EVALUATION OF CRITICAL HYDRAULIC HEAD DIFFERENCES FOR SEEPAGE FAILURE OF SOIL BY STANDARDS-Standard-formulation, design and real safety factors-
During excavation of soil from an area with a high groundwater level,seepage failure of soil such as piping or boiling becomes a problem.In recent years,a new type of accident has occurred with respect to seepage failure,because deep excavation has been proceeding due to the construction of large-scale structures.The critical hydraulic head differences between up-and downstream of sheet piles,Hc,that are calculated using standard evaluation methods for seepage failure of soil within a cofferdam,are discussed.In the standards,Hc is usually calculated conservatively,so a safety factor based on the standard s formulation,Fs (formula),is defined.In practice,construction work is also conducted under a design safety factor,Fs (design).Thus,the actual or true safety factor,Fs (true),is equal to a product of Fs (formula) and Fs (design):Fs (true) =Fs (formula) × Fs (design).In this paper,the evaluation methods by standards are classified into four groups.The actual safety factors for seepage failure of soil are discussed for three flow conditions (2D-,2DC-and AXS flow).The exact value of Hc is estimated by a Prismatic failure concept presented by the first author,which gives the almost same value of Hc as that obtained by experiments.
seepage failure standard evaluation methods flow conditions, safety factor
TSUTOMU TANAKA SHUANG SONG TAKUYA HIRAO TETSUO HIROSE
Department of Agricultural and Environmental Engineering,Kobe University,Nada,Kobe 657-8501,Japan CTI Engineering International Co.,Ltd.,Kamedo,Koto-ku,Tokyo 136-0071,Japan
国际会议
5th China-Japan Geotechnical Symposium(第五届中日岩土工程学术会议)
成都
英文
398-403
2013-05-18（万方平台首次上网日期，不代表论文的发表时间）