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

Deiveegan Ramasamy, Devarajan Veerasamy, Selvaraju Sivamani

Deep Learning (DL) has rapidly become a transformative force across various industries, and geotechnical engineering is no exception. The ability of DL models to autonomously learn and identify intricate patterns in vast datasets has made them invaluable in addressing the complexities inherent in geotechnical problems. These advanced computational models have the potential to revolutionize how engineers analyze subsurface conditions, predict geological phenomena, and design infrastructure, making them an essential tool in the evolving landscape of geotechnical research and practice. This review paper presents a thorough exploration of DL techniques specifically tailored to the needs of geotechnical engineering. The paper begins by providing an in-depth analysis of the foundational principles of deep learning, followed by an examination of various DL architectures such as convolutional neural networks (CNNs), recurrent neural networks (RNNs), and generative adversarial networks (GANs), and their applicability to geotechnical challenges. The discussion includes the integration of these methods into traditional geotechnical practices such as soil characterization, rock mechanics, foundation design, and slope stability analysis. Furthermore, this review highlights the advantages of utilizing DL for modeling complex geotechnical systems, particularly in the context of predictive modeling and forecasting. It showcases examples where DL has been employed to improve the accuracy of site-specific predictions, enhance decision-making processes, and optimize resource allocation in engineering projects. Alongside these advancements, the paper also delves into the obstacles and limitations encountered when implementing DL in geotechnical applications, including the need for high-quality data, interpretability of results, and computational resource requirements. The paper concludes by identifying emerging opportunities for future research and technological advancements in this domain. A particular emphasis is placed on the integration of artificial intelligence (AI) with geotechnical engineering, exploring the potential synergy between DL and other AI techniques such as machine learning and evolutionary algorithms. As the field of DL continues to evolve, the paper suggests avenues for continued exploration, particularly in improving the robustness of models, enhancing their interpretability, and scaling them for large-scale, real-world geotechnical projects.

Shu Ouyang, Xiaobo Zhang, Chi Yao et al.

The study of the shear behavior of bonded rock-cement interface is important for understanding the strength and stability of grouted rock masses. This research aims to reveal the failure mechanism behind the shear property of bonded rock-cement interfaces. For the study, sandstone and granite joint blocks with specific morphology were fabricated by using a three-dimensional (3D) engraving technique. Bonded rock-cement joints with asperity inclination angles of 15°, 30°, and 45° were prepared. Shear tests were performed on these bonded rock-cement joints to investigate the shear response and failure modes considering the effect of applied normal stress and interface morphology. Meanwhile, the two-dimensional particle flow code (PFC2D) was utilized to model the entire shear process of bonded rock-cement interfaces. The macroscopic shear behavior and mesoscopic failure mechanism were comprehensively investigated by the laboratory test and numerical simulation. The results showed that the shear stress-displacement curves of bonded rock-cement joints exhibit two distinct peaks, and the shear stress evolution can be categorized into four stages including elastic growth, rapid stress drop, secondary stress growth, and progressive softening. Significantly, the number of acoustic emission events also exhibits two distinct peaks related to the double peak of the shear stress curves. The failure of bonded rock-cement interfaces is mainly induced by shear fractures, while the failure of rock and cement blocks is primarily caused by tensile fractures. The number of shear cracks in the bonded rock-cement interfaces reaches the peak when the shear stress reaches the primary peak; whereas as the shear stress continuously approaches the residual stage, the fracture of the bonded rock-cement joints is primarily characterized by tensile cracks in the blocks.

HAO Wenhua, WANG Fangtian, WU Peilin et al.

This study investigates the mechanical response mechanism and temporary support method of surrounding rock in coal mines under varying unsupported roof distances, with 9103 transportation roadway of Wangzhuang coal mine taken as a case study. We established a mechanical model of shallow surrounding rock in the unsupported roof area of coal mines by drawing on the thin slabs and universal falling arch theories, where an expression of the maximum unsupported roof distance was derived. Numerical simulation was conducted using FLAC 3D software to simulate the spatiotemporal evolution of deformation, stress, and plastic zone of surrounding rock in roadway with varying top spacing. Results show that: identified roadway width, the tensile strength of the roof, the load on the roof, and the thickness of the shallow separated rock mass as main controlling factors affecting the empty roof distance. As the unsupported roof distance increases from 0.5 m to 1.0 m, 1.5 m, and 2.0 m, the increments in roof subsidence are 4.82 mm, 3.67 mm, and 8.31 mm, respectively, showing an initial steady subsidence followed by an accelerated trend. The minimum vertical stress at the center of the cross-section along the excavation direction decreases from 7.85 MPa to 1.24 MPa. When the unsupported roof distance increases to 2.5 m and 3.0 m, internal damage in the surrounding rock intensifies, leading to surface deformation instability. The critical value for a reasonable unsupported roof distance is determined to be 2.0 m. To address the limitations of the temporary support device of the coal roadway, we proposed a new type of machine-mounted temporary support device, and its sufficient supporting capacity is verified using Ansys software. The 9103 transportation roadway adopts this support device, the excavation speed is increased by 33.3 % by increasing the cyclic feed of the roadheader and through the parallel operation of knocking on the top and temporary support.

Chuangang Fan, Xiaoxian Fei, Maozhen Liu et al.

The development of traffic networks in mountainous areas has led to an increasing number of tunnels being constructed in regions of high geothermal activity. This study examined the effects of geothermal temperature, heat release rate, and fire source location on temperature distribution and smoke movement in construction tunnel fires through a series of scaled-down experiments. Results showed that geothermal conditions heat the air, creating layered flow within construction tunnels. The temperature and velocity of the induced airflow along the tunnel length were characterized. The upper airflow caused by geothermal conditions hinders the spread of smoke toward the tunnel face, resulting in a complex thermal stratification phenomenon. A model for predicting the smoke diffusion length upstream of the fire source was developed, considering geothermal temperature, heat release rate, and fire source location. Additionally, the ceiling temperature distribution was analyzed, showing that downstream temperature decay is insensitive to fire location, while upstream temperature decay can be divided into geothermal-affected and non-affected zones based on the fire source position. Prediction models for the ceiling temperature distribution upstream and downstream were established, respectively. These findings enhance the understanding of smoke dynamics in construction tunnel fires under high geothermal conditions.

Gajalakshmi G, Meenakshi S

This paper explores the intricate relationship between man and nature in Ernest Hemingway’s The Old Man and the Sea through the lens of deep ecology. It challenges the traditional anthropocentric interpretation of the novella, proposing that the protagonist Santiago’s struggle is not merely a tale of human triumph over nature but a journey towards understanding and coexisting with the natural world. By applying the principles of deep ecology, the study reveals how Santiago’s evolving relationship with the marlin and other sea elements reflects a broader ecological consciousness. The analysis also draws parallels between Santiago’s experience and the Biblical narrative of Jonah, suggesting that Santiago’s success is not solely due to his physical endurance but also the cosmic forces that aid him. This paper ultimately rethinks the themes of struggle and victory in the novella, emphasising the need for a harmonious relationship between humanity and the environment.

Dejene Tadesse Banjaw, Habtamu Gudisa Megersa

Garlic is a versatile vegetable commonly grown in subtropical and highland agroecosystems, which is utilized for its culinary, medicinal, and spice properties. The use of garlic as a medicinal aid can be traced back to ancient times. The health benefits of garlic production are attributed to its antiviral, antibacterial, and antifungal properties. The use of garlic is prevalent in both traditional and modern healthcare systems, where it is used to treat a wide range of conditions. Numerous studies have reported the therapeutic properties of garlic, and its effectiveness has been demonstrated in clinical trials. The growing global interest in health and wellness, the widespread use of garlic as a spice, and its potential economic, social, and health benefits have contributed to a surge in its demand worldwide. This review aims to provide a comprehensive overview of the scientific literature on the morphological descriptions of garlic and its nutritional and health significance.

Anil Kumar Adukadukkam, Rachna Pillai, Mamatha Puthiyathara Kanakamma

Abstract Limestone is one of the essential raw materials in the cement, paint, steel, ceramic, glass, chemical, pharmaceutical, paper, and fertilizer industries. In India, only 8% of the limestone resources are placed under the reserve category, of which 97% is of cement grade. Thus, India depends on imports to bridge the demand‐supply gap of steel, blast furnace, and chemical‐grade limestone. Efforts of Geological Survey of India (GSI) to locate alternate sources for limestone led to the discovery of enormous quantities of carbonate minerals called limemud from the continental shelf margin of the west coast of India. GSI carried out systematic studies to explore the nature of the disposition, quality, quantity, and suitability of the offshore limemud for various industrial applications. A preliminary estimate of resources using high‐resolution subbottom profiling and sediment core sample studies established the occurrence of more than 172 billion tonnes of high‐grade (The content of CaCO3 is greater than 80 wt%) limemud in 0.4–28.0 m thick stratified sediment layers spread over an area of 18 000 km2. Chemical, physical, mineralogical, beneficiation, and agglomeration studies found the offshore limemud as a potential replacement for limestone in the cement, filler, blast furnace, steel melting shop, lime production, paint, and Grade‐I steel industries. An assessment of mining and transportation costs indicates that the offshore limemud (USD 5–6/ton) is more cost‐effective than that imported from other countries (USD16‐18/ton). With several advantageous factors like low impurity, mode of occurrence in overburden‐free stratified form, fine‐grained slurry nature, and shallow water depth, sustainable mining of offshore limemud could be a future reality with controllable technological, economic, and environmental challenges.

TAO Gaoliang 1, 2, PENG Yinjie 1, CHEN Yin 1, XIAO Henglin 1, LUO Chenchen 1, ZHONG Chuheng 1, LEI Da 1

The permeability coefficient of unsaturated soils is a particularly important parameter to study the moisture migration in unsaturated soils. The direct measurement methods have a straightforward principle, but they require larger sample sizes and longer testing time. The indirect prediction methods based on the soil-water characteristic curve (SWCC) also demand significant time and effort due to the necessity of acquiring the SWCC data. Thus, this paper combines the nuclear magnetic resonance (NMR) theory with the seepage theory to establish the relationship between the permeability coefficient and the relaxation time of pore channels with different pore sizes. Through the accumulation of permeability coefficients of different pore channels, an NMR-based prediction model and a rapid prediction method for the permeability coefficients of saturated/unsaturated soils are proposed. To verify the rationality of the model, taking the Hunan clay as the research object, 95 times NMR tests are conducted on desorption, absorption and saturated samples with different initial void ratios to obtain the corresponding NMR curves. The unsaturated relative permeability of samples with different void ratios is gained by the instantaneous profile method and compared with the predicted value of the model. The study shows that the NMR curves of desorption, absorption and saturated samples all possess good prediction effecst, while the saturated state NMR curves have the best prediction accuracy with the lowest measurement cost and the shortest time consumption. Therefore, it is suggested to use the NMR curves of saturated samples to predict the unsaturated relative permeability coefficient directly.

Maksym Reva, O. Lysenko, Dmytrо Chomko

Formulation of the problem. The paper examines landslide processes that occurred on the right bank of the city of Kyiv. The authors demonstrate the general statistics of the development of landslides in the city, which is a dangerous phenomenon for the safety of the city. In Kyiv, 42 landslides have been recorded, which are in the active phase. The authors identify the main reasons for the development of landslides as engineering-geological, geomorphological conditions, climate and anthropogenic impact. The article examines the use of GIS technologies as a modern and quite effective method of monitoring landslide processes. The authors focus attention on two landslides that occurred and differ from the rest due to the atypical mechanics of the process, which was affected by the overwetting of the soil mass. It was this difference that led to this scientific research. This theoretical study was conducted on a site in the Park of Vichnoyi Slavy, since by all indicators this slope has the potential for the development of just such a landslide. Overmoistened soil mass has a special mechanics of movement on the slope and is classified as – a landslide flows. Purpose. The article examines this movement of the overmoistened soil mass on the slope as a rheological process. Methodic. The authors analyzed the theoretical foundations of soil mass behavior in such conditions, they consider it as a rheological model. The solution to the problem is based on the classical Bingham-Shvedov, Newton, and Maxwell models. The methodology for solving such tasks is given in the study. The authors investigated the necessary parameters of the soil, which are used in the construction of the calculation model. The article highlights the coefficient viscosity of soil, this coefficient deserves special attention when considering rheological processes in the soil. The considered solution model of the rheological process cannot be solved without the coefficient viscosity of soil. Using the scientific work of Ukrainian scientists, the authors determined this coefficient in the laboratory. The main material. The article investigates the possibility of a landslide occurring on one of the cultural objects in order to preserve the latter. The authors built their research on the basis of engineering investigations, which were carried out for the purpose of reconstructing the stairs in the Vichnoyi Slavy Park in Kyiv. The surveys show an engineering-geological section of the slope, which consists of 14 soil layers. The researchers established that under natural conditions this slope is in a stable state Kst=1.56. The studies have shown that at this site, with excessive moistening of the upper soil layer, a rheological process may occur. This process can develop in bulk soils (dusty sandy loam) due to its large angles of inclination and rather weak physical and mechanical properties. The article analyzes the possibility of the occurrence of rheological processes on the slopes and their role in the safety and life of the city of Kyiv. Conclusions. The calculated model is solved and shows the capture depth D=1,08 m and speed V0=0,75 m/day of movement of a potential landslide in case of overwetting of the soil on the slope in the Vichnoyi Slavy Park in the city of Kyiv.

Yin-long Tan, Jiaming Cao, Wentao Xiang et al.

Z. Tao, Yuxuan Shu, Xiaojie Yang et al.

Abstract A physical model for the footwall slope of Nanfen open-pit mine, China was established using a self-developed deep geological engineering disaster model test system. A thermosensitive similar material, paraffin, was selected to simulate a weak structural plane in the slope to reproduce the landslide process. From an experimental perspective, the variation trend of shear strength parameters of weak structural plane and the mechanical support characteristics of NPR (negative Poisson’s ratio) anchor cable under the condition of a large landslide deformation and failure were examined. The results of this model test showed that slope failure has four distinct stages: (1) soil compaction stage, (2) crack generation stage, (3) crack propagation stage, and (4) sliding plane transfixion stage. According to the test results, the rock mechanics parameters of weak surface in the footwall slope of Nanfen open-pit mine were calculated. The cohesion is approximately 1.35 × 105 Pa, and the internal friction angle is approximately 6.33°. During slope failure, the NPR anchor cable experiences a large deformation but no damage occurs, indicating that the NPR anchor cable can be continuously monitored and reinforced during the deformation and failure of landslide. The stress characteristics of NPR anchor cables during the test are consistent with the monitoring results of Newtonian force at the landslide site, proving that NPR anchor cables are effective and reasonable in landslide monitoring and early warning.

WANG Mingyuan 1, SUN Jizhu 2, WANG Yong 3, YANG Yang 4

In ocean engineering practice, laterally loaded piles are usually analyzed using the nonlinear Winkler foundation beam method, in which the soil-structure interaction is modelled by means of the p-y curve, but now the API/DNV rules are only valid for few soils and pile conditions, and the p-y hysteresis curve is not given under cyclic loading. A simplified bounding surface plastic shear stress-shear strain model for sandy soil under monotonic and cyclic loads is proposed, and a method is introduced for the establishment of p-y curves from the proposed model. Based on the scaling of stress and strain into compatible soil reaction p and pile deflection y respectively, the proposed method has good theoretical basis. According to the p-y curve of sand in the API rule, the API p-y hysteresis curve is established using the Masing rule and compared with the bounding surface plastic p-y curve, and the variation characteristics of secant stiffness and damping ratio with displacement amplitude are analyzed. Finally, the validity of the proposed p-y curve is verified by the model test results.

Liu Gao, Dong Liao, Pin-Qiang Mo

Sand typically exhibits anisotropic internal structure which may significantly influence its mechanical behavior. The material point method (MPM) can eliminate mesh distortion and thus is suitable for investigating geotechnical problems with large deformation. In this study, an advanced anisotropic critical state theory (ACST)-based soil model is implemented in MPM to study the response of strip footing resting on anisotropic sand. The capability of the model is verified by simulating several element tests and strip footing tests with different soil densities and fabric bedding plane orientations. For the footing problem with a vertical load, as the fabric bedding plane orientation increases, the bearing capacity decreases and its corresponding settlement increases. The failure pattern becomes asymmetrical when the bedding plane orientation or the loading direction is inclined. A comparison between the simulation results predicted by the anisotropic and isotropic models is made, which demonstrates that neglecting the fabric anisotropy may lead to the overestimation of the bearing capacity.

Shan Wu, Qi Zhao, Hui Yang et al.

Understanding the failure process of tight reservoir rocks is essential for reservoir stimulation with hydraulic fracturing. The acoustic emission (AE) technique has proven to be an effective tool to monitor fracture propagation and thus characterize the rock failure process. In the present study, AE is employed to investigate different rock failure processes under uniaxial compression. We use four typical tight reservoir rocks from oil and gas production fields in China. We employed an unsupervised machine learning method to classify the recorded AE waveforms and evaluated the results via two score systems: elbow and silhouette scores. The cluster number is approximately constant for all samples, indicating that this method provides a more precise and reliable interpretation of the rock failure process. Machine learning results demonstrate that AE events could be distinguished into three clusters, which could relate to the mechanisms of the microscopic ruptures, i.e., tensile, shear, and mixed cracking types. Our results reveal that cracks formed under low-stress conditions are predominantly in tensile failure mode, and the failure mode transit into shear ruptures before the compression peak strength. In addition, different strength of weak planes could diversify the process of tensile-to-shear rupture transition by affecting the local stress concentration. This research may help understand the failure mechanism in tight reservoir rocks and shed light on further hydraulic fracturing technology in reservoir development. Tight reservoirs contain rich oil and gas resources, collectively known as tight oil and gas (Abdel-Aal et al., 2003; Jia et al., 2022; Ma and Holditch, 2015; Pang et al., 2015; Zendehboudi and Bahadori, 2016). The vast reserves of tight oil and gas are an important supplement to conventional oil and gas, and their effective commercial development relies on new underground reservoir engineering technologies such as horizontal drilling and hydraulic fracturing (Rezaei et al., 2020; Zhang et al., 2016; Zou et al., 2018). The development of these technologies requires the support of rock mechanics, with the most important part being the problem of fracture propagation in tight reservoirs. Different from conventional oil and gas reservoirs, tight reservoirs have abundant layers of weak planes formed by geological sedimentation, leading to the special rock mechanical behaviour (Heng et al., 2020; Kumar et al., 2019; Suo et al., 2020). Based on traditional rock mechanics models, it is not possible to predict the underground fracture expansion, which brings various disasters such as fracturing failure, reservoir pollution, and induced earthquakes (Ham and Kwon, 2020; Wu et al., 2022; Xie et al., 2020). Therefore, it is necessary to conduct in-depth research on rock fracture in tight reservoirs.

Mihály Dobróka, Norbert Péter Szabó, Tünde Edit Dobróka et al.

We present new quantitative model describing the pressure dependence of acoustic P- and S-wave velocities. Assuming that a variety of individual mechanisms or defects (such as cracks, pore collapse and grain crushing) can contribute to the pressure-dependent change of the wave velocity, we order a characteristic pressure to all of them and allow a series of exponential terms in the description of the (P- and S-waves) velocity-pressure function. We estimate the parameters of the multi-exponential rock physical model in inversion procedures using laboratory measured P- and S-wave velocity data. As is known, the conventional damped least squares method gives acceptable results only when one or two individual mechanisms are assumed. Increasing the number of exponential terms leads to highly nonlinear ill-posed inverse problem. Due to this reason, we develop the spectral inversion method (SIM) in which the velocity amplitudes (the spectral lines in the characteristic pressure spectrum) are only considered as unknowns. The characteristic pressures (belonging to the velocity amplitudes) are excluded from the set of inversion unknowns, instead, they are defined in a set of fixed positions equidistantly distributed in the actual interval of the independent variable (pressure). Through this novel linear inversion method, we estimate the parameters of the multi-exponential rock physical model using laboratory measured P- and S-wave velocity data. The characteristic pressures are related to the closing pressures of cracks which are described by well-known rock mechanical relationships depending on the aspect ratio of elliptical cracks. This gives the possibility to estimate the aspect ratios in terms of the characteristic pressures.

Jinquan Liu, Tao Yang, Zhou Yong et al.

Numerous natural and engineering disasters are observed frequently due to the climate change and the human engineering activities. In recent years, a large number of tunnels, metros and underground spaces were constructed to reduce congestion and store potential resources with the development of infrastructure construction (Font-Capoet al., 2011; Liu and Zou 2022). A respective example in China is that the length of constructed, under constructing, and planning railway tunnels were up to 15,781 km, 8,200 km, and 12,800 km, as reported by Guo (2018). The rapid construction caused significant challenges of engineering disasters when encountering the unfavorable conditions, e.g., karst, fault, and weathered slot (Høien and Nilsen, 2014; Liu et al., 2018a, b; Golian et al., 2021). As shown in Figure 1, main engineering disasters related to the engineering construction include the water and mud inrush, soil/rock collapse, erosion, surface subsidence and crack (Liu et al., 2019, 2022; Zhang et al., 2019). These disasters may induce the serious influences on the hydraulic-geological-ecological environment (e.g., groundwater decline) and usually cause the stoppages for the projects, huge property damages, and deaths to the constructors and surface residents (Hayashi et al., 2009; Wang et al., 2019). Thus, it is necessary to establish the effective model or method to predict these disasters and their related influences on the ground and surface environment. Considering this practical demand, a special topic, entitled “Spatial Modelling and Failure Analysis of Natural and Engineering Disasters through Data-based Methods” was initiated with several editors to process the timely peer-review and publication of relevant manuscript by 12 March 2021. The main objective of this Research Topic is to provide a set of peer-reviewed OPEN ACCESS

Yuryi L. Rebetsky

In the article by N.A. Sycheva and L.M. Bogomolov, the authors proposed to combine the interrelated data on the stress drop in the earthquake sources, ∆σ, and reduced seismic energy, ePR, to analyze the dependence of these parameters on earthquake scale along with expansion of the measurement statistics (assessments). The dependence of these parameters of a source on the seismic moment or on the earthquake magnitude within 2.2 ≤ М ≤ 4.0 magnitude range has been determined using the example of the Northern Tien Shan (Bishkek geodynamic polygon with the KNET network). The author of the letter to the editor notes the article conclusions to be limited, because such relationship is only manifested within the more or less narrow range of the magnitudes. Attention is also drawn to the semantic difference between the ∆σ and ePR parameters. It is the reduced seismic energy that reflects the mean strain in the source area, and its appliance to the analysis of scale dependences of earthquake sources is more informative.

Santiago Peña Fernández, Enrique Asanza Izquierdo

Este artículo introduce algunos conceptos e ideas básicas del campo del aprendizaje automático, con los que afrontar la caracterización geotécnica y perfilado del terreno a partir de ensayos de penetración tipo CPTU. Se muestran los resultados prácticos obtenidos para una campaña para un puerto español. En última instancia se pretende mostrar al diseñador algunos algoritmos que permitan ayudar a la elaboración, en los casos que sea posible, de modelos de terreno objetivamente evaluables, repetibles y precisos.

Hongsu Ma, Ju Wang, K. Man et al.

Abstract Underground research laboratory (URL) plays an important role in safe disposal of high-level radioactive waste (HLW). At present, the Xinchang site, located in Gansu Province of China, has been selected as the final site for China’s first URL, named Beishan URL. For this, a preliminary design of the Beishan URL has been proposed, including one spiral ramp, three shafts and two experimental levels. With advantages of fast advancing and limited disturbance to surrounding rock mass, the tunnel boring machine (TBM) method could be one of the excavation methods considered for the URL ramp. This paper introduces the feasibility study on using TBM to excavation of the Beishan URL ramp. The technical challenges for using TBM in Beishan URL are identified on the base of geological condition and specific layout of the spiral ramp. Then, the technical feasibility study on the specific issues, i.e. extremely hard rock mass, high abrasiveness, TBM operation, muck transportation, water drainage and material transportation, is investigated. This study demonstrates that TBM technology is a feasible method for the Beishan URL excavation. The results can also provide a reference for the design and construction of HLW disposal engineering in similar geological conditions. © 2020 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ).