The effect of frost weathering at the dinosaur tracksite in Seoyu-ri, Hwasun, Korea

Abstract

Cultural monuments and geological heritage sites composed of natural stone are severely affected by frost weathering in cold regions or during the winter season in mid-altitude regions. The effect also occurs at the dinosaur tracksite in Seoyu-ri, Hwasun, Korea, which is not sheltered. To assess the influence of frost weathering on the tracksite, freeze–thaw experiments were carried out in the laboratory up to 100 cycles, simulating geological and meteorological conditions of the site. The variation on physical properties were measured at a core scale as weathering progressed. The decreases in dry weight, P- and S-wave velocity, and elastic modulus, and the increase in absorption rate and Poisson’s ratio showed the physical deterioration of the specimens. The microstructural properties were also measured using micro-computed tomography (micro-CT) images as weathering progressed. The variation on porosity (especially open porosity), pore size distribution, local thickness, and crack orientation showed the propagation and expansion of the pores and microcracks in rock specimens at a pore scale. Because every measurement was performed using non-destructive methods, the variation on the same specimens can be analyzed continuously. The results showed that frost weathering can cause damage to the tracksites. This research, therefore, suggests the construction of a shelter to maintain the temperature of the tracksite and to prevent groundwater seepage. This research can be applied to assess the effects of frost weathering at other cultural stone heritage or geological heritage sites.