지반-말뚝 시스템에 대한 3차원 동적 수치 모델링 기법 개발 = Development of 3D Dynamic Numerical Simulation Method on a Soil-Pile System

다국어 초록 (Multilingual Abstract)

The dynamic behavior of piles becomes very complex due to soil-pile dynamic interaction, soil non-linearity, resonance phenomena of soil-pile system and so on. Therefore, the proper numerical simulation of the pile behavior needs much effort and calculation time. In this research, a new modeling method, which can be applied to the conventional finite difference analysis program FLAC 3D, was developed to reduce the calculation time. The soil domain in this method is divided into a near-field region and a far-field region, which is not influenced by the soil-pile dynamic interaction. Then, the ground motion of the far-field is applied to the boundaries of the near-field instead of modeling the far-field region as finite meshes. In addition, the soil non-linearity behavior is modeled by using the hysteretic damping model, which determines the soil tangent modulus as a function of shear strain and the interface element was applied to simulate the separation and slip between the soil and pile. The proposed method reduced the calculation time by as much as one third compared with a usual modeling method and maintained the accuracy of the calculated results. The calculated results by the proposed method showed a good agreement with the prototype pile behavior, which was obtained by applying a similitude law to the 1-g shaking table test results.

참고문헌 (Reference)

1 Dobry, R, "Simple Method for Dynamic Stiffness and Damping of Floating Pile Groups" 38 (38): 557-574, 1988

2 Iai, S, "Similitude for shaking table tests on soil-structurefluid model in 1g gravitational field" 29 : 105-118, 1989

3 Hardin, B. O, "Shear Modulus and Damping in Soils: Design Equations and Curves" ASCE 98 (98): 667-692, 1972

4 Boulanger, R.W., "Seismic Soil-Pile-Structure Interaction Experiments and Analyses" ASCE 125 (125): 750-759, 1999

5 Remaud, D, "Piles under Lateral Forces: Experimental Study of Piles Group" University of Nantes, France 1999

6 Itasca Consulting Group, "FLAC3D (Fast Lagrangian Analysis of Continua in 3Dimensions) User’s Guide" Minnesota, USA 2006

7 Yang, E. K, "Evaluation of Dynamic p-y curves for a Pile in Sand from 1g Shaking Table Tests" Seoul National University, South Korea 2009

8 Kaynia, A, "Dynamic behavior of pile groups" 509-532, 1982

9 Makris, N, "Dynamic Pile-Soil-Pile Interaction - Part II: Lateral and Seismic Response" 21 (21): 145-162, 1992