Research and application of coral reef limestone similar material development and model testing

Abstract

Abstract: To develop suitable similar materials for underground engineering model tests on islands, a series of experiments were conducted on various types of coral reef limestones in the South China Sea region. Using calcareous sand, white cement, silicone oil, and purified water as raw materials, 25 groups of orthogonal proportion tests and sensitivity analyses of different factors were performed on coral reef limestone similar materials. The reliability of the similar materials was also verified through laboratory-scale model tests. The study indicates that four groups of similar materials were formulated, which are closely related to the physico-mechanical properties and hydrological properties of different coral reef limestones. Among them, when the ratio of white cement to calcareous sand exceeds 1/12, it predominantly affects the physical and mechanical properties of the similar materials; when the ratio of silicone oil to white cement exceeds 1/3, it has better regulatory effects on the coefficient of permeability of similar materials. The content of purified water is negatively correlated with the compressive strength and elastic modulus of the similar materials, exerting a greater influence when it exceeds 20% of the total mass. Based on the multiple linear regression method for analyzing the test results, an empirical formula for the proportion of coral reef limestone similar materials was established. This allows for the precise calculation and formulation of different types of coral reef limestone similar materials, which can be widely applied to model testing and research in marine, geological, and geotechnical engineering.