Subcritical crack growth of edge and center cracks in façade rock panels subject to periodic surface temperature variations

Abstract

This paper examines subcritical cracking in a rock panel or slab containing either a pre-existing edge or a center crack perpendicular to the panel surface. The panel is subject to periodic surface temperature variation on one side of the panel while the other is kept at a constant temperature. The thermally induced stress intensity factors are determined using superposition technique by employing the fundamental point load solution for an edge crack or a center crack in a slab of finite thickness. Rock panel is modeled as a long elastic strip with either a free or a fully constrained lateral end condition. The temperature variations versus time at various depths of the rock panel appear roughly as a sinusoidal function. The lateral thermal stress for the free end case is larger than the constrained end case; whereas stress intensity factors for both edge and center cracks in the constrained end slab are 1000 times larger than that of free end case. Subcritical crack propagation in rock panels on façade is then estimated as a function of time. This subcritical crack propagation continues until a critical crack size is attained and the rock panel will fail under wind load. This new theoretical framework provides a new paradigm to examine the mechanisms of time-dependent cracking in rock panels on façade of buildings.

Influence of mineralogy on granite decay induced by temperature increase: Experimental observations and stress simulation

“…This is the case of marble, whose thermoelastic behavior in marbles has been widely studied and modeled (Bellopede et al, 2006;Chau and Shao, 2006;Ferrero et al, 2009). Marble is one of the rocks used most extensively for modeling thermal cracking at high temperatures because it is a monomineralic compact rock.…”

Influence of relative humidity on fracture toughness of rock: Implications for subcritical crack growth

“…Such issues are of particular importance when dealing with longer term effects such as the integrity of subsurface structures like repositories for radioactive waste, caverns for the storage of liquid natural gas or liquid petroleum gas, and underground power plants. Chau and Shao (2006) reported that time-dependent crack growth in rock played an important role for the failure of rock panels on façade of buildings. Therefore, a number of investigations related to time-dependent fracturing in rock have been conducted.…”

Effects of humidity and temperature on subcritical crack growth in sandstone

“…Therefore, study of subcritical crack growth is also important for seismology and volcanology. Chau and Shao (2006) reported that time-dependent crack growth in rock played an important role for the failure of rock panels on façade of buildings. It is considered that study of time-dependent crack growth in rock is essential to understand the failure of most structures made of rock.…”