TY - JOUR AU - Besharatinezhad, Ali AU - Török, Ákos TI - Numerical simulation of P and S wave propagation in porous and low porosity carbonate rocks: laboratory tests, automatic P and S waves detection and FLAC3D simulation JF - BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT J2 - B ENG GEOL ENVIRON VL - 83 PY - 2024 IS - 8 PG - 14 SN - 1435-9529 DO - 10.1007/s10064-024-03817-4 UR - https://m2.mtmt.hu/api/publication/35159591 ID - 35159591 N1 - Export Date: 5 August 2024 Correspondence Address: Török, Á.; Department of Engineering Geology and Geotechnics, Muegyetem rkp 3, Hungary; email: torok.akos@emk.bme.hu Funding details: Nemzeti Kutatási, Fejlesztési és Innovaciós Alap, NKFIA, K 116532 Funding details: Nemzeti Kutatási, Fejlesztési és Innovaciós Alap, NKFIA Funding text 1: The research was partly funded by project no. BME-NVA-02 (Ministry of Innovation and Technology of Hungary from the National Research, Development and Innovation Fund), under the TKP2021 funding scheme. The same office provided support from a research grant to \\u00C1.T (ref. no. K 116532), which is also appreciated. AB - This study presents laboratory measurements of P and S wave velocities of two carbonate rocks (porous limestone and yellow cemented limestone). The experimental results were validated and compared with the numerical simulation outputs using the 3D Fast Lagrangian Analysis of Continua software (FLAC3D). The main aim of this study is to evaluate the effect of frequency and mode of emission on ultrasonic pulse velocity (UPV) by applying an automatic method for the determination of P and S wave velocities. Based on the results, automatic detection of UPV can provide reliable outputs. The difference between numerical simulation results and laboratory measurement in terms of P and S wave velocities was, on average, around 7%, suggesting the applicability of the automatic detection method. Our study implies less noise in the perfect shear (PS) mode than in the single zone (SZ) emission mode. In summary, higher frequencies and the PS mode of emission are recommended. © The Author(s) 2024. LA - English DB - MTMT ER - TY - JOUR AU - Besharatinezhad, Ali AU - Török, Ákos TI - The Effect of Freeze-thaw on Mechanical and Ultrasonic Properties of Hungarian Oolitic Stones JF - PERIODICA POLYTECHNICA-CIVIL ENGINEERING J2 - PERIOD POLYTECH CIV ENG VL - 68 PY - 2024 IS - 3 SP - 1013 EP - 1020 PG - 8 SN - 0553-6626 DO - 10.3311/PPci.23268 UR - https://m2.mtmt.hu/api/publication/34962189 ID - 34962189 N1 - Export Date: 15 July 2024 Correspondence Address: Török, Á.; Department of Engineering Geology and Geotechnics, Műegyetem rkp. 3, Hungary; email: torok.akos@emk.bme.hu LA - English DB - MTMT ER - TY - JOUR AU - Fradj, Nourhen AU - Török, Ákos AU - Kádár, István TI - Biopolymers in geotechnical engineering for soil improvement JF - POLLACK PERIODICA: AN INTERNATIONAL JOURNAL FOR ENGINEERING AND INFORMATION SCIENCES J2 - POLLACK PERIODICA VL - 19 PY - 2024 IS - 2 SP - 82 EP - 86 PG - 5 SN - 1788-1994 DO - 10.1556/606.2023.00937 UR - https://m2.mtmt.hu/api/publication/34962272 ID - 34962272 AB - Several biopolymer applications in geotechnical engineering have been adopted in recent years, notably dust control, soil strengthening, and erosion control. Although biopolymer soil treatment approaches can assure engineering efficiency while satisfying environmental protection standards, this technology requires more validation regarding site adaptability, durability, and economic feasibility. The influence of biopolymers on soil behavior is discussed within geotechnical engineering applications and practices, including soil consistency limits, strength and deformation parameters, hydraulic conductivity, soil-water properties, and erosion prevention. LA - English DB - MTMT ER - TY - JOUR AU - Józsa, Sándor AU - Pintér, Farkas AU - Török, Ákos AU - Heinrich-Tamaska, Orsolya Mariann TI - Habarcsok a Keszthely-fenékpusztai késő római erődből: a petrográfiai-geokémiai és mérnökgeológiai vizsgálatok eredményei [Mortar samples from the Late Roman fortress of Keszthely-Fenékpuszta: results of petrographic-geochemical and engineering geological analyses] JF - ARCHEOMETRIAI MŰHELY J2 - ARCHEOMETRIAI MŰHELY VL - 21 PY - 2024 IS - 2 SP - 161 EP - 182 PG - 22 SN - 1786-271X DO - 10.55023/issn.1786-271X.2024-014 UR - https://m2.mtmt.hu/api/publication/34763422 ID - 34763422 N1 - in Hungarian with English abstract AB - The Roman fortress of Keszthely-Fenékpuszta, built in the 4th century AD, was located at the western edge of Lake Balaton on a peninsula bordered by open water and marshy peat bogs. The well-protected fortification played a significant infrastructural role, due to the fact that the lake could be crossed here along a main north-south road of Pannonia. Archaeological excavations started in 2009 had the primary goal to clarify the location, floor plan and dating of individual buildings (nos. 24, 25 and 27). Based on petrographic, geochemical, and engineering geological investigations of mortars used in the constructions, we were able to gain insight into the possibilities of answering certain archaeological questions with geoarchaeometric methods. Mortar samples were systematically collected from the different locations representing the functions and construction phases. Based on the archaeological research three chronological groups (I.-III: end of 3rd c. to early 7th c. AD) were distinguished; two of them belong to the late Roman Period (I.-II.) and one (III.) to the Migration Period. The aggregates of the mortars were analyzed by polarized light microscopy and thermoanalytical method. The chemical examination of the binder was carried out by scanning electron microscopy. Additionally, water absorption, density and compressive strength of the mortars were also determined. Based on the results, we can conclude that the mortars of all three periods are of air lime nature containing Mg and Si impurities and both the binders and additives were produced using local raw materials rich in dolomite components. The higher compressive strength values of the mortars of the 3rd period (late 5th to early 7th c. AD) are probably due to the slightly different composition of the binder, or they can also be explained by the static role of the selected pillars. © by the author(s) LA - Hungarian DB - MTMT ER - TY - CHAP AU - Tarifard Karvigh, Abolfazl AU - Török, Ákos AU - Görög, Péter ED - Tomás, Roberto ED - Cano, Miguel ED - Riquelme, Adrián ED - Pastor, José Luis ED - Benavente, David ED - Ordóñez, Salvador TI - A new visco-elastoplastic model for modeling the creep behavior of soft rocks T2 - New Challenges in Rock Mechanics and Rock Engineering PB - CRC Press CY - London SN - 9781032551449 PY - 2024 SP - 676 EP - 682 PG - 7 DO - 10.1201/9781003429234-100 UR - https://m2.mtmt.hu/api/publication/35172393 ID - 35172393 N1 - Conference code: 315419 Export Date: 16 August 2024 AB - The creep behavior of rocks significantly affects the long-term stability of underground spaces. This phenomenon becomes more remarkable in the case of soft rocks, deep underground construction, and rocks subjected to high stresses. A better understanding of the creep behavior of rocks is crucial for the analysis of the time-dependent behavior of rocks. In this study, a new creep constitutive model is proposed by replacing a Newtoniandashpot in the Burger model with the fractional derivative dashpot and introducing a visco plastic element to model the accelerated phase of rock creep. The proposed model is validated by the creep test results of soft rocks, which shows that this model can comprehensively describe rock creep characteristics. © 2024 The Author(s). LA - English DB - MTMT ER - TY - JOUR AU - Tarifard Karvigh, Abolfazl AU - Török, Ákos AU - Görög, Péter TI - Fractional Derivative-based Burger Creep Model for Soft Rocks and its Verification Using Tunnel Monitoring Results and Experimental Data JF - ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING J2 - ARAB J SCI ENG PY - 2024 PG - 12 SN - 2193-567X DO - 10.1007/s13369-024-09740-w UR - https://m2.mtmt.hu/api/publication/35562896 ID - 35562896 N1 - Correspondence Address: Tarifard, A.; Department of Engineering Geology and Geotechnics, Műegyetem Rkp. 3, Hungary; email: abolfazl.tarifard.karvigh@emk.bme.hu Funding details: Nemzeti Kutatási, Fejlesztési és Innovaciós Alap, NKFIA, TKP-6-6/PALY-2021 Funding text 1: The support provided by the Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Fund, financed under the TKP2021-NVA funding scheme (project no. TKP-6-6/PALY-2021), is acknowledged. AB - Considering the creep behavior of soft and weak rocks is critical for analyzing the long-term stability of underground constructions. This paper introduces a novel creep constitutive model to characterize the creep behavior of rocks under uniaxial and triaxial stress states. The fractional derivative Abel dashpot was used to improve the Burger model, and a viscoplastic component was added in series with the modified Burgers model to replicate the tertiary phase of rock creep. The effectiveness of the model was verified using creep test data from various soft rocks and monitoring measurements from a tunnel excavated in heavily jointed weak rock masses. Furthermore, a sensitivity analysis was carried out to assess the impact of the model parameters on creep deformation, and a comparative study was performed to evaluate the efficacy of the suggested model in modeling the accelerated stage of rock creep compared with some existing models. The strong agreement observed between the calculated results and both the creep test data and tunnel monitoring measurements underscores the accuracy and validity of the proposed model. The comparative analysis further revealed that the proposed model offers the highest fitting efficiency for describing the tertiary stage of rock creep. These findings suggest that the model effectively captures the creep behavior of rocks and precisely represents the entire creep process. LA - English DB - MTMT ER - TY - JOUR AU - Tarifard Karvigh, Abolfazl AU - Török, Ákos AU - Görög, Péter TI - Review of the creep constitutive models for rocks and the application of creep analysis in geomechanics JF - ROCK MECHANICS AND ROCK ENGINEERING J2 - ROCK MECH ROCK ENG VL - 57 PY - 2024 IS - 10 SP - 7727 EP - 7757 PG - 31 SN - 0723-2632 DO - 10.1007/s00603-024-03939-x UR - https://m2.mtmt.hu/api/publication/34962252 ID - 34962252 N1 - Export Date: 10 June 2024 CODEN: RMRED Correspondence Address: Tarifard, A.; Department of Engineering Geology and Geotechnics, Műegyetem Rkp. 3, Hungary; email: abolfazl.tarifard.karvigh@emk.bme.hu Funding details: Nemzeti Kutatási, Fejlesztési és Innovaciós Alap, NKFIA, TKP-6-6/PALY-2021 Funding details: Nemzeti Kutatási, Fejlesztési és Innovaciós Alap, NKFIA Funding text 1: The authors acknowledge the support provided by the Ministry of Culture and Innovation of Hungary from the National Research, Development, and Innovation Fund, financed under the TKP2021-NVA funding scheme (project no. TKP-6-6/PALY-2021). The funding of the Stipendium Hungaricum PhD Scholarship is also appreciated. AB - The creep behavior of rocks has been broadly researched because of its extensive application in geomechanics. Since the time-dependent stability of underground constructions is a critical aspect of geotechnical engineering, a comprehensive understanding of the creep behavior of rocks plays a pivotal role in ensuring the safety of such structures. Various factors, including stress level, temperature, rock damage, water content, rock anisotropy, etc., can influence rocks’ creep characteristics. One of the main topics in the creep analysis of rocks is the constitutive models, which can be categorized into empirical, component, and mechanism-based models. In this research, the previously proposed creep models were reviewed, and their main characteristics were discussed. The effectiveness of the models in simulating the accelerated phase of rock creep was evaluated by comparing their performance with the creep test results of different types of rocks. The application of rock’s creep analysis in different engineering projects and adopting appropriate creep properties for rock mass were also examined. The primary limitation associated with empirical and classical component models lies in their challenges when it comes to modeling the tertiary phase of rock creep. The mechanism-based models have demonstrated success in effectively simulating the complete creep phases; nevertheless, additional validation is crucial to establish their broader applicability. However, further investigation is still required to develop creep models specific to rock mass. In this paper, we attempted to review and discuss the most recent studies in creep analysis of rocks that can be used by researchers conducting creep analysis in geomechanics. LA - English DB - MTMT ER - TY - CONF AU - Zenah, Jalal AU - Görög, Péter AU - Török, Ákos TI - Singular and twin tunnels behaviour: the role of material properties, and cover on stability T2 - Mérnökgeológia-Kőzetmechanika 2024 PB - BME Geotechnika és Mérnökgeológia Tanszék T3 - Mérnökgeológia és Kőzetmechanika Kiskönyvtár ; 27. PY - 2024 SP - 59 EP - 70 PG - 12 UR - https://m2.mtmt.hu/api/publication/35569077 ID - 35569077 LA - English DB - MTMT ER - TY - JOUR AU - Zomborácz, Tamás AU - Török, Ákos TI - Geology, Architecture and Archaeological Overview of Four Ancient Rock-Cut Tombs in the Theban Necropolis at el-Khokha (Egypt) JF - ÉPÍTÉS-ÉPÍTÉSZETTUDOMÁNY J2 - ÉPÍTÉS-ÉPÍTÉSZETTUDOMÁNY VL - 52 PY - 2024 IS - 3-4 SP - 175 EP - 211 PG - 37 SN - 0013-9661 DO - 10.1556/096.2024.00122 UR - https://m2.mtmt.hu/api/publication/35578874 ID - 35578874 N1 - Export Date: 19 November 2024 Correspondence Address: Török, Á.; Department of Engineering Geology and Geotechnics, K. Mf. 10, Műegyetem rkp. 3, Hungary; email: torok.akos@emk.bme.hu Funding details: Tempus Közalapítvány, TPF Funding text 1: The financial support of the doctoral fellowship DK\\u00D6P-23 to Tam\\u00E1s Zombor\\u00E1cz (grant no. 2020-2.1.1-ED-2023-00239) is acknowledged. The fieldwork conducted at the area would have been impossible without the support of the National Scientific Research Fund of Hungary (OTKA) and the research scholarship granted by Tempus Public Foundation. We are grateful to the field director of the area of TT 184, Zolt\\u00E1n Imre F\\u00E1bi\\u00E1n for providing us with the research documentation archive and for his thoughtful review of the manuscript. We thank Sayed El Qurany, Bori N\\u00E9meth, D\\u00F3ra Zsom and G\\u00E1bor Somodi for their advice and assistance whilst working at el-Khokha. AB - Egyptian Dynasties, noble families and privileged people used the Theban Mountain for funerary purposes. The study site is located on the west bank of the River Nile in Upper Egypt, near Luxor. The use of this necropolis was long-lasting. Four tombs were studied, representing the late Old Kingdom, the First Intermediate Period and the 18th and 19th Dynasties of the New Kingdom. The tombs were reused as dwellings till the end of the past century, reflected in the alteration of the original structures. The paper describes the complex excavation history of the Theban necropolis. It provides an overview of the geological conditions of the region with a special focus on Tarawan Chalk, which is the host formation of the tombs, and briefly describes the overlaying Esna Shale and Thebes Limestone formations. The most important rock properties and their field appearance are also considered. Besides geological conditions, the current study includes the archaeological and architectural description of the four studied tombs, TT 184, TT 185, TT 412 and TT 413 (TT=Theban Tomb). It explains these tombs’ complex geometries and architectural elements with ground plans and cross-sections. The current conditions of the interiors and exteriors of the tombs, as well as the preservation of wall paintings, are richly illustrated. An overview of possible preservation measures and protection of these tombs is also given, aiming to provide data for further archaeological works and restoration projects. © 2024 The Authors. LA - English DB - MTMT ER - TY - JOUR AU - Davarpanah, Seyed Morteza AU - Sharghi, Mohammad AU - Narimani Ghourtlar, Samad AU - Török, Ákos AU - Vásárhelyi, Balázs TI - Brittle-ductile transition stress of different rock types and its relationship with uniaxial compressive strength and Hoek–Brown material constant (mi) JF - SCIENTIFIC REPORTS J2 - SCI REP VL - 13 PY - 2023 IS - 1 SN - 2045-2322 DO - 10.1038/s41598-023-28513-3 UR - https://m2.mtmt.hu/api/publication/33581825 ID - 33581825 N1 - Funding Agency and Grant Number: Ministry of Innovation and Technology of Hungary from the National Research, Development and Innovation Fund [TKP2021] Funding text: AcknowledgementsThe research reported in this paper is part of Project No. BME-NVA-02, implemented with the support provided by the Ministry of Innovation and Technology of Hungary from the National Research, Development and Innovation Fund, financed under the TKP2021 funding scheme. AB - Rocks deformed at low confining pressure are brittle, which means that after peak stress, the strength declines to a residual value established by sliding friction. The stress drop is the variation between peak and residual values. But no tension reduction takes place at high confining pressure. A proposed definition of the brittle-ductile transition is the transition pressure at which no loss in strength takes place. However, studies that consider information about the brittle-ductile transition, the criterion's range of applicability, how to determine mi, and how confining pressures affect m i 's values are scarce. This paper aims to investigate the link between brittle-ductile transition stress, uniaxial compressive strength and Hoek–Brown material constant ( m i ) for different kinds of rock. It is essential to accurately determine the brittle-ductile transition stress to derive reliable values for m i . To achieve this purpose, a large amount of data from the literature was chosen, regression analysis was carried out, and brittle-ductile transition stress (σ TR ) was determined based on the combination of Hoek–Brown failure criteria and the recently used brittle-ductile transition stress limit of Mogi. Moreover, new nonlinear correlations were established between uniaxial compressive strength and Hoek–Brown material constant ( m i ) for different igneous, sedimentary and metamorphic rock types. Regression analyses show that the determination coefficient between σ TR and UCS for gneiss is 0.9, sandstone is 0.8, and shale is 0.74. Similarly, the determination coefficient between σ TR and m i for gneiss is 0.88. The correlation between Hoek–Brown material constant ( m i ) and σ TR was not notable for sedimentary and metamorphic rocks, probably due to sedimentary rocks' stratification and metamorphic ones' foliation. LA - English DB - MTMT ER -