分离式加筋土桥台性能及气候因素的影响研究

Research on the performance of disconnect-type reinforced soil abutment and the influence of climatic factors on the abutment

为研究分离式加筋土桥台的工程性能及气候因素的影响,依托明巢高速公路分离式加筋土桥台进行现场试验,重点讨论了桥台内部土压力、桥台变形等工程性能,以及温度、降雨等气候因素作用下桥台内部温度场分布及工程性能的变化规律.试验结果表明:桥台面板后的侧向土压力沿墙高逐渐减小,底部竖向土压力沿筋长方向呈近似直线型增大;工后加筋土桥台最大水平位移发生在桥台顶部位置附近,约为桥台高的0.15%;工后桥台整体沉降量向靠近面板侧递减;根据土工格栅应变的分布特征,判断加筋土桥台的潜在破裂面形状为折线形.加筋土桥台内部温度随着环境温度而变化,但会产生滞后现象,环境温度对桥台内部温度的影响主要集中在桥台边界约3 m范围内;环境温度对桥台侧向土压力和水平位移影响较小,对竖向土压力和沉降无影响;而降雨可能对桥台的水平位移和沉降均产生较大影响,造成水平位移和整体沉降额外增加.研究结果可为类似工程提供参考.

In order to study the engineering performance of the disconnect-type reinforced soil abutment and the influence of climate factors,a field test was conducted based on the disconnect-type reinforced soil abutment of MingChao Expressway.The engineering performance characteristics such as the soil pressure change and the abutment deformation inside the abutment,as well as the distribution of internal temperature field of reinforced soil abutment and changes in engineering performance under the influence of climate factors such as temperature and rainfall were mainly discussed.The test results show that the lateral soil pressure behind the abutment panel gradually decreases along the wall height,while the vertical soil pressure at the bottom increases in an approximately linear manner along the length of the reinforcement,the maximum horizontal displacement of the abutment occurs near the top of the reinforced soil abutment,which is about 0.15% of the abutment height,the overall settlement of the abutment after construction decreases towards the panel,and the shape of the potential rupture surface of the reinforced soil abutment is determined to be a broken line based on the strain distribution characteristics of geogrids.The internal temperature of the reinforced soil abutment changes with the ambient temperature,but there is a hysteresis phenomenon.The influence of the ambient temperature on abutment internal temperature is primarily focused within 3 m of the abutment boundary.The ambient temperature has little effect on the lateral earth pressure and horizontal displacement of the abutment and has no effect on the vertical earth pressure and settlement,while rainfall has a great impact on the horizontal displacement and settlement of the abutment,resulting in an additional increase in horizontal displacement and overall settlement.The findings of the study can provide reference for similar projects.