Xiashu loess strata are widely distributed along the middle-lower reaches of the Yangtze River in East China with the stratum near Nanjing,Jiangsu Province being typical.The cyclic variability of the stratum was inves...Xiashu loess strata are widely distributed along the middle-lower reaches of the Yangtze River in East China with the stratum near Nanjing,Jiangsu Province being typical.The cyclic variability of the stratum was investigated through comparison of geological features,chemical composition,and swelling-shrinkage properties between the loess and the paleosol layers.Based on the investigation of such a cyclic variability,soil behavior associated with the unsaturated state of the Xiashu loess stratum and its usefulness for geotechnical design and construction in the Nanjing area was analyzed. The stratum consisted of two types of cyclically alternating soil layers,namely the loess and the paleosol layers,which was the major cause for its cyclic variability.The loess and the paleosol layers were formed in different sedimentary environments.In order to avoid detrimental results from the differential engineering properties between them,this study suggested for the practitioners the importance of inspecting the variation of water content and controlling the downward net fluxes during geotechnical construction in the Nanjing area.展开更多
The swell-shrinking mineral of saturated and unsaturated expansive soil has important effect on engineering mechanical behavior. Based on the swelling-shrinkage change regularity of montmorillonite crystal in this pap...The swell-shrinking mineral of saturated and unsaturated expansive soil has important effect on engineering mechanical behavior. Based on the swelling-shrinkage change regularity of montmorillonite crystal in this paper, the actions between various interlayers of montmorillonite crystal are generally summarized as two kinds of action potentials-shrinkage potential and swelling potential. Moreover, through the experimental research and analysis, the expression formula for variations of the swelling potential and shrinkage potential with interlayer distance is presented, and the regularity of matric suction variations with interlayer distance is also obtained for unsaturated expansive soil. It may provide a new theoretical basis and research path for further research on the swelling-shrinkage mechanism of expansive soil and matric suction potential of unsaturated soil.展开更多
基金Project supported by the Foundation for the Key Disciplines of Nanjing University of Technology.
文摘Xiashu loess strata are widely distributed along the middle-lower reaches of the Yangtze River in East China with the stratum near Nanjing,Jiangsu Province being typical.The cyclic variability of the stratum was investigated through comparison of geological features,chemical composition,and swelling-shrinkage properties between the loess and the paleosol layers.Based on the investigation of such a cyclic variability,soil behavior associated with the unsaturated state of the Xiashu loess stratum and its usefulness for geotechnical design and construction in the Nanjing area was analyzed. The stratum consisted of two types of cyclically alternating soil layers,namely the loess and the paleosol layers,which was the major cause for its cyclic variability.The loess and the paleosol layers were formed in different sedimentary environments.In order to avoid detrimental results from the differential engineering properties between them,this study suggested for the practitioners the importance of inspecting the variation of water content and controlling the downward net fluxes during geotechnical construction in the Nanjing area.
基金the National Natural Science Foundation of China (Grant No. 19972068).
文摘The swell-shrinking mineral of saturated and unsaturated expansive soil has important effect on engineering mechanical behavior. Based on the swelling-shrinkage change regularity of montmorillonite crystal in this paper, the actions between various interlayers of montmorillonite crystal are generally summarized as two kinds of action potentials-shrinkage potential and swelling potential. Moreover, through the experimental research and analysis, the expression formula for variations of the swelling potential and shrinkage potential with interlayer distance is presented, and the regularity of matric suction variations with interlayer distance is also obtained for unsaturated expansive soil. It may provide a new theoretical basis and research path for further research on the swelling-shrinkage mechanism of expansive soil and matric suction potential of unsaturated soil.
