Hasil untuk "Engineering geology. Rock mechanics. Soil mechanics. Underground construction"

Hajar Habbani, Hippolyte Djizanne, Benoit Brouard et al.

Patricia G. F. Matsubara, Tayana Conte

Over twenty years ago, the Software Engineering (SE) research community have been involved with Evidence-Based Software Engineering (EBSE). EBSE aims to inform industrial practice with the best evidence from rigorous research, preferably from systematic literature reviews (SLRs). Since then, SE researchers have conducted many SLRs, perfected their SLR procedures, proposed alternative ways of presenting their results (such as Evidence Briefings), and profusely discussed how to conduct research that impacts practice. Nevertheless, there is still a feeling that SLRs' results are not reaching practitioners. Something is missing. In this vision paper, we introduce Evidence to Decision (EtD) frameworks from the health sciences, which propose gathering experts in panels to assess the existing best evidence about the impact of an intervention in all relevant outcomes and make structured recommendations based on them. The insight we can leverage from EtD frameworks is not their structure per se but all the relevant criteria for making recommendations to practitioners from SLRs. Furthermore, we provide a worked example based on an SE SLR. We also discuss the challenges the SE research and practice community may face when adopting EtD frameworks, highlighting the need for more comprehensive criteria in our recommendations to industry practitioners.

Zehua Chen, Wenjian Yue, Chengwen Wang

The incorporation of fibers represents a crucial technique for improving the mechanical properties and other relevant characteristics of cement-based composites (CBC), including concrete, cement mortar, and oil-well cement. Especially, carbon fiber (CF) has a great potential for reinforcing oil-well cement due to its high strength, modulus, stiffness, high temperature, corrosion and fatigue resistance as well as chemical stability. There is a huge amount of waste CFs all over the world which show better performance in cement industry, while their reuse will realize waste recovery (good environment impact) and greatly reduce cost. This review paper presents the recent progress of using CF in enhancing mechanical properties of CBC. We put high emphasis on the CF surface modification for reinforcing bond strength at the cement/CF interface. Comprehensive discussion with respect to effects of CF and modified CF on CBC properties is performed. The key properties of CBC examined in this study encompass mechanical characteristics (compressive strength, flexural strength, and tensile strength), dimensional stability (shrinkage behavior), durability indicators (water absorption and permeability), and fracture-related properties (toughness, crack resistance, and impact performance). Thus, suggestions are given for the future study and application of CF in oil-well cement.

John P. Brooks, Martin J. Wubben, Renotta K. Smith et al.

IntroductionPredicting, or correlating, soil microbiome metrics with above ground phenotypic plant measurements would enable rapid diagnosis of soil microbiome imbalances. Rapid plant measurements through remote sensing are a leading innovation in agriculture and have reduced the need for labor-intensive plant and soil measurements. In the current study we utilized cotton (Gossypium hirsutum) as a plant model whereby stress was induced by drought and root-knot nematode (RKN; Meloidogyne incognita) infection to induce a change in the soil microbiome which would be reflected as a plant phenotypic response.MethodsThe experiment was a randomized complete block design with two cotton genotypes (RKN-susceptible or RKN-resistant) and four stress combinations. Rootzone samples were collected upon plant termination and quantified for five soil health genes: 16S rRNA, 18S rRNA, ureC, phoA, and cbbLR. Plant physiology, biomass, and remote sensing hyperspectral readings were previously reported. Results and discussionOverall, RKN infection and plant genotype treatments had little effect on genes. Interestingly, drought stress increased most gene abundances, while plant physiological and biomass measurements decreased, indicating microbiome response to plant stress. Hyperspectral reflectance, through machine learning, accurately predicted the presence of drought stress with an area under the receiver operating characteristic curve value of 0.864. Furthermore, the readings were able to predict the abundance values for all genes except 18S rRNA within one standard deviation of ground truth levels. This study demonstrated that there are key plant characteristics that are registered via hyperspectral wavelengths which can be used to accurately predict soil health gene abundance. While the use of hyperspectral readings and soil microbiome status to inform plant health and vice versa are still in their infancy, the current study provides us with future directions towards this end.

Bela Schulte Westhoff

Classical Electrodynamics in ponderable media remains defined by a century-long debate over force and energy localization. While the prevailing view treats competing formulations (Minkowski, Abraham, etc.) as equivalent conventions, this monograph argues that global conservation is insufficient for physical validity. A formulation must be mechanically coherent: power transfer must strictly equal the work rate of the force acting on the mass target. We formalize this requirement as the Force--Energy Consistency Criterion (FECC) -- a ``Kinematic Lock'' ($ P = \mathbf{f} \cdot \mathbf{v} $) -- and use it to audit standard macroscopic tensors. The analysis demonstrates that only the Macroscopic Vacuum (Lorentz) Formulation offers a mechanically consistent description of total energy-momentum transfer. The internal distribution of this energy is shown to be macroscopically indeterminate. By reinterpreting spatial averaging as spectral filtering, we reconstruct the theory from the microscopic baseline. This perspective identifies a universal host interface that routes electromagnetic energy into mechanical work, heat, and reversible storage, revealing a structural isomorphism where thermodynamics, mechanics, and electrodynamics emerge as coupled spectral projections.

Kai Xie, Wei Chen, Dong-Zhou Xie et al.

Underground salt cavern gas storage has been widely applied due to its numerous advantages. Most of China’s salt resources are derived from lacustrine deposits. As high–quality resources in the central sedimentary area are gradually exploited, exploring the utilization of thin salt layers at the edges of sedimentary centers is the future development trend. However, the use of thin salt layers faces challenges such as low resource utilization, small cavern volumes, and poor economic feasibility, which limit its engineering applications. Therefore, a comprehensive assessment of constructing gas storage in thin salt layers is necessary. This paper first analyzes the necessity of building gas storage in thin salt layers and surveys cavern construction methods and their applicability. Based on geological seismic data, the feasibility of constructing gas storage in the Pingdingshan thin salt layer is proposed. A novel I–shaped cavern design is introduced, which, according to engineering economic evaluations, reduces investment by 9.6% compared to traditional single–well vertical cavern construction methods. Finally, rock mechanics tests were conducted to study the impact of mudstone interlayers and cyclic operation modes on the stability of the I–shaped cavern under three different injection and production conditions. The analysis shows that multi–cycle injection and production can effectively suppress cavern shrinkage and the development of the rock–relative plastic zone. The safety factor (SF) for different conditions is greater than 1, indicating that the I–shaped cavern has good stability and can adapt to various operational conditions. This study provides valuable insights into the geological conditions and rock mechanics characteristics for the future construction of gas storage in thin salt layers in China.

ZHANG Jian 1, 2, YANG Ligong 1, 2, ZHANG Yuting 1, 2, ZHAO Yue 1, 2, LIU Yongjun 3, WU Wenhua 3

In view of the deformation of sheet piles and the pile-soil interaction mechanism of revetment slopes during channel excavation, the key physical parameters such as displacement of sheet piles, earth pressure and deformation of the adjacent soils are monitored by selecting typical sections for the field tests. Combined with the theoretical calculation, the stability of the sheet piles and the bank slope is analyzed, and the interaction mechanism between the soil deformation behind the piles and the active earth pressure with complex geological conditions is explored, and some useful conclusions are drawn. The horizontal displacement of the soils behind the sheet piles increases gradually with the excavation. When the slope reaches stability, the soil displacement at different depths is about 0.8~1 mm, and the horizontal displacement at the top of the sheet piles is about 1.2 mm. During channel excavation, the active earth pressure of the sheet piles gradually decreases with the excavation, and the reduction value of the earth pressure at pile side at different depths is about 1 kPa. Compared with the theoretical results, the field test results are small, indicating that the theoretical calculation is slightly conservative for the field tests. The conclusion can provide a useful reference for the revision of the existing related specifications for the sheet piles.

Jianhua Yan, Xiansen Xing, Zhihai Li et al.

In open pit mining, uncontrolled block instabilities have serious social, economic and regulatory consequences, such as casualties, disruption of operation and increased regulation difficulties. For this reason, bench face angle, as one of the controlling parameters associated with block instabilities, should be carefully designed for sustainable mining. This study introduces a discrete fracture network (DFN)-based probabilistic block theory approach for the fast design of the bench face angle. A major advantage is the explicit incorporation of discontinuity size and spatial distribution in the procedure of key blocks testing. The proposed approach was applied to a granite mine in China. First, DFN models were generated from a multi-step modeling procedure to simulate the complex structural characteristics of pit slopes. Then, a modified key blocks searching method was applied to the slope faces modeled, and a cumulative probability of failure was obtained for each sector. Finally, a bench face angle was determined commensurate with an acceptable risk level of stability. The simulation results have shown that the number of hazardous traces exposed on the slope face can be significantly reduced when the suggested bench face angle is adopted, indicating an extremely low risk of uncontrolled block instabilities.

Yongbo Pan, Junzhi Cui, Zhenhao Xu

Multiform fractures have a direct impact on the mechanical performance of rock masses. To accurately identify multiform fractures, the distribution patterns of grayscale and the differential features of fractures in their neighborhoods are summarized. Based on this, a multiscale processing algorithm is proposed. The multiscale process is as follows. On the neighborhood of pixels, a grayscale continuous function is constructed using bilinear interpolation, the smoothing of the grayscale function is realized by Gaussian local filtering, and the grayscale gradient and Hessian matrix are calculated with high accuracy. On small-scale blocks, the pixels are classified by adaptively setting the grayscale threshold to identify potential line segments and mini-fillings. On the global image, potential line segments and mini-fillings are spliced together by progressing the block frontier layer-by-layer to identify and mark multiform fractures. The accuracy of identifying multiform fractures is improved by constructing a grayscale continuous function and adaptively setting the grayscale thresholds on small-scale blocks. And the layer-by-layer splicing algorithm is performed only on the domain of the 2-layer small-scale blocks, reducing the complexity. By using rock mass images with different fracture types as examples, the identification results show that the proposed algorithm can accurately identify the multiform fractures, which lays the foundation for calculating the mechanical parameters of rock masses.

Chao LIU, Hanyong BAO, Yunqiang WAN

Objective The Fuling Gas Field as the first commercial shale gas field in China has stably achieved an annual gas production of over 7 billion cubic meters in recent years, which is a good development result. With the increasing demand for development, the development targets have gradually shifted from the high-pressured shale gas reservoirs, e.g., the Jiaoshiba region, to the normal-pressured shale gas reservoirs of the Baima region. In 2021, the Baima area submitted a proven reserve of 104.883 billion cubic meters, consolidating its geological resource foundation. Development geology evaluation and target optimization are the first steps to efficiently achieve the utilization of reserves. Methods Based on core testing, well logging interpretation, seismic prediction, and gas testing data, the favourable intervals and targets for the development of normal-pressured shale gas in the Baima area were evaluated in this study. Results The research results indicate that the organic-rich shale of the Ordovician Wufeng Formation and Silurian Longmaxi Formation in the Baima area was deposited on the deep-water shelf. Thereinto, the deep-water shelf siliceous shale is the most favourable layer for development. The key parameters for the development geology evaluation of normal-pressured shale gas include the formation pressure coefficient, porosity, natural fractures, and stress properties. Conclusion A geological parameter system has been established for the development of target areas, which suggests that the southern part of the Baima Syncline can be selected as the first target for development and production. The Baima Region has achieved large-scale economic production and can be an important reference for the development of normal-pressured shale gas.

Dezhi Ran, Mengzhou Wu, Wei Yang et al.

By treating data and models as the source code, Foundation Models (FMs) become a new type of software. Mirroring the concept of software crisis, the increasing complexity of FMs making FM crisis a tangible concern in the coming decade, appealing for new theories and methodologies from the field of software engineering. In this paper, we outline our vision of introducing Foundation Model (FM) engineering, a strategic response to the anticipated FM crisis with principled engineering methodologies. FM engineering aims to mitigate potential issues in FM development and application through the introduction of declarative, automated, and unified programming interfaces for both data and model management, reducing the complexities involved in working with FMs by providing a more structured and intuitive process for developers. Through the establishment of FM engineering, we aim to provide a robust, automated, and extensible framework that addresses the imminent challenges, and discovering new research opportunities for the software engineering field.

Marcin Maździarz

The paper gathers and unifies mechanical stability conditions for all symmetry classes of 3D and 2D materials under arbitrary load. The methodology is based on the spectral decomposition of the fourth-order stiffness tensors mapped to second-order tensors using orthonormal (Mandel) notation, and the verification of the positivity of the so-called Kelvin moduli. An explicit set of stability conditions for 3D and 2D crystals of higher symmetry is also included, as well as a Mathematica notebook that allows mechanical stability analysis for crystals, stress-free and stressed, of arbitrary symmetry under arbitrary loads.

David A. Lazo Vasquez, Jaione Tirapu Azpiroz, Rodrigo Neumann Barros Ferreira et al.

Predicting the geometrical evolution of the pore space in geological formations due to fluid-solid interactions has applications in reservoir engineering, oil recovery, and geological storage of carbon dioxide. However, modeling frameworks that combine fluid flow with physical and chemical processes at a rock's pore scale are scarce. Here, we report a method for modeling a rock's pore space as a network of connected capillaries and to simulate the capillary diameter modifications caused by reactive flow processes. Specifically, we model mineral erosion, deposition, dissolution, and precipitation processes by solving the transport equations iteratively, computing diameter changes within each capillary of the network simultaneously. Our automated modeling framework enables simulations on digital rock samples as large as (1.125mm)$^3$ with 125$\times 10^6$ voxels within seconds of CPU time per iteration. As an application of the computational method, we have simulated brine injection and calcium carbonate precipitation in sandstone. For quantitatively comparing simulation results obtained with models predicting either a constant or a flow-rate dependent precipitation, we track the time-dependent capillary diameter distribution as well as the permeability of the connected pore space. For validation and reuse, we have made the automated simulation workflow, the reactive flow model library, and the digital rock samples available in public repositories.

A. Khamitova, Fidelis T. Suorineni, Y. Madenova

Martin (1993) established the m-zero failure criterion following extensive field and laboratory testing at the Atomic Energy of Canada Limited Underground Research laboratory. The m-zero criterion is widely used for assessing excavations in rockmasses with a Geological Strength Index ≥75. Based on the m-zero criterion stopes in massive sulfides in underground nickel mines that were expected to fail did not fail. This observation prompted further studies on the m-zero criterion at the Geomechanics Research Centre. According to the m-zero failure criterion, damage in massive rockmasses is caused by destruction of the Hoek-Brown failure criterion constant "s" with the frictional constant "m" playing no role. The value of the constant "s" to initiate damage was established as 0.11. However, this value was based on studies on the La du Bonnet granite. Suorineni and Kaiser (2002) argued that the "s" value of 0.11 should vary depending on the rock type, and hence the need for rock type-specific "s" values. Suorineni et al. (2009) presented a procedure for the determination of rock type specific "s" values. This paper presents "s" values for different rock types from Kazakhstan in a continuing effort to provide users of the criterion with a database of rock type-specific "s" values. There are various failure criteria that exist in rock engineering for the evaluation of the performance of underground excavations in rock. Two frequently used failure criteria are the Mohr-Coulomb (Mohr, 1900; Coulomb) and Hoek-Brown (1980) failure criteria. This paper focuses on the latter, given its history. Given the long history of the Mohr-Coulomb failure criterion which dates to the 1700s, one would ask why there was the need for another failure criterion in the 1980s? The Mohr-Coulomb failure criterion has its foundation in soil mechanics. Hoek and Brown (1980) provide the key reasons why the Hoek-Brown failure criterion was necessary for rocks. These authors noted that to utilize the knowledge of stresses induced around underground excavations it was necessary to have available a criterion or a set of rules which will predict the response of a rockmass to a given set of induced stresses. The search for such a criterion for rockmasses had been challenging because of the complexity of the rockmass compared to a soil in that the behaviour of the rockmass transitions from an intact rock to a heavily jointed rockmass as shown in Fig. 1. All the rockmass components in Fig.1 are of concern to the underground excavation designer or rock engineer. The stability of the entire system of underground openings which make up a mine or any underground excavations network depends upon the behaviour of the entire rock mass surrounding these openings, including all the various components of the rockmass in Fig. 1. This observation implies that a failure criterion developed for soils is unlikely to be applicable to a rockmass, and hence the need for a more suitable failure criterion for rockmasses.

Katia Bicalho

This special issue contains fifteen (15) peer-reviewed papers on geotechnical engineering education (Geo-engineering education). The themed issue includes the fundamental and interdisciplinary areas of geo-engineering: geomechanics (soil mechanics and rock mechanics), engineering geology, geotechnical engineering, and environmental engineering. This editorial presents a brief introduction of each article and highlights its key findings, main points, and conclusions. The papers in this issue cover a wide range of Geo-engineering topics in undergraduate curricula. This themed issue brings together articles from different universities and countries with inequalities in research funding for the current and future mutually beneficial exchange of ideas and experiences in Geo-engineering education. While this issue focuses especially on Geo-engineering education, some approaches or strategies presented here have applications to different topics in education and teaching.

Yuki Matsuoka, Mamoru Kikumoto, S. Ogata et al.

Rock masses are characterized by numerous structural discontinuities, such as joints and faults, which exert a significant influence on their deformation responses. Therefore, it is important to develop a constitutive model that can accurately anticipate the mechanical response of rock joints. A previous study proposed an elastoplastic constitutive model based on the critical state framework originally developed in soil mechanics. The fundamental assumption of this model is that a rock joint reaches a critical state, where the shear stress and aperture is uniquely determined relative to the applied normal stress, after a large shear displacement. This model accounts for the joint matching by evaluating the difference in joint aperture between the current and the critical state. However, its applicability to rock joints remains incomplete, particularly in accommodating the influence of roughness degradation. Roughness degradation on joint surfaces can lead to a reduction in the asperity angle, resulting in a decrease in aperture at the critical state and a dilatancy response. In this study, we extend the aforementioned model by introducing a state parameter to account for the changes in critical state aperture. The proposed model effectively captures alterations in the shear response associated with the roughness degradation, providing a more comprehensive understanding of the mechanical behavior of rock joints. The precise anticipation of rock mass behavior is critical in designing and maintaining rock structures such as tunnels, dam foundations, geological repositories for radioactive waste, and energy storage facilities. Within the rock mass, numerous discontinuities, such as faults and joints, characterized by reduced stiffness and strength compared to the rock materials, exert a significant influence on the overall rock mass behavior. In addition, alterations in stress conditions within the rock mass resulting from subsurface activities can induce slippage of these discontinuities, precipitating the failure or collapse of the entire rock mass. Therefore, comprehending and managing the slip behavior of discontinuities, particularly those surrounding underground structures, represents one of the critical challenges in rock engineering. Although various studies have explored slip/shear behavior, the surface roughness (Barton, 1973) and interlocking (Zhao, 1997a) of rock joints are important factors influencing shear behavior under applied stress conditions common in rock engineering. Numerous numerical methodologies have been proposed to forecast the behavior of discontinuities in rock. Nevertheless, enhancing constitutive models to incorporate geological characteristics of in-situ joints remain imperative.

Xiuyan Wang, Lin Sun, Shuai-wei Wang et al.

: The increasing severity of ground subsidence, ground fissure and other disasters caused by the excessive exploitation of deep underground resources has highlighted the pressing need for effective management. A significant contributing factor to the challenges faced is the inadequacy of existing soil mechanics experimental instruments in providing effective indicators, creating a bottleneck in comprehensively understanding the mechanisms of land subsidence. It is urgent to develop a multi-field and multi-functional soil mechanics experimental system to address this issue. Based soil mechanics theories, the existing manufacturing capabilities of triaxial apparatus and the practical demands of the test system, a set of multi-field coupled high-pressure triaxial system is developed tailored for testing deep soils (at depths of approximately 3 000 m) and soft rock. This system incorporates specialized design elements such as high-pressure chamber and horizontal deformation testing devices. In addition to the conventional triaxial tester functions, its distinctive feature encompass a horizontal deformation tracking measuring device, a water release testing device and temperature control device for the sample. This ensemble facilitates testing of horizontal and vertical deformation water release and other parameters of samples under a specified stress conditions, at constant or varying temperature ranging from −40°C–90°C. The accuracy of the tested parameters meets the requirements of relevant current specifications. The test system not only provides scientifically robust data for revealing the deformation and failure mechanism of soil subjected to extreme temperature, but also offers critical data support for major engineering projects, deep exploration and mitigation efforts related to soil deformation-induced disaster.

Ruxian Chen, Jiagen Hou

Objective In order to clarify the occurrence characteristics of movable fluids in medium- and low-permeability reservoirs, so as to better guide the increase in oil reserves and production in the oilfield. Methods This study focuses on the medium- and low-permeability sandstone reservoirs in the Es32+3 submember of the Gao3102 fault block in the Gaoshangpu Oilfield. Based on thin section data, whole-rock diffraction analysis, high-pressure mercury injection curves, closed core nuclear magnetic resonance data, scanning electron microscopy, and oil-water phase permeability curves, the occurrence characteristics and influencing factors of movable fluids in reservoirs with different pore structures were conducted. Results The results show that (1) the movable fluid saturation of reservoirs with different pore structures varies greatly. The T2 spectrum of the nuclear magnetic resonance of the class Ⅰ medium porosity and medium throat reservoir is bimodal with left low and right thigh, and the average saturation of movable fluid is 61.14%. The T2 spectrum of the nuclear magnetic resonance of the class Ⅱ medium and small pore fine throat reservoir shows a double peak type with left high and right high, and the average of movable fluid saturation is 45.24%. The T2 spectrum of the nuclear magnetic resonance of the class Ⅲ fine porous micro throat reservoir shows a double peak type of left high and right low, and the average of movable fluid saturation is 30.45%. The T2 spectrum of the nuclear magnetic resonance of the class Ⅳ microporous micro throat reservoir shows a left high single peak, and the average saturation of movable fluid is 13.86%. (2) The macroscopic physical properties, microscopic pore structure, clay mineral content and reservoir wettability of the reservoir jointly control the occurrence characteristics of the movable fluid. Among them, the microscopic pore structure is a key factor in the occurrence of movable fluid. The larger the pore throat radius is, the better the reservoir seepage capacity, the lower the clay mineral content is, the weaker the reservoir wettability is, and the higher the movable fluid saturation is. Conclusion The results of this research can provide a reasonable scientific basis for high-efficiency water injection development of the Es32+3 reservoir in the Gaoshangpu Oilfield.

Lorenc Wojciech, Bartoszek Błażej

The article presents a prototype steel–concrete bridge with the results of trial load tests. In the design of the structure, new approaches were used, the so-called concept of a hybrid cross section. The obtained results were interpreted against the background of theoretical analysis performed and the experience of the behavior of the existing standard bridge structures. The obtained results are to be the starting point for the development of methods of calculating this type of structure, with particular emphasis on the degree of cracking of the concrete part of the structure. The paper is intended to be a starting point for demonstrating that it is possible to calculate longitudinal shear in the fatigue limit state (of steel dowels) differently than in the fully cracked section. Similarly, it is supposed to be a point of discussion on how to perform a global analysis of hybrid systems.

Guozheng Jing, Xiaoyun Wang, Zhiqiang Zhang et al.

A large-scale mineralization occurred in the East Kunlun during the Early Mesozoic, forming a series of lode gold, quartz vein-type Ag-Pb-Zn, porphyry Cu-Mo, and skarn Fe polymetallic deposits. However, the genetic link between these deposits is still unclear. The eastern segment of the East Kunlun has diverse types of deposits which provides an excellent opportunity to decipher the genetic link. Here we summarize the geological features and spatial-temporal distribution of the major types of deposits in the eastern segment of the East Kunlun, and discuss their metallogenic ages, tectonic settings, and sources of ore-forming fluids and materials to explore possible genetic links between them. The results show that they were mainly formed in the Middle-Late Triassic (240-220 Ma), controlled by the Paleo-Tethys continental collision and post-collision extension. Additionally, these different types of deposits in the study area and the surrounding Northern East Kunlun Terrane have similar metal and fluid sources. They are closely related to the extensive deep magmatism developed during this period. We suggest that these deposits formed a giant magmatic-hydrothermal metallogenic system, and different mineralization types might be the products of different evolution stage. The deep subduction and break-off of the Bayankura Plate induced the upwelling of the asthenospheric mantle and the subsequent large-scale magmatic-fluid activities. The metal- and volatile-rich hydrothermal fluids extensively interacted with upper crustal rocks and shallow-derived fluids, and formed a regional-scale magmatic-hydrothermal metallogenic system. Based on the metallogenic system, the eastern segment of the East Kunlun has potential for multi-type paragenetic deposit exploration.