吸力强度修正对数模型在地基承载力中的应用

为准确反映非饱和土体中吸力对抗剪强度的影响规律，提出了吸力强度修正对数模型。与国内外试验结果相此，发现该模型在低吸力范围内与以往的模型有很好的同一性，而在高吸力范围内有着更大的优越性。该模型中各参数物理意义更为明确，与土-水特征曲线的特征值的关系更为紧密，通过引入参数b能更好地模拟具有不同特征残余值的土体。把该修正对数模型引入到地基承载力的分析中，发现饱和度对地基承载力的影响显著，吸力的存在能大大地提高承载力，并且饱和度越低，递增的速率也越大。

Application of modified logarithmic model for suction strength to bearing capacity of subsoil

In order to reflect the law on shear strength with respect to matric suction in unsaturated soil, a modified logarithmic model is presented. Through comparisons between some important test results at home and abroad, it can be found that the modified logarithmic model is identical with others in low suction range while it has obvious advantages than others in high suction range. In this modified logarithmic model, parameters have explicit physical meanings, and intrinsical characteristics of soil-water characteristic curve can be reflected. Various kinds of soils with different residual values can be modeled well by introducing the parameter named b. The modified logarithmic model is used to analyze the bearing capacity of subsoil under drained condition. The bearing capacity is influenced obviously by water saturation degree. Suction can increase the bearing capacity significantly. The rate of increment increases with the reduction of saturation degree.