Mehdi Serati

Thermo-Mechanical Damage Behavior of Rock Under Polyaxial Stresses

Knowledge of rock damage behaviour is of great importance in many engineering applications including the design of open-pit mines, deep underground tunnels, repositories, and deep wells, as well as in geophysics, tectonics, and seismology disciplines. It is therefore imperative to understand how environmental parameters affect rock damage in such applications for better and safer designs. In deep underground operations, in particular, accumulation of damage is predominantly controlled by (high) temperature and pressure (HTP) that rock is exposed to. This project aims to:

1. Evaluate the effect of temperature on the mechanical strength of rocks under true triaxial (3D) stress conditions,
2. Investigate fracture pattern of rocks under elevated temperatures as well as far-field external loads, and
3. Introduce a more accurate and reliable coupled 3D thermo-mechanical damage model for rocks.

We are seeking a full-time, highly motivated PhD candidate to perform high-quality research in the field of rock fracture mechanics. The successful candidate will be working under the supervision of Dr Mehdi Serati and Professor David Williams the Geotechnical Engineering Centre (GEC) within the School of Civil Engineering. The candidate will join a multidisciplinary team in partnership with industry partners.

Combined Dynamic/Biaxial Compression Failure Mode of Geostructures

Mechanical response of geomaterials (e.g. brick, rock, shotcrete, and concrete) under cyclic, dynamic and fast strain-rate loads are substantially different from that of a quasi-static or homogenous loading. Such impact/cyclic stresses could, for instance, be exerted to geostructures during drilling and blasting (D&B) or spalling and rockburst events in deep excavations, which usually deform the near-field rocks at very high strain rates. While quasi-static compression tests have been widely performed on geostructures since the 1960s, coupled dynamic/cyclic and biaxial loading on geostructures have largely been ignored since it would require sophisticated laboratory equipment to model the complex stress conditions. Using the new Hybrid Biaxial/True Triaxial testing facility at UQ Civil, the main objective of this PhD project is to investigate the fracture growth in geomaterials under combined dynamic/cyclic/biaxial stresses by adopting digital image correlation (3D DIC) and high-speed photography techniques.

We are seeking a full-time, highly motivated PhD candidate to perform high-quality research in the field of rock testing and fracture mechanics. The successful candidate will be working under the supervision of Dr Mehdi Serati and Professor David Williams the Geotechnical Engineering Centre (GEC) within the School of Civil Engineering. The candidate will join a multidisciplinary team in partnership with industry partners.

Utilization of Waste Glass In Concrete Mixes

Due to their widespread, prolonged and expanding exploitation, reserves of natural sand are depleting worldwide. It is estimated that globally nearly 50 billion tonnes of sand are consumed per annum, which makes sand the most widely consumed natural resource on the planet, after freshwater. The depletion of sand reserves has also resulted in a dramatic increase in sand price to almost six times over the last 25 years. In civil engineering, therefore, crushed waste glass (CWG) has been investigated for some time as a potential substitute for sand and fine-grained aggregate in concrete production, or Glascrete. This study aims to assess the applicability of CWG (also known colloquially as Cullet) in concrete mixes and investigate further how this replacement affect concrete physical properties. Unconfined compressive strength, tensile and true triaxial strength of concrete mixes will be particularly investigated. The advisory team of teh project includes Dr Mehdi Serati, Dr Harry Ashe, and Mr Niki Jackson (of GCP Applied Technologies).