Abstract：Generally，the tension and anchorage length of geotextile are calculated based on Mohr-Coulomb strength theory，and the intermediate principal stress is not taken into account. The influence of intermediate principal stress can be considered with twin shear theory，and the parameters of Mohr-Coulomb strength theory ( ， ) are modified with the twin shear strength parameters ( ， ). Based on the twin shear theory，the tension and length of geotextile are modified. The example shows that the tension and anchorage length of geotextile with twin shear theory( ) is close to that with Mohr-Coulomb strength theory when the wall height is small；while upon a further increase in wall height，the tension and anchorage length of geotextile become bigger than those calculated by Mohr- Coulomb strength theory.
