土工格栅与压实膨胀土的界面模型及其参数

针对土工格栅与膨胀土界面特性研究的不足,采用单向和双向土工格栅,以及南水北调中线工程新乡段的膨胀性泥灰岩风化土,在填土尺寸为600mm×600mm×600mm的大型叠环式剪切仪上进行一系列拉拔试验,研究了不同含水量及干密度下筋土界面的平均摩阻力-相对位移特征和界面强度特征。采用理想弹塑性模型模拟界面行为,并将界面强度曲线表达为线性函数,基于界面平均摩阻力和筋土平均相对位移研究了界面参数。此外,探讨了考虑渐进屈服时界面参数的反馈分析方法。

Interface model and its parameters between geogrids and compacted expansive soil

The characteristics of the interface between geogrid and expansive soil are lack of study.To make a contribution to this respect,applying the uniaxial and biaxial geogrids and the soil weathered from the expansive marlite in Xinxiang section of the middle route of South to North Water Transfer Project(SNWT),a giant laminated-ring type shear test apparatus with soil filling of dimensions of 600 mm×600 mm×600 mm was adopted to do a series of pull-out tests to investigate the ralations of the average friction versus the relative displacement and the interface strength characteristics under different water contents and dry densities of the expansive soil.An ideal elastoplastic model was used to simulate the interface behavior,the interface strength curves were expressed as the linear functions,and the parameters were analyzed based on the average friction and the average relative displacement of the interface between soil and geogrids.Furthermore,the feedback analysis of the interface parameters was discussed when the progressive yield occured at the interface.