended from the counterforts Deflection Contours for the wall Load vs Deflection at H/2 In the middle counterfort of the wall Maximum strains in anchors at ultimate load at left counterfort Maximum strains in anchors at ultimate load at middle counterfort ANSYS results for load vs. strain in anchors at the middle counterfort Variation of deflection vs. elapsed time from 3 LVDTs at H/2 of the wall Stress distribution at the level of the base slab