长期反复荷载作用下软黏土地基的变形特性

软黏土地基在长期反复荷载作用下容易产生变形大、沉降时间长且难于预测等问题。针对该问题，通过太沙基一维固结理论，求解了矩形及梯形反复荷载作用下软黏土地基的一维固结解析解；利用ABAQUS有限元软件，提出了一种反复荷载作用下软黏土地基长期固结变形的数值分析预测方法。利用该方法结合工程实例详细分析了反复荷载下软黏土地基沉降、孔隙压力和有效应力及孔隙比等随时间的长期发展变化规律，发现沉降量与反复荷载的水平加载段时间成正比；孔隙水压力的最终发展趋势是围绕0值上下波动；有效应力随着加载次数逐渐增加；孔隙比的变化与土层深度、加载大小与加载次数有关，并将不同荷载类型下的模拟值、理论值和实测数据进行了分析比对，发现等效的反复荷载下的沉降曲线与实测值吻合较好。

Deformation characteristics of soft soil foundation under long-term repeated loading

Soft soil foundations are prone to large deformation, long settling time and difficult to predict under long-term repeated loading.Aiming at this problem, the one-dimensional consolidation analytical solution of soft soil foundation under rectangular and trapezoidal repeated loads is solved by the one-dimensional consolidation theory of K.Terzaghi.The soft soil under repeated loading is proposed by ABAQUS finite element software.Numerical analysis and prediction method for long-term consolidation deformation of foundation.This method is combined with engineering examples to analyze the long-term development and change of soft soil foundation settlement, pore pressure, effective stress and void ratio under repeated loading with time.It is found that the settlement is proportional to the horizontal loading time of repeated load; pore water the final development trend of pressure is to fluctuate around 0; the effective stress increases with the total number of loading times; the change of void ratio is related to soil depth, loading size and loading times, the simulated values, theoretical values and measured data under different load types are compared and analyzed, and the settlement curve under the equivalent repeated load was found to be in good agreement with the actual measurement.