Development of a strain/temperature/suction-controlled true triaxial testing device for modeling unsaturated soil behavior under multi-axial stress states

将开发一种真正的三轴试验装置，用于在应变、温度和吸力同时控制的条件下测试每侧3英寸的非饱和土立方体试件。该设备将是一种混合边界类型的装置，将样品放置在9个5棒陶瓷圆盘的顶部，并在立方体其余两侧的5个柔性膜之间。该装置将配备两个独立的孔隙空气和孔隙水压力控制/监测系统。为了校准和验证所提出的装置，将对几个粉砂样品进行从简单到复杂的大范围的应力路径。试件中的吸力状态将通过轴平移技术来诱导。这项开发工作的成功完成将极大地促进对非饱和土应力-应变-强度行为的现有知识和基本理解。该装置将是美国有史以来第一个在任何学术机构实施的此类装置，并将构成UTA在地质力学学科中进行研究和综合研究/教育活动的主要最先进的仪器。这种设备的开发还旨在促进学术研究人员和对推进非饱和土力学学科感兴趣的私人仪器开发商之间的伙伴关系。

A true triaxial testing apparatus will be developed to test 3-in per side, cubical specimens of unsaturated soil under simultaneous strain-, temperature- and suction-controlled conditions. The equipment will be a mixed-boundary type of device, with the specimen seated on top of an arrangement of nine 5-bar ceramic disks and between five flexible membranes on the remaining sides of the cube. The device will feature two independent pore-air and pore-water pressure control/monitoring systems. Several specimens of silty sand will be subjected to a wide range of simple-to-complex stress paths for calibration and validation of the proposed device. Suction states in the specimens will be induced via the axis-translation technique. Successful completion of this development effort will considerably advance the existing knowledge and fundamental understanding of the stress-strain-strength behavior of unsaturated soils. The device will be the first of its kind to be ever implemented at any academic setup in the US, and will constitute a major state-of-the-art instrumentation for research and integrated research/education activities at UTA in the geomechanics discipline. Development of this equipment is also aimed at promoting partnerships between academic researchers and private instrument developers interested in the advancement of the unsaturated soil mechanics discipline.