基于FLAC3D的堆载预压结合塑料排水板软土路基复合加固研究

在城市道路建设过程中，通常会遇到各种地质情况，软土地基是常见的地质问题之一。城市道路的路基是路面的基础，应满足强度、变形和稳定性的要求，由于软土具有天然含水量大、压缩性高、承载力低和抗剪强度很低等特点，当遇到软土作为路基基础时，应采取各类地基加固处理措施来对软土地基进行处理，使得城市道路能满足设计的要求。以湖南省益阳市经济开发区团圆南路道路工程为案例，通过FLAC3D数值计算，详细介绍了建立软土路基堆载预压结合塑料排水板复合加固有限差分法模型的步骤，通过数值模拟得到软土地基在堆载预压结合塑料排水板作用下的响应情况，并得到预压荷载施加后超静孔隙水压力消散规律，揭示了软土路基在堆载预压结合塑料排水板作用下的孔隙水压力、固结沉降分布特征，最终，获得了软土路基土体中孔隙水压力、各层总沉降、各层的分层沉降随着深度方向的变化规律，研究结论对软土地基处理起到很好的指导作用。

Study on Composite Reinforcement of Soft Soil Subgrade with Preloading and Plastic Drainage Board Based on FLAC3D

In the process of urban road construction, various geological conditions are usually encountered. The soft soil subgrade is one of the common geological problems. The roadbed of urban road is the foundation of pavement and should meet the requirements of strength, deformation and stability. Due to the soft soil with the characteristics of large natural water content, high compressibility, low bearing capacity and low shear strength, when soft soil is used as roadbed foundation, various subgrade reinforcement measures should be taken to treat the soft soil subgrade in order to make the urban roads able to satisfy the design requirements. Taking the South Tuanyuan Road Project in Yiyang City Economic Development Zone of Hunan Province as an example, the steps of establishing the finite difference method model of soft soil roadbed reinforced by preloading with plastic drainage board are introduced in detail through FLAC3D numerical calculation. The response of soft soil subgrade under the preloading and plastic drainage board is obtained through the numerical simulation, and the dissipation law of excess pore water pressure is obtained after preloading load is applied. The distribution characteristics of pore water pressure and consolidation settlement of soft soil roadbed under the preloading and plastic drainage board are revealed. Finally, the changes of pore water pressure, total settlement of each layer and stratified settlement of each layer in soft soil roadbed with the depth direction are obtained. The research conclusion plays a good guiding role in the treatment of soft soil subgrade.