Effect of spatial variation of strength and modulus on the lateral compression response of cement-admixed clay slab

被引：155
作者：
Liu, Y. [1 ]
Lee, F. -H. [1 ]
Quek, S. -T. [1 ]
Chen, E. J. [1 ,2 ]
Yi, J. -T. [1 ,3 ]
机构：
[1] Natl Univ Singapore, Dept Civil & Environm Engn, Singapore 117548, Singapore
[2] Huazhong Univ Sci & Technol, Sch Civil Engn & Mech, Wuhan 430074, Peoples R China
[3] Chongqing Univ, Coll Civil Engn, Chongqing 630044, Peoples R China
来源：
GEOTECHNIQUE | 2015年 / 65卷 / 10期
基金：
新加坡国家研究基金会;
关键词：
finite-element modelling; ground improvement; soil stabilisation; statistical analysis;
D O I：
10.1680/geot.14.P.254
中图分类号：
P5 [地质学];
学科分类号：
0709 ; 081803 ;
摘要：
In deep excavation construction, improved soil layers consisting of overlapping cement-admixed columns formed by deep mixing method or jet grouting are often used to stabilise an excavation in soft soils. The purpose of such soil layers is to resist lateral compression generated by movement of the retaining wall. Cement-admixed soils are well known to have high heterogeneity in strength. In this paper, the heterogeneity in strength and Young's modulus are studied using random finite-element analyses, considering three sources of variation: namely, a deterministic radial trend in strength and Young's modulus; a stochastic fluctuation component due to non-uniform mixing; and positioning errors arising from off-verticality of the mixing shafts. The results show that positioning errors have the largest effect on the strength of the slab as a whole, whereas the radial trend has the smallest effect, when normalised by the volume-average strength. Based on the results obtained, methods are proposed which allow equivalent homogeneous mass strength and modulus of the improved slab to be determined for a chosen percentile of exceedance or reliability index, which can be used in deterministic finite-element analyses.
引用
收藏
页码：851 / 865
页数：15
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