新型可视土工拉拔试验仪的研发与应用

Development and application of new visual pullout test apparatus for geosynthetics

研制了一台新型可视自动采集数据的土工拉拔试验装置,可用于多种土工材料和填料作用下的拉拔试验。该装置改进了加载系统和反力系统,实现了拉拔界面的可视与数据采集的自动化,并可量测土工材料不同嵌固长度处的位移,获取土工材料变形值,探索筋土作用过程中筋材受力机理及界面土体位移变化规律。使用新研制的试验装置开展了以砾类粗粒土为填料的格栅拉拔试验,结果表明:上覆荷载增大,土中格栅的应变变小,土体与格栅的界面摩擦和嵌固作用越显著;筋土界面处土体颗粒存在平移及转动两种运动模式,且界面处土体形成稳定的位移集中带。

A new visual pullout test model device is developed, which can be used to carry out pullout tests on geosynthetics and soil. The device improves the loading system and the reaction system, and realizes the pullout interface visualization and data acquisition automation. It can measure the displacements of geosynthetics with different embedment lengths, and obtain the deformation values of geosynthetics. The reinforcement mechanism and displacement evolution of interface soil in the process of reinforcement soil interface interaction are studied. The newly developed test equipment is used to carry out the pullout tests on coarse grained soil and geogrid. The results show that the greater the vertical pressure, the smaller the soil grid strain, the more significant the interfacial friction between soil and geogrid and the embedment effect. Two modes of translational and rotational displacements can be found on the reinforcement soil interface, and the interface particles form a stable soil displacement concentrated zone.