考虑冠梁的桩锚支护边坡试验与数值模拟

Experiment and numerical simulation of pile-anchor supporting slope considering top beam

以兰州港务区桩锚支护边坡实例为依托,通过无线自动化监测与有限元软件数值模拟相结合的方式,研究桩锚支护在未设冠梁(填土过程)阶段和设置冠梁(运营期间)阶段的支护结构内力与边坡稳定性的变化规律.结果表明:在未设冠梁阶段,随着填土高度的增加,桩身弯矩、锚杆轴力和边坡位移逐渐增大;冠梁设置后,可有效地减小桩身弯矩和锚杆轴力并且对桩顶附近土体有较强的约束作用,对边坡顶部位移的约束效果最为显著,边坡位移的影响从坡顶至坡底逐渐减小,也明显地提高了边坡的稳定性;随着运营期内支护结构与边坡土体应力的相互调整,两者的内力与位移趋于平稳变化.该试验可为西北黄土地区桩锚支护边坡的设计、施工和监测分析提供有益的参考.

Relying on the example of pile-anchor supporting slope in Lanzhou Port Affairs District,the combined approach of wireless automatic monitoring and finite element software numerical simulation was employed to investigate the variations in internal forces and slope stability of the pile-anchor supporting at the stage of no top beam(filling process)and setting of the top beam(during the operation period).The results show that at the stage without top beam,as the height of the fill increases,the pile bending moment,anchor axial force,and slope displacement gradually increase.After the installation of the top beam,the pile bending moment and the anchor axial force can be effectively reduced.The axial force of the anchor rod has a strong restraining effect on the soil near the top of the pile with the most significant constraint effect observed on the top displacement of the slope.The influence of the displacement of the slope gradually decreases from the top of the slope to the bottom of the slope,which also significantly improves the side stability of the slope.With the mutual adjustment of the supporting structure and the slope soil stress during the operation period,the internal force and displacement of both tend to stabilize.This test provides a useful reference for the design,construction,and monitoring analysis of the pile-anchor-supported slopes in the northwest loess area.