Mechanisms of Property Changes of Soft Clays Around Deep Mixing Column

DOI

10.2991/ifeesd-16.2016.77How to use a DOI?

Keywords

soil mechanics; deep mixing column; mechanisms of property changes; disturbance; fracturing

Abstract

Installation of displacement types of columns such as driven pile, sand compaction pile,lime compaction pile,and deep mixing column causes stress changes in the surrounding soil. The properties will change in surrounding soil. Strength of the surrounding soil will decrease,recover,and increase after column installation. The mechanisms of effects of deep mixing column installation on surrounding clay can be identified into seven categories:disturbance or structure damage of soil surrounding the column due to blade mixing and expansion of admixture injection;thixotropic behaviour of soft clay;soil fracturing around column during mixing and expansion;cement penetration and diffusion from column to surrounding soil through fractures and soil pores;cementation due to increase of cation concentration in pore water;consolidation effect due to increase of effective stress in surrounding soil after excess pore pressure dissipation;heating caused by the chemical reaction of hydration and pozzolanic reaction. These influential factors were investigated through laboratory tests and theoretical analysis. As a result, for soft Ariake clay,test results show that strength due to thixotropic hardening regained completely within 70 days. Theoretical result shows that even in a very low admixture injection pressure,fracturing will occur in surrounding soil.

Copyright

© 2016, the Authors. Published by Atlantis Press.

Open Access

This is an open access article distributed under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).

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TY  - CONF
AU  - Yunhua Zhu
PY  - 2016/05
DA  - 2016/05
TI  - Mechanisms of Property Changes of Soft Clays Around Deep Mixing Column
BT  - Proceedings of the 2016 International Forum on Energy, Environment and Sustainable Development
PB  - Atlantis Press
SP  - 436
EP  - 442
SN  - 2352-5401
UR  - https://doi.org/10.2991/ifeesd-16.2016.77
DO  - 10.2991/ifeesd-16.2016.77
ID  - Zhu2016/05
ER  -