Search

Interferometric synthetic aperture radar (InSAR) is a remote sensing tool used for monitoring urban areas affected by geological hazards. Here we analysed the effectiveness of stabilization works on a slow-moving landslide in Arcos de La Frontera (Cádiz, Spain) using a persistent scatterer interferometric approach. The works consisted on jet grouting of cement-based injections and were applied locally to stabilize the most damaged neighbourhood. We processed a large stack of Sentinel-1 SAR satellite acquisitions covering the period January, 2016, to March, 2023, and obtained surface velocity and displacement trends measured along the line of sight (LOS) of the satellite on both ascending and descending orbits. The results show a clear deceleration of the landslide head after mid-2018, suggesting the local stabilization works were effective after that time. Prior to mid-2018, the maximum LOS velocity of the landslide head was 2.2 cm/year in ascending orbit and 1.3 cm/year in the descending orbit, decreasing to 0.43 cm/year and 0.23 cm/year, respectively. The InSAR results were compared to in-situ monitoring data and revealed that the extent of the stabilization has influenced a much larger area beyond the zone of the local interventions. Overall, InSAR has proved a powerful and versatile tool to be implemented in operational geotechnical monitoring. [ABSTRACT FROM AUTHOR]

Monitoring natural slopes, embankments, and unstable slopes is crucial to reducing predisposition to mass movements, especially in areas with geotechnical instability and high rainfall. This study proposes a methodology to identify geotechnical and pluviometric triggers of mass movements in railway slopes. It involves registering slopes and embankments along the railroad, recording accumulated rainfall indices, and documenting associated accidents. The experimental program included a cadastral survey at a pilot site on the MRS company's railway network in the Paraopeba branch, Minas Gerais, Brazil. Surface and subsurface drainage conditions, anthropic interventions, and modifications affecting slope stability were also examined. Additionally, the history of accidents involving geotechnical and regional rainfall indices were incorporated to identify potential triggering events for mass movements. The study found a good correlation between landslide records and geotechnical risk mapping but a low correlation between landslide records and rainfall isohyets. The latter result is attributed to the low density and poor distribution of rainfall data and active pluviometers in the region. Overall, understanding the geological–geotechnical characteristics of slopes and the correlation between accidents and rainfall indices provides valuable insights for predicting potential landslide occurrences. [ABSTRACT FROM AUTHOR]

The Paper presents the results, interpretation and intervention measures obtained from inclinometer monitoring performed for a retaining structure built for the accomplishment of a hydrotechnical structure on Jiu River. The accomplishment of the hydrotechnical structure on Jiu River required a retaining structure of approximately 100m length adjacent to the slope which is crossed by the railway line Tg. Jiu - Simeria. The retaining structure made of 1500mm piles also keeps in safe condition the adjacent E79 Road section.

The construction of tunnels in conditions of dense urban development affects buildings, structures, and engineering communications located at the surface. In this work, through dispersion analysis, factors influencing the settlement of the earth's surface and buildings during tunneling were selected. Subsequently, a model based on statistically significant parameters that can predict deformations at the pre-design stage was created. This research was conducted using data from geotechnical monitoring obtained during the construction of underground structures, with information about the technological parameters of shield tunneling in the construction of the single-track lines of the Moscow Metro using TBM with face-support pressure and engineering–geological conditions. In the obtained model, there is a clear dependency between the additional displacement of the monitoring object located above the projected tunnel and the average face-support pressure causing the mentioned deformations. The response is also affected by the soil deformation model at the tunnel face, the depth of the tunnel, and the soil excavation for the installation of one ring. [ABSTRACT FROM AUTHOR]

Monitoring erosion is an important part of understanding the causes of this geotechnical and geological phenomenon. In order to monitor them, it is necessary to develop equipment that is sophisticated enough to resist the sun and water without damage, that is self-mechanized, and that can support the amount of data collected. This article introduces a rain-triggered field erosion monitoring device composed of three main modules: control, capture, and sensing. The control module comprises both hardware and firmware with embedded software. The capture module integrates a camera for recording, while the sensing module includes rain sensors. By filming experimental soil samples under simulated rain events, the device demonstrated satisfactory performance in terms of activation and deactivation programming times, daytime image quality without artificial lighting, and equipment protection. The great differences about this monitoring device are its ease of use, low cost, and the quality it offers. These results suggest its potential effectiveness in capturing the progression of field erosive processes. [ABSTRACT FROM AUTHOR]

Everything in the world is about risk, from individual decisions to global manipulations, which is of fundamental importance in a nuclear power plant environment. The question is whether, in a given situation, this risk is acceptable or no longer acceptable. In some respects, the risk analysis applied to construction projects differs from the risk analysis applied to nuclear installations. For nuclear installations, the risk as such is primarily nuclear risk. In view of this, for investments involving a nuclear installation, the risk analysis to be carried out must be carried out at two separate levels. The first level is the traditional construction risk analysis, and then as a second level, each risk item should be classified from a nuclear risk point of view. In this study, the nuclear exposure of construction risks will be presented. [ABSTRACT FROM AUTHOR]

Thermo-poro-mechanical responses along sliding zone/surface have been extensively studied. However, it has not been recognized that the potential contribution of other crucial engineering geological interfaces beyond the slip surface to progressive failure. Here, we aim to investigate the subsurface multi-physics of reservoir landslides under two extreme hydrologic conditions (i.e. wet and dry), particularly within sliding masses. Based on ultra-weak fiber Bragg grating (UWFBG) technology, we employ special-purpose fiber optic sensing cables that can be implanted into boreholes as “nerves of the Earth” to collect data on soil temperature, water content, pore water pressure, and strain. The Xinpu landslide in the middle reach of the Three Gorges Reservoir Area in China was selected as a case study to establish a paradigm for in situ thermo-hydro-poro-mechanical monitoring. These UWFBG-based sensing cables were vertically buried in a 31 m-deep borehole at the foot of the landslide, with a resolution of 1 m except for the pressure sensor. We reported field measurements covering the period 2021 and 2022 and produced the spatiotemporal profiles throughout the borehole. Results show that wet years are more likely to motivate landslide motions than dry years. The annual thermally active layer of the landslide has a critical depth of roughly 9 m and might move downward in warmer years. The dynamic groundwater table is located at depths of 9–15 m, where the peaked strain undergoes a periodical response of leap and withdrawal to annual hydrometeorological cycles. These interface behaviors may support the interpretation of the contribution of reservoir regulation to slope stability, allowing us to correlate them to local damage events and potential global destabilization. This paper also offers a natural framework for interpreting thermo-hydro-poro-mechanical signatures from creeping reservoir bank slopes, which may form the basis for a landslide monitoring and early warning system.

We present an in-depth landslide map of the ‘Umka’ landslide near Belgrade, Serbia, at a scale of 1:5000. The map delineates elements at risk, primarily buildings and road infrastructure impacted by the landslide displacements of several cm per year, introduced during frequent reactivation stages. The Main map results from a survey of over 350 buildings and more than 7 km of state and local roads. The acquisition techniques included engineering geological field mapping, building survey, and visual interpretation of high-resolution UAV images. This is the first case of an integrated approach to mapping elements at risk within an urbanized active landslide in Serbia. Presently, over 490 people continue to reside at the site, facing daily landslide risks. This research and map hold substantial value for local authorities and decision-makers, providing a basis for conducting landslide risk analyses and implementing effective risk mitigation strategies or remedial measures.

Anti-slide piles are one of the most important reinforcement structures against landslides, and evaluating the working conditions is of great significance for landslide mitigation. The widely adopted analytical methods of pile internal forces include cantilever beam method and elastic foundation beam method. However, due to many assumptions involved in calculation, the analytical models cannot be fully applicable to complex site situations, e.g. landslides with multi-sliding surfaces and pile-soil interface separation as discussed herein. In view of this, the combination of distributed fiber optic sensing (DFOS) and strain-internal force conversion methods was proposed to evaluate the working conditions of an anti-sliding pile in a typical retrogressive landslide in the Three Gorges reservoir area, China. Brillouin optical time domain reflectometry (BOTDR) was utilized to monitor the strain distribution along the pile. Next, by analyzing the relative deformation between the pile and its adjacent inclinometer, the pile-soil interface separation was profiled. Finally, the internal forces of the anti-slide pile were derived based on the strain-internal force conversion method. According to the ratio of calculated internal forces to the design values, the working conditions of the anti-slide pile could be evaluated. The results demonstrated that the proposed method could reveal the deformation pattern of the anti-slide pile system, and can quantitatively evaluate its working conditions.

Defects in cast-in-situ piles have an adverse impact on load transfer at the pile‒soil interface and pile bearing capacity. In recent years, thermal integrity profiling (TIP) has been developed to measure temperature profiles of cast-in-situ piles, enabling the detection of structural defects or anomalies at the early stage of construction. However, using this integrity testing method to evaluate potential defects in cast-in-situ piles requires a comprehensive understanding of the mechanism of hydration heat transfer from piles to surrounding soils. In this study, small-scale model tests were conducted in laboratory to investigate the performance of TIP in detecting pile integrity. Fiber-optic distributed temperature sensing (DTS) technology was used to monitor detailed temperature variations along model piles in sand. Additionally, sensors were installed in sand to measure water content and matric suction. An interpretation method against available DTS-based thermal profiles was proposed to reveal the potential defective regions. It shows that the temperature difference between normal and defective piles is more obvious in wet sand. In addition, there is a critical zone of water migration in sand due to the water absorption behavior of cement and temperature transfer-induced water migration in the early-age concrete setting. These findings could provide important insight into the improvement of the TIP testing method for field applications.

Monitoring natural slopes, embankments, and unstable slopes is crucial to reducing predisposition to mass movements, especially in areas with geotechnical instability and high rainfall. This study proposes a methodology to identify geotechnical and pluviometric triggers of mass movements in railway slopes. It involves registering slopes and embankments along the railroad, recording accumulated rainfall indices, and documenting associated accidents. The experimental program included a cadastral survey at a pilot site on the MRS company’s railway network in the Paraopeba branch, Minas Gerais, Brazil. Surface and subsurface drainage conditions, anthropic interventions, and modifications affecting slope stability were also examined. Additionally, the history of accidents involving geotechnical and regional rainfall indices were incorporated to identify potential triggering events for mass movements. The study found a good correlation between landslide records and geotechnical risk mapping but a low correlation between landslide records and rainfall isohyets. The latter result is attributed to the low density and poor distribution of rainfall data and active pluviometers in the region. Overall, understanding the geological–geotechnical characteristics of slopes and the correlation between accidents and rainfall indices provides valuable insights for predicting potential landslide occurrences.

The article presents the results of a detailed spatiotemporal comparative analysis of the data obtained by platform and bottom inclinometers at the V. Filanovsky field. The slope spectra obtained by the platform inclinometers fundamentally do not coincide with the data of the bottom sensors. It turned out that platform inclinometers effectively detect exogenic deformation effects and hardly identify deformations of the seabed associated with field development processes. Using the geomechanical poroelastic inclusion model, the authors mathematically modeled the spatial distribution of the seabed slopes during a period of intensive water injection into the developed reservoir. The proposed model shows that only the system of bottom inclinometers is a geodynamic monitoring element. It is concluded that sensor systems installed only on the platforms themselves (accelerometers, inclinometers, GNSS) do not pertain to geodynamic monitoring systems (geodynamic survey areas) and cannot ensure safe and rational subsurface use. [ABSTRACT FROM AUTHOR]

Anthropogenic activity-induced sinkholes pose a serious threat to building safety and human life nowadays. Real-time detection and early warning of sinkhole formation are a key and urgent problem in urban areas. This paper presents an experimental study to evaluate the feasibility of fiber optic strain sensing nerves in sinkhole monitoring. Combining the artificial neural network (ANN) and particle image velocimetry (PIV) techniques, a series of model tests have been performed to explore the relationship between strain measurements and sinkhole development and to establish a conversion model from strain data to ground settlements. It is demonstrated that the failure mechanism of the soil above the sinkhole developed from a triangle failure plane to a vertical failure plane with increasing collapse volume. Meanwhile, the soil-embedded fiber optic strain sensing nerves allowed deformation monitoring of the ground soil in real time. Furthermore, the characteristics of the measured strain profiles indicate the locations of sinkholes and the associated shear bands. Based on the strain data, the ANN model predicts the ground settlement well. Additionally, micro-anchored fiber optic cables have been proven to increase the soil-to-fiber strain transfer efficiency for large deformation monitoring of ground collapse.

The risks of reducing the stability of buildings and structures are increasing in conditions of climate change and the active development of the territories under the influence of natural and anthropogenic factors. The main causes include: loss of the bearing capacity of frozen soils, various geocryological processes, errors at the stages of design, construction and operation of facilities. Main actual task when conducting research and industrial operations in the cryolithozone is monitoring and, if necessary, managing thermal processes in the permafrost layers interacting with facilities. In this article the obtained positive experience of various technologies applying at various stages of the life cycle of civil and industrial facilities was analyzed. It helps to eliminate or prevent the structure deformation or destruction under the influence of climate change. The methods of permafrost stabilization used in the oil and gas industry in process of industrial infrastructure development of the fields have been studied – freezing (cooling) of foundation soils during construction on heterogeneous foundations. The solution to the problems of minimizing accidents when locating production wells in the permafrost zone of the Yamal Peninsula is considered using the example of an oil and gas condensate field and restoring of the temperature regime of perennial unfrozen soils in areas of valve units of main gas pipelines. An assessment of methods used to maintain the industrial and residential infrastructure within the northern municipalities that ensure the functioning of the fuel and energy complex of the Russian Federation in the Arctic was made. The systems of thermal stabilization in the foundations of buildings and industrial facilities built and operated on permafrost soils allow to fully use the high strength and low deformability of frozen grounds. It ensures the state's long-term plans of the industrial development in the Arctic.

The construction of tunnels in conditions of dense urban development affects buildings, structures, and engineering communications located at the surface. In this work, through dispersion analysis, factors influencing the settlement of the earth’s surface and buildings during tunneling were selected. Subsequently, a model based on statistically significant parameters that can predict deformations at the pre-design stage was created. This research was conducted using data from geotechnical monitoring obtained during the construction of underground structures, with information about the technological parameters of shield tunneling in the construction of the single-track lines of the Moscow Metro using TBM with face-support pressure and engineering–geological conditions. In the obtained model, there is a clear dependency between the additional displacement of the monitoring object located above the projected tunnel and the average face-support pressure causing the mentioned deformations. The response is also affected by the soil deformation model at the tunnel face, the depth of the tunnel, and the soil excavation for the installation of one ring.

Monitoring erosion is an important part of understanding the causes of this geotechnical and geological phenomenon. In order to monitor them, it is necessary to develop equipment that is sophisticated enough to resist the sun and water without damage, that is self-mechanized, and that can support the amount of data collected. This article introduces a rain-triggered field erosion monitoring device composed of three main modules: control, capture, and sensing. The control module comprises both hardware and firmware with embedded software. The capture module integrates a camera for recording, while the sensing module includes rain sensors. By filming experimental soil samples under simulated rain events, the device demonstrated satisfactory performance in terms of activation and deactivation programming times, daytime image quality without artificial lighting, and equipment protection. The great differences about this monitoring device are its ease of use, low cost, and the quality it offers. These results suggest its potential effectiveness in capturing the progression of field erosive processes.

For long-distance water conveyance shield tunnels in operation, the high internal water pressure may cause excessive deformation of composite linings, affecting their structural integrity and serviceability. However, the deformation and failure characteristics of lining structures under internal water pressure are not well investigated in the literature, particularly for three-layer composite linings. This study presents an in situ experimental investigation on the response of two types of composite linings (i.e. separated and combined lining structures) subjected to internal pressures, in which a fiber optic nerve system (FONS) equipped with distributed strain and displacement sensing nerves was employed to monitor the performance of the two composite linings during testing. The experimental results clearly show that the damage of the tunnel lining under different internal pressures was mainly located in the self-compaction concrete layer. The separated lining structure responded more aggressively to the variations in internal pressures than the combined one. Moreover, two evaluation indices, i.e. radial displacement and effective stiffness coefficient, are proposed for describing the changes in the structural bearing performance. The effective stiffness coefficients of the two types of lining structures were reduced by 39.4% and 29.5%, respectively. Considering the convenience of field monitoring, it is suggested that the average strains at different layers can be used as characteristic parameters for estimating the health conditions of lining structures in service. The analysis results provide a practical reference for the design and health evaluation of water conveyance shield tunnels with composite linings.

The highway section on the D3 highway Hričovské Podhradie – Žilina – Strážov was carried out on the left branch of the highway body on the overpass and on the right branch on the embankment body. The stability of the embankment body was ensured by a geosynthetics reinforced retaining wall. The retaining wall was assembled from reinforced concrete prefabs, on which the uniaxial geogrids were attached. The article presents a numerical analysis of the deformations of this reinforced structure in the profile monitored by geotechnical monitoring. The results of the numerical analysis of the deformations of the retaining wall were confronted with geotechnical monitoring measurements. Geotechnical monitoring measurements confirmed the reality of the numerical model of the retaining wall. Verification of the reality of the numerical model of the retaining wall made it possible to use this model for a parametric study of the influence of the reinforcement method on the deformation of the face of the reinforced retaining wall. In the parametric study, the effects of the change in the horizontal length and vertical spacing of the reinforcement elements, as well as their interaction with the backfill soil on the deformation values of the face of the retaining wall are analyzed.

Relevance. Determined by the need for geotechnical monitoring in the areas of distribution of permafrost soils for underground pipelines. The geotechnical system “permafrost soil – underground pipeline” is subject to the influence of exogenous geological processes during operation, cyclical changes in the state of soils of the seasonal layer of thawing and freezing, thawing of permafrost soils from the thermal effect of the pipeline, changing the plan-altitude position. The variety of schemes for interaction of the pipeline body with varieties of lithological structure of permafrost soils along the route should be worked out in detail at the design stage and also assessed in detail during geotechnical monitoring of the pipeline. The lack of regulatory requirements for the monitored parameters of underground pipelines leads to the use of non-standardized and varied monitoring networks from project to project. The lack of standard values ​​for the maximum deformations of an underground pipeline leads to the need to use calculation methods for determining the maximum deformations of the base and pipeline. The authors proposed the use of a comprehensive methodology for calculating underground pipelines, developed by employees of JSC TomskNIPIneft to determine the maximum permissible deformations of the pipeline at each point of the route with the presence of permafrost soils at the design stage, with further use of the results obtained as a controlled criterion when conducting geotechnical monitoring. Aim. To determine the controlled parameters for geotechnical monitoring of underground pipelines in the cryolithozone at the operational stage based on the application of a comprehensive methodology for calculating underground pipelines, as well as the formation of requirements for the system of information points. Methods. Review of the regulatory framework for geotechnical monitoring, analysis and evaluation of the applied methods and designs for monitoring underground pipelines, analysis of a comprehensive methodology for calculating underground pipelines in relation to the purposes of geotechnical monitoring. Results. Based on the results of the review of regulatory and technical documentation, the authors have revealed a lack of specification of methods, equipment, volume of the geotechnical monitoring network and frequency of pipeline monitoring, as well as the requirement for the use of the calculation method of limiting deformations and the lack of description of possible methods. A detailed analysis of the complex methodology for pipeline calculations, developed at JSC TomskNIPIneft, substantiates its use for geotechnical monitoring purposes, and notes the advantage of the methodology in the detail of the obtained limit values ​​of deformation with an accuracy of one meter along the axis of the pipeline route. The authors studied the methods and designs used for monitoring deformations of underground pipelines and established the compatibility of using a complex methodology with any design and method of monitoring. The paper introduces the list of the main monitored parameters and justification for the scope of the geotechnical monitoring network for underground pipelines.

Copyright of Revue Française de Géotechnique is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Engineer Military Bulletin / Muszaki Katonai Közlöny is the property of National University of Public Service and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The real-time evaluation of slope stability is a crucial technical issue in foundation excavation and slope construction. However, conventional monitoring methods often fall short of achieving real-time and accurate measurements, which poses challenges to the timely assessment of slope stability. To address this problem, laboratory tests and numerical simulations were jointly used to evaluate slope stability in this paper. In numerical simulations, the finite element method (FEM) results clearly illustrate the distribution and evolution of internal strain during slope excavation, and the limit equilibrium method (LEM) calculates changes in the safety factor. In laboratory tests, the fiber Bragg grating (FBG) sensing technology was employed to monitor the internal strain of the slope in real time. The distribution characteristics of the slope internal strain field under the condition of stepped excavation were analyzed, and the feasibility of strain-based evaluation of slope stability was discussed. The measurements with FBG sensing technology agree well with the numerical simulation results, indicating that FBG can effectively monitor soil strain information. Of great significance is that the maximum horizontal strain of the slope is closely related to the safety factor and can be used to evaluate slope stability. Notably, the horizontal soil strain of the slope provides insight into both the formation and evolution of the critical sliding surface during excavation. The combination of numerical simulation and intelligent monitoring technology based on FBG proposed in this paper provides a reference for capturing strain information inside the slope and realizing real-time assessment and critical warning of slope stability. [ABSTRACT FROM AUTHOR]

The engineering geological interface is defined as the contact surfaces between two or more media in strata, as well as the transition surfaces that control the migration of three-phase matter, the change in physical states and the stability of rock and soil masses. Under the combined action of natural loads and engineering activities, they play a controlling role in the emergence, propagation, and triggering of geological disasters. How to accurately capture multifield evolution information, understand the catastrophic dynamics, and clarify the interaction mechanism of the interface are key scientific issues in the research field of geohazard mitigation and prevention. On the basis of reviewing the development history of engineering geological interface-related research areas, this paper summarizes the basic concepts, classification systems, and critical characteristics of the interface. Taking the landslides in the Three Gorges reservoir area of the Yangtze River as an example and combined with the research works of our team, we elaborated the latest research progress in multivariate characterization and evolution mechanism of engineering geological interfaces, and finally prospected the future development trends in this paper. The above review shows that the engineering geological interfaces is the critical zone inducing geological hazards, which can be divided into three types: material interface, state interface, and motion interface. By introducing fiber optic sensing and other technologies, the intelligent characterization of multivariate of engineering geological interfaces is preliminarily realized. On the basis of long-term in-situ monitoring of reservoir landslides, the disaster evolution mechanism and interface control modes are systematically summarized. According to the discipline development trend and national demand, more attention should be given to developing and building an integrated three-dimensional space-sky-surface-body monitoring network in the future, considering the characteristics of engineering geological interface. In this way, real-time acquisition and identification of thermal-hydrologic-mechanical multifield coupling information of key interfaces will be realized. By combining big data and artificial intelligence technologies, corresponding early warning and forecasting systems will be developed, so as to improve the prevention level and response capability of major geological disasters.

Abstract Geotechnical monitoring currently plays a key role in the research of the processes taking place in the ground medium and preventing hazardous events. In the case of open-pit mining, several solutions are commonly used to monitor various geotechnical parameters. However, geotechnical situation is usually assessed based on recorded values of deep and surface displacement, which allow to accurately predict landslides. The measurements are most often carried out manually, which, due to the difficult terrain conditions in the case of open-pit mining, are often timeconsuming and complicated, especially taking into account dangerous landslide movements. Therefore, in order to ensure a higher degree of safety against the risk of landslides, modern solutions are required in the field of geotechnical monitoring. This article presents modern automatic measurement techniques, compares various solutions available on the market and illustrates the benefits of their application in open-pit mining. It also discusses the expansion and modernization of the control and measurement network at KWB Turów, carried out in recent years, as well as the observational method for controlling the efficiency of stackers, developed after the installation of automated measuring stations, with its impact on the geotechnical safety of an internal waste heap. The paper as a case study presents, what a modern and effective geotechnical monitoring system should look like, which in practice will ensure continuous observation of selected parameters and enable a quick response in the event of a landslide threat. Last but not least, the author focuses on the creation of an innovative landslide early warning system, implemented at KWB Turów.

This paper sets forth a geomechanics framework for assessing the energy efficiency of rotary percussive drilling using the energy criterion, which has been proposed by Victor Oparin for volumetric destruction of high-stress rocks having nonuniform physico-mechanical properties. We review the long-term research and development in the specified area of science and technology, including research and development projects implemented at the Institute of Mining, Siberian Branch of the Russian Academy of Sciences. A new modified expression of Oparin's dimensionless energy criterion of volumetric rock destruction k is introduced. The range of in situ values is determined for the energy criterion of volumetric rock destruction at the optimized energy efficiency of rotary percussive drilling. The temporo-spatial intervals of geotechnical monitoring are found to control pneumatic drilling energy efficiency at subsoil use objects in Russia. The integrated experimental, theoretical and geotechnical approach to the comprehensive investigation of real-time processes of rock fracture in rotary percussive drilling using the energy concept possesses the necessary geomechanical performance-and-technology potential to create the next level geotechnical monitoring of drilling systems for various purposes, including determination of physico-mechanical properties and the stress-strain analysis of rock mass in full-scale drilling.

Convergence and rockmass failure are significant hazards to personnel and physical assets in underground tunnels, caverns, and mines. Mobile Laser Scanning Systems (MLS) can deliver large volumes of point cloud data at a high frequency and on a large scale. However, current change detection approaches do not deliver sufficient sensitivity and precision for real-time performance on large-scale datasets. We present a novel, octree-based computational framework for intra-voxel statistical inference change detection and deformation analysis. Our approach exploits high-density MLS data to test for statistical significance for appearing objects caused by rockfall and for low-magnitude deformations, such as convergence. In field tests, our method detects rock falls with side lengths as small as 0.03 m and convergence as low as 0.01 m, or 0.5% wall-to-wall strain. When compared against a state-of-the-art multi-scale model-to-model cloud comparison (M3C2)-based method, ours is less sensitive to noisy data and parameter selection while also requiring fewer parameters. Most notably, our method is the only one tested that can perform real-time change detection on large-scale datasets on a single processor thread. Our method achieves a computational improvement of 50 times over single-threaded M3C2 while maintaining a performance scalability that is four times greater with dataset size. Our framework shows significant potential to enable accurate real-time geotechnical monitoring of large-scale underground spaces. [ABSTRACT FROM AUTHOR]

Worldwide, landslides are one of the most significant natural hazards regarding human and material losses. Landslides can significantly increase road construction or maintenance costs. This paper summarises the slope stability problems associated with the design and execution of road cuts in landslide areas. The case study investigated East Slovakia in central Europe. Slope stability failures are discussed in detail in the article. Fossil shear surfaces were identified during road construction in layered or laminated clays. Moreover, limit equilibrium calculations and finite element analysis results are compared with the measurements during geotechnical monitoring. Calculations are consistent with measurements and support the presented concept of slope movements in overconsolidated clays in the presence of fossil landslides. [ABSTRACT FROM AUTHOR]

Geotechnical engineering is characterized by many uncertainties, including soil material properties, environmental effects, and engineering design and construction, which bring a significant challenge to geotechnical monitoring. However, conventional sensors with several inherent limitations, such as electromagnetic interference, signal loss in long-distance transmission, and low durability in harsh environments cannot fully meet current monitoring needs. Recently, fiber optic sensing technologies have been successfully applied in geotechnical monitoring due to the significant advantages of anti-electromagnetic interference, stable signal long-distance transmission, high durability, high sensitivity, and lightweight, which can be considered an ideal replacement for conventional sensors. In this paper, the working principle of different fiber optic sensing technologies, the development of fiber optic-based sensors, and the recent application status of these sensing technologies for geotechnical monitoring were comprehensively reviewed and discussed in detail. Finally, the challenges and countermeasures of the sensing technologies in geotechnical monitoring were also presented and discussed. [ABSTRACT FROM AUTHOR]

Tunneling in urban conditions requires costly measures, in order to ensure the safety of existing buildings. On average, there are up to 17–20 buildings per 1 km of Moscow Subway Lines under construction. Analysis and comparison of geotechnical monitoring data and results of geotechnical estimations for underground construction using cut-and-cover and tunneling methods in conditions of high-density urban area shows an unsatisfactory correlation between estimated and actual data. This can be described in the following way: insufficient geotechnical survey data; discrepancy between the accepted estimation model and the actual behavior of soil under load; insufficient qualification of the construction workers; and overcutting. The study was aimed at solving the urgent scientific and engineering problem of determining the characteristics of overcutting during mechanized tunnel boring. At the first stage, the investigations were aimed at identifying the key reasons and factors which determine the quantitative parameters of overcutting in urban underground construction by tunneling. These factors include the following: mismatch between the cutting diameter and the outer lining diameter; displacement of the soil mass in front of the face; incomplete grouting of voids beyond the lining; incomplete filling of beyond-shield voids with clay mortar or slow-curing grouting mortar or no filling at all; and human factor (low qualifications of personnel). The overcutting coefficient was determined on the basis of the proposed empirical dependence of its values with regard to the depth of tunneling. The experimental data allowed the depth dependence of the overcutting coefficient for different tunneling depths to be defined, as well as for tunnel diameters from 4 to 10 meters in the case of mechanized tunnel boring machine (TBM) using the earth pressure balanced tunneling method. The practical importance of the studies consists in determining the range of the empirical overcutting coefficient variation from 0.5 % (for TBMs with nominal diameter of 10 m) up to 5 % (for TBMs with nominal diameter of 4 m). The development of organizational measures and justification of process solutions, aimed at ensuring the safety of the existing buildings in conjunction with the scientific and technical support of underground construction has led to a shortening of tunneling time between the Okskaya and Nizhegorodskaya stations of Nekrasovskaya Line of Moscow Subway by about six months. It has also provided savings of about 2.5 billion rubles.

The main aim of the article is demonstrating successful design of spread foundations of a commercial centre building, where geotechnical monitoring allows us to check design efficiency and calculate reliability in comparison with real vertical deformation of building. Introduction to the case study area and building structure and foundations was done in previously published first part of the article in which engineering geological conditions were described. There was also presented a comparison of calculated vertical settlement of selected footings with the real geodetic measurement provided during construction time till the period of two years’ operation time after completion of civil works. Geotechnical engineers do not have many opportunities to evaluate their designs, especially when everything passes successfully. Our presented case study is one of the examples, which could be evaluated from the point of view of reliability index of design adjusted with real geodetic measurement. Index of reliability of selected foundations was calculated by deterministic probability methods. In order to evaluate thousands of statistical data combinations, programing tool in Python language was developed for batch processing calculation of vertical displacement of foundation in Plaxis software. Discussion part of the article contains the actual state of reliability theory in structural standards in Europe.

Geotechnical monitoring currently plays a key role in the research of the processes taking place in the ground medium and preventing hazardous events. In the case of open-pit mining, several solutions are commonly used to monitor various geotechnical parameters. However, geotechnical situation is usually assessed based on recorded values of deep and surface displacement, which allow to accurately predict landslides. The measurements are most often carried out manually, which, due to the difficult terrain conditions in the case of open-pit mining, are often timeconsuming and complicated, especially taking into account dangerous landslide movements. Therefore, in order to ensure a higher degree of safety against the risk of landslides, modern solutions are required in the field of geotechnical monitoring. This article presents modern automatic measurement techniques, compares various solutions available on the market and illustrates the benefits of their application in open-pit mining. It also discusses the expansion and modernization of the control and measurement network at KWB Turów, carried out in recent years, as well as the observational method for controlling the efficiency of stackers, developed after the installation of automated measuring stations, with its impact on the geotechnical safety of an internal waste heap. The paper as a case study presents, what a modern and effective geotechnical monitoring system should look like, which in practice will ensure continuous observation of selected parameters and enable a quick response in the event of a landslide threat. Last but not least, the author focuses on the creation of an innovative landslide early warning system, implemented at KWB Turów. [ABSTRACT FROM AUTHOR]

The article briefly discusses the experience of large cities in the integrated development of underground space together with ground construction. This document lists the major cities of Russia in which underground systems operate or are being designed. Based on the existing classification of geological and construction risks of megacities - Moscow and St. Petersburg, the necessity of continuous monitoring and risk management in the development of underground space is shown. The existing latest methodological documents are considered, on the basis of which, construction risks are managed, as well as geotechnical monitoring during the construction and operation of underground structures. Promising directions in developing means and methods of scientific and technical support of underground construction are shown. [ABSTRACT FROM AUTHOR]

The real-time evaluation of slope stability is a crucial technical issue in foundation excavation and slope construction. However, conventional monitoring methods often fall short of achieving real-time and accurate measurements, which poses challenges to the timely assessment of slope stability. To address this problem, laboratory tests and numerical simulations were jointly used to evaluate slope stability in this paper. In numerical simulations, the finite element method (FEM) results clearly illustrate the distribution and evolution of internal strain during slope excavation, and the limit equilibrium method (LEM) calculates changes in the safety factor. In laboratory tests, the fiber Bragg grating (FBG) sensing technology was employed to monitor the internal strain of the slope in real time. The distribution characteristics of the slope internal strain field under the condition of stepped excavation were analyzed, and the feasibility of strain-based evaluation of slope stability was discussed. The measurements with FBG sensing technology agree well with the numerical simulation results, indicating that FBG can effectively monitor soil strain information. Of great significance is that the maximum horizontal strain of the slope is closely related to the safety factor and can be used to evaluate slope stability. Notably, the horizontal soil strain of the slope provides insight into both the formation and evolution of the critical sliding surface during excavation. The combination of numerical simulation and intelligent monitoring technology based on FBG proposed in this paper provides a reference for capturing strain information inside the slope and realizing real-time assessment and critical warning of slope stability.

Most residential buildings and capital structures in the permafrost zone are constructed on the principle of maintaining the frozen state of the foundation soils. The changing climate and the increasing anthropogenic impact on the environment lead to changes in the boundaries of permafrost. These changes are especially relevant in the areas of piling foundations of residential buildings and other engineering structures located in the northern regions since they can lead to serious accidents caused by the degradation of permafrost and decrease the bearing capacity of the soil in such areas. Therefore, organization of temperature monitoring and forecasting of temperature changes in the soil under the buildings is an actual problem. To solve this problem, we use computer simulation methods of three-dimensional nonstationary thermal fields in the soil in combination with real-time monitoring of the temperature of the soil in thermometric wells. The developed approach is verified by using the temperature monitoring data for a specific residential building in the city of Salekhard. Comparison of the results of numerical calculations with experimental data showed good agreement. Using the developed computer software, nonstationary temperature fields under this building are obtained and, on this basis, the bearing capacities of all piles are calculated and a forecast of their changes in the future is given. To avoid decreasing the bearing capacity of piles it is necessary to prevent the degradation of permafrost and to supply the thermal stabilization of the soil. The proposed approach, based on a combination of the soil temperature monitoring and computer modeling methods, can be used to improve geotechnical monitoring methods. [ABSTRACT FROM AUTHOR]

Due to increasing urban populations, many modern cities attempt to solve problems associated with the increasing demand for public transportation by constructing these systems underground. To create new metro lines, multiple underground excavations must be carried out in several locations; these are often close to each other in shallow and weak geological environments due to geometric limitations as well as access-related restrictions. Settlement troughs can occur as a result of these excavations, potentially causing serious damage to the structures within the settling area. This study evaluated the data collected by monitoring the extent of surface deformation during the excavation process in four different locations on the Kirazlı-Olimpiyat-Başakşehir Metro Line as well as two different locations on the Ataköy-İkitelli Metro Line; all of these sites were located on the European side of Istanbul. The geometry of the surface settlement troughs that formed due to these tunnel excavations was examined; a total of 12 sections were investigated in this study. An analysis of the monitoring data reveals that, in similar geological environments, successively excavated tunnels with the same geometry and tunnelling methods can disturb the geological environment through which the tunnels are constructed; in particular, if the second tunnel passes through the same section, this results in the formation of an increasing and asynchronous surface settlement trough. This result indicates that the material parameter (K), which affects the size of the settlement trough formed in scenarios with twin subway tunnels with close axes and that are excavated at shallow depths, has different values at the wings of the settlement trough that forms after the tunnels have been excavated, and that this change in K influences the shape of the surface settlement trough. This study suggests that predicting any changes in K, which is dependent on the characteristics of the surrounding rock, is important in order to mitigate any potential risks, especially at the design stage of any project that requires the excavation of multiple tunnels at shallow depths and in weak geological environments. [ABSTRACT FROM AUTHOR]

Convergence and rockmass failure are significant hazards to personnel and physical assets in underground tunnels, caverns, and mines. Mobile Laser Scanning Systems (MLS) can deliver large volumes of point cloud data at a high frequency and on a large scale. However, current change detection approaches do not deliver sufficient sensitivity and precision for real-time performance on large-scale datasets. We present a novel, octree-based computational framework for intra-voxel statistical inference change detection and deformation analysis. Our approach exploits high-density MLS data to test for statistical significance for appearing objects caused by rockfall and for low-magnitude deformations, such as convergence. In field tests, our method detects rock falls with side lengths as small as 0.03 m and convergence as low as 0.01 m, or 0.5% wall-to-wall strain. When compared against a state-of-the-art multi-scale model-to-model cloud comparison (M3C2)-based method, ours is less sensitive to noisy data and parameter selection while also requiring fewer parameters. Most notably, our method is the only one tested that can perform real-time change detection on large-scale datasets on a single processor thread. Our method achieves a computational improvement of 50 times over single-threaded M3C2 while maintaining a performance scalability that is four times greater with dataset size. Our framework shows significant potential to enable accurate real-time geotechnical monitoring of large-scale underground spaces.

The impact of facilities of various branches of Russia's fuel and energy complex (FEC) on the Arctic permafrost zone and their stability due to climate change and the state of the upper horizons of the permafrost zone are discussed. Effective approaches are described in the design, construction, and operation of FEC facilities in permafrost. For the most significant subsectors of the energy sector (oil and gas production and transportation, electricity provision), an assessment of the economic damage as a result of changes in engineering and cryological conditions under the influence of natural and anthropogenic factors was carried out. The necessity of introducing new design and construction methods, carrying out complex background and geotechnical monitoring at the FEC enterprises, and creating a center for analyzing the received data is shown. [ABSTRACT FROM AUTHOR]

To optimize the rotation parameters of the drill and reduce the load on it during the drilling process, it is necessary to have information about the composition of the layers of the geological environment through which it passes. This information will reduce the wear of technical equipment and tools, as well as allow to plot optimal drilling trajectories and track the penetration of the drill into the target layer of the geological environment. This issue is especially relevant for the mining industry, where work is carried out at great depths with a complex structure of soil and rocks. Effective extraction of this information can be obtained by monitoring the phase changes of the recorded electrical signals from the receiving lines of the electrodes of the geoelectric monitoring system. The paper considers the general mechanism of implementation of the phasometric method in relation to the tasks of monitoring the drilling process, describes the equipment, as well as laboratory and field experiments to study the effectiveness of monitoring the drilling process by the phasometric method. The study of the dynamics of changes in the phase signals of the receiving lines of the electrodes during passage through the layers of soil with different electrical characteristics, which affects the change in the parameters of the recorded geoelectric signals. The research results are accompanied by graphic material confirming the possibilities of the proposed method and the prospects of its application in the extractive industry to optimize the parameters of drilling wells in real time. [ABSTRACT FROM AUTHOR]

The purpose of this work was to develop a prototype of a soil stress sensor using a new technique for converting mechanical quantities, with functions for measuring stress changes in soils emerging under the action of a dynamic load associated with earthworks using construction machinery, impact of transport, underground explosions and earthquakes. The development is intended to solve problems in increasing the overall efficiency of monitoring buildings and structures and measurement accuracy. Within the framework of the study, the basic requirements for primary converters of mechanical quantities operating underground were formulated. The design solutions of such sensors, which affect the quality of the information received, have been evaluated. As a result of the study, a new effect of "elastic charging of the interfacial layer of a solid metal electrode" for measuring normal stress in soils was explored and proposed eligible for this purpose. Consequently it became possible to apply this new approach to developing the soil stress measurement sensor, including the creation of its functional scheme of operation, and selection of the hardware set, construction elements and materials taking into account the nature of sensor work. Eventually, laboratory experiments obtaining numerical characteristics were carried out. [ABSTRACT FROM AUTHOR]