褶皱情况下土工织物尾砂界面的剪切性状

Shear behavior of interface between tailings and geotextiles with wrinkle

尾砂的合理处置利用涉及国民经济发展和区域环境保护,无纺土工布和编织土工布等土工织物使得尾砂在边坡工程中的应用潜力大大提升。在尾砂模袋筑坝工程中土工织物会由于不均匀变形产生褶皱,明确褶皱对土工织物/尾砂界面的剪切特性的影响有利于工程安全分析。为此,利用改进的直剪仪对无纺型和编织型2种土工织物分别与铜尾砂和钨尾砂2种材料界面进行了剪切试验;通过预先设定土工织物褶皱方向和宽度的方法,试验分析了褶皱情况下土工织物/铜尾砂界面的剪切性状。研究结果表明:无纺土工布与铜、钨尾砂间的界面剪切强度要高于编织土工布界面,界面剪切峰值强度主要取决于土工织物的类型和尾砂的抗剪强度;土工织物褶皱大部分情况下对界面剪切强度具有提升作用,然而土工织物褶皱的方向和宽度对界面强度提升的影响具有不确定性。

The reasonable disposal and utilization of tailings involves national economic development and regional environmental protection.Nonwoven and woven geotextiles may greatly enhance the application potential of tailings in slope engineering.Wrinkles of the geotextile can be generated due to uneven deformation in the construction of mold-bagged tailings dam.To clarify the influence of wrinkles on the shear characteristics of the geotextile/tailings interface is beneficial to engineering safety analysis.For this purpose,an improved direct shear testing method is used to conduct shear tests of the interfaces between two types of geotextiles(i.e.nonwoven and woven)and two types of tailings(i.e.copper tailings and tungsten tailings)respectively.With the direction and width of geotextile wrinkle pre-set,shear behavior of the geotextile/copper tailings interface is analyzed.The experimental results show that the peak shear strength of nonwoven geotextile/tailings(copper tailings and tungsten tailings)interface is higher than that of woven geotextile/tailings interface.The peak shear strength of the geotextile/tailings interface mainly depends on the type of geotextile and the internal shear strength of the tailings.In most cases,geotextile wrinkles can improve the shear strength of geotextile/tailings interfaces.However,the direction and width of the geotextile wrinkle have uncertain effects on the improvement of the geotextile/tailings interface shear strength.