Numerical Modelling of Uniaxial Compressive Tests on Sille Bimrock

This study numerically investigates the mechanical behaviour of a welded blocky pyroclastic rock mass located in Sille (Turkey), that can be assigned as agglomerate-bimrock (block-in-matrix rock). Two cultural-archaeological heritage sites, very attractive tourist destinations, were carved in the Sille bimrock mass about 1500 years ago: a hill settlement called “Sekili Cave” and a semi-underground Church called “Koimesis Tes Panagias Church”. These antique rock-hewn structures suffer from serious stability problems such as shear fractures of the pillars, structurally controlled rock falls, overbreak and matrix erosion, but still a significant part of them has nevertheless maintained instability for years. To preserve these historical structures, the knowledge of the mechanical behaviour of the Sille agglomerate is crucial. This paper focuses on numerical simulations of uniaxial compressive tests performed on the Sille bimrock, with the aim to calibrate the mechanical parameters to be used for future stability analyses of the rock-hewn structures. Suitable heterogeneous models have been considered for 2D Finite Element (FEM) analyses, by introducing the interfaces between the matrix and blocks, for a reliable simulation of the behaviour of this challenging rock mass.