土工合成材料层间摩擦试验研究

随着我国矿产资源的开发,尾矿的粒度越来越细,尾矿库的库容和尾矿坝的高度在不断的增加,尾矿库的安全与稳定日益成为广受关注的方向。近些年来,一些学者将土工织物、土工格栅等土工合成材料运用到尾矿库筑坝工程中以提高尾矿坝的稳定性,具有重大的意义。根据不同的应用形式,形成尾砂－土工合成材料、土工合成材料－土工合成材料的接触面。作者开展尾砂与土工织物、土工织物之间、土工织物与土工格栅之间界面摩擦特性直剪试验。试验结果表明土工织物与尾矿砂界面直剪剪切曲线为理想弹塑型。土工织物与尾矿砂界面强度指标粘聚力为38.3kpa,摩擦角为30.4°。土工织物之间的直剪剪切曲线为应变软化型。土工织物之间界面峰值强度指标粘聚力为0kpa,摩擦角为18.7°。土工织物与土工格栅直剪实验曲线在5mm剪切位移之前剪应力增长较快,此后剪应力上升平缓,三条应力应变曲线都在剪切位移达到35mm时产生突降。剪切位移35mm时,土工织物与土工格栅界面强度指标粘聚力为79.6kpa,摩擦角为21.6°。试验结果可以为类似坝体的稳定计算提供依据。

Experimental study on interlayer friction of geosynthetics

With the development of China"s mineral resources, the size of the tailings becomes finer and finer. The storage capacity of tailings pond and the height of tailings dam are constantly increasing. The safety and stability of tailings pond has increasingly become concern. In recent years, geosynthetics such as geotextiles and geogrids have be applied to the dam of tailings pond by some scholars in order to improve the stability of the dam, which is of great significance. According to different application forms, the contact surfaces of tailings - geosynthetics and geosynthetics - geosynthetics are formed. Direct shear tests of interfacial friction between tailings and geotextiles, between geotextiles and geotextiles and between geotextiles and geogrids are carried out. The test results show that the direct shear curve of the interface between geotextiles and tailing sand is an ideal elastic-plastic type.The interfacial strength of geotextiles and tailing sand is 38.3 kPa, and the friction Angle is 30.4°. The direct shear shear curves between the geotextiles are of strain softening type.The peak strength of the interface between the geotextiles is 0 kPa, and the friction Angle is 18.7°. The direct shear test curves of geotextiles and geogrids show a rapid increase in shear stress before the shear displacement of 5mm, and then the shear stress rises gently. All the three stress-strain curves show sudden drop when the shear displacement reaches 35mm. When the shear displacement is 35mm, the interface strength of the geotextile and geogrids is 79.6kPa, and the friction Angle is 21.6°. The experimental results can provide a basis for the stability calculation of similar dam.