冻土空心圆柱仪的研发与应用

发布时间：2018-11-27 09:43

【摘要】：为研究复杂应力路径条件下冻土的力学特性,中国科学院冻土工程国家重点实验室与美国GCTS公司合作研发了新型冻土力学试验设备——冻土空心圆柱仪(FHCA-300),该设备通过独立施加内围压、外围压、轴向荷载和扭矩来改变3个主应力的大小和方向,从而更为真实地模拟冻土在地震荷载、交通荷载等多向应力和主应力轴旋转等复杂应力路径下的应力-应变行为.详细介绍了该仪器各部分的组成、传感器和动荷载频率的选取过程以及目前可实现的具体试验类型.此外,着重介绍了冻土空心圆柱仪温度控制系统的设计原理,并且对其控温能力进行了验证,结果证明该系统可以达到预期的降温能力和控温要求.最后利用冻土空心圆柱仪进行了主应力轴静态旋转和循环旋转测试试验,验证了仪器实现包括主应力轴旋转在内的复杂应力路径的能力,初步试验结果表明该设备能够准确再现冻土在复杂应力路径条件下的力学行为和变形行为,可为系统开展冻土在复杂应力条件下的强度、变形特性和本构关系等研究提供技术手段.
[Abstract]:In order to study the mechanical properties of frozen soil under complex stress paths, the State key Laboratory of Frozen soil Engineering of the Chinese Academy of Sciences and GCTS Company of the United States have developed a new type of mechanical test equipment of frozen soil, called permafrost Hollow Cylinometer (FHCA-300). The device changes the magnitude and direction of the three principal stresses by applying independent internal confining pressure, peripheral pressure, axial load and torque, thus more realistic simulation of the frozen earth in the earthquake load. The stress-strain behavior under complex stress paths such as traffic load and rotation of principal stress axis. The composition of each part of the instrument, the selection process of the sensor and the frequency of dynamic load, and the specific test types that can be realized at present are introduced in detail. In addition, the design principle of the temperature control system of the frozen soil hollow cylinder is introduced, and its temperature control ability is verified. The results show that the system can meet the expected cooling capacity and temperature control requirements. Finally, the static and cyclic rotation tests of the principal stress axis are carried out by using the permafrost hollow cylindrical instrument, which verifies the ability of the instrument to realize the complex stress path including the rotation of the principal stress axis. The preliminary test results show that the equipment can accurately reproduce the mechanical behavior and deformation behavior of frozen soil under the condition of complex stress path, and can be used for the systematic development of the strength of frozen soil under complex stress conditions. Research on deformation characteristics and constitutive relations provides technical means.
【作者单位】：中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室;中国科学院大学;
【基金】：国家重点基础研究发展计划(973项目)(2012CB026106) 冻土工程国家重点实验室基金(SKLFSE-2T-17) 国家自然科学基金(41071048)
【分类号】：TU415

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