Engineering Geology最新文献

{"title":"Combining acoustic emission and unsupervised machine learning to investigate microscopic fracturing in tight reservoir rock","authors":"Shan Wu ,&nbsp;Qi Zhao ,&nbsp;Hui Yang ,&nbsp;Hongkui Ge","doi":"10.1016/j.enggeo.2025.107939","DOIUrl":"10.1016/j.enggeo.2025.107939","url":null,"abstract":"<div><div>We use the acoustic emission (AE) and unsupervised machine learning to investigate the influence of bedding structures on the tight rock fracturing at the microscale, aiming to uncover the macro failure mechanisms relevant to oil and gas production engineering. We compared the AE characteristics of typical tight rocks, specifically tight sandstone and shale, under uniaxial loading both perpendicular and parallel to the bedding structure. Additionally, we applied unsupervised machine learning to cluster AE waveforms to analyze microscopic fracturing. The clustering results, constrained using the elbow method and silhouette score, revealed that a consistent number of three clusters was suitable for categorizing all samples. We then used the classification results, together with other AE parameters, to interpret the fractures influenced by bedding structures. Our results revealed that AE waveforms could be classified into three clusters, corresponding to microscopic fracturing, including tensile, shear, and mixed cracking types. Cracks formed under low-stress conditions tend to exhibit tensile failure modes, transitioning into shear fracturing before reaching peak compressive stress. Tight sandstones exhibited higher strength in their bedding structures compared to shale, possibly due to differences in pre-existing microcrack structure characteristics. This study advances our knowledge of tight reservoir rock failure mechanisms and provides valuable guidance for tight reservoir development engineering.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"347 ","pages":"Article 107939"},"PeriodicalIF":6.9,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated geophysical data and Bayesian evidential learning approach for rockhead estimation and uncertainty quantification","authors":"Yu Zhang ,&nbsp;Jian Chu ,&nbsp;Hao-Qing Yang ,&nbsp;Shifan Wu ,&nbsp;Yunhuo Zhang ,&nbsp;Kiefer Chiam","doi":"10.1016/j.enggeo.2025.107944","DOIUrl":"10.1016/j.enggeo.2025.107944","url":null,"abstract":"<div><div>Rockhead estimation and uncertainty quantification are essential for underground constructions such as tunneling. However, deep boreholes that are required for rockhead determination are not always available at every site due to their high cost and logistical challenges. Furthermore, geological profiling using solely borehole data can introduce biases, especially when boreholes are sparsely distributed or limited in coverage. This study proposes a method that integrates geophysical data with borehole data for rockhead estimation and uncertainty quantification. Seismic surface wave data, specifically the Horizontal-to-Vertical Spectral Ratio (HVSR), are utilized for rockhead investigation. The Bayesian Evidential Learning (BEL) method employs the rockhead positions determined using HVSR to update the initial rockhead estimates derived from boreholes. The proposed HVSR-BEL approach was initially validated using a hypothetical case and applied subsequently to two real sites in Singapore for rockhead estimation, with results verified against nearby boreholes. The analysis of geophone spacing indicates that the ratio of geophone spacing to site size of 0.3 is cost-effective for achieving accurate rockhead estimation. When the ratio increases from 0.3 to 0.4, the relative difference of uncertainty reduction is most significant, reaching approximately 28 %. For Site 1, the uncertainty in rockhead estimation along the geophone lines using the proposed method is significantly reduced by 40 % to 60 % as compared with prior variance estimates. For Site 2, uncertainty reductions in the range of 5 % to 40 % are primarily observed near the geophone locations. The accuracy of the estimated rockhead at both sites is acceptable, with an average absolute error of 2.7 m. The proposed HVSR-BEL approach can provide reliable estimation of rockhead profile.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"347 ","pages":"Article 107944"},"PeriodicalIF":6.9,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143134500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of trench drain systems on pore water pressures in slow, deep, clayey landslides: Influence of hydraulic properties of the slip zone","authors":"Roberto Vassallo,&nbsp;Caterina Di Maio","doi":"10.1016/j.enggeo.2025.107943","DOIUrl":"10.1016/j.enggeo.2025.107943","url":null,"abstract":"<div><div>Trench drain systems are widely used as remedial measures for slow landslides in saturated fine-grained soils. Among the factors that influence their effectiveness, the hydraulic peculiarities of the slip zone have not been sufficiently investigated. This paper presents the results of numerical analyses of the effects of trench drain systems on clay slope models characterised by very low hydraulic conductivities of the landslide body (k_l) and stable formation (k_f), with the conductivity of the slip zone (k_sz) being several orders of magnitude higher. The hydraulic models reproduced the conditions of a real landslide. Analyses were performed using the code SEEP3D. SEEP/W 2D and PLAXIS 2D were used for comparison. The 3D model shows that, as the k_sz/k_l ratio increases, the effectiveness of a drain system shallower than the slip surface significantly decreases. As an example, in the case of 12-m-deep trenches, a 25-m-deep slip surface, k_sz = k_l = 10⁻⁹ m/s, and k_f = 10⁻¹⁰ m/s, the drains reduce the pore water pressure in the deepest points of the slip zone by approximately 100 kPa. Conversely, if k_sz = 10⁻⁶ m/s, the pore pressure reduction is only about 10 kPa. Therefore, a drain system designed without considering the hydraulic peculiarities of the slip zone may not be effective. As the trench depth increases, drainage reduces the pore water pressure with a highly non-linear trend, exerting significant effects when the trenches reach the slip surface. Furthermore, 2D models may significantly overestimate the pore water pressure. The differences between the results of 2D and 3D models depend on the trench depth, hydraulic conductivity, and hydraulic boundary conditions.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"347 ","pages":"Article 107943"},"PeriodicalIF":6.9,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental research on geological fissure monitoring based on distributed piezoelectric sensing technology","authors":"Yuanqiang Cai ,&nbsp;Junjie Jiang ,&nbsp;Zhiming Liu ,&nbsp;Jun Wang ,&nbsp;Ziyang Gao ,&nbsp;Hongtao Fu ,&nbsp;Junfeng Ni","doi":"10.1016/j.enggeo.2025.107941","DOIUrl":"10.1016/j.enggeo.2025.107941","url":null,"abstract":"<div><div>The causes of geological fissures are complex, and the disaster situation is very serious, and it is very difficult to carry out early warning and monitoring. To this end, a new type of Sensor-enabled piezoelectric geocables (SPGC) is used for geological fissure monitoring, which has piezoelectric effect and impedance-strain effect. Model tests were carried out to study the accuracy of fixed-point SPGC to determine the location of geological cracks, and the characteristics of soil internal deformation were analyzed based on SPGC monitoring data, so as to achieve early warning effect. The test results show that SPGC can accurately locate the crack location compared with the traditional point sensor, and the shorter the segmentation, the more accurate the identification of the crack location. The faster the soil collapse rate, the smaller the crack volume, the smaller the normalized impedance of SPGC, and the smaller the soil strain change. The voltage generated by the vibration of SPGC can react significantly to the internal collapse of the soil. The results show that SPGC can realize the catastrophic location and precursor identification of ground fissures.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"347 ","pages":"Article 107941"},"PeriodicalIF":6.9,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization study on separate-layer fracturing of a coal–rock composite based on inter-fracture interference effect","authors":"Aitao Zhou ,&nbsp;Yizheng He ,&nbsp;Kai Wang ,&nbsp;Yuexin Yang ,&nbsp;Yida Wang ,&nbsp;Yifu Liu","doi":"10.1016/j.enggeo.2025.107930","DOIUrl":"10.1016/j.enggeo.2025.107930","url":null,"abstract":"<div><div>Optimization measures that can improve the effectiveness of fracturing coal–rock composites through separate-layer fracturing under the effect of inter-fracture interference are required. In this context, a reservoir–fracture interference extension model was established for coal–rock composites based on the extended finite element method by embedding cohesive units. Hydraulic fracturing simulations were conducted under different geo-stresses and fracturing sequences, and a comprehensive assessment of the fracturing effect was provided. The results showed that the high pore stress on both sides of the first fracture can induce the expansion of secondary fractures toward the interface with a greater degree of deflection. The difficulty of fracture initiation in the rock formation increased in secondary fracturing, the fracture initiation pressure decreased in the coal seam during secondary fracturing. An appropriate reduction in the fracture spacing can enhance the inter-fracture interference effect and thus enrich the morphology of the hydraulic fracture network. In the separate-layer fracturing of coal composite reservoirs, the synergistic effect of interlayer physical differences and inter-fracture interference effect can be utilized to fracture the rock formation after fracturing the coal seam; this induces the rock fractures to be captured by structurally weak surfaces. Repeated fracturing of the coal seam and utilization of the rupture expansion effect of the rock roof to form long-term stable fractures can be useful for further strengthening the transformation effect of the coal seam. This study can provide some theoretical support for the stratified co-mining of coalbed methane in deep coal reservoirs.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"347 ","pages":"Article 107930"},"PeriodicalIF":6.9,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of initial particle deposition in collapse dynamics and deposition morphology of submarine granular flows using CFD-DEM coupling method","authors":"Yu Huang ,&nbsp;Xiaolin Tan ,&nbsp;Yandong Bi ,&nbsp;Shu Zhou ,&nbsp;Jian Pu ,&nbsp;Zhen Guo","doi":"10.1016/j.enggeo.2025.107940","DOIUrl":"10.1016/j.enggeo.2025.107940","url":null,"abstract":"<div><div>Submarine landslides represent a significant marine geohazard, making it essential to understand their underlying dynamics. Initial deposition plays a crucial role in determining the flow behavior and ultimate runout distance of submarine granular materials. Despite the importance of particle interactions, especially considering the wide range of particle sizes involved, their impact on submarine landslide dynamics has not been thoroughly explored. In this study, we employ a three-dimensional coupled CFD-DEM method to simulate the collapse of granular columns under varying initial deposition conditions, aiming to uncover the dynamic characteristics of submarine landslides at the particle scale. Our findings reveal that initial depositions with a higher concentration of larger particles at the top lead to their upward migration toward the upper and frontal regions of the flow, while smaller particles tend to settle at the base. This enhances the overall mobility of the landslide. Notably, initial depositions with larger aspect ratios result in greater particle segregation and more efficient conversion of initial potential energy into vertical kinetic energy. This segregation extends the range of kinetic energy variation, reduces energy dissipation through horizontal velocity, and ultimately increases the runout distance. Moreover, the presence of an ambient fluid significantly prolongs the duration of movement compared to dry cases, although it results in a shorter final runout distance. These insights provide a deeper understanding of the mechanics governing submarine landslides and highlight the critical role of initial deposition conditions in shaping their behavior.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"347 ","pages":"Article 107940"},"PeriodicalIF":6.9,"publicationDate":"2025-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative analysis of geological and seismic microtremors models of a large translational landslide: The case of San Vito Romano (Central Italy)","authors":"Francesco Seitone ,&nbsp;Andrea Vergnano ,&nbsp;Cesare Comina ,&nbsp;Mauro Bonasera ,&nbsp;Giandomenico Fubelli","doi":"10.1016/j.enggeo.2025.107934","DOIUrl":"10.1016/j.enggeo.2025.107934","url":null,"abstract":"<div><div>This study investigates the San Vito Romano landslide, a significant but poorly documented gravitational phenomenon in central Italy. The local geological setting is characterized by siliciclastic rock units forming a monocline parallel to the slope, dipping 15–20° eastward. For the first time, a detailed geological model of the landslide was developed by integrating extensive geological-technical inventory data with specific geomorphological field mapping. To further analyze the landslide's dynamics and scale, seismic microtremor measurements were conducted and interpreted using the Horizontal-to-Vertical Spectral Ratio (HVSR) method. To streamline the HVSR data analysis, a semi-automatic visualization tool was developed in the R environment and released as open-source. The integrated interpretation of geophysical and geological models revealed a landslide area of approximately 0.5 km², significantly larger than previously estimated, with a maximum thickness of about 48 m and a total volume of approximately 1 × 10⁷ m³. The primary failure mechanism is identified as a translational rock slide, a common process in sedimentary basins with cuesta morphologies. This research provides the first comprehensive assessment of the San Vito Romano landslide and demonstrates the utility of the HVSR technique in complex geological contexts. It also highlights strategies for integrating geophysical microtremor-based models with geological interpretations, offering insights for future landslide investigations.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"347 ","pages":"Article 107934"},"PeriodicalIF":6.9,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A general solution for groundwater flow around deep excavations based on non–dimensionalization techniques","authors":"Iván Alhama ,&nbsp;Salvador Navarro Carrasco ,&nbsp;José Antonio Jiménez-Valera ,&nbsp;Teresa M. Bodas Freitas ,&nbsp;Juan Manuel García Guerrero","doi":"10.1016/j.enggeo.2025.107938","DOIUrl":"10.1016/j.enggeo.2025.107938","url":null,"abstract":"<div><div>In the context of excavations, the seepage flow rate under retaining earth structures can be pre-quantified using numerical methods, analytical solutions, flow networks, or sets of abacuses. The type curves existing in the literature generally examine 2D scenarios of isotropic hydraulic conductivity in which the horizontal extension of the domain is infinite. Employing the protocol of discriminated non-dimensionalization of the governing equations and boundary conditions, the dimensionless groups that govern the solution to seepage in anisotropic scenarios can be derived. This solution is established through an unknown functional dependence by applying the pi theorem. Three scenarios are studied here: i) a finite horizontal extension of the domain, ii) a finite vertical extension of the domain, and iii) a finite domain size in the vertical and horizontal directions. Numerical simulations are used to verify the results, and new type curves are presented for a wide range of values of the deduced groups. A case study consisting of a 400 m-long excavated trench in a free aquifer is presented to illustrate and validate this study by comparing the pumping rate applied during construction with that calculated using the type curves.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"347 ","pages":"Article 107938"},"PeriodicalIF":6.9,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Formation mechanism and characteristics of longitudinal cracking on embankment with TPCTs in permafrost regions of the QTP","authors":"Qinguo Ma ,&nbsp;Yuanming Lai ,&nbsp;Xiaoxiao Luo ,&nbsp;Haiyong Chen ,&nbsp;Peifeng He ,&nbsp;Xiaojie Lin","doi":"10.1016/j.enggeo.2025.107927","DOIUrl":"10.1016/j.enggeo.2025.107927","url":null,"abstract":"<div><div>Owing to high cooling efficiency without external cooling requirement, two-phase closed thermosyphons (TPCTs) play a certain role in maintaining the stability of embankment in permafrost regions of the QTP. However, pavement disease still exists in the embankments with TPCTs along the Qinghai-Tibet Highway (QTH). We aimed to summarize the type, position and characteristics of pavement disease, and determine the cause, emergence time, and spatiotemporal evolution of longitudinal cracking. This paper involves an on-site investigation, geological radar detection and multi-physics coupling numerical simulation on the pavement disease of embankments with TPCTs along the QTH. The results show that differential settlement and longitudinal cracking are main pavement disease for embankment with vertical TPCTs (VTPCTs), while longitudinal cracking is the main form for embankment with inclined TPCTs (ITPCTs). Longitudinal cracking in embankment with ITPCTs is more developed than the embankment with VTPCTs. Longitudinal cracking at the pavement is attributed to the combination of ground temperature and soil water distributions, and the inflection point for the deformation distribution is the potential position for longitudinal cracking. In embankment with ITPCTs, longitudinal cracking is initiated at the pavement bottom near sunny side center in the 4th service year and propagates at the sunny side. However, in embankment with VTPCTs, longitudinal cracking is initiated at pavement top surface near EC in the 7th service year and propagates at both sunny and shady sides taking EC as the axis of symmetry. This analysis can provide theoretical guidance for the maintenance of the QTH, and the design for the planned Qinghai-Tibet Expressway.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"347 ","pages":"Article 107927"},"PeriodicalIF":6.9,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143035344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation on capturing bedding planes in laminated shale through advanced physics-informed image processing for multiscale geomechanical simulation","authors":"Gaobo Zhao ,&nbsp;Mindi Ruan ,&nbsp;Deniz Tuncay ,&nbsp;Xin Li","doi":"10.1016/j.enggeo.2025.107929","DOIUrl":"10.1016/j.enggeo.2025.107929","url":null,"abstract":"<div><div>Shale is characterized by its laminated and fissile nature, consisting of numerous thin layers that easily split along bedding planes. Traditional geomechanical simulations often simplify shale's complex structure by representing bedding planes as continuous and equidistant. While this approach is numerically efficient and useful for approximating general shale behavior, it limits our understanding of the shale's true mechanical response to mining-induced stress. This study proposes an advanced physics-informed image processing method to capture bedding planes across different orientations, scales, and shale types. The method includes five procedures: 1) projection transfer, where a 3D cylinder is projected onto a 2D image; 2) edge detection, where physics-informed edges are detected to obtain bedding plane pixels; 3) clustering, where bedding plane pixels are clustered to form bedding plane lines; 4) representation of bedding planes; and 5) feature extraction of bedding planes. Our method effectively captures bedding planes across different orientations (0°, 45°, and 90°), scales (interim bedding planes at the laboratory scale and ordinary bedding planes at the rock mass scale), and shale types (Opalinus shale, sandy shale, gray shale, black shale, and carbonaceous shale). The geometric information extracted from the bedding planes—including coordinates, number, spacing, length, and distribution characteristics—has been summarized into a comprehensive database for different shales at different scales. The results show that: at the laboratory scale, the captured interim bedding planes are neither continuous nor equidistant. Their lengths follow a log-normal distribution, with the mean length (LN) ranging from 1.227 to 1.823 and the standard deviation (LN) varying between 1.069 and 5.062. The fitting statistical parameters, including the mean and standard deviation of this distribution, have been summarized. At the rock mass scale, the ordinary bedding planes are continuous but not equidistant. Successful multiscale geomechanical simulations in UDEC and FLAC3D were conducted to model uniaxial compression tests at the laboratory scale and shale roof failure at the entry scale, calibrated using laboratory and field observations.</div></div>","PeriodicalId":11567,"journal":{"name":"Engineering Geology","volume":"347 ","pages":"Article 107929"},"PeriodicalIF":6.9,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143035342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}