### Numerical Analysis of the Soil Compaction Degree Under Multi-Location Tamping

WANG Wei1,2 (王威), DOU Jinzhong2 (窦锦钟), CHEN Jinjian2 (陈锦剑), WANG Jianhua2* (王建华)

1. (1. Engineering Research Center of Railway Environment Vibration and Noise of Ministry of Education, East China Jiaotong University, Nanchang 330013, China; 2. School of Naval Architecture Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240, China)
2. (1. Engineering Research Center of Railway Environment Vibration and Noise of Ministry of Education, East China Jiaotong University, Nanchang 330013, China; 2. School of Naval Architecture Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240, China)
• Online:2017-08-03 Published:2017-08-03
• Contact: WANG Jianhua(王建华) E-mail:wjh417@sjtu.edu.cn

Abstract: Abstract: Dynamic compaction (DC) is an efficient soil improvement technique. The previous numerical studies mainly focus on the soil response of single location tamping, but ignore the soil compaction degree under multilocation tamping. In this study, a numerical investigation of multi-location tamping in granular soils is carried out using three-dimensional (3D) finite element model (FEM). The behaviors of the granular soils are described by means of the viscoplastic cap model. The constitutive relationship of the soils is implemented into LS-DYNA and is integrated with 3D FEM for numerical investigation. Then utilizing the field data from the previous studies, we investigate the soil compaction degree at different stages by a case of two basic patterns, and discuss the cause of soil response. Lastly, we evaluate the effect of construction parameters on soil compaction. The simulation results show that the previous tamping affects the soil compaction degree beneath the adjacent tamping location, and the effect is greater near the side of previous location. Meanwhile, the soil compaction degree around the existing tamping crater weakens due to the adjacent tamping. Moreover, the rational selection of DC construction parameters can improve the soil compaction degree, and some hints on the effect of soil compaction are given.

Key words: dynamic compaction (DC)| soil improvement| multi-tamping locations| finite elements| plastic volumetric strain

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