Y-Mat: an improved hybrid finite-discrete element code for addressing geotechnical and geological engineering problems

PurposeContinua and discontinua coexist in natural rock materials. This paper aims to present an improved approach for addressing the mechanical response of rock masses based on the combined finite-discrete element method (FDEM) proposed by Munjiza.Design/methodology/approachSeveral algorithms have been programmed in the new approach. The algorithms include (1) a simpler and more efficient algorithm to calculate the contact force; (2) An algorithm for tangential contact force closer to the actual physical process; (3) a plastic yielding criterion (e.g. Mohr-Coulomb) to modify the elastic stress for fitting the mechanical behavior of elastoplastic materials; and (4) a complete code for the mechanical calculation to be implemented in Matrix Laboratory (MATLAB).FindingsThree case studies, including two standard laboratory experiments (uniaxial compression and Brazilian split test) and one engineering-scale anti-dip slop model, are presented to illustrate the feasibility of the Y-Mat code and its ability to deal with multi-scale rock mechanics problems. The results, including the progressive failure process, failure mode and trajectory of each case, are acceptable compared to other corresponding studies. It is shown that, the code is capable of modeling geotechnical and geological engineering problems.Originality/valueThis article gives an improved FDEM-based numerical calculation code. And, feasibility of the code is verified through three cases. It can effectively solve the geotechnical and geological engineering problems.

Preface

International Conference on Geological Engineering and Geosciences ICGoES 2021 International Conference on Geological Engineering and Geosciences (ICGoES 2021) presents ‘Big City Challenges on Geohazard and Georesources’ as the main conference theme. This conference provides a forum for international researchers, academics, practitioners, policymakers and related communities to discuss, share and exchange their latest research and experience progress associated with the field of geological engineering and geosciences. In addition, this conference also aimed to address a common issue of georesources sustainability, renewable energy sources and climate change-related geohazard and disasters in the development of urban areas. Certainly, those issues require an integrated approach and collaborative efforts in particular to build and enhance resilient cities in the respective countries. ICGoES 2021 provides opportunities to all participants in expanding their network, as an important step to achieve a coordinated approach and interdisciplinary collaboration at the regional and international level in the field of geological engineering and geosciences. We invited research papers on the topic of geohazard and georesources; but not limited to research papers, recent cases, and in-depth reviews of basic geology, applied geology, geophysics, geochemistry, engineering geology, geo-environmental engineering and any related geoscience. Due to the COVID-19 pandemic situation during the year, it is not easy to hold a regular conference in a specific place. There were travel restrictions and regulations from the World Health Organization and the Indonesian Government to be complied with to cut the spread of the COVID-19 virus in terms of physical distancing. In this uncertain condition, the ICGoES should not be postponed since participants have arranged to address their research findings at this conference. Thus, the committees of ICGoES have decided to switch the conference format into a virtual meeting using ZOOM. List of Committees, Conference Photos are available in this pdf.

Application Research Of 3D Digital Evaluation And Analysis Method In Geological Engineering

In order to adapt to the construction and development of informatization and digitization of engineering survey industry, a method of rock mass quality classification based on 3D geological modeling analysis is proposed. Based on a hydropower station as an example, this paper build a refinement 3D geological visualization model, simulate and analysis engineering geology of the hydropower station from the perspective of the three-dimensional digital. According to features of rock mass damage and elastic-plastic mechanics of dissipation energy principle, which gives the optimize evaluation index and method of rock mass quality classification in water resources and hydropower engineering, endowed with classification attribute values of each level and restructured model shows the spatial distribution characteristics of rock mass quality. In conclusion, this method improves the efficiency and intuitiveness of the engineering geology analysis and engineering rock mass quality classification. Furthermore, the 3D digital evaluation method was verified more rationality and intuitiveness in geological engineering comparing with traditional 2D geological analysis method.

Transformation of geological sciences and geological engineering field methods course to remote delivery using manual, virtual, and blended tools in fall 2020

Geological (Engineering) Field Methods (GEOE/L 221) is a core course for two programs at Queen’s University in Kingston, Ontario, Canada where students learn foundational knowledge, skills, and methods to conduct field work that is used to investigate geological and geological engineering aspects of the Earth. Typically, this fall-term course involves weekly field trips in the Kingston area to visit a variety of rock outcrops to learn and practice methods of field navigation, observation, and measurement. Remote delivery of this course in fall 2020 due to COVID-19 without in-person field trips required a significant transformation, which included creating field and demonstration instructional videos, using 3D digital photogrammetry models of rock samples and outcrops, developing independent outdoor activities for pace and compass navigation, manual sketching and graphical measurements on paper, and utilizing a culminating immersive 3D video game style geological field mapping exercise. This paper examines these new course elements, how well the course learning objectives were achieved in a remote setting, and the successes and limitations of remote delivery. Although many new virtual elements enhance the course and should be incorporated to future offerings, a return to in-person field methods teaching for geological sciences and geological engineering courses is strongly recommended.

Petrographic and Geotechnical Characteristics of Carbonate Aggregates from Poland and Their Correlation with the Design of Road Surface Structures

The paper presents the basic problem related with practical application of carbonate rocks in construction: are carbonate aggregates produced from such rocks favorable for building engineering, particularly for road design and construction? To resolve this problem, (1) the geological-engineering properties of aggregates are presented, (2) the correlation between petrographic and engineering parameters is shown, and (3) a strict correlation between the geological-engineering properties and the freezing-thawing and crushing resistance is recognized. This knowledge has allowed to assess the usefulness of asphalt concrete (AC) made from dolomite and limestone aggregates in the design and construction of road surface structures. The petrography was characterized using optical microscopy and scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscope (EDS). Engineering properties were determined in accordance with European and Polish norms and guidelines. Statistical and design calculations were performed using dedicated software. The petrographic properties, and selected physical and mechanical parameters of the aggregates, were tested to show their influence on the freezing–thawing and crushing resistance. Strong functional relationships between the water adsorption, and the freezing–thawing and crushing resistance have been observed. Aggregate strength decreased after saturation with increasing concentrations of salt solutions. Calculations of AC fatigue durability and deformation allow for reducing the thickness of the road surface structure by about 20% in comparison to normative solutions. This conclusion has impact on the economy of road design and construction, and allows for a rational utilization of rock resources, which contributes to sustainable development of the construction industry.