常规次固结沉降计算方法的改进研究

Study of improvement of secondary consolidation settlement calculation method

软土具有高含水率、大孔隙比等特点,在荷载作用下超静孔隙水压力消散后会产生次固结变形。实际工程中很多工程问题是由土体的次固结引起,因此对其沉降进行计算和预测很有必要。针对常规次固结沉降计算方法的不足,进行了改进,使随时间的发展,次固结沉降趋于一个定值而不是无限增长。对Yin&Graham一维弹黏塑性模型进行了简要介绍,并进行了改进,结合改进模型提出一种次固结沉降起讫时间的确定方法。与常规计算公式相比,改进公式可行,且更加合理,可用于实际工程地基次固结沉降的计算。

Soft clay has characteristics such as high moisture content and large void ratio.After excess pore water stress dissipation under loading,secondary consolidation settlement is produced.A lot of geotechnical engineering problems are caused by it and it is necessary to calculate and predict the settlement.The general secondary consolidation settlement calculation method has a shortage that when load duration is infinite,settlement infinite.An improved formula is presented aiming at the shortcoming.Brief review is given on Yin Graham 1-D elastic viscoplastic model and improvement is given on it.A method to determine starting and finishing time of secondary consolidation settlement of soft foundation is put forward combined with the improved elastic viscoplastic model.The improved formula is feasible and more reasonable and can be used to calculate secondary consolidation settlement of foundation in actual engineering.