Influence of Natural Rubber Latex Thickness on the Behavior of Jointed Rocks during Shear Wave Propagation

Abstract

Understanding the dynamics of rock mass behavior necessitates the study of seismic waves generated by various sources of vibration within rocks. Joints and fractures are prevalent in rock masses and substantially impact their dynamic response to seismic waves. The present study has identified natural rubber latex (NRL) as an effective energy-absorbing medium in the rock masses for limiting wave propagation across the joint. Gypsum plaster has been used to replicate the natural rocks as a model material for conducting this study. The damping properties of rock mass have been determined using split shear plate (SSP) and resonant column (RC) tests. The mechanical response of intact gypsum plaster and NRL has been examined using resonant column testing. The influence of the thickness of the NRL layer on the damping characteristics of the jointed rock mass was studied by varying the thickness of the NRL layer within the joints from 2 to 5 mm. Using RC testing, the variations of shear moduli and damping ratios with different thicknesses of NRL have been studied. The variations of transmission coefficient (T), absorption coefficient (A), and reflection coefficient (R) with variable NRL thickness have been investigated utilizing SSP testing. The findings of the present study can be applied to developing numerical models that can anticipate the behavior of rock masses under dynamic loading conditions and for utilizing the NRL as an effective energy-absorbing material in the rock mass to reduce the vibrations that are transmitted to the structures. The utilization of natural rubber latex (NRL) as an infill material in rock masses presents promising practical applications across various engineering domains. Its application extends to tunneling, mining, and stabilizing rock slopes. In tunneling and mining, NRL aids in increasing ground stability and controlling water intrusion during excavation, thereby enhancing safety and efficiency. In addition, it proves beneficial in stabilizing roofs and walls and preventing water and gas infiltration in mining operations. NRL reinforces joints within rock masses, reducing permeability and enhancing structural integrity. NRL stands out for its environmentally friendly and sustainable nature compared to synthetic polymers. Research indicates that NRL-stabilized soil has a lower carbon footprint than traditional cement-stabilized soil, thus offering an ecofriendly solution. Moreover, NRL presents opportunities for repurposing waste materials and reducing the environmental impact of concrete production. This study pioneers the application of NRL for vibration damping in jointed rocks, expanding the understanding of its dynamic properties under shear wave propagation. Through resonant column and split shear plate tests, this research explores the influence of NRL thickness on wave propagation, providing valuable insights for engineering practices in rock-dominated environments.