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| INCREMENT CALCULATION OF SOIL SHEAR STRENGTH FOR SAND DRAIN FOUNDATIONS CONSIDERING GROUNDWATER LEVEL |
| BAO Shufeng1，2，3，MO Haihong1，DONG Zhiliang2，3，CHEN Pingshan2，3 |
| (1. School of Civil Engineering and Transportation，South China University of Technology，Guangzhou，Guangdong 510641，China；2. CCCC Fourth Harbor Engineering Institute Co.，Ltd.，Guangzhou，Guangdong 510230，China；3. CCCC Key Laboratory of Environmental Protection and Safety in Foundation Engineering of Transportation，Guangzhou，Guangdong 510230，China) |
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Abstract The actual development of shear strengths of soft soils in the thick hydraulic reclaimed foundations improved by the technology of pumped vacuuming combined with heaped preloading was qualitatively analyzed in terms of the principle of effective stresses and the method of stress paths. The development of soil shear strength under the groundwater level was found to be different from that of above the groundwater level. An analytical solution for soil shear strengths considering the effect of groundwater levels was therefore derived based on the theory of the uniqueness of effective stresses. The increments of soil shear strength at different depths after the dissipation of the excess pore water pressure under constant load in an area at Gaolan，Zhuhai seaport were calculated with the derived analytical solution. Comparisons with the results from the unconfined compression test and triaxial compression test revealed that the averaged error between the calculated and measured values is only 8.0% in terms of the undrained shear strength and is only 3.2% in terms of the shear strength in soil failure surface. Therefore，the calculated results based on the analytical solution agree well with the measured results.
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Received: 18 June 2013
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2014, Vol. 33 
