线性加载作用下软土地基固结变形分析

Consolidation Deformation Analysis of Soft Soil Foundation under Linear Loading

为明确线性加载作用下软土固结变形规律,通过一维固结理论和有效应力原理的方法求解了软土地基在任意加载速率下一维固结方程的通解,并求解线性加载下固结方程的解析解。结果表明:线性加载下软土地基产生的超静孔压可以分成增长期、快速消散期和缓慢消散期三个时期;加载速率影响超静孔压的增长路径、消散速率以及最大超静孔压值,最大超静孔压值与加载量近似成线性增长关系,加载速率对最大超静孔压值的影响存在临界值;固结系数影响临界加载速率,排水距离影响超静孔压的消散时间;加载速率改变沉降路径而不影响沉降值、改变固结路径并且影响固结时间;最后结合工程实例进行对比分析,发现基于线性加载固结方程解析解得到的理论值及变化规律与实测值有较好的吻合性。

In order to clarify the law of consolidation deformation of soft soil under linear loading,the general solution of the one-dimensional consolidation equation of soft soil at any loading rate was solved by using the one-dimensional consolidation theory of K.Terzaghi and the principle of effective stress,and the analytical solution of the consolidation equation under linear loading was solved.The results show that the excess pore pressure generated by the soft soil foundation under linear loading can be divided into three periods of growth period,rapid dissipation period and slow dissipation period.All factors of the growth path,dissipation rate,and maximum excess pore pressure value of the excess pore pressure are affected by the loading rate.The value of the maximum excessing pore pressure,with critical values existing for the effect of loading rate,and the loading amount grow approximately linearly.The consolidation coefficient affects the critical loading rate and the drainage distance affects the dissipation time of excessing pore pressure.The loading rate changes the settlement path and the consolidation path without affecting the settlement value or the consolidation time.Finally,the theoretical values and variation rules obtained from the analytical solutions of the linear loading consolidation equation are in good agreement with the measured values comparativing analysis with engineering examples.