Buildings, Vol. 16, Pages 2771: Triaxial Shear Behaviour and Strength Prediction Models of Recycled Tyre-Derived Grid-Reinforced Weathered Sand

Buildings, Vol. 16, Pages 2771: Triaxial Shear Behaviour and Strength Prediction Models of Recycled Tyre-Derived Grid-Reinforced Weathered Sand

Buildings doi: 10.3390/buildings16142771

Authors:
Chuyi Wang
Sheng Chang
Hao Wang
Dongfang Wei
Hongbo Zhang
Gang Chen
Xiuguang Song
Jingxiang Deng

This paper presents a method of using recycled tyre-derived grids (RTDG) as reinforcement materials for mechanical stabilised weathered sand embankment. To demonstrate the effectiveness of the RTDG-reinforced weathered sand on shear behaviour, large-scale triaxial tests were conducted under different confining pressures and reinforcement layers. The test results indicate: (1) RTDG reinforcement significantly alters the shear failure mode of weathered sand, transitioning it from shear failure to bulging failure. (2) RTDG reinforcement enhances the ultimate deviatoric stress of specimens by 20–30%, transforming the stress–strain response from strain softening to strain hardening. (3) RTDG reinforcement causes apparent cohesion to increase at an approximate linear rate of 37.2% per reinforcement layer, whereas the internal friction angle exhibits only a gradual increase. (4) The coupled effect of RTDG reinforcement and confining pressure alter volumetric behaviour from shear contraction–dilation patterns to solely shear contraction. It also reduces maximum dilation strain by about 50% and the dilation angle by 23%. (5) Two shear strength prediction models based on confinement enhancement (CEB) and interface friction (IFB) were proposed. Comparative analysis shows that, within the present dataset, the IFB model exhibits lower prediction error and a more stable error distribution than the CEB model, with a WRAI value of 0.033. Accordingly, the IFB model provides an effective prediction approach for estimating the shear strength of RTDG-reinforced weathered sand within the investigated test range, and the corresponding prediction results may serve as a preliminary reference for the engineering evaluation of RTDG-reinforced weathered sand.