含土工复合排水网衬里的界面剪切特性研究

Interface shear strength of liners with geocomposite

采用大尺寸界面直剪仪对土工复合排水网与粗糙土工膜以及土工织物之间界面力学特性进行试验研究。试验发现,土工网芯较大地影响了含土工复合排水网衬里的界面剪切特性。对于挤压型土工膜/土工复合排水网界面,当正应力大于210 kPa时,土工网芯严重破坏了土工膜粗糙表面,导致其界面强度参数减少,峰值摩擦角从17.4°降低到8.6°。而对于土工织物/土工复合排水网界面,当正应力大于50 kPa时,土工网芯的嵌固作用较大地增加了犁沟分量,使其界面强度参数显著增加,峰值摩擦角从10.6°增加到21.3°。

The large direct shear tests on interfaces of geomembranes/geocomposite and geotextile /geocomposite are described.It is found that the presence of drainage nets has an important effect on the shear strength of interfaces with geocomposite.When the normal stress is larger than 210 kPa,the drainage nets severely damage the rough surface of coextruded geomembrane,resulting in a reduction of shear strength parameters,i.e.,the peak friction angle decreases from 17.4° to 8.6°.However,on the geotextile/geocomposite interface,when the normal stress is larger than 50 kPa,the embedment of drainage nets increases the plowing effect,resulting in an increase of shear strength parameters,i.e.,the peak friction angle increases from 10.6° to 21.3°.