Zeitschriftenartikel: „Hydro-mechanical loading“

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Hao, Qi-Jun, Zhao-Peng Zhang, Xin-Zhong Wang, Ru Zhang, An-Lin Zhang, Lan-Bin Zhang und Chen-Di Lou. „Study on mechanical properties and acoustic emission response of deep granite under hydro-mechanical coupling“. Thermal Science 27, Nr. 1 Part B (2023): 631–38. http://dx.doi.org/10.2298/tsci2301631h.

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The study on the mechanical response of deep rock under hydromechanical couplings condition can guide the safe excavation and stability evaluation of deep tunnel engineering. The effects of monotonic loading and cyclic loading on the mechanical properties of granite under 5 MPa pore water pressure and 10 MPa confining pressure were studied by laboratory tests. Before the peak stress, the permeability under monotonic loading was significantly higher than that under cyclic loading, and the permeability under cyclic loading increased sharply after the peak stress. There were two active periods of the acoustic emission energy before peak stress under monotonic loading, but it was always in relative quiet period under cyclic loading before peak stress. Based on the energy theory, the energy evolution of granite was discussed. The dissipation energy can better reflect the effect of loading mode on the energy evolution.

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Ashrafi, Mehran, Farzan Ghalichi, Behnam Mirzakouchaki und Iman Zoljanahi Oskui. „Numerical simulation of hydro-mechanical coupling of periodontal ligament“. Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 234, Nr. 2 (13.11.2019): 171–78. http://dx.doi.org/10.1177/0954411919887071.

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Orthodontic tooth movement in the alveolar bone is due to the mechanical response of periodontal ligament to applied forces. Definition of a proper constitutive model of the periodontal ligament to investigate its response to orthodontic loading is required. For this purpose, a three-dimensional finite element model of incisor tooth, periodontal ligament, and bone was built utilizing the hydro-mechanical coupling theory. Tooth displacement in response to orthodontic loading was then investigated, and the effect of different mechanical behaviors assigned to the solid phase of the periodontal ligament was compared. Results showed that where the periodontal ligament was placed in tension, pore volume was filled with fluid intake from the bone, but fluid flow direction was from the periodontal ligament toward the bone where the periodontal ligament was placed in compression. Because of the existence of interaction between solid and fluid phases of the periodontal ligament, considering biphasic material formulation was capable to address its microscopic behavior as well as time-dependent and large deformation behaviors. This article provides beneficial biomechanical data for future dental studies in determination of optimal orthodontic force.

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Zhou, Yimeng, Cheng Zhao, Chunfeng Zhao, Chuangchuang Ma und Junfei Xie. „Experimental Study on the Fracturing Behaviors and Mechanical Properties of Cracks under Coupled Hydro-Mechanical Effects in Rock-like Specimens“. Water 10, Nr. 10 (29.09.2018): 1355. http://dx.doi.org/10.3390/w10101355.

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The artificial fracturing technique under coupled hydro-mechanical effects is widely used in many rock engineering. Therefore, the study on the fracturing behaviors and mechanical properties of hydro-mechanical coupled cracks is very crucial. In this study, a series of fracturing tests were conducted on the cylinder gypsum specimens with single pre-existing cracks using triaxial compression loading system. Water pressure was applied inside the pre-existing cracks and led to the specimen failure with external compression loading. A new type of cracks, namely horizontal coupled cracks (HCC), were found in some specimens. Macroscopic observations reveal that HCC, which were mainly caused by the hydraulic pressure, were different from any tensile wing cracks, shear secondary cracks, or shear anti-wing cracks. Subsequently, a microscopic study was performed using scanning electron microscope (SEM), the outcomes suggest that: (1) Shear fracturing zones (SFZ) and tensile fracturing zones (TFZ) under coupled hydro-mechanical effects displayed distinct characteristics on orientations, length, and independence of gypsum grains; and (2) the HCC were tensile cracks when they just initiated from outer tips of pre-existing cracks. While tensile stress made major contribution to the specimen failure during the whole fracturing processes, the HCC became tensile and shear mixed cracks when the specimen was about to fail.

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Song, Zhixiang, Junwen Zhang und Shaokang Wu. „Energy Dissipation and Fracture Mechanism of Layered Sandstones under Coupled Hydro-Mechanical Unloading“. Processes 11, Nr. 7 (07.07.2023): 2041. http://dx.doi.org/10.3390/pr11072041.

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Rock burst is easy to occur in the water-rich roadway of coal mines, which is closely related to the energy dissipation and fracture mechanism of rocks under coupled hydro-mechanical (H-M) unloading. Therefore, in combination with the triaxial loading and unloading process and H-M coupling effect, the mechanical test of layered sandstones under coupled hydro-mechanical unloading (TLUTP) was conducted. The energy dissipation and fracture mechanism were revealed. The results show that: (1) The influence of layered angles on the peak volumetric strain is more sensitive than that of confining pressure under conventional triaxial loading with H-M coupling (CTLTP). On the contrary, the influence of confining pressure on the peak volumetric strain is more sensitive than that of layered angles under TLUTP. (2) With increasing layered angles, the peak elastic energy density under CTLTP shows the “W” shaped evolution characteristic, while that of under TLUTP shows the “N” shaped evolution characteristic. (3) The “Energy Flow” chain is proposed. Meanwhile, combined with the domino effect and the structural evolution theory, the energy dissipation and fracture mechanism of layered sandstones under coupled hydro-mechanical unloading are both revealed. The conclusions obtained can provide certain fundamental theoretical references for the effective prevention of rock burst in a layered water-rich roadway.

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Alcantara, Arisleidy Mesa, Enrique Romero, Nadia Mokni und Sebastià Olivella. „Microstructural and hydro-mechanical behaviour of bentonite pellets and powder mixtures“. E3S Web of Conferences 195 (2020): 04003. http://dx.doi.org/10.1051/e3sconf/202019504003.

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Binary mixtures of high-density MX-80 bentonite pellets (80%) and bentonite powder (20%) at hygroscopic water content have been recently considered as an alternative engineered barrier system for the long-term disposal of radioactive wastes. These mixtures display a dry density of around 1.49 Mg/m3 on pouring and present components with multi-modal pore size distributions that significantly evolve during the hydro-mechanical paths. To better understand the hydro-mechanical behaviour of this multiple porosity mixture, the contribution initially focuses on describing the initial state, as well as the main microstructural features determined by mercury intrusion porosimetry tests for the mix and each of the components (pellets and powder). Afterwards, hydro-mechanical results of both components and the mixture are presented. The hydraulic results focus on the water retention and water permeability, while the mechanical tests concentrate on the compressibility properties on loading.

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Zhao, Youqun, Han Xu, Yaoji Deng und Qiuwei Wang. „Multi-objective optimization for ride comfort of hydro-pneumatic suspension vehicles with mechanical elastic wheel“. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 233, Nr. 11 (08.10.2018): 2714–28. http://dx.doi.org/10.1177/0954407018804909.

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The new mechanical elastic wheel has the following advantages: non-pneumatic, anti-puncture, and explosion-proof. However, the larger radial stiffness is detrimental to vehicle ride comfort. To solve this problem, an integrated design method of hydro-pneumatic suspension matching mechanical elastic wheel is proposed in this paper. First, the nonlinear radial stiffness of mechanical elastic wheel is fitted by static loading experiment. Next, the mathematical model of hydro-pneumatic suspension is derived. Then, a half-car model, integrating hydro-pneumatic suspension and mechanical elastic wheel, is established. Finally, the top two optimization objectives, including vertical centroid acceleration root mean square and pitch acceleration root mean square, are optimized simultaneously, based on the Pareto multi-objective artificial fish swarm algorithm. The obtained results show that the optimization effect of multi-objective artificial fish swarm algorithm is obvious; the two optimization objectives have been optimized significantly. The proposed method that hydro-pneumatic suspension integrated with mechanical elastic wheel gains critical reference value for the design and optimization of vehicle chassis in theory and practice.

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Nishimura, Tomoyoshi. „Cyclic behaviour of an unsaturated silty soil subjected to hydro-mechanical damage“. E3S Web of Conferences 195 (2020): 03037. http://dx.doi.org/10.1051/e3sconf/202019503037.

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The dynamic behaviour of unsaturated soil subjected to cyclic loading is considered using two stress state variables, net normal stress and matric suction. Though the influence of excess pore-water pressures in fully saturated soils has been investigated through experimental works for decades, it is significant in practice for unsaturated soil dynamic behaviour to be compared to saturated soil dynamic strength-deformation properties. Matric suction can be described as a scalar, which is useful in establishing safety factors and in mathematical simulations. This study focused on the dynamic behaviour of unsaturated soil leading to liquefaction failure. Solving practical problems requires considering the properties of unsaturated soil subjected to creep before introducing dynamic loading effects. This testing program consisted of a creep test and a cyclic loading test. Notably, a low suction range of soil structure is closely related to large deformations or leads to failure impacting the resistance of soil particle cohesion, including the macro-micro structure. Creep force was applied under lateral confining pressure, and suction measurements are indicating a gradual growth of excess pore-water pressure. Moreover, this study considered a dynamic triaxial compression test under the undrained condition for unsaturated soil with suction and creep history.

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Galek, Artur, Harald Moser, Thomas Ring, Matthias Zeiml, Josef Eberhardsteiner und Roman Lackner. „Mechanical and Transport Properties of Concrete at High Temperatures“. Applied Mechanics and Materials 24-25 (Juni 2010): 1–11. http://dx.doi.org/10.4028/www.scientific.net/amm.24-25.1.

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When concrete structures are subjected to fire loading, temperature-dependent degradation of the material properties as well as spalling of near-surface concrete layers has a considerable effect on the load-carrying capacity and, hence, the safety of these structures. Spalling is caused by interacting thermo-hydro-chemo-mechanical processes with both mechanical and transport properties playing an important role. Within experimental research activities at the IMWS, these properties are subject of investigation, i.e., (i) the strain behavior of concrete under combined thermal and mechanical loading and (ii) the permeability increase of temperature-loaded concrete and cement paste.

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Yu, Hongdan, Weizhong Chen, Zhe Gong, Xianjun Tan und Diansen Yang. „Loading-unloading behavior of a clayey rock under thermo-hydro-mechanical conditions“. International Journal of Rock Mechanics and Mining Sciences 148 (Dezember 2021): 104966. http://dx.doi.org/10.1016/j.ijrmms.2021.104966.

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Ghasemzadeh, H., und S. A. Ghoreishian Amiri. „A hydro-mechanical elastoplastic model for unsaturated soils under isotropic loading conditions“. Computers and Geotechnics 51 (Juni 2013): 91–100. http://dx.doi.org/10.1016/j.compgeo.2013.02.006.

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Arzanfudi, Mehdi M., Rafid Al-Khoury, L. J. Sluys und G. M. A. Schreppers. „A thermo-hydro-mechanical model for energy piles under cyclic thermal loading“. Computers and Geotechnics 125 (September 2020): 103560. http://dx.doi.org/10.1016/j.compgeo.2020.103560.

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Ouagne, Pierre, Joël Bréard, Tariq Ouahbi, Abdelghani Saouab und C. H. Park. „Hydro-mechanical loading and compressibility of fibrous media for resin infusion processes“. International Journal of Material Forming 3, S2 (17.12.2009): 1287–94. http://dx.doi.org/10.1007/s12289-009-0671-x.

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Hashemi, Amirhossein, und Melis Sutman. „Thermo-hydro-mechanical behaviour of partially saturated fine-grained soils in the context of energy geostructures“. Soils and Rocks 45, Nr. 1 (18.02.2022): 1–17. http://dx.doi.org/10.28927/sr.2022.076821.

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The multi-physical phenomena, particularly water content and temperature variations, governing the behaviour of soils should be considered in the design and analysis of the energy geostructures. Soil temperature and water content variations impose a significant risk on the stability and serviceability of existing and future geostructures. Although potential failure modes, impacts at a system scale, and the response of saturated soils to thermal loads are previously discussed, interpretation of the thermo-hydro-mechanical behaviour of partially saturated soils in the context of energy geostructures is not thoroughly investigated. In this regard, this paper brings together the experimental data from several laboratory investigations to attain a comprehensive understanding of the partially saturated fine-grained soils response under thermo-hydro-mechanical loading, which plays a vital role in the analysis of the soil behaviour and energy geostructures in contact with them. In this paper, the effect of thermal loading in different matric suctions and hydraulic loading at different temperatures on soil preconsolidation stress, water content variation, thermal and hydraulic conductivities, and compression indexes are studied. Furthermore, soil thermal deformation is studied in detail for different overconsolidation ratios and matric suctions.

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Akay, S. B., E. F. Şükür, M. Turkoz, S. Halkaci, M. Koç und S. Avcı. „Determination of Proper Loading Profiles for Hydro-Mechanical Deep Drawing Process Using FEA“. Applied Mechanics and Materials 686 (Oktober 2014): 540–48. http://dx.doi.org/10.4028/www.scientific.net/amm.686.540.

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Hydro-mechanical Deep Drawing (HMD) is an advanced manufacturing process developed to form sheet metal blanks into complex shapes with smooth surfaces using hydraulic pressure as an additional source of deformation force. There are many factors affecting the successful production of desired parts using this manufacturing process. The most important factors are the fluid pressure and blank holder force. Having proper values of these parameters during forming has a direct impact on part properties such as drawing ratio and thinning. In order to determine desired the fluid pressure and blank holder force profiles, which are different for every geometry, material and other process conditions, finite element simulations are conducted to save time and cost. Abaqus FEA software is used in this study. In order to define the continuously changing fluid pressure application area on the sheet material, which is not an available module or standard interface of software, sub-programs (sub-routines) are developed to properly and dynamically define the fluid pressure area. Proper, if not optimal, fluid pressure and blank holder force profiles, which allow the formability (LDR) of sheet material to be maximum, were obtained using trial and error method. Maximum thinning values on metal blank were used as a control parameter to determine if selected loading profiles result in the highest LDR with lowest thinning.

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Ghobadi, Behnam, Hamidreza Nejati und Kamran Goshtasbi. „Numerical Modeling of Hydro-Mechanical Behavior of Rock Joints under Direct Shear Loading“. Journal of Aalytical and Numerical Methods in Mining Engineering 7, Nr. 13 (01.12.2017): 35–44. http://dx.doi.org/10.29252/anm.7.13.35.

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Motoshima, Takayuki, Sachie Iso und Tomoyoshi Nishimura. „Behavior of compacted Ca-bentonite subjected to HMC loading: observations and interpretation“. MATEC Web of Conferences 337 (2021): 04004. http://dx.doi.org/10.1051/matecconf/202133704004.

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This study presents result of HMC experimental test and discussions of chemical effort in Cabentonite. SWCC test, swelling pressure test and unconfined compression test as hydro-mechanical-chemical (HMC) test were applied to Cabentonite-sand mixture. Na-type bentonite has been studied to predict safety and confidence for artificial barrier layer consist of bentonite that many experimental research reports are represented, and can offer technology advanced comprehensive performance due to mathematical simulation models associated to physical parameters on thermal-hydration-mechanical-chemical properties. This study proposed a significant property for calcium bentonite to relate evaluating safety in radioactive waste disposal system, which emphasised much influence of suction and salinity chloride to hydration-mechanical behaviour for Calcium bentonite.

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Zeng, Hao, Laura Gonzalez-Blanco, Enrique Romero und Alessandro Fraccica. „Microstructure and hydro-mechanical behaviour of compacted granular bentonite“. E3S Web of Conferences 382 (2023): 14010. http://dx.doi.org/10.1051/e3sconf/202338214010.

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In recent years, granular bentonite GB has become a reference material since it facilitates the backfilling operation due to high-density compacted granules with extended grain size distribution(maximum sizes around 10 mm). This investigation explores the initial microstructure of MX80-type GB and the hydro-mechanical HM response observed at the phenomenological scale. Samples were statically compacted at a fixed dry density (1.55 Mg/m3 ), encompassing dry and wet sides of the optimum. Themicrostructural study was performed using a combination of X-ray micro-computed tomography and mercury intrusion porosimetry. The results indicate that the pore size density function of compacted GB can be simplified as a double-porosity network with micropores (intra-granular/aggregate pores) and macropores(inter-granular/aggregate pores). Compacting at the dry side increases macropores, making the sample more compressible on loading under as-compacted states despite the higher matric suction. The time evolution of the swelling pressure displays a double-peak pattern attributed to the particular microstructure of the samples. Moreover, the initial microstructure does not significantly influence the water retention properties without a marked hysteresis in the high-suction range under confined wetting/drying cycles. This work’s outcomes highlight the microstructure’s significance in the HM behaviour of compacted GB and provide further insight into the geotechnical properties of this material.

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Rodrigues Borges, Camilla, Bruna de Carvalho Faria Lima Lopes und Manoel Porfírio Cordão Neto. „Pore size distribution of Brasilia tropical soil in 3 different initial states“. E3S Web of Conferences 92 (2019): 01009. http://dx.doi.org/10.1051/e3sconf/20199201009.

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In the last decades there was an evolution in the analysis of the soil structure, most importantly, there was an improvement in the evaluation and in the ways of determining the mentioned structure and how it relates to the hydro-mechanical behaviour of soils. Due to the necessity of understanding the behaviour of tropical soils under different structures (natural, compacted and slurry) this study was developed by means of the Mercury Intrusion Porosimetry (MIP), enabling the analysis of the structural characteristics of these samples. The main objective of this work is to evaluate how the different structures are affected by external loading and how the changes in the pore sizes influences the hydro-mechanical behaviour of the soil in both, saturated and unsaturated conditions. It has been observed that the results regarding the influence of the structure showed a bimodal behaviour. The structural modification of the soil under study, due to the mechanical and / or hydraulic loading, leads to changes in the structure of the macropores and does not affect the micropores. With this, it is noticed that even fixing the parameters related to the microstructure it is possible to make a good adjustment of the macro. This is justified by the fact that the microstructure of all samples are very similar.

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Cerroni, Daniele, Mattia Penati, Giovanni Porta, Edie Miglio, Paolo Zunino und Paolo Ruffo. „Multiscale Modeling of Glacial Loading by a 3D Thermo-Hydro-Mechanical Approach Including Erosion and Isostasy“. Geosciences 9, Nr. 11 (30.10.2019): 465. http://dx.doi.org/10.3390/geosciences9110465.

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We present a computational framework that allows investigating the Thermo-Hydro- Mechanical response of a representative part of a sedimentary basin during a glaciation cycle. We tackle the complexity of the problem, arising by the mutual interaction among several phenomena, by means of a multi-physics, multi-scale model with respect to both space and time. Our contribution addresses both the generation of the computational grid and the algorithm for the numerical solution of the problem. In particular we present a multi-scale approach accounting for the global deformation field of the lithosphere coupled with the Thermo-Hydro-Mechanical feedback of the ice load on a representative part of the domain at a finer scale. In the fine scale model we also include the erosion possibly caused by the ice melting. This methodology allows investigating the evolution of the sedimentary basin as a response to glaciation cycle at a fine scale, taking also into account the large spatial scale movement of the lithosphere due to isostasy. The numerical experiments are based on the analysis of simple scenario, and show the emergence of effects due to the multi-physics nature of the problem that are barely captured by simpler approaches.

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Woodman, Nicholas D., William G. Burgess, Kazi Matin Ahmed und Anwar Zahid. „A partially coupled hydro-mechanical analysis of the Bengal Aquifer System under hydrological loading“. Hydrology and Earth System Sciences 23, Nr. 5 (22.05.2019): 2461–79. http://dx.doi.org/10.5194/hess-23-2461-2019.

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Abstract. The coupled poro-mechanical behaviour of geologic-fluid systems is fundamental to numerous processes in structural geology, seismology, and geotechnics, but is frequently overlooked in hydrogeology. Substantial poro-mechanical influences on groundwater head have recently been highlighted in the Bengal Aquifer System, however, driven by terrestrial water loading across the Ganges–Brahmaputra–Meghna floodplains. Groundwater management in this strategically important fluvio-deltaic aquifer, the largest in southern Asia, requires a coupled hydro-mechanical approach which acknowledges poroelasticity. We present a simple partially coupled, 1-D poroelastic model of the Bengal Aquifer System, and explore the poro-mechanical responses of the aquifer to surface boundary conditions representing hydraulic head and mechanical load under three modes of terrestrial water variation. The characteristic responses, shown as amplitude and phase of hydraulic head in depth profile and of ground surface deflection, demonstrate (i) the limits to using water levels in piezometers to indicate groundwater recharge, as conventionally applied in groundwater resources management; (ii) the conditions under which piezometer water levels respond primarily to changes in the mass of terrestrial water storage, as applied in geological weighing lysimetry; (iii) the relationship of ground surface vertical deflection with changes in groundwater storage; and (iv) errors of attribution that could result from ignoring the poroelastic behaviour of the aquifer. These concepts are illustrated through application of the partially coupled model to interpret multi-level piezometer data at two sites in southern Bangladesh. There is a need for further research into the coupled responses of the aquifer due to more complex forms of surface loading, particularly from rivers.

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Rui, Yi, und Mei Yin. „Investigations of pile–soil interaction under thermo-mechanical loading“. Canadian Geotechnical Journal 55, Nr. 7 (Juli 2018): 1016–28. http://dx.doi.org/10.1139/cgj-2017-0091.

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Thermo-active piles that couple load bearing with ground source heat pump systems are one of the new technologies in geotechnical engineering. This paper investigates the pile–soil interaction behaviour of a thermo-active pile in overconsolidated London clay by conducting a thermo-hydro-mechanical finite element analysis using an advanced soil constitutive model. Negative and positive excess pore pressures are computed around the pile during cooling and heating, respectively. However, the difference in the radial effective stress acting on the pile–soil interface between the cooling and heating stages is small, and the pile–soil interaction is governed by the shear mobilization associated with thermally induced cyclic movements of pile expansion and contraction. During the first cooling stage, the shear stress at a small portion in the upper part of the pile reaches close to the yield values, which leads to an additional settlement about 3 mm from the original mechanical load–induced settlement of 2 mm. The shear stresses in subsequent heating and cooling cycles are much smaller than the ultimate shear stress values, because of the heavily overconsolidated nature of the London clay.

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Wildenborg, A. F. B., B. Orlic, J. F. Thimus, G. de Lange, S. de Cock, C. S. de Leeuw und E. J. M. Veling. „Radionuclide transport in clay during climate change“. Netherlands Journal of Geosciences - Geologie en Mijnbouw 82, Nr. 1 (April 2003): 19–30. http://dx.doi.org/10.1017/s0016774600022769.

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AbstractThe Dutch national research programme into the feasibility of retrievable storage of radioactive waste (CORA Programme Phase I; CORA: Comité Opslag Radioactief Afval = Committee on Radioactive Waste Disposal) examined the suitability of Tertiary clay deposits for such storage. Long-term isolation – up to 1 million years – of high-level radioactive waste under varying conditions is essential. A key concern is the hydro-mechanical response of the clay deposits in which radioactive waste might possibly be stored, in particular during glacial climate conditions as has happened repeatedly in the Netherlands during the Pleistocene. To evaluate this possibility hydro-mechanical computer simulations and mechanical laboratory experiments have been performed to analyse the effects of glacial loading by a thousand-metre-thick ice sheet on the permeability characteristics, fluid flow rates and the associated migration of radio-nuclides both within and out of Tertiary clays.Glacial loading causes the expulsion of pore water from deeply buried clay deposits into adjoining aquifers. The rates and duration of the consolidation-driven outflow of water from the clay deposit, are very sensitive to the permeability of the clay and the dynamics of the advancing ice sheet. The maximum outflow rate of pore water is 1 mm per year. This rate is approximately three times faster than the flow rate of water in clay prior to ice loading. These preliminary simulation studies also indicate that cyclic loading can result in more rapid migration of radio-nuclides in clays. In clay deposits that are covered by a thick ice sheet, the contribution of dispersed transport relative to the total transport by diffusion amounts to 14%, assuming that there is no absorption of radio-nuclides by the clays and a longitudinal dispersivity of 50 m.

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Tartière, Jérémie, Michel Arrigoni, Alain Nême, Hugo Groeneveld und Sjoerd Van Der Veen. „PVDF Based Pressure Sensor for the Characterisation of the Mechanical Loading during High Explosive Hydro Forming of Metal Plates“. Sensors 21, Nr. 13 (28.06.2021): 4429. http://dx.doi.org/10.3390/s21134429.

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High explosive hydro forming (HEHF) is a suitable technique for large metal plate forming. Manufacturing stages of such a part requires an adapted design of explosive charge configurations to define the mechanical loading exerted on the part. This mechanical loading remains challenging to be experimentally determined but necessary for predictive numerical simulation in the design of parts to form. Providing that the actual mechanical impulse would allow the neglecting of the modelling of the detonation stage, this considerably increases the computational time. The present work proposes an experimental method for obtaining the exerted mechanical loading by HEHF on the part to form. It relies on the development of low-cost sensor based on a polyvinyliden fluorid (PVDF) gauge. In addition to it, an analytical approach based on shock physics is proposed for the sensor signal interpretation. The method considers the multi-layer aspect of the sensor and its intrusiveness with respect to waves propagation. Measurements were repeated to assess their relevance and the reproducibility by using steel and aluminium anvils in HEHF. Numerical modelling in 2D plane geometry of the experiments was performed with two commercial hydrocodes. The comparison of mechanical impulses shows an agreement in terms of chronology but a noticeable difference in terms of amplitude, explained by mesh size and numerical diffusion.

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Sun, Yazhen, Rui Guo, Lin Gao, Jinchang Wang, Xiaochen Wang und Xuezhong Yuan. „Study on Dynamic Response Characteristics of Saturated Asphalt Pavement under Multi-Field Coupling“. Materials 12, Nr. 6 (22.03.2019): 959. http://dx.doi.org/10.3390/ma12060959.

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To study the dynamic response of saturated asphalt pavement under moving load and temperature load, 3-D finite element models for asphalt pavements with hydro-mechanical coupling and thermal-hydro-mechanical coupling were built based on the porous media theory and Biot theory. First, the asphalt pavement structure was considered as an ideal saturated fluid–solid biphasic porous medium. Following this, the spatial distribution and the change law of the pore-water pressure with time, the transverse stress, and the vertical displacement response of the asphalt pavement under different speeds, loading times, and temperatures were investigated. The simulation results show that both the curves of the effective stress and the pore-water pressure versus the external loads have similar patterns. The damage of the asphalt membrane is mainly caused by the cyclic effect of positive and negative pore-water pressure. Moreover, the peak value of pore-water pressure is affected by the loading rate and the loading time, and both have positive exponential effects on the pore-water pressure. In addition, the transverse stress of the upper layer pavement is deeply affected by the temperature load, which is more likely to cause as transverse crack in the pavement, resulting in the formation of temperature cracks on the road surface. The vertical stress at the middle point in the upper layer of the saturated asphalt pavement, under the action of the temperature load and the driving load, shows a single peak.

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Mir Tamizdoust, Mohammadreza, und Omid Ghasemi-Fare. „Comparison of thermo-poroelastic and thermo-poroelastoplastic constitutive models to analyze THM process in clays“. E3S Web of Conferences 205 (2020): 04008. http://dx.doi.org/10.1051/e3sconf/202020504008.

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Thermal pore pressurization in soil media has been investigated for the past few decades. It has been shown that temperature variations may significantly affect thermal pore pressure in clay soils confined deep into the ground. Moreover, thermal loading may lead to stress change and thermal deformation. Thermo-poroelastic and advance thermo-poroelastoplastic constitutive models have been formulated and incorporated numerically to simulate the thermo-hydro-mechanical process. However, the accurate response of soil media during THM process has not been completely understood. Although numerical modelling reasonably predicts the experimental observations, they still could not be used to completely justify the field observations. In this study, the main features of the thermo-poroelastic model are incorporated in a thermo-poroelastoplastic constitutive model (ACMEG-T) to further investigate the effect of different thermal and hydraulic properties on thermo-hydro-mechanical (THM) response of the soil media.

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Xu, Yongchao, Yu Chen und Shijian Yuan. „Influences of loading paths on thickness of aluminium alloy cup with Hydro-mechanical Deep Drawing“. International Journal of Materials and Product Technology 38, Nr. 2/3 (2010): 173. http://dx.doi.org/10.1504/ijmpt.2010.032098.

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Prassetyo, Simon Heru, und Marte Gutierrez. „Effect of surface loading on the hydro-mechanical response of a tunnel in saturated ground“. Underground Space 1, Nr. 1 (September 2016): 1–19. http://dx.doi.org/10.1016/j.undsp.2016.06.001.

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LIU, WEI, LINZHI WU und SHIJIAN YUAN. „EFFECT OF HYDRAULIC PRESSURE ON WARM HYDRO MECHANICAL DEEP DRAWING OF MAGNESIUM ALLOY SHEET“. International Journal of Modern Physics B 23, Nr. 06n07 (20.03.2009): 1975–80. http://dx.doi.org/10.1142/s0217979209061925.

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The uniaxial tensile test and hydraulic bulging test of AZ31 magnesium alloy sheets were applied to study the influence of temperature on the material properties and obtain the forming limit curves at different temperatures. Numerical simulations of warm hydro mechanical deep drawing were carried out to investigate the effect of hydraulic pressure on the formability of a cylindrical cup, and the simplified hydraulic pressure profiles were used to simulate the loading procedure of hydraulic pressure. The optimal hydraulic pressure at different temperatures were given and verified by experimental studies at temperature 100°C and 170V.

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Ivanov, Konstantin Samson. „Creation of Adaptive-Mechanical Continuously Variable Transmission“. Applied Mechanics and Materials 436 (Oktober 2013): 63–70. http://dx.doi.org/10.4028/www.scientific.net/amm.436.63.

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Recently there were patents on not switched gear continuously variable transmission (CVT) without hydro transformer. In transmission wheelwork with two degrees of freedom and one entrance is used. Adaptive mechanism of CVT provides possibility of output link movement with speed inversely to resistance force at constant input power. However the theoretical description of such transmissions is not convincing enough. Obviously at the basis of creation of adaptive transfers with two degrees of freedom essentially new regularity of mechanics lies. Purpose of present work is to formulate regularities of the mechanics allowing creating the adaptive-mechanical continuously variable transmission. The using of the found regularities will allow creating transmissions with mechanical adaptation to variable technological loading.

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DURUKAN, Seda, und Ender BAŞARI. „Experimental Investigation of Hydro-Mechanical Soil Properties of a Slope Failure“. Gazi University Journal of Science Part A: Engineering and Innovation 9, Nr. 4 (31.12.2022): 392–400. http://dx.doi.org/10.54287/gujsa.1141808.

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A sudden slope failure occurred in Manisa possibly due to the effect of water infiltration because of a slightly damaged sewage pipe. Considering that there was no other evidence such as rainfall or any loading conditions to trigger the slope failure, a laboratory investigation on the soil’s unsaturated hydro-mechanical properties was initiated. Slopes are naturally unsaturated soils, and they may lose their stability with increased saturation degrees with water infiltration. Thus, for a proper investigation, the unsaturated hydro-mechanical properties of soils should be determined. The results presented in this study are focused on determining the key parameters to evaluate the slope failure for unsaturated soil conditions. In this regard, hydraulic conductivity and suction characteristics and the shear strength parameters were determined as well as the classical geotechnical properties of the soil. Classification of soil was determined as silty sand which is known to have slight to moderate suction stresses and mostly affected suddenly by water infiltration. A flexible-wall permeability test was run with a falling head procedure and the saturated hydraulic conductivity of the soil sample was measured as 1x10-7 m/s. Suction characteristics were detected by filter paper method, besides, the soil water retention curve of the soil was constructed. The maximum matric suction of the soil was measured as 2887 kPa for an air-dried sample. Following, the shear strength parameters were measured by conventional direct shear test for both dry and soaked conditions. Finally, the friction angle due to suction was calculated to be 1.7 degrees from the results of dry and saturated shear strength parameters.

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Saeidi Rashk Olia, Arash, und Dunja Perić. „Cross validation of analytical solutions against the computational model predictions of the response of end bearing energy pile“. E3S Web of Conferences 205 (2020): 05019. http://dx.doi.org/10.1051/e3sconf/202020505019.

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Predictions of responses of a single energy pile to a combined mechanical and thermal loading are presented. They were obtained from computational and analytical models. The former model provided predictions based on a coupled thermal hydro-mechanical finite element analysis while the predictions of the latter were obtained from the recently derived analytical solutions. The energy pile is surrounded by a single uniform soil layer underlain by a very stiff bedrock. Two scenarios of temperature history were considered. In the first scenario the pile remained in a net heated state while the second one induced a net cooled state. In both loading scenarios a compressive axial load was applied at the pile head prior to the thermal loading. The net heating induced an upward axial displacement, tensile strain and compressive stress while the net cooling induced a downward vertical pile displacement, compressive strain and tensile stress. In spite of different methods of obtaining the soil stiffness for computational and analytical models the predictions of the axial pile displacement, stress and strain show a very good agreement.

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Song, Jie-Fang, Cai-Ping Lu, Zhao-Wei Zhan, Hai-Feng Cui, Yan-Min Wang und Jian-Hua Wang. „Numerical and Field Investigations of Acoustic Emission Laws of Coal Fracture under Hydro-Mechanical Coupling Loading“. Materials 15, Nr. 19 (20.09.2022): 6510. http://dx.doi.org/10.3390/ma15196510.

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Taking coal under hydro-mechanical coupling as the research object, the discrete element software PFC3D (particle flow code) was used to analyze the relationships among the force, acoustic emission (AE), and energy during coal fracture. Based on the moment tensor (MT) inversion, we revealed the AE event distribution and source type during crack initiation and propagation until the final failure of coal. Meanwhile, we examined the relationships among the stress, number and type of cracks, magnitude, KE, and b value of AE under different water and confining pressures. The results show that the numerical simulation can effectively determine the microscopic damage mechanism of coal under different conditions. Moreover, the rupture type of the numerical simulation is consistent with the field investigations, which verifies the rationality of the simulation. These research results can provide reference for safety production evaluation of water inrush mines.

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Riad, Beshoy, und Xiong Zhang. „Modified State Surface Approach to Study Unsaturated Soil Hysteresis Behavior“. Transportation Research Record: Journal of the Transportation Research Board 2674, Nr. 10 (21.07.2020): 484–98. http://dx.doi.org/10.1177/0361198120937014.

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Unsaturated soils are often used as a construction material in transportation infrastructures. In this situation, unsaturated soils are subjected to cyclic mechanical loading from traffic loads or wetting-drying cycles in seasonal climatic conditions. While mechanical hysteresis is a common feature of soils in general, hydraulic hysteresis is associated with unsaturated soils. Although several constitutive models for unsaturated soils have been proposed, the mechanical and hydraulic hysteresis behavior of unsaturated soils has been little studied. A modified state surface approach (MSSA) was first proposed for investigating the mechanical behavior of unsaturated soils. It was then extended to study the coupled hydro-mechanical behavior of unsaturated soils with a special focus on the consistency between different soil phases. However, hydraulic and mechanical hysteresis were neglected in MSSA formulations. In this paper, based on evidence from experimental results, the MSSA is extended further to study the coupled hydro-mechanical hysteresis behavior of unsaturated soils. The extended MSSA can reproduce several forms of mechanical and hydraulic behavior observed in experimental results that cannot be represented by existing constitutive models. To demonstrate the capabilities of the extended MSSA, typical behaviors are simulated and compared, qualitatively, with the characteristic trends of the behavior of unsaturated soils. Experimental results from the literature are then used to evaluate the model to predict, quantitatively, the observed behaviors. The agreement between measured and predicted results is considered satisfactory and confirms the possibility of the proposed approach to reproduce the hysteresis behavior of unsaturated soils.

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Pereira, Jean-Michel. „Effects of microstructure on THM behaviour of geomaterials“. E3S Web of Conferences 382 (2023): 11001. http://dx.doi.org/10.1051/e3sconf/202338211001.

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In this paper, we discuss the thermo-hydro-mechanical behaviour of geomaterials at the light of their microstructure and its changes induced by multiphysics loading. After recalling the strong links between the microstructure and the water retention properties of unsaturated soils, the relation between themicrostructure and the physical properties ruling heat and mass transfers are discussed. The mechanical behaviour of unsaturated soils is then discussed focussing on the definition of an effective stress based on a microstructure description. The experimental determination of this microstructurally-based effective stressis presented, including recent advances to identify the stress coefficient from Mercury Intrusion Porosimetry data. Opening remarks towards macroscopic modelling of unsaturated geomaterials accounting for their microstructure and its changes is finally discussed.

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Yu, Dunji, Ke An, Carrie Y. Gao, William T. Heller und Xu Chen. „A portable hydro-thermo-mechanical loading cell forin situsmall angle neutron scattering studies of proton exchange membranes“. Review of Scientific Instruments 84, Nr. 10 (Oktober 2013): 105115. http://dx.doi.org/10.1063/1.4826349.

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Taghipour, Ehsan, und Ahmad Assempour. „The effects of proportional loading, plane stress, and constant thickness assumptions on hydro-mechanical deep drawing process“. International Journal of Mechanical Sciences 53, Nr. 5 (Mai 2011): 329–37. http://dx.doi.org/10.1016/j.ijmecsci.2011.02.002.

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Varnosfaderani, Alireza Mokhtari, Ehsan Motevali Haghighi, Behrouz Gatmiri und Seonhong Na. „Investigation of Climate Change on Unsaturated Porous Media via a Discrete Thermo-Hydro-Mechanical Model“. Applied Sciences 11, Nr. 16 (19.08.2021): 7617. http://dx.doi.org/10.3390/app11167617.

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The impacts of climate change on unsaturated porous media have been investigated through the coupled thermo-hydro-mechanical analysis by leveraging a discrete fracture model. The transport of gas and liquid phases in unsaturated porous media is captured under non-isothermal conditions. The balance principles of moisture energy and mass are associated with crack propagation. The temperature-dependent degree of saturation and permeability of water are incorporated into fracture based on the cubic law. Numerical examples are designed to evaluate the applicability of the proposed model against climate change. First, a double-notch plate domain is used to identify the sensitivity of various material properties on crack propagation associated with mechanical loading. Then, a masonry wall of drying under thermal action is studied to investigate its degradation by mimicking climatic load conditions. The results of numerical tests demonstrate the capabilities of the proposed model for practical application well.

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Yi, Wei, Qiuhua Rao, Zhuo Li und Charlie Chun-Lin Li. „A New Method for Predicting the Crack Propagation Process of Brittle Rock Under Thermo-Hydro-Mechanical Loading Conditions“. IEEE Access 9 (2021): 82888–902. http://dx.doi.org/10.1109/access.2021.3076001.

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Kou, Miaomiao, Xinrong Liu, Shangding Tang und Yunteng Wang. „3-D X-ray computed tomography on failure characteristics of rock-like materials under coupled hydro-mechanical loading“. Theoretical and Applied Fracture Mechanics 104 (Dezember 2019): 102396. http://dx.doi.org/10.1016/j.tafmec.2019.102396.

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Rotisciani, Giada M., Leonardo M. Lalicata, Augusto Desideri und Francesca Casini. „Numerical modelling of the response of an unsaturated silty soil under wetting and gravitational loading processes“. E3S Web of Conferences 195 (2020): 02012. http://dx.doi.org/10.1051/e3sconf/202019502012.

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This paper presents the results of a numerical study aiming at simulating the response of an unsaturated fine-grained soil under wetting and gravitational loading processes. This study is based on the results of some centrifuge tests carried out to assess the influence of partial saturation on the laterally loaded pile response. The hydro-mechanical behaviour of the silty soil is described using a constitutive model adapted to unsaturated conditions. The model predictions are compared with the measurements provided by LVDTs and laser transducers in the first phases of the experimental study. Besides validating the model, the numerical study aimed at investigating the influence of the after-compaction conditions on both the displacement field and the evolution of the more significant state variables during imbibition and gravitational loading processes. Finally, an additional analysis is conducted to determine the effects of the pile installation on the soil response.

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Cordão Neto, Manoel Porfirio, Oisy Hernández, Raydel Lorenzo Reinaldo, Camila Borges und Bernardo Caicedo. „Study of the relationship between hydro-mechanical soil behavior and microstructure of a structured soil“. Earth Sciences Research Journal 22, Nr. 2 (01.04.2018): 91–101. http://dx.doi.org/10.15446/esrj.v22n2.65640.

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Structured soils, such as residual laterites or volcanic ashes, abound in tropical regions. The hydro-mechanical behavior of these soils is clearly related to their structure. New techniques based on microstructural studies constitute a powerful tool for investigating these soils. This work presents an experimental investigation that documents the relationships between the microstructure and the mechanical behavior of these soils. This study focuses on the microstructural behavior of Brasilia clay, a structured, highly porous tropical soil (n>50%) with a bimodal pore size distribution. The microstructure was investigated using pore size distribution analyses of different structural states and void ratios. The mercury intrusion porosimetry (MIP) technique was used to explore the pore size distribution of samples in various conditions, i.e., natural, compacted, slurry or consolidated states. Modeling of the pore size distribution curves was performed using the bimodal van Genuchten curve, which permits the linking of the pore size distribution curves (PSD) to the water retention curve. We observed that loading and compacting did not affect the micro-pores of this soil, and we conclude that the changes occurred entirely within the macro-pores.

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Bonnelye, Audrey, Pierre Dick, Marco Bohnhoff, Fabrice Cotton, Rüdiger Giese, Jan Henninges, Damien Jougnot, Grzegorz Kwiatek und Stefan Lüth. „CHENILLE: Coupled Behavior Understanding of Faults: from the Laboratory to the Field“. Advances in Geosciences 58 (17.03.2023): 177–88. http://dx.doi.org/10.5194/adgeo-58-177-2023.

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Abstract. The understanding of coupled thermo-hydro-mechanical behaviour of fault zones or in naturally fractured reservoirs is essential both for fundamental and applied sciences and in particular for the safety assessment of radioactive waste disposal facilities. The overall objective of the CHENILLE project is to better understand the physical processes resulting from thermal and hydraulic loading in a small fault zone in a highly consolidated shale formation. Consequently, a thermally controlled in-situ fluid injection experiment is intended to be performed on a strike-slip fault zone outcropping at the Tournemire/France Underground Research Laboratory (URL). A heating system has been installed around the injection area to enable a precise and controlled incremental increase of the thermal load. Different monitoring systems are designed to measure the seismic and aseismic deformation induced either by thermal and/or by hydraulic loading. The seismic monitoring system is composed of Acoustic Emission (AE) and broadband seismic sensors enabling monitoring of seismic fracturing processes down to sub-decimetre scale as well as slow deformation processes. Furthermore, we are about to install an injection chamber allowing to perform a controlled gaz injection test. The injection borehole will also be partly equipped with fiber optics in order to measure temperature in a distributed manner in the borehole. Time-lapse active seismic surveys are scheduled for before and after the experiment to image the structural network but also to detect the appearance of new structures triggered from the hydro-thermal pressurization of the fault as well as eventual changes in the velocity field.

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Kayser, Timon, Wiebke Baille, Merita Tafili und Torsten Wichtmann. „Coupled hydro-mechanical behaviour of a Kaolin Clay in the context of the geothermal use of geotechnical structures“. E3S Web of Conferences 382 (2023): 23002. http://dx.doi.org/10.1051/e3sconf/202338223002.

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An experimental study regarding the hydro-mechanical behaviour of a Malaysian Kaolin is presented. Strain rate-controlled oedometer tests have been conducted on compacted samples. The influence of initial water content on the pore-size distribution (PSD) of compacted samples was investigated by Mercury Intrusion Porosimetry (MIP) tests. The drying path of the soil-water characteristic curve was experimentally determined for initially compacted samples and slurry samples. The preconsolidation stress was found to increase with increase in initial dry density and with decrease in initial water content. The compression curves merge into a single line, as soon as they have reached full saturation during loading. Samples at the dry side of Proctor water content showed a bi-modal PSD, whereas a mono-modal PSD was found for Proctor water content and at the wet side. The different initial compaction states of the samples were getting reflected in the drying SWCC until a suction of about 2 MPa, beyond which the drying paths were found to be identical.

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Haghi, Amir H., und Richard Chalaturnyk. „Experimental Characterization of Hydrodynamic Properties of a Deformable Rock Fracture“. Energies 15, Nr. 18 (16.09.2022): 6769. http://dx.doi.org/10.3390/en15186769.

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Characterization of stress-dependent single-phase and multiphase fluid transport in fractured geo-materials is essential for a wide range of applications, including CO2 sequestration, energy storage, and geo-energy extraction. However, pivotal studies on capillarity and multiphase fluid flow in deformable rock fractures are surprisingly sparse. In this study, we initially investigated the hydro-mechanical properties of an intact mixed-wet Calumet carbonate from the Waterways formation (Alberta) under isothermal conditions (40 °C). Then, we conducted core-flooding experiments using water and N2 to assess changes in the aperture, absolute permeability, relative permeability, and capillary pressure of an artificially fractured Calumet core in response to changes in effective confining stress during loading (0–10 MPa) and unloading (10–3 MPa). We quantified the fracture’s non-linear closure and hysteresis effect during the cyclic loading–unloading processes. We found that porosity and absolute permeability of the fracture decreased from 1.5% and 19.8 D to 1.18% and 0.22 D, respectively, during the loading. We revealed a systematic rightward shift in the relative permeability and a significant upward shift in the dynamic capillary pressure curves as the fracture deformed. This fundamental study demonstrates the critical role of fracture deformation on fluid flow in fractured rocks, which paves the way for future research in geoscience and engineering.

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FATHALIKHANI, MARZIYEH, und BEHROUZ GATMIRI. „COUPLED ANALYSIS OF DAMAGE IN MULTIPHASE MEDIA“. Journal of Multiscale Modelling 04, Nr. 02 (Juni 2012): 1250008. http://dx.doi.org/10.1142/s1756973712500084.

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In this paper, the theoretical framework of a coupled thermo-hydro-mechanical damage model dedicated to non-isothermal unsaturated porous media is presented. The damage variable is a second-order tensor, and the model has been formulated in independent state variables. The approach combines thermodynamic and micromechanical theories. The behavior laws have been derived from a postulated expression of Helmholtz free energy. The damaged rigidities have been computed by applying the Principle of Equivalent Elastic Energy (PEEE). Internal length parameters have been introduced in the expressions of liquid water conductivity, to account for cracking effects on fluid flows. Damage has been assumed to have an isotropic influence on air and heat flows, through the inelastic component of volumetric strains. The damage model has been implemented in θ-Stock Finite Element program. Some numerical studies are conducted to the impact of the thermal and mechanical loading on the evaluation of response of the unsaturated bentonite, and investigation of model parameters effect on damage development.

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Pedone, Giuseppe, Lidija Zdravkovi, David Potts und Aikaterini Tsiampousi. „Numerical modelling of unsaturated MX-80 bentonite subjected to two different hydration paths and subsequent loading to high-pressures“. E3S Web of Conferences 382 (2023): 14009. http://dx.doi.org/10.1051/e3sconf/202338214009.

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MX-80 bentonite has been considered as a suitable material for the construction of engineered barriers employed in deep geological radioactive waste repositories. These barriers are generally formed of compacted unsaturated bentonite, the latter experiencing a slow saturation due to its low permeability whileinteracting with the surrounding groundwater. In order to verify the long-term safety requirements of engineered barriers, their response to hydration has to be carefully assessed. As part of the recent European project BEACON (Bentonite Mechanical Evolution), the behaviour of MX-80 bentonite subjected to different hydration paths was investigated in a number of laboratory and field experiments and numerical studies. This paper is concerned with numerical simulations of two laboratory experiments performed during the project, with the objective of examining the predictive capabilities of the proposed numerical modelling approach. The experiments were selected due to the granular state of bentonite at its placement in the testingapparatus, which differed from the large number of previous experiments conducted on specimens of compacted bentonite blocks. The paper provides a brief introduction to the adopted modelling framework, a summary of calibrated parameters for the hydro-mechanical constitutive modelling and the results of numerical simulations, concluding that a satisfactory numerical simulation of the experiments was achieved.

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Lin, Hai, Jingen Deng, Xiaocheng Zhang und Jiajia Gao. „Porothermoelastic Response of a Borehole in Fluid-Saturated Medium Subjected to Thermal Osmosis Effect“. Geofluids 2023 (22.05.2023): 1–13. http://dx.doi.org/10.1155/2023/4030804.

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With the thermo-hydro-mechanical coupling process considered, this paper derives a set of analytical porothermoelastic solutions to field variables including the stress, displacement, and pore pressure fields to evaluate the wellbore stability around a vertical borehole drilled through an isotropic porous rock. The thermal effect on the wellbore stability of the low-permeability saturated rock also introduces the thermal osmosis term. The wellbore problem is decomposed into axisymmetric and deviatoric loading cases considering the borehole subjected to a nonhydrostatic stress field. It obtains the time-dependent distributions of field variables by performing the inversion technique for Laplace transforms to the porothermoelastic solutions in the Laplace domain. The results suggest that the thermal osmosis effect should not be neglected on the premise that a lower permeability porous rock is characterized by the substantially large thermal osmotic coefficient and the small thermal diffusivity values. The case that the thermal osmosis effect reduces the undrained loading effect leads to the decrease of the mean shear stress that is determined by the effective maximum and minimum stress around a borehole, since, and accordingly contributes to the wellbore stability to resist the shear failure.

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Liu, Kaiwen, Qian Su, Fei Yue, Bao Liu, Ruizhe Qiu und Ting Liu. „Effects of suffosion-induced contact variation on dynamic responses of saturated roadbed considering hydro-mechanical coupling under high-speed train loading“. Computers and Geotechnics 113 (September 2019): 103095. http://dx.doi.org/10.1016/j.compgeo.2019.103095.

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Qiao, Liping, Zhechao Wang, Wei Li, Huan Liu und Lei Yang. „Effect of Lateral Stress on the Mechanical Properties of Rock Fracture and Its Implication on the Stability of Underground Oil Storage Caverns“. Journal of Marine Science and Engineering 10, Nr. 5 (16.05.2022): 677. http://dx.doi.org/10.3390/jmse10050677.

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It is of great significance to study the mechanical properties of rock fracture for the stability of rock engineering projects. The mechanical properties, including the normal compression and shear properties of rock fracture, are studied by a series of shear tests considering the effect of lateral stress using the self-developed true triaxial test apparatus. The test results show that the initial normal stiffness and the maximum normal closure value of rock fracture increase with the increase of lateral stress, and the peak shear strength and the peak dilatancy angle increase with the increase of lateral stress, whereas the peak shear displacement decreases with the increase of lateral stress. Considering the effect of lateral stress, the improved normal loading model, peak shear strength model and peak dilatancy angle model of rock fracture are established. Using the equivalent parameters of rock fracture obtained based on the test, the hydro-mechanical coupling analysis considering lateral stress is carried out for an underground water sealed oil storage cavern project. It can be concluded that with the increase of lateral stress, the displacement of surrounding rock decreases, and the surrounding rock tends to be more stable.

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Blöcher, Guido, Christian Kluge, Harald Milsch, Mauro Cacace, Antoine B. Jacquey und Jean Schmittbuhl. „Permeability of matrix-fracture systems under mechanical loading – constraints from laboratory experiments and 3-D numerical modelling“. Advances in Geosciences 49 (05.09.2019): 95–104. http://dx.doi.org/10.5194/adgeo-49-95-2019.

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Abstract. The permeability of single fractures is commonly approximated by the cubic law assumption, which is however only valid under the condition of a single phase laminar flow between parallel plates. Departure from cubic law are related to many features like aperture fluctuations due to fracture surface roughness, relative shear displacement, the amount of flow exchange between the matrix and the fracture itself, etc. In order to quantify constitutive relationships among the aforementioned aspects, we have conducted a flow-through experiment with a porous rock sample (Flechtinger sandstone) containing a single macroscopic fracture. Based on this experiment, we obtained range of variations of intrinsic rock parameters, permeability and stress-strain relationships of the combined matrix-fracture system under hydrostatic loading. From the measured deformation of the matrix-fracture system, we derived the evolution in the mechanical aperture of the fracture. In order to quantify the processes behind the laboratory observations, we carried out coupled hydro-mechanical simulations of the matrix-fracture system. Navier–Stokes flow was solved in the 3-dimensional open rough fracture domain, and back-coupled to the Darcy flow and the poroelastic behaviour of the rock matrix. The results demonstrate that the elastic behaviour and the related permeability alteration of the fracture domain could be captured by the numerical simulation. Furthermore, the stress-strain values obtained in the vicinity of the fracture asperities suggest that inelastic deformation develops at low mechanical load. An attempt was made to quantify the inelastic deformation by using the failure envelope obtained by laboratory experiments (whether tensile, shear, compaction, or a combination of those). However, change in permeability observed in the experiments are significantly larger than that in the simulation showing the importance of plastic deformation during opening and closure of the fracture and its impact on the cubic law approximation.

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