岩土力学2017，Vol.38Issue(6)：1832-1840,9.DOI:10.16285/j.rsm.2017.06.035
新型土工单轴拉伸试验装置的研制及应用
Development and application of a new geotechnical device for direct tension test
摘要
Abstract
Since the current device for geotechnical direct tension tests is limited,a new direct tension device was developed in this study.The testing device consists of four components:sample preparation,loading,control and data acquisition system.With the novel design of"dovetail" groove and a double sliding plate on the device,direct tension tests can be conducted on prepared samples with different lengths.Due to the chosen sampling forms and their corresponding stretching fixture,the problems of relaxation and stress concentration on the ends of the specimen can be solved during the drawing process.The phenomenon of eccentric stress appearing in the drawing process can be avoided using the double rail stretching device.The minimum tensile rate of the device is 0.001 mm/min assisted by the two-stage gearbox design.Therefore,the device can be used to describe the evolution of uniaxial tensile failure and to determine tensile strength and tensile stress-displacement curve in the whole process.Direct tension tests were carried out on clay specimens using the developed device.The results show that the uniaxial tensile failure mode of clay is not purely brittle fracture,but there exists a softening stage after the tensile strength,and at this moment,clay specimens still have the certain beating capacity.With the increase of the length of stretching section,the tensile strength decreases logarithmically while the peak displacement increases logarithmically.With the increase of tensile rate,tensile strength increases logarithmically while the peak displacement increases linearly.Both tensile strength and the peak displacement increase linearly with increasing compactness.With the growth of moisture content,tensile strength increases initially and decreases afterward,but the peak displacement linearly increases.关键词
单轴拉伸/试验装置/拉伸段长度/破坏形式/抗拉强度/峰值位移Key words
direct tension/test device/stretching section length/failure mode/tensile strength/peak displacement分类
建筑与水利引用本文复制引用
崔猛,韩尚宇,洪宝宁..新型土工单轴拉伸试验装置的研制及应用[J].岩土力学,2017,38(6):1832-1840,9.基金项目
国家自然科学基金项目(No.51609114) （No.51609114）
江西省青年科学基金项目(No.20114BAB216010) （No.20114BAB216010）
河海大学岩土力学与堤坝工程教育部重点实验室开放基金项目(No.2016001).This work was supported by the National Natural Science Foundation of China (51609114),Jiangxi Province Science Foundation for Youths (20114BAB216010),and Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University (2016001). （No.2016001）
