包裹式加筋土桥台结构性能现场试验研究

Field Monitoring on Structural Performance of a Mixed Geosynthetics Reinforced Soil Abutment

为探究包裹式加筋土桥台结构性能,依托安徽省明(光)巢(湖)高速公路包裹式加筋土桥台项目,进行现场原位监测。通过工后330 d的现场监测,研究了包裹式加筋土桥台面板后水平土压力、桩侧水平土压力、面板水平位移、面板沉降,以及土工格栅应变等分布和变化规律,同时探讨了绕桩格栅截断对面板后水平土压力分布的影响。结果表明:面板后水平土压力沿墙高呈非线性分布,面板中部水平土压力大于其他位置,同时墙趾约束会使底部水平土压力逐渐增大,格栅绕桩截断对面板后水平土压力未造成显著影响;桩侧水平土压力沿高度呈近线性分布,盖梁的存在会使桩侧上部水平土压力偏小;面板水平位移和沉降在工后150~180 d内达到稳定状态,最大变形值均出现在道路中线附近;墙背土工格栅应变随墙高呈非线性分布,随桥台运营时间出现收缩现象。总体上,包裹式加筋土桥台在工后较为稳定,服役期间的监测数据可为今后类似工程设计施工提供参考。

Field test was conducted to examine the structural performance of a mixed geosynthetics reinforced soil(GRS)abutment in the Mingguang to Chaohu Expressway project in Anhui Province.The horizontal stresses behind face slab and pile,horizontal dislacement and settlement of the face slab,and the geogrid strains were examined based on monitoring data collected over 330 days post-construction of the mixed GRS abutment.The impact of geogrid truncation on horizontal stresses was also examined.Results indicated that horizontal stress distribution behind the face slab was non-linear,with maximum values occurring in the middle,while stresses gradually increased towards the bottom due to toe restraint.Geogrid truncation around piles had minimal influence on horizontal stresses.Horizontal stress distribution behind pile was linear along the elevation,with reduced stress on the top due to the presence of cap beam.Furthermore,face slab deformations stabilized within 150-180 days post-construction,with maximum deformations observed near the road’s centerline.Geogrid strain distributed non-linearly along the wall height,demonstrating elastic behavior with shrinkage and rebound under service conditions,indicating the geogrid is far from reaching ultimate strain.Overall,the mixed GRS abutment exhibits minimal deformation,and the monitoring data collected during the service period can inform the design and construction of similar projects.