李雪

摘要：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。

关键词：岩土力学;公路边坡;多步开挖;模型试验;合位移

中图分类号：TU41文献标识码：ADOI：10.7535/hbgykj.2021yx06011

Analysis on the evolution of combined displacement of

highway slope under model test

LI Xue

（Guangzhou Expressway Company Limited，Guangzhou，Guangdong 511458，China）

Abstract：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.

Keywords：rock and soil mechanics;highway slope;multi-step excavation;model test;combined displacement

近年來，由于降雨、地震等自然灾害导致的滑坡频繁发生，造成了一定的财产损失和人员伤亡[1-2]。长期以来，一直有学者对滑坡进行监测分析[3-4]。在监测手段中，全球导航卫星系统（GNSS）是获取滑坡表面实时三维矢量变形指标的主要技术之一，已经成为高精度监测复杂区域滑坡的通用系统[5-6]。但是，无论是从设备造价还是安装技术方面，专业的GNSS监测设备要求较高，设备的高成本限制了其大规模应用，大部分发展中国家不可能大规模部署GNSS监测设备[7]。……