复合土工膜与粗粒砂砾料垫层的界面摩擦特性对工程结构稳定性十分重要。现有的试验研究多集中在粒径较小的土料与土工织物接触, 对于由粒径较大的砂砾料与土工膜界面特性的研究较少。利用大型土工合成材料直剪仪开展了砂砾料与土工膜界面直剪摩擦试验研究, 讨论了砂砾料级配以及相对密度对界面摩擦特性的影响。试验结果表明:相对密度一定时, 粗颗粒含量越大, 摩擦因子越大;相同级配条件下, 相对密度越高, 摩擦因子越大。最后探讨了土工膜与剪切下盒基座间的固定方式对界面摩擦参数的影响, 求得不同的固定方式导致界面摩擦角相差可达1倍以上。
The friction characteristic of the interface between composite geomembrane and coarse sand-gravel is of great importance to the structural stability. Most of the present experimental studies focus on the contact between soil of finer particles and geotextile, but research on the characteristics of interface between gravel of coarse soil particles and geomembrane is rarely seen. In this paper, direct shear friction tests were conducted for the interface by using large-scale direct shear apparatus. The influence of gradation and relative density on the friction characteristics are discussed. Results show that in the presence of equal relative density, the friction factor increases with the increase of coarse particle content, and in the presence of equal gradation, the friction factor increases with the increase of relative density. Furthermore, the influence of the fixation pattern between geomembrane and the lower base of shear box are analyzed. Test results reveal that the discrepancy of interface friction angle in different fixation patterns could be as great as 2 times.
[1] 土工合成材料工程应用手册编写委员会.土工合成材料工程应用手册[M].北京:中国建筑工业出版社, 2000.(Compilation Committee of the Engineering Application of Geosynthetics. The Engineering Application of Geosynthetics[M]. Beijing: China Architecture & Building Press, 2000.(in Chinese))
[2] 王 琦, 臧光文.横山水库除险加固工程的安全论证——土工膜与结构面摩擦试验[J].岩土力学, 2003, 24(增刊):83-85.(WANG Qi, ZANG Guang-wen. Safety Evaluation for Reinforcement for Hengshan Reservoir: Friction Test Between Geomembrane and Interface [J]. Rock and Soil Mechanics, 2003, 24(Sup.):83-85. (in Chinese))
[3] 张广禹, 李振灵.西霞院反调节水库复合土工膜摩擦因数研究[J].华北水利水电学院学报, 2007, 28(1):32-35.(ZHANG Guang-yu, LI Zhen-ling. Study of the Friction Coefficient of the Composite Geomembrane Core in Xixiayuan Balancing Reservoir[J]. Journal of North China Institute of Water Conservancy and Hydroelectric Power, 2007, 28(1):32-35.(in Chinese))
[4] 魏红卫, 喻泽红, 邹银生.土工合成材料加筋土抗剪作用的试验研究[J].水利学报, 2005, (5):555-562.(WEI Hong-wei, YU Ze-hong, ZOU Yin-sheng. Shear Characteristics of Soil Reinforced with Geosynthetic Material [J]. Journal of Hydraulic Engineering, 2005, (5):555-562.(in Chinese))
