中文摘要：

长板-短桩工法综合了排水固结法和水泥土搅拌桩法在加固软土地基工程中的优点，适用于处理高速公路深厚软土地基。以江苏省淮安-盐城高速公路盐城试验段为原型和依据，利用Plaxis软件，针对长板-短桩工法、排水固结法和水泥土搅拌桩法三种工况下的路堤和地基性状进行了二维有限元计算分析。从数值分析的角度研究了长板-短桩复合地基的加固机理和特性，进一步认识了总沉降、分层沉降、侧向位移、潜在滑动面及超孔隙水压力等指标的特征，得到了一些有益的结论。

英文摘要：

Newly developed D-M method was a combination of vertical drain consolidation and cement mixing, and it had been proved to be suitable for the improvement of deep soft soil under highway embankment. According to the Yancheng test section of Huai＇an-Yancheng Highway project, three kinds of construction conditions including D-M method, PVD consolidation and cement mixing, were simulated by 2D finite element software Plaxis. The simulated results were contrasted and analyzed to cognize the mechanism and behavior of embankment and soft soil improved by D-M method. The characteristics of total settlement, settlement of different layers, lateral displacement, potential slip surface and dissipation of excess pore pressure were also presented.