Article
Engineering, Geological
M. Williams, M. Ziegler, Stephan Schennen, S. Loew
Summary: The text presents the results of seismic experiments conducted in two excavation damaged zones (EDZs) in Mont Terri Underground Rock Laboratory. The findings provide valuable insights into the integrity of the rock mass surrounding the excavation and its implications for mid-term safety assessments.
ENGINEERING GEOLOGY
(2022)
Article
Engineering, Ocean
Yixiao Luan, Xiaowei Tang, Yubin Ren, Xiwen Zhang
Summary: This paper investigates the development of pore pressure under the suction anchor lid during the undrained pullout process. The effectiveness and accuracy of a numerical model based on solid-fluid two-phase theory were verified through laboratory experimental studies. Parametric analysis reveals the impact of key soil properties on pore pressure accumulation. The results demonstrate the efficiency and accuracy of the numerical method in capturing the failure pattern and simulating pore pressure evolution.
APPLIED OCEAN RESEARCH
(2023)
Article
Energy & Fuels
Yujie Yuan, Reza Rezaee, Hongyan Yu, Jie Zou, Kouqi Liu, Yihuai Zhang
Summary: The study classified shales into 12 lithofacies and compared the Goldwyer shales with other shale lithofacies, pure clays, and isolated kerogens using various techniques. Results show that the argillaceous OM-rich lithofacies have more interconnected pores with better hydrocarbon storage potential, while other lithofacies and isolated kerogens have their own characteristics in shale gas storage capacities.
Article
Engineering, Geological
Zhiyong Liu, Jianfeng Xue, Mohammadjavad Yaghoubi
Summary: The study found that reducing confining pressure accelerates strain accumulation in soils during cyclic loading, with greater reductions leading to larger accumulated strain and excess pore water pressure. The direction of strain accumulation in soil is controlled by the shear stress ratio, and the final accumulated strain is not significantly affected by unloading schemes.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2021)
Article
Geosciences, Multidisciplinary
Ke Man, Xiaoli Liu, Zhifei Song
Summary: The study conducted blasting tests in the Beishan Exploration Tunnel and monitored blasting vibration velocity and excavation damaged zone, identifying the impact of different blasting parameters on vibration velocity and damaged depth, and proposing a method to control rock damaged depth.
GEOMATICS NATURAL HAZARDS & RISK
(2021)
Article
Geosciences, Multidisciplinary
Guoxi Cheng, Bo Jiang, Fengli Li, Ming Li, Caifang Wu
Summary: This paper investigates the evolution rules and mechanisms of micro- and mesopore structures of various tectonically deformed shales (TDSs). The results show that different degrees of structural deformation have a significant impact on the micro- and mesopores of shales, mainly due to changes in organic matter content and mineral composition.
NATURAL RESOURCES RESEARCH
(2023)
Article
Geosciences, Multidisciplinary
Hui Xiao, Nan Xie, Yuanyuan Lu, Tianyue Cheng, Wei Dang
Summary: The study of the pore structure and its controlling factors in shale reservoirs is crucial for the exploration and exploitation of shale gas. This study focused on the effects of organic and inorganic compositions on the pore structure development of Shanxi shale in the Ordos Basin. The results showed that the mineral composition and organic matter type are key factors in determining the pore structure of shale. The pore structure plays a significant role in the characteristics and development potential of shale.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Chemistry, Analytical
Xiaorong Wan, Chuan Li, Zhengang Zhao, Dacheng Zhang, Yingna Li, Jiahong Zhang
Summary: A Fiber Bragg Grating stress sensor was developed in this study to measure stress variations in rock, with applications in safety monitoring and stability prediction in underground coal mines. The sensor compensates for environmental temperature disturbances and has shown sensitivity to stress changes in the Excavation Damaged Zone. Monitoring results indicate that the sensor is effective in measuring stress amplitudes and creep times during blasting, providing important data for mine safety.
Article
Chemistry, Physical
Jiaqi Chang, Xiaodong Fan, Zhenxue Jiang, Xingmeng Wang, Lei Chen, Jitong Li, Lin Zhu, Chengxiang Wan, Zhixiang Chen
Summary: This study investigated the effects of organic matter, clay minerals and organo-clay composites on the pore structure and pore complexity of shale reservoirs. The results showed that the type and maturity of macerals, illite, kaolinite, and organo-clay composites are the main factors influencing shale pore development. The study also found that different clay mineral types have different effects on shale pore structure and pore complexity.
APPLIED CLAY SCIENCE
(2022)
Article
Geochemistry & Geophysics
Sina Hale, Xavier Ries, David Jaeggi, Philipp Blum
Summary: In this study, a hydromechanical characterization of an evolving excavation damaged zone (EDZ) in the Mont Terri underground rock laboratory in Switzerland was conducted using three different handheld devices. The study found permeable fractures with specific hydraulic apertures, observed cyclic long-term fracture aperture oscillations, and determined the uniaxial compressive strength of the rock. The study's methodological approach is suitable for time-dependent monitoring of EDZs, providing spatially resolved investigation of hydraulic and mechanical fracture apertures, surface roughness, and rock parameters.
Article
Engineering, Geological
Yuqi Wu, Dayong Li, Yukun Zhang
Summary: This paper presents a modified three-dimensional failure mechanism to predict the anti-overturning bearing capacity of suction caissons in clay under undrained condition. The modified mechanism consists of a meniscus-conical wedge at the mudline and a spherical failure in deeper soil. The anti-overturning bearing capacity is deduced based on the work-energy balance equation, and two parameters are optimized to approach the critical failure mechanism that offers the minimum energy dissipation. The reliability of the presented analysis is verified against finite element limit analysis and existing experimental and theoretical methods.
Article
Geochemistry & Geophysics
Cunhui Fan, Huwei Cao, Jing Li, Maolong Xia, Jing Liu, Jing Liang, Lifeng Meng, Haihua Zhu
Summary: There are various fault, fold, and unconformity structures in the southwestern Sichuan Basin, which greatly influence hydrocarbon preservation. The preservation conditions of key horizons were analyzed based on regional geological, seismic, and formation water data, as well as caprock characteristics and production. The southwestern Sichuan Basin margin has two distinct tectonic layers, with different fault orientations and outcrop characteristics. The hydrocarbon preservation evaluation system was established considering faults, outcrops, formation water type, mineralization, and caprock thickness, dividing the areas into Class I, II, and III based on preservation conditions.
Article
Engineering, Geological
Huatao Zhao, Ming Tao, Xibing Li, Hitoshi Mikada, Shibo Xu
Summary: The research utilizes the Hoek Brown criteria to calculate the distribution of excavation damaged zone around the cavity at different burial depths, and investigates the dynamic responses of the excavation-damaged cavity under dynamic disturbance using the SEM method. Influencing factors such as the shapes of EDZ, the incident direction of dynamic disturbance, and the dynamic source frequency are identified.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2021)
Article
Construction & Building Technology
Changbai Wang, Jimin Liu, Hua Cheng, Haibing Cai
Summary: This paper investigates the excavation-induced disturbance range and mechanism of adjacent pipeline jacking group on surrounding soils. Through field tests and evaluations, it is found that the disturbance intensity is greatly affected by the parallel distance and buried depth.
ADVANCES IN CIVIL ENGINEERING
(2021)
Article
Chemistry, Physical
Kun Yu, Kaidi Zhao, Yiwen Ju
Summary: The low permeability of unconventional reservoirs, particularly coal and clay-rich shale, can significantly impact the production efficiency of methane due to the unique water sensitivity and swelling mechanism of clay minerals. Hydraulic fracturing can enhance the permeability of these reservoirs, with clay-rich shale showing better improvement than coal.
APPLIED CLAY SCIENCE
(2022)
Editorial Material
Engineering, Geological
Qinghua Lei, Simon Loew
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2022)
Article
Engineering, Geological
Shucai Li, Jie Hu, Florian Amann, Liping Li, Hongliang Liu, Shaoshuai Shi, Pooya Hamdi
Summary: The paper introduces a new rock testing system that can simulate complex tensile-compressive-shear stress states. The system allows for laboratory tests under various failure modes and provides valuable information on failure characteristics.
JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING
(2022)
Article
Engineering, Geological
Ali Aminzadeh, Florian Amann
Summary: This article studies the stresses at the center of a disk made of transversely isotropic rocks in Brazil. It finds that the solution for these stresses depends on the radius of the disk, the applied load, the material orientation, and two dimensionless ratios related to Young's modulus and apparent shear modulus. Finite element simulations are conducted to determine the stresses at the disk center, and an approximate formula is derived from analytical results. The formula is compared to numerical solutions, and simple and practical equations are proposed for estimating the stresses at the center of the disk specimen.
JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING
(2023)
Article
Chemistry, Analytical
Claudia Post, Niklas Heyden, Andre Reinartz, Aaron Foerderer, Simon Bruelisauer, Volker Linnemann, William Hug, Florian Amann
Summary: The entire water cycle is contaminated with undetected micropollutants, which poses a threat to wastewater treatment. In our case study, we used Deep-UV laser-induced Raman and fluorescence spectroscopy in combination with a CNN-based AI support to analyze samples from different treatment stages of a wastewater treatment plant. The results showed the potential of this method for online monitoring and analysis of micropollutants in wastewater treatment.
Article
Energy & Fuels
Zhengyang Song, Yunfeng Wu, Heinz Konietzky, Florian Amann, Zhen Yang, Wengang Dang
Summary: The mechanical responses of coal exposed to wetting-drying conditions and compressive cyclic loading were investigated to reveal its behaviors. Experimental results showed that wetting-drying cycles had an exponential attenuation effect on the P-wave velocity of coal, while different loading rates led to different failure modes and energy dissipation. In addition, wetting-drying action induced macro-cracks, and the width of the cracks was proportional to the number of cycles. These testing results provide practical guidance for evaluating the stability of coal mines in in-situ applications.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2022)
Article
Construction & Building Technology
Martin Ziegler, Arash Alimardani Lavasan, Simon Loew
Summary: This study presents in-situ datasets obtained from the monitoring section of a faulted section in the new Belchen tunnel tube in the Swiss Jura Mountains. The data reveals heterogeneous radial pressures on the tunnel support and a gradual increase over the course of four years. Numerical simulations also show a significant temperature effect on the measured total pressures.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Garri Gaus, Eva-Maria Hoyer, Timo Seemann, Reinhard Fink, Florian Amann, Ralf Littke
Summary: This study investigates the potential effects of diagenesis on permeability, pore space, and unconfined compressive strength in organic-lean mudstones that have undergone different maximum burial depths. The results show that permeabilities and porosities significantly decrease up to a maximum burial depth of approximately 2,500 m, while further burial to 3,600 m has negligible impact on these properties. The findings provide important insights into the physical properties of mudstones and their relevance in oil and gas exploration and development.
ZEITSCHRIFT DER DEUTSCHEN GESELLSCHAFT FUR GEOWISSENSCHAFTEN
(2022)
Article
Chemistry, Multidisciplinary
Florian Amann, Francesca Badaracco, Riccardo DeSalvo, Luca Naticchioni, Andrea Paoli, Luca Paoli, Paolo Ruggi, Stefano Selleri
Summary: This paper proposes a new topology for the Einstein Telescope that separates key components and noise-inducing equipment into separate excavations, allowing continuous detection during maintenance and upgrades. The distribution of seismic attenuation chain components over multiple tunnel levels improves event detection efficiency and leaves room for future upgrades. The design also eliminates mechanical crowding around the test masses, reducing the need for support measures.
APPLIED SCIENCES-BASEL
(2022)
Article
Geochemistry & Geophysics
Y. Li, K. Leith, M. A. Perras, S. Loew
Summary: Moisture variation affects the strains and elastic properties of granite. Increasing the ambient humidity from 20% to 90% results in an average decline of 13% in Young's modulus, which nearly returns to the initial dry value when the humidity is reduced to 20%. Poisson's ratio increases by 130% in response to the same humidity change, and approximately 60% of it is reversed when dried. These changes occur linearly with a volumetric strain of up to 8 x 10(-4), equivalent to 24.5 MPa internal stress.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Retraction
Construction & Building Technology
Manuel Entfellner, Pooya Hamdi, Xiaoyue Wang, Helmut Wannenmacher, Florian Amann
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Qinghua Lei, Didier Sornette, Haonan Yang, Simon Loew
Summary: Researchers have developed a physics-based framework to assess the potential risk of landslide slope failures. By studying extreme events in natural systems, they have developed statistical tools to detect the emergence of "dragon-kings" events during landslide evolution. They have also constructed a phase diagram to determine whether the slope is evolving towards a catastrophic or slow landslide.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geochemistry & Geophysics
L. Winhausen, K. Khaledi, M. Jalali, M. Bretthauer, F. Amann
Summary: This study investigates the anisotropic behavior of Opalinus Clay, a selected host rock for nuclear waste disposal in Switzerland, by examining its unconfined compressive and tensile strength, poromechanical response, and effective shear strength. The results reveal that the rock exhibits a directional dependency in its strength properties, with the lowest values observed at specific angles between the bedding orientation and the load direction. The study also shows that the orientation of the bedding plane with respect to the maximum principal stress significantly influences the poromechanical behavior and the effective strength of the rock.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geosciences, Multidisciplinary
N. Oestreicher, Q. Lei, S. Loew, C. Roques
Summary: Seasonal deformation of mountain rock slopes can be driven by groundwater infiltration and depletion, with fracture network geometry, fracture aperture, and regional stress field being the key geological factors controlling the type and magnitude of reversible slope deformations. Heterogeneity and anisotropy of bedrock hydromechanical responses also play a critical role in groundwater recharge and slope deformation.
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
(2023)
Article
Geochemistry & Geophysics
Xiaodong Ma, Marian Hertrich, Florian Amann, Kai Broeker, Nima Gholizadeh Doonechaly, Valentin Gischig, Rebecca Hochreutener, Philipp Kaestli, Hannes Krietsch, Michele Marti, Barbara Naegeli, Morteza Nejati, Anne Obermann, Katrin Plenkers, Antonio P. Rinaldi, Alexis Shakas, Linus Villiger, Quinn Wenning, Alba Zappone, Falko Bethmann, Raymi Castilla, Francisco Seberto, Peter Meier, Thomas Driesner, Simon Loew, Hansruedi Maurer, Martin O. Saar, Stefan Wiemer, Domenico Giardini
Summary: The increased interest in subsurface development and associated seismicity requires a better understanding of hydro-seismo-mechanical coupling in fractured rock masses. In order to bridge the knowledge gap between laboratory and reservoir scales, controllable in situ experiments are necessary. The BedrettoLab provides a testing ground for studying the hydro-seismo-mechanical response of fractured crystalline rock masses.