A method for identification and reconstruction of hard structural planes, weak interlayer and cavities in the limestone near surface

Abstract

The main purpose of this paper is to develop a method for modelling spatial structure of hard structural planes, weak interlayer and cavities in the limestone near surface. The proposed methodology is on the basis of ground penetrating radar (GPR) investigation and data fitting. To testify the validity and application of the method, a model test was performed. The test model initially constructed as two poured parts, which were then combined. The interface between the upper and the lower segment of the model was used to simulate a hard structural plane, and a 0.05-m thickness clay layer was located at a depth of 0.475 m simulated the weak layer. Cavities, comprising an empty sphere with a diameter of 0.15 m, and an empty cube with 0.1 m side lengths were buried vertically with their tops at depths of 0.2 m. During investigation process, the occurrence of reverberation phenomena in the signal pattern was confirmed. Besides, the data fitting result is approximately consistent with the spatial distribution of objects within the model. These validation results indicate the developed method may provide a simple and effective method for identification and reconstruction of hard structural planes, weak interlayer and cavities in the limestone near surface.