现场监测和数值模拟在土质边坡加固中的对比

COMPARISON BETWEEN WORKSITE MONITORING AND NUMERICAL SIMULATION IN THE SOIL SLOPE REINFORCEMENT

为分析土质边坡的加固效果、得出现场监测与数值模拟的异同点、保证施工质量、优化工程设计,以某农村村围预应力锚索——框架梁永久加固边坡为例,在ADINA有限元分析优化的基础上,通过现场实测变形及平面和空间模型数值模拟,对比分析得出:边坡位移和其变化速率大小均与坡度成正比,较大坡度区域是加固的重点;降水对边坡变形影响较大,应做好边坡排水防护工程;随着时间的增长,边坡变形幅度越来越小,变形趋于稳定,加固效果满足要求;平面和空间模型模拟边坡变形的趋势相同,空间模型与现场实测变形相吻合,误差±3 mm,满足工程要求,而平面模型模拟结果总小于现场实测值,且不稳定,最大误差达20 mm;空间模型和平面模型分别模拟出定量和定性的结果;空间模型更符合实际,但建模比较复杂且分析时间长;通过平面模拟可定性分析问题。因此,应根据不同阶段和分析的需要选用正确模型并进行有限元分析的优化;这些结论为边坡的加固、变形预测、有限元分析优化及边坡分析模型的选择提供了参考依据。

Aiming at analysing the reinforcement effect of soil slope,obtaining the differences and similarities between worksite monitoring and numerical simulation,thus construction quality can be ensured and the project design optimized.Taking the permanent reinforcement slope using prestressed anchor-cable and frame-beam in one village for example,based on the optimization of ADINA FEM,the following conclusions were got by comparison study on worksite monitoring and numerical simulations of plane and space models.Slope displacement and variation rate are directly proportional to the slope-angle,the area with big slope-angle needs the emphasizing reinforcement.Raining has a obvious influence on the slope deformation,so the drainage and protection engineering should be done well.Slope deformation rate becomes less and less,and the deformation tends to be stable with the time,the reinforcement effect meets the needs.Trends of slope deformation of plane and space simulations are the same,and the values of space simulation are in accordance with the worksite monitoring,the difference is only about ± 3 mm,while the values on plane simulation are always less than worksite monitoring,the biggest difference is about 20 mm.Simulations of space and plane model can get quantity-oriented and quality-oriented result respectively.Space model is more practical,while the model building is complex and the analysis time is long,we can use plane model to have quality-oriented analysis can be used,so,selecting proper model and optimizing the FEM are very necessary in different phases and needs.These conclusions provide references for slope reinforcement,deformation prediction,FEM optimization and the model selection of slope analysis.