College of Engineering

A Master thesis was discussed in Department of Civil Engineering / College of Engineering at University of Mosul entitled “Behavior of retaining walls under static and dynamic loads: A numerical study” submitted by (Rowida Salih Khalaf Al-Khafaji), Supervised By Prof. Dr. Moataz A. Al-Obaydi and Dr. Qutayba N. Al-Saffar On Sunday, Nov. 20, 2022.The main objective of this research is to study the effect of the surcharge load distance on the behavior of the cantilever retaining wall under static and dynamic loads using the finite element software PLAXIS-2D. Many parameters have been considered in this study, including; the distance of the surcharge load (X) with respect to the width of the heel (Bh) (X/Bh=0, 0.25, 0.5, 0.75, 1, 1.5 and 2) and the magnitude of the earthquake excitation (kh=0.1, 0.2 and 0.3). The study also tackles the effect of the backfill soil type (sand and clay) where its simulation is considered the hysteretic damping. The effect of the height of the retaining wall has also been studied here.The results show a complex behavior of the cantilever retaining wall under both static and dynamic conditions. In general, the behavior of the cantilever retaining wall in terms of changing the surcharge load distance becomes clearer with the decrease in the height of the wall. Under static condition, the reductions in the lateral earth pressure that are produced by moving the surcharge load away from the wall (i.e. from X/Bh=0 to 2) are 44, 30 and 17% for retaining wall of H=5, 6 and 7m respectively that retain sandy soil. While with clayey soil, these values become 33, 20 and 8.3%. Under dynamic conditions, the reductions in the lateral earth pressure are 43.6, 32.4 and 21.5% for walls of H=5, 6 and 7m respectively with sandy soil, which become 33.3, 20.3 and 16% with clayey soil. Increasing the magnitude of the earthquake leads to a small increase in the lateral earth pressure when the surcharge load is close to the wall.