模型试验下的公路边坡合位移演化分析

为了明确底部开挖对公路边坡稳定性的影响，以梅州至平远高速公路工程为背景，采用多步开挖的方法结合全尺寸边坡模型进行试验。在坡体中布置6个监测点记录坡向及垂直位移，随后将两方向位移作为分量进行组合位移计算分析，并结合试验结果进行归纳。研究结果表明：1）边坡上部区域整体稳定，内部应力变化慢，滑坡往往由内部蠕变造成，因此上部区域合位移偏角值较为稳定，而下部区域因易受开挖影响，位移角波动显著；2）通过对边坡下部区域计算，其滑动面倾角理论值为30°～60°，试验中观测到了一致的情况，而受土体堆积作用，后期土体断面几乎与坡面平行。研究得到了滑坡发生前合位移的偏转角及滑坡断面方向变化规律，相关结果可作为预测边坡稳定性的重要指标，对评估公路边坡稳定性具有一定的借鉴意义。

Analysis on the evolution of combined displacement of highway slope under model test

In order to clarify the influence of bottom excavation on highway slope stability,taking Meizhou-Pingyuan highway project as the background,the multi-step excavation method combined with full-scale slope model was used for test.Six monitoring points were arranged in the slope to record the slope direction and vertical displacement,and then the two-direction displacement was calculated and analyzed as components,which was summarized in combination with the test results.The results show that:1) the upper part of the slope is stable as a whole,the internal stress changes slowly,and the landslide is often caused by internal creep.Therefore the upper combined displacement angle is more stable,while the lower area is more easily affected by excavation,and the displacement angle fluctuates significantly;2) through the calculation of the lower part of the slope,the theoretical value of the inclination angle of the sliding surface is 30°~60°.The consistent situation has been observed in the test,but due to the accumulation of soil,the cross section of the soil is almost parallel to the slope in the later stage.The deflection angle of the displacement before the occurrence of the landslide and the changing law of the direction of the landslide section are obtained.the relevant results can be used as an important index for predicting slope stability and have certain reference for evaluating highway slope stability.HQ]