基于有限元数值模拟的风积沙台背稳定性研究与实践

Research and Practice on Stability of Aeolian Sand Platform Backs Based on Finite Element Numerical Simulation

摘要:

沙漠地区优质筑路材料匮乏，乌玛公路沙漠段箱涵台背采用风积沙填筑，为评价风积沙台背稳定性，采用ABAOUS有限元数值模拟方法，分析风积沙台背的竖向沉降与应力分布特征，并以传统砂砾填料和新型轻质陶粒混凝土填料作为对照组开展研究。结果表明，三种填料最大竖向沉降、台后土压力及侧边反力的大小排序为砂砾＞风积沙＞陶粒混凝土，说明采用轻质填料是提高台背稳定性的有效措施，在资源匮乏的沙漠地区，风积沙可作为优良的台背回填材料，其沉降值可降低至砂砾类材料的50%左右，且涵台与填土应力水平可减少10%以上；通过风积沙台背实体工程观测可得，其最大沉降值11 mm与数值模拟所得沉降11.46 mm的相对误差仅为4.2%，进一步表明风积沙台背具有良好的稳定性。

Abstract:

The high-quality road construction materials are scarce in the desert area, and the box culvert platform back in the desert section of Uma Highway is filled with aeolian sand. In order to evaluate the stability of the aeolian sand platform back, ABAOUS finite element numerical simulation method is used to analyse the vertical settlement and stress distribution characteristics of the aeolian sand platform back, and the research is conducted on the traditional gravel filler and the new lightweight ceramsite concrete filler for comparison. The results show that the maximum vertical settlement, platform-back soil pressure and side reaction force of three kinds of fillers are in the order of gravel > aeolian sand > ceramsite concrete, indicating that the use of lightweight filler is an effective measure to improve the stability of the platform back. In the resource-scarce desert areas, the aeolian sand can be used as an excellent backfill material for the back of the platform, and its settlement value can be reduced to about 50% of the gravel materials, and the stress level between the culvert platform and the filler can be reduced by 10% or more. The relative error between the maximum settlement value of 11mm and the settlement of 11.46mm obtained through numerical simulation can be observed through the actual engineering on the back of the aeolian sand platform, which is only 4.2%, further indicating that the back of the aeolian sand platform has good stability.