抛石挤淤加固公路软基机理研究-《建筑科学与工程学报》

文章信息/Info

Title:: Study on Mechanism of Reinforcing Soft Soil Foundation of Highway by Dumping Riprap to Extrude Silt

Author(s):: ZHU Yan-peng, CHEN Yan-jiao; School of Civil Engineering, Lanzhou University of Technology

Keywords:: foundation treatment; dumping riprap to extrude silt; reinforcement mechanism; numerical simulation; monitoring data

摘要:: 选取兰永一级公路的9标段抛石挤淤处理段作为模型，采用有限元软件PLAXIS对其进行数值模拟研究并与实际监测资料进行对比分析；首先对比未处理和经抛石挤淤处理后的地基沉降、水平位移及孔隙水压力，然后选择模型的1个影响因素作为变量，研究该变量对抛石挤淤处理软土地基效果的影响，最后将模拟结果与实际监测数据进行对比。结果表明：经处理后的地基沉降和水平位移均明显减小，并且复合模量较大，整体性较强；孔隙水压力减小说明抛石挤淤处理使地基固结加快；路基沉降量均随抛石体模量、宽度及厚度的增大而减小；随回填砂土厚度变化不规律，需考虑实际情况及当地经验选取抛石体；模拟结果与实际监测结果相差不大，满足工程需求。

Abstract:: Selecting the 9th section of Lanyong firstclass highway which treating soft soil foundation by dumping riprap to extrude silt as the model, finite element software PLAXIS was used to make numerical simulation research and the numerical simulation results were compared with the actual monitoring data. Firstly, the subsidence, horizontal displacement and pore water pressure of foundation treated by dumping riprap to extrude silt and untreated foundation were compared. Secondly, a factor of the model was selected as variable, and the influences of the variable on the soft foundation treating effect by dumping riprap to extrude silt were studied. Finally, the simulation results were compared with the actual monitoring data. The results show that the foundation settlement and horizontal displacement significantly decrease after treatment. The composite modulus is larger and the integrity is stronger after treatment. The decrease of pore water pressure shows that the dumping riprap to extrude silt process accelerates the consolidation of foundation. The subgrade settlement decreases with the increase of width, modulus and thickness of riprap. Since the thickness of backfill sand changes irregularly, the riprap can be chosen according to the actual situation and local experience. The results of simulation and actual monitoring are not quite different, which meet the engineering requirements.