多雨地区斜坡地基上不同高度加筋格宾挡土墙力学行为研究

Study on Mechanical Behavior of Reinforced Gabion Retaining Wall with Varying Height on Sloping Foundation in Rainy Area

摘要:

为研究多雨地区斜坡地基上不同高度加筋格宾挡土墙在施工期多雨条件下的力学行为演化规律,依托沪渝蓉高速铁路宜昌北动车所加筋格宾挡土墙工程,采用现场试验和数值模拟的方法对相互衔接的不同高度加筋格宾挡土墙(双级和单级墙体型)应力和变形演化规律进行对比分析研究。研究结果表明:双级和单级加筋格宾挡土墙各级基底处竖向应力在填筑期间沿土工格栅铺设方向呈非线性分布,但双级挡土墙上级墙基底竖向应力小于单级挡土墙;随着填筑高度的增加,双级和单级挡土墙各层墙背水平土压力逐渐增大,但增长速率随填筑高度的增加而减小;双级和单级挡墙各层土工格栅应变随填筑高度的增加而增大,沿其铺设方向呈非线性分布,且格栅应变分布曲线出现明显峰值现象,主要有单峰分布和双峰分布两种形式。工后双级和单级加筋格宾挡土墙变形的数值模拟分析可知,二者墙顶差异沉降很小,仅为4.24 mm;墙面水平变形整体呈外倾形式,最大水平位移分别为5.42、2.55、5.69 mm,分别占本级墙高的0.068%、0.059%和0.071%。双级挡墙上级墙墙面的水平变形形式及大小与单级挡墙较为一致。

Abstract:

To investigate the mechanical behavior evolution of the reinforced Gabion retaining wall at different heights on slope foundation in the rainy area under the condition of rainfall infiltration during the construction period, a study on the stress and deformation evolution of a reinforced gabion retaining wall with varying height was conducted using field tests and numerical simulations, relying on an actual engineering of the EMU Maintenance Station in the Yichang North Railway Station of the Shanghai-Chongqing-Chengdu High-speed Railway. The research results show that the vertical stress at the base of each level of the double-level and single-level reinforced gabion retaining walls distributes non-linearly along the direction of the geogrid laying during the filling process, but the vertical stress at the base of the upper wall of the double-level retaining wall is less than that of the single-level retaining wall; as the filling height increases, the horizontal earth pressure on the back of each layer of the double-level and single-level retaining walls increases, but the growth rate decreases with the increase in filling height; the strain of the geogrid in each layer of the double-level and single-level retaining walls increases with the increase in filling height, and it is distributed non-linearly along its laying direction, and the strain distribution curve shows a significant peak phenomenon, mainly in the form of single peak and double peaks. The numerical simulation analysis of the deformation of the post-construction double-level and single-level reinforced gabion retaining walls shows that the difference in settlement at the top of the two retaining walls is very small, only 4.24 mm; the overall horizontal deformation of the wall surface is in an outward-inclined form, and the maximum horizontal displacement is 5.42 mm, 2.55 mm, and 5.69 mm respectively, accounting for 0.068%, 0.059%, and 0.071% of the height of this layer of the wall. The horizontal deformation form and size of the wall surface of the upper wall of the double-level retaining wall are relatively consistent with those of the single-level retaining wall.