作　　者： (许海楠）; (谢强）; (赵梦怡）; (郭永春）;

机构地区： 西南交通大学,成都610031

出　　处： 《工程地质学报》 2017年第4期953-958,共6页

摘　　要： 冷镜露点技术是一种快速测试非饱和土吸力的间接方法。本文简要介绍了冷镜露点仪的工作原理和试验方法,利用Decagon公司生产的WP4C冷镜露点仪测试非饱和成都黏土压实土样的总吸力,以Van Genuchten模型为基础,结合Origin软件对试验结果进行了曲线拟合,得到成都黏土的SWCC曲线,并给出拟合参数参考值。借助CT-3031型电导率仪测得土样的渗透吸力,由基质吸力等于总吸力减去渗透吸力,间接得到土样的基质吸力-含水率关系曲线。对比滤纸法测试相同土样得到的SWCC曲线,得出相同含水率时冷镜露点技术测得的吸力值低于滤纸法测得的值,和国外文献的相关结论一致,验证了冷镜露点技术测试吸力具有快捷、方便、准确等特点。指出冷镜露点技术在非饱和成都黏土吸力测试应用中是可行的,同时可推广到国内岩土工程相关领域的吸力测试中。 The aim of this study is to assess the method for measuring the total suction of compacted soil samples of Chengdu Clay with Chilled-mirror dew-point technology, an indirect measurement method for soil suction. The total suction of compacted soil samples of Chengdu Clay is measured with a WP4-C dew point potentiometer. Soil samples are taken from the depths of a foundation pit in the eastern suburbs of Chengdu. After grinding to pass 0. 075mm sieve, configured into 10 different initial moisture content, the remoulded soil is then statically compacted into a fixed volume with a custom mold of diameter 3. 5cm and thickness 0. 5cm. A total of 40 soil samples are prepared. The average dry density is 1. 7g＊cm 3.Based on the Van Genuchten model and the Origin software, we obtain the SWCC curve of the Chengdu Clay, and the reference value of the fitting parameter. The conductivity of the soil sample is measured by the CT-3031 conductivity meter. It is calculated with the conversion formula to obtain the osmotic suction. For the matrix suction is equal to the total suction minus the osmotic suction, the relationship between the matrix suction and the water content is indirectly obtained. It is pointed out that there is a certain deviation between the design moisture content and the actual moisture content of the soil sample, because the size of the soil sample is too small to maintain a constant water content when it is transferred from the sealed bag to the chilled-mirror dew-point meter. After the end of the test, it is necessary to recalculate the moisture content of soil samples. Next, another SWCC curve is obtained using the filter paper method to test the same soil samples. The test results obtained by the two test methods are compared. It is concluded that the suction values measured by the chilled-mirror dew-point technology is lower than that measured by the filter paper method, when the soil samples are at the same water content. This conclusion is in accordance with that of S.S.Agus, which proves that the

关 键 词： 冷镜露点仪 非饱和土 吸力 岩土工程 滤纸法