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.

This paper presents a theoretical investigation on the lateral force of pile in liquefaction site. Regarded liquefied soil as fluid, the vector method can be used to analyze the liquefaction velocity field and solve the analytical solution of the dynamic field by making use of the principle of fluid mechanics. In addition, by solving the velocity field with vector symbol operation method, the analytical expression of the lateral force in the liquefied flow field is obtained, and the sensitivity of the parameters in the analytical expression is analyzed. The results show that the stress field of the pile contains both the pressure resistance caused by surface pressure and the friction resistance caused by shear stress, when the liquefied soil flows laterally. The lateral forces on the pile are mainly composed of inertial forces and damping forces and are related to density, fluid viscosity, pile radius, and vibration frequency. With the increase of density, fluid viscosity, and pile radius, the added mass and added damping increase gradually. In a certain range, added mass and added damping are sensitive to vibration frequency.

To investigate the fracture performance of high-strength concrete (HSC) under different steam curing systems, this research conducted three-point bending tests on HSC and monitored the fracture process using acoustic emission (AE) and digital image correlation (DIC) technology. The experimental results indicate that both the delay period before steam curing and the duration of high-temperature steam curing have a significant impact on the strength and fracture performance of HSC. When the steam curing duration increased from 6 h to 12 h, the strength and fracture performance of the concrete initially improved and then declined. When the delay period was reduced from 4 h to 2 h, the strength and fracture performance exhibited a decreasing trend. The ratio of splitting tensile strength to compressive strength of HSC ranges from 1/10 to 1/12. The strain cloud map obtained through DIC technology revealed the development of cracks, and the variation in the length of the fracture process zone (FPZ) with the loading process was calculated. The activity of the HSC fracture process was reflected by the AE ringing count, and the damage evolution law of the fracture process was evaluated using the b-value. Shortened delay periods or excessive steam curing increased internal defects in HSC, leading to fracture via low-energy microcrack propagation. Properly cured HSC, with a denser microstructure, exhibited higher-energy failure along dominant fracture paths.