南水北调中线工程土工格栅——膨胀岩的拉拔试验研究

Pullout Test Study on the Interaction between Geogrid and Swelling Rock

针对南水北调中线工程河南新乡段膨胀岩渠段的中-弱膨胀岩,采用改造的叠环剪切试验仪进行了不同上覆荷载条件下两种土工格栅的拉拔试验,对格栅与膨胀岩的界面相互作用机理进行了初步研究,得到界面似摩擦角和似黏聚力参数,分析格栅不同埋深处界面摩阻力的分布规律,并对由于界面摩阻力作用而引起的土体附加剪应力分布进行初步的探讨。

The interaction mechanism between geogrid and mid-weak swelling rock in the Project of South-to-North Water Diversion is analyzed by pull-out tests which used the modified laminated shear test instrument. Through the experiments with different vertical loads and two kinds of geogrid, quasi-friction angle and quasi-cohesive force of the interface is calculated, the distribution law of interface frictional resistance（IFR）at the different location of geogrid is discussed. The test result of lamination displacement indicates that the additional-shear-stress in soil bought by IFR decayed from the interface.