The development of underground space in the South China Sea islands is an important way to enhance their protection capabilities. This study focuses on the stress loading and unloading conditions of surrounding rock during the excavation of underground caverns in island reefs. Laboratory variable confining pressure permeability tests were conducted to quantify the stress sensitivity of permeability in coral reef limestone base...

A lime–sand island–reef formation has a dual structure consisting of an overlying loose or weakly consolidated coral sand (CS) layer and an underlying reef limestone layer. The coral sand layer is the sole carrier of the underground freshwater lens in the lime–sand island–reef, and it differs in terms of its hydraulic properties from common terrigenous quartz sand (QS). This study investigated the mechanism of freshwater lens...

Coral islands are home to unique underground freshwater bodies generally known as freshwater lenses. There are differences in the development, formation, and properties of steady-state freshwater lenses among different coral islands because of the influence of tides, precipitation, island sizes, and hydrogeological conditions. This study investigated the response pattern of the groundwater system of coral islands to tides and...