新型多功能土-土工合成材料试验机在筋土相互作用研究中的应用

土-土工合成材料的相互作用是加筋机理研究中的重要问题，筋材性质是加筋土结构设计中的关键参数。为了真实模拟筋材在土中的受力条件，获得更符合实际的材料特性参数，深入探讨筋土相互作用规律，在原土-土工合成材料界面直剪试验仪的基础上，研制了新型的土-土工合成材料多功能试验机。该机采用双伺服电机控制及全自动数据采集系统，通过不同辅助手段和控制模式，可完成土-土工合成材料的界面直剪、拉拔、侧限约束拉伸以及侧限约束蠕变试验。采用不同类型的土工格栅和砂土进行了多项试验，对筋材与土的界面特性、以及筋材在约束作用下的拉伸特性和蠕变特性及其影响因素进行了探讨。试验成果充分验证了该机性能的稳定性和可靠性，为深入掌握筋土相互作用特性提供重要试验依据。

Application of a Multifunctional Soil-geosynthetics Testing Machine to Research on Soil-geogrid Interaction

The interaction between soil and geosynthetics is an important issue in the research of reinforcement mechanism,and the properties of reinforcement material are key parameters in the design of reinforced-soil struc-ture.A new multifunctional soil-geosynthetics testing machine has been developed on the basis of conventional di-rect-shear test apparatus.The machine consists of two sets of servo motor,automatic control and data acquisition system,and a set of shear box with dimension of 600mm×300mm×300mm,etc.Direct-shear test,pull-out test, confined-tension test and confined-creep test can be conducted on the machine through several auxiliary means and control modes.Furthermore,the sand-confined tensile strength and creep properties of different geogrids were tested and compared.The contribution of geogrid-soil interaction to the strength of soil-geosynthetics was also analyzed. The tests validated that the machine has good operability and accuracy.