Task 4: DEM Modeling of Soil-Pile System Status Report Claudia Medina Mourad Zeghal RPI, February 15, 2005

Objective DEM modeling of soil-pile system – Coupled Soil-Pile model – Flexible (Elastic) Pile

Soil-Pile System

Soil-Pile Model Soil: Discrete Element Method (DEM) Pile: FEM (Bernoulli-Euler beam theory) Algorithm: DEM for particles Displacement for particles Force acting on the pile Forces acting on particles Displacement for pile FEM for pile

Bernoulli-Euler beam theory Beam finite elements – 2 end nodes and 4 DOF – Neglects transverse shear deformations

Element Equation

Global Equation [KG] =[KG] = K1K1 K2K2 K3K3 KnKn Assembly procedure for the beam with n elements

DEM model for a 10 element beam node 4 {u 4,  4 } node 5 {u 5,  5 } Element E5 q5q5 E1 E2 E3 E4 E5 E6 E7 E8 E9 E

Model Properties DEM modelPrototype g-level50g1g Pile Radius, R3 mm15 cm Length, L5 cm2.5 m Young’s modulus, E200 GPa Moment of inertia, I mm cm 4 No elements10 Deposit Slope5 (deg) Particle radius, r1 mm

DEM Simulation t = 0

DEM Simulation t = 0.05 sec

DEM Simulation t = 0.10 sec

DEM Simulation t = 0.15 sec

DEM Simulation t = 0.20 sec

DEM Simulation t = 0.25 sec

DEM Simulation t = 0.30 sec

DEM Simulation t = 0.35 sec

DEM Simulation t = 0.40 sec

DEM Simulation t = 0.45 sec

DEM Simulation t = 0.50 sec

Pile displacement

Thank you