Consolidation solution for composite foundation considering a time-and depth-dependent stress increment along with three distribution patterns of soil permeability  

作　　者：Meng-meng LU Kang-he XIE Chuan-xun LI Kun WANG 

机构地区：[1]State Key Laboratory for Geomechanics and Deep Underground Engineering, School of Meehanics & Civil Engineering, China University of Mining & Technology, Xuzhou 221008, China [2]MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, Hangzhou 310058, China

出　　处：《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》2011年第4期268-277,共10页浙江大学学报（英文版）A辑（应用物理与工程）

基　　金：Project supported by the National Natural Science Foundation of China(No.51009135);the National Science Foundation for Post-doctoral Scientists of China(No.20100481183);the Science Foundation for Young Scholars of China University of Mining&Technology(No.2009A008)

摘　　要：In actual engineering practice,the stress increment within a composite foundation caused by external loads may vary simultaneously with depth and time.In addition,column installation always leads to a decay of soil permeability towards the column.However,almost none of the consolidation theories for composite foundation comprehensively consider these factors until now.For this reason,a stress increment due to external loads changing simultaneously with time and depth was incorporated into the analysis,and three possible variation patterns of soil's horizontal permeability coefficient were considered to account for the detrimental influence of column installation.These three patterns included a constant distribution pattern(Pattern I),a linear distribution pattern(Pattern II),and a parabolic distribution pattern(Pattern III).Solutions were obtained for the average excess pore water pressures and the average degree of consolidation respectively.Then several special cases were discussed in detail based on the general solution obtained.Finally,comparisons were made,and the results show that the present solution is the most general rigorous solution in the literature,and it can be broken down into a number of previous solutions.The consolidation rate is accelerated with the increase in the value of the top to the bottom stress ratio.The consolidation rate calculated by the solution for Pattern I is less than that for Pattern II,which in turn is less than that for Pattern III.In actual engineering practice, the stress increment within a composite foundation caused by external loads may vary simultaneously with depth and time. In addition, column installation always leads to a decay of soil permeability towards the column. However, almost none of the consolidation theories for composite foundation comprehensively consider these factors until now. For this reason, a stress increment due to external loads changing simultaneously with time and depth was incorporated into the analysis, and three possible variation patterns of soil＇s horizontal permeability coefficient were considered to account for the detrimental influence of column installation. These three patterns included a constant distribution pattern （Pattern Ⅰ）, a linear distribution pattern （Pattern Ⅱ）, and a parabolic distribution pattern （Pattern Ⅲ）. Solutions were obtained for the average excess pore water pressures and the average degree of consolidation respectively. Then several special cases were discussed in detail based on the general solution obtained. Finally, comparisons were made, and the results show that the present solution is the most general rigorous solution in the literature, and it can be broken down into a number of previous solutions. The consolidation rate is accelerated with the increase in the value of the top to the bottom stress ratio. The consolidation rate calculated by the solution for Pattern Ⅰ is less than that for Pattern Ⅱ, which in turn is less than that for Pattern Ⅲ.

关 键 词：CONSOLIDATION Composite foundation Stone column PERMEABILITY Ramp load Disturbance effect 

分 类 号：TU43[建筑科学—岩土工程]