新型高量程张力计在吸力量测中的应用  

Applications of a high-capacity tensiometer for direct measurement of suction

作　　者：陈锐[1,2] 陈中奎[1] 张敏[3] 邓刚[4] 

机构地区：[1]哈尔滨工业大学深圳研究生院土木与环境工程学院,广东深圳518055 [2]浙江大学软弱土与环境土工教育部重点实验室,浙江杭州310058 [3]深圳大学土木工程学院深圳市土木工程耐久性重点实验室,广东深圳518060 [4]中国水利水电科学研究院流域水循环与模拟国家重点实验室,北京100048

出　　处：《水利学报》2013年第6期743-747,755,共6页Journal of Hydraulic Engineering

基　　金：国家自然科学基金项目(50909030);中国水利水电科学研究院科研专项(岩集1238);国家科技支撑计划项目(2011BAB10B07);软弱土与环境土工教育部重点实验室(浙江大学)开放基金资助项目(2011P05)

摘　　要：一般张力计仅能量测低于100kPa的吸力,超过该吸力后张力计将由于量测系统汽化等原因失去可用性。采用国产普通压力传感器研制了一种能够直接量测大于100kPa吸力的新型高量程张力计。在室内试验中吸力量测值与土样预加吸力一致,验证了400kPa吸力范围内该高量程张力计的响应速度和准确度。将此高量程吸力计应用于0～500kPa范围内高岭土土水特征曲线试验,并与应用轴平移法的压力板仪试验结果比较,进一步验证了该高量程张力计的准确性、持久性和对干湿循环过程的可用性。应用新型张力计在室外进行了长达25d的吸力监测试验,证明了该张力计的长历时可用性和反应速度。应用结果表明,所研制的高量程张力计具有量值准确、反应灵敏、持时长及量测稳定等良好工作性态。Only matric suctions below 100kPa can be measured by conventional tensiometers. When the measured suctions are larger than 100kPa, the conventional tensiometers fail due to the cavitation in mea- surement system. A new high-capacity tensiometer, which is able to directly measure matric suctions great- er than 100kPa, was developed in this study on the basis of a general pressure transducer made in China. Suction measurement on soil specimens shows that the suction values measured by the new tensiometer are consistent with those pre-applied on the soil specimens by using the axls-translation technique. This compar- ison validated the response speed and accuracy of the tensiometer within the suction range of 400kPa. The new tensiometer was also used to measure the soil-water characteristic curve along a drying-wetting cycle within the suction range from 0 to 500kPa. By comparing with the results from the pressure plate test, the accuracy and endurance of the tensiometer and its applicability to drying-wetting cycle were further veri- fied. Finally, the new tensiometer was used to monitor suction in the field and the monitoring lasted for 25 days, thereby justifying long duration and quick response of the tensiometer for suction measurement. The above applications suggest that the newly developed high-capacity tensiometer performs well regarding re- sponse, reliability, endurance and stability.

关 键 词：基质吸力 张力计 高量程 土水特征曲线 

分 类 号：TU415[建筑科学—岩土工程]