A combined survey including infrared thermography(IRT)and field-laboratory tests were conducted to analyze the thermal responses and thermal properties of loess on a landslide-prone loess slope in the Heifangtai terra...A combined survey including infrared thermography(IRT)and field-laboratory tests were conducted to analyze the thermal responses and thermal properties of loess on a landslide-prone loess slope in the Heifangtai terrace in Northwest China aiming at preliminarily demonstrating the potential of IRT as a complementary technique to the investigation of irrigation-induced loess landslides.Multitemporal thermographic surveys corresponding to various solar radiation intensities during the afternoon were carried out on the landslide-prone loess slope.Accordingly,the spatiotemporal distribution of the thermal responses within the observed slope surface was analyzed qualitatively and quantitatively.Meanwhile,field and laboratory investigations were also performed on the thermal properties of different landslide materials.The results indicate that loess,a landslide-prone deposit that usually has a relatively high water content,exhibits different thermal properties and anomalies,including a lower surface temperature and greater thermal inertia,compared to surrounding zones without landslides.The groundwater table and corresponding seepage line could also be obtained by determining the potential boundary between the thermal response distribution of landslide scarps and that of saturated deposits in the presence of landslides.The results of these investigations are expected to provide insight for future endeavors combining infrared thermography with other efficient survey methodologies(e.g.,InSAR,which can monitor the active displacement of a loess slope)to evaluate the activity of this kind of excessive irrigation-induced loess landslide.展开更多
与地下水位以下的饱和黄土力学性质相比,包气带黄土力学性质具有不同的表征参数和测试方法,其对黄土斜坡渗流场和稳定性的影响不容忽视。以甘肃黑方台地区黄土为例,分别采用张力计和轴平移技术量测了黄土的部分区段土-水特征曲线,依据Ga...与地下水位以下的饱和黄土力学性质相比,包气带黄土力学性质具有不同的表征参数和测试方法,其对黄土斜坡渗流场和稳定性的影响不容忽视。以甘肃黑方台地区黄土为例,分别采用张力计和轴平移技术量测了黄土的部分区段土-水特征曲线,依据Gardner、Van Genuchten和Fredlund and Xing 3种经验公式对轴平移测试数据进行拟合,获取了完整的土-水特征曲线。基于GDS多功能三轴仪,通过控制基质吸力的三轴剪切试验,获取了考虑基质吸力的黄土强度参数。结果显示:张力计和轴平移技术量测的部分区段土-水特征曲线具有相近的曲线形态,但张力计曲线位于轴平移技术曲线的上方;当基质吸力由100kPa减小至20kPa时,黄土内摩擦角减小约1°,粘聚力下降近22kPa;拟合所得的黑方台地区黄土的基质吸力摩擦角为15.6°。试验为进行黑方台黄土斜坡的非饱和渗流和稳定性分析提供了参数。展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant No.41672348,41931286,52008246).
文摘A combined survey including infrared thermography(IRT)and field-laboratory tests were conducted to analyze the thermal responses and thermal properties of loess on a landslide-prone loess slope in the Heifangtai terrace in Northwest China aiming at preliminarily demonstrating the potential of IRT as a complementary technique to the investigation of irrigation-induced loess landslides.Multitemporal thermographic surveys corresponding to various solar radiation intensities during the afternoon were carried out on the landslide-prone loess slope.Accordingly,the spatiotemporal distribution of the thermal responses within the observed slope surface was analyzed qualitatively and quantitatively.Meanwhile,field and laboratory investigations were also performed on the thermal properties of different landslide materials.The results indicate that loess,a landslide-prone deposit that usually has a relatively high water content,exhibits different thermal properties and anomalies,including a lower surface temperature and greater thermal inertia,compared to surrounding zones without landslides.The groundwater table and corresponding seepage line could also be obtained by determining the potential boundary between the thermal response distribution of landslide scarps and that of saturated deposits in the presence of landslides.The results of these investigations are expected to provide insight for future endeavors combining infrared thermography with other efficient survey methodologies(e.g.,InSAR,which can monitor the active displacement of a loess slope)to evaluate the activity of this kind of excessive irrigation-induced loess landslide.
文摘与地下水位以下的饱和黄土力学性质相比,包气带黄土力学性质具有不同的表征参数和测试方法,其对黄土斜坡渗流场和稳定性的影响不容忽视。以甘肃黑方台地区黄土为例,分别采用张力计和轴平移技术量测了黄土的部分区段土-水特征曲线,依据Gardner、Van Genuchten和Fredlund and Xing 3种经验公式对轴平移测试数据进行拟合,获取了完整的土-水特征曲线。基于GDS多功能三轴仪,通过控制基质吸力的三轴剪切试验,获取了考虑基质吸力的黄土强度参数。结果显示:张力计和轴平移技术量测的部分区段土-水特征曲线具有相近的曲线形态,但张力计曲线位于轴平移技术曲线的上方;当基质吸力由100kPa减小至20kPa时,黄土内摩擦角减小约1°,粘聚力下降近22kPa;拟合所得的黑方台地区黄土的基质吸力摩擦角为15.6°。试验为进行黑方台黄土斜坡的非饱和渗流和稳定性分析提供了参数。
