The application of scrap tires as construction materials in civil engineering is one of the most promising ways to recycle this pollutant. The objective of this study was to investigate the shear strength and liquefaction potential of saturated rubber‐sand mixtures. Direct shear tests and cyclic triaxial tests were conducted on rubber‐sand mixtures at various rubber contents. It was found that the addition of rubber particles to sand changed the shear stress‐horizontal displacement development. The addition of rubber particles to sand improved the shear strength slightly and improved resistance to liquefaction significantly. Additionally, a hyperbolic model was proposed to describe the pore water pressure generation. This study demonstrates the effect of rubber particles on the physical properties of sand.

As reuse materials, waste tyres mixed with soils are valuable materials to be used for many purposes in geotechnical projects that may be subjected to dynamic loads. The aim of this study is to assess the efficacy of using waste tyres in buried pipe protection. To achieve this purpose, a series of laboratory model tests were carried out to investigate the dynamic responses of pipe buried in pure soil and rubber soil mixtures with volume content of 10%, 20% and 30% rubber particles. Test results such as earth pressure and strain of buried pipe are discussed in this study. The results indicate that inclusion of 20–30% rubber particles in the mixtures leads to a change in earth pressure increment distribution, and these mixtures lead to obvious reductions in earth pressure increments. For the mixtures with 20–30% rubber particles, the pipe had lower strain under the dynamic loading. Compared with pure soil, the mixtures with 20–30% rubber particles exhibited better performance with regard to the responses of the pipe–soil system. Hence, the research undertaken in this paper provides a viable approach to protect buried pipes subjected to dynamic loading.

The primary purpose of this work is to evaluate the viability of using waste rubber particles as buried pipe backfill. By applying confined compression test and model test, this research studied the compressibility of sand and rubber-sand mixtures (RSM) and also, investigated the behavior of pipe surrounded by sand and RSM subjected to impact loading. The findings are as follows: 1) The vertical elastic strain and plastic strain of compression test samples increase with rubber content, and the elastic strain and plastic strain of saturated samples are greater than those of dry samples. 2) The settlement of RSM model soil is greater than that of pure sand model soil subjected to impact loading. The addition of rubber particles to pure sand reduces the earth pressure increment. The cumulative strain of pipe surrounded by dry RSM is less than that surrounded by dry pure sand. However, the cumulative strain of pipe surrounded by saturated RSM is greater than that surrounded by saturated pure sand. This investigation provides an environmentally friendly approach for recycling waste tire particles in geotechnical engineering.

Dynamic triaxial experiments of the saturated Nanjing fine sand are designed and accomplished. The slope of the relationship curves of the shear stress-shear strain rate of saturated sands under cyclic loading decreases with the build-up of the pore water pressure. Meanwhile, the apparent viscosity weakens gradually, and more and more strong fluid properties are shown. The rate-dependence of apparent viscosity is tested. The apparent viscosity decreases with the increase of shear strain rate. A typical shear-thinning fluid feature and power law relationship is discovered. A kind of fluid dynamic constitutive model was proposed for the saturated Nanjing fine sand. The effects of the cyclic stress ratio and the effective consolidation pressure on the flow characteristics of the saturated Nanjing fine sand were discussed