Consolidation analysis of underlying soil stratum in composite ground with floating impervious columns(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2016年06期
- Page:
- 32-38
- Research Field:
- 道路工程
- Publishing date:
Info
- Title:
- Consolidation analysis of underlying soil stratum in composite ground with floating impervious columns
- Author(s):
- YANG Tao; YANG Huan; LI Guo-wei
- 1. School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, China; 2. Highway and Railway Engineering Institute, Hohai University, Nanjing 210098, Jiangsu, China
- Keywords:
- road engineering; analytical solution; consolidation; underlying soil stratum; impervious column; impeded boundary
- PACS:
- U416.1
- DOI:
- -
- Abstract:
- Impervious columns often penetrate partially into soft soil with a great thickness as floating columns. The overall average consolidation rate of a composite ground with floating impervious columns depends largely on that of the underlying untreated soil. So far, no simplified solution was available to estimate the consolidation rate of the underlying soil. Based on the analytical solutions to average excess pore water pressures within a composite ground with floating impervious columns, analytical solution to the average degree of consolidation of underlying soil was derived. Influences of the penetration ratio and replacement ratio of impervious columns and the constrained modulus ratio of columns to surrounding soil on consolidation rate of the underlying untreated soil were investigated using the proposed analytical solution for parameter analysis. The results show that for the composite ground with impervious columns whose rigidity are larger than soil-cement material, the consolidation rate of the underlying soil depends mainly on the penetration ratio of the impervious columns. It increases with the increase of penetration ratio of impervious columns, and increases slightly with the increase of replacement ratio of the columns. Based on the consolidation behavior of the underlying soil, a new method for calculating average consolidation degree of the underlying soil, called as “equivalent impeded boundary method”, is proposed by use of the one-dimensional consolidation theory of natural ground with impeded drained boundary through regarding the reinforced zone in the composite ground as an impeded boundary of the underlying soil. The formula for calculating the thickness of impeded boundary is presented considering the effect of penetration ratio and area replacement ratio of the impervious columns. Correctness and calculation accuracy of the proposed method are verified through the comparison of consolidation degree of the underlying soil by the proposed method and the analytical solution.
Last Update: 2016-12-02