In 1998, the Permo-Triassic Sandstone aquifer of the West Midlands-Worfe (WMW) area became the subject of one of the first major groundwater modelling project initiated under the Environment Agency of England's national groundwater modelling framework. The 4R runoff-recharge code that allowed these models to apply a semi-integrated approach to simulating catchment hydrology was developed and trialled in parallel with the WMW project. This combined groundwater and surface water modelling approach has enabled the Environment Agency of England to make complex water resource management decisions in a wide range of aquifers and catchments based, in part, on outputs from such models. Since that time, the Environment Agency has used the framework to develop around a dozen further models of Permo-Triassic Sandstone aquifers, of varying levels of complexity. Many of the older models have subsequently been through one or more cycles of updating and/or recalibration. This paper provides a high level review of these models based on the personal experience of the author and compares and contrasts their implementation in the USGS groundwater modelling code MODFLOW. This includes a discussion of key conceptual issues that are common across the models, or unique to particular models, and the uses to which the models have been put. The paper concludes with a discussion of future opportunities and challenges for the programme. Thematic collection: This article is part of the Hydrogeology of Sandstone collection available at: https://www.lyellcollection.org/topic/collections/hydrogeology-of-sandstone
{"title":"A personal perspective of 20 years of regional groundwater resource modelling of the Permo-Triassic Sandstone aquifers in England","authors":"M. Streetly","doi":"10.1144/qjegh2022-090","DOIUrl":"https://doi.org/10.1144/qjegh2022-090","url":null,"abstract":"In 1998, the Permo-Triassic Sandstone aquifer of the West Midlands-Worfe (WMW) area became the subject of one of the first major groundwater modelling project initiated under the Environment Agency of England's national groundwater modelling framework. The 4R runoff-recharge code that allowed these models to apply a semi-integrated approach to simulating catchment hydrology was developed and trialled in parallel with the WMW project. This combined groundwater and surface water modelling approach has enabled the Environment Agency of England to make complex water resource management decisions in a wide range of aquifers and catchments based, in part, on outputs from such models. Since that time, the Environment Agency has used the framework to develop around a dozen further models of Permo-Triassic Sandstone aquifers, of varying levels of complexity. Many of the older models have subsequently been through one or more cycles of updating and/or recalibration. This paper provides a high level review of these models based on the personal experience of the author and compares and contrasts their implementation in the USGS groundwater modelling code MODFLOW. This includes a discussion of key conceptual issues that are common across the models, or unique to particular models, and the uses to which the models have been put. The paper concludes with a discussion of future opportunities and challenges for the programme.\u0000 \u0000 Thematic collection:\u0000 This article is part of the Hydrogeology of Sandstone collection available at:\u0000 https://www.lyellcollection.org/topic/collections/hydrogeology-of-sandstone\u0000","PeriodicalId":20937,"journal":{"name":"Quarterly Journal of Engineering Geology and Hydrogeology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42152621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A major mining project by Anglo American plc. at Woodsmith Mine is targeting deep polyhalite deposits in the Cleveland Basin of North Yorkshire. The mine shaft design included hydrogeological assessment of the full 1,600m hydrostratigraphic sequence to be intersected. Of this sequence the most significant aquifer that will be intersected is the Sherwood Sandstone Group (SSG), which will be encountered at depths of between 800m and 1,050m below surface. Deep exploratory cored boreholes were completed at the site to enable both laboratory and field testing. The methods used to determine the aquifer characteristics comprised of geotechnical laboratory testing of rock core and oil field downhole wireline technology. Geotechnical triaxial tests were used to determine the horizontal and vertical permeability of rock core recovered from deep exploration boreholes. Wireline Elementary Log ANalyses (ELAN) and Modulation Dynamic Testing (MDT) were used to determine hydraulic conductivity and porosity of the SSG sequence encountered. Formation Micro Imager (FMI) was used to determine sedimentary depositional features. This paper presents a review of the ground investigation data collected to characterise anisotropy between horizontal and vertical flow within the SSG in this part of the Cleveland basin. Thematic collection: This article is part of the Hydrogeology of Sandstone collection available at: https://www.lyellcollection.org/cc/hydrogeology-of-sandstone
{"title":"Depositional environment and aquifer properties of the Sherwood Sandstone Group in the Cleveland Basin based on investigations at Woodsmith Mine","authors":"C. Timmen, L. Brown, M. Heap, A. Hornung","doi":"10.1144/qjegh2022-041","DOIUrl":"https://doi.org/10.1144/qjegh2022-041","url":null,"abstract":"A major mining project by Anglo American plc. at Woodsmith Mine is targeting deep polyhalite deposits in the Cleveland Basin of North Yorkshire. The mine shaft design included hydrogeological assessment of the full 1,600m hydrostratigraphic sequence to be intersected. Of this sequence the most significant aquifer that will be intersected is the Sherwood Sandstone Group (SSG), which will be encountered at depths of between 800m and 1,050m below surface. Deep exploratory cored boreholes were completed at the site to enable both laboratory and field testing.\u0000 The methods used to determine the aquifer characteristics comprised of geotechnical laboratory testing of rock core and oil field downhole wireline technology. Geotechnical triaxial tests were used to determine the horizontal and vertical permeability of rock core recovered from deep exploration boreholes. Wireline Elementary Log ANalyses (ELAN) and Modulation Dynamic Testing (MDT) were used to determine hydraulic conductivity and porosity of the SSG sequence encountered. Formation Micro Imager (FMI) was used to determine sedimentary depositional features.\u0000 This paper presents a review of the ground investigation data collected to characterise anisotropy between horizontal and vertical flow within the SSG in this part of the Cleveland basin.\u0000 \u0000 Thematic collection:\u0000 This article is part of the Hydrogeology of Sandstone collection available at:\u0000 https://www.lyellcollection.org/cc/hydrogeology-of-sandstone\u0000","PeriodicalId":20937,"journal":{"name":"Quarterly Journal of Engineering Geology and Hydrogeology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47723533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gravel soil slopes were not only prevalent in nature but also widely used in engineering. Understanding the damage characteristics of gravel soil slopes and preventing slope hazards required a thorough investigation of the stability and deformation of gravel soil slopes. In this study, the stability and macroscopic deformation of slopes with varying gravel content (GC) were examined using lab tests and digital image correlation (DIC) techniques, and the rock-winding motion on the shear zone was investigated in detail by capturing the relative motion of soil particles and gravels from a micro-view perspective. In addition, the effects of loading location and slope angle were considered. The results indicated that there are two thresholds of 20% and 70% for the effect of GC on slope ultimate bearing capacity. Gravel soil slope shear damage was primarily caused by the gravel rotation at critical locations. There were at least five rock-inclusive movement patterns in the shear zone, and the primary cause of irregular damage on gravelly soil slopes was the difference in the relative movement of soil particles and gravels. High GC slopes were less sensitive to changes in LL and SA than slopes with low GC.
{"title":"Multi-scale Investigation on the Stability of Soil-Gravel Mixture Slopes Using Imaging Analyses","authors":"Yeong-Wei Lu, Yang Hu","doi":"10.1144/qjegh2022-119","DOIUrl":"https://doi.org/10.1144/qjegh2022-119","url":null,"abstract":"Gravel soil slopes were not only prevalent in nature but also widely used in engineering. Understanding the damage characteristics of gravel soil slopes and preventing slope hazards required a thorough investigation of the stability and deformation of gravel soil slopes. In this study, the stability and macroscopic deformation of slopes with varying gravel content (GC) were examined using lab tests and digital image correlation (DIC) techniques, and the rock-winding motion on the shear zone was investigated in detail by capturing the relative motion of soil particles and gravels from a micro-view perspective. In addition, the effects of loading location and slope angle were considered. The results indicated that there are two thresholds of 20% and 70% for the effect of GC on slope ultimate bearing capacity. Gravel soil slope shear damage was primarily caused by the gravel rotation at critical locations. There were at least five rock-inclusive movement patterns in the shear zone, and the primary cause of irregular damage on gravelly soil slopes was the difference in the relative movement of soil particles and gravels. High GC slopes were less sensitive to changes in LL and SA than slopes with low GC.","PeriodicalId":20937,"journal":{"name":"Quarterly Journal of Engineering Geology and Hydrogeology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44122783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. N. Shirlaw, T. Henderson, Ivan S. Haryono, Francois Dudouit, David Salisbury
Parallel running tunnels were driven by a 7.46m diameter slurry tunnel boring machine (TBM) through weathered Kowloon granite in Hong Kong for MTR Contract SCL 1103. The final part of the tunnelling was in a full face of Grade III or Grade II rock, up to 50m below rockhead. Using the data obtained during the tunnelling, the average strength of the rock was calculated for every ring of advance. The distribution of the rock strength calculated from the two drives was similar, and comparable with the data from the ground investigation. The strength assessed from the TBM data shows a notably sawtooth profile along each drive, with large changes in strength over relatively short distances. The change in strength between each advance averaged 13 MPa, and locally reduced by 80% over 9m. The changes in strength indicate that the rock had been weakened locally by weathering, consistent with the early stages of the formation of a corestone weathering profile. The focus of the weathering was on a set of inferred joints spaced at an average of about 17m that represented a small proportion of the joints encountered during tunnelling.
{"title":"Using slurry TBM data to assess the variability of weathered Kowloon granite","authors":"J. N. Shirlaw, T. Henderson, Ivan S. Haryono, Francois Dudouit, David Salisbury","doi":"10.1144/qjegh2022-032","DOIUrl":"https://doi.org/10.1144/qjegh2022-032","url":null,"abstract":"Parallel running tunnels were driven by a 7.46m diameter slurry tunnel boring machine (TBM) through weathered Kowloon granite in Hong Kong for MTR Contract SCL 1103. The final part of the tunnelling was in a full face of Grade III or Grade II rock, up to 50m below rockhead. Using the data obtained during the tunnelling, the average strength of the rock was calculated for every ring of advance. The distribution of the rock strength calculated from the two drives was similar, and comparable with the data from the ground investigation. The strength assessed from the TBM data shows a notably sawtooth profile along each drive, with large changes in strength over relatively short distances. The change in strength between each advance averaged 13 MPa, and locally reduced by 80% over 9m. The changes in strength indicate that the rock had been weakened locally by weathering, consistent with the early stages of the formation of a corestone weathering profile. The focus of the weathering was on a set of inferred joints spaced at an average of about 17m that represented a small proportion of the joints encountered during tunnelling.","PeriodicalId":20937,"journal":{"name":"Quarterly Journal of Engineering Geology and Hydrogeology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43622049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Affected by the excavation, the phenomenon of groundwater level drop around mountain tunnels is widespread, resulting in poor accuracy of the existing water inflow calculation formula derived when the groundwater level is fixed. Based on this, a simplified calculation model of tunnel water inflow is constructed when considering drainage, and the tunnel water inflow is calculated according to the Dupuit assumption and conformal transformation. The law of conservation of fluid mass is used to solve the equivalent water head around the tunnel after drainage, and the Taylor formula is used for degradation analysis, and the rationality of the model construction and the correctness of the formula derivation are verified through the tunnel under construction and numerical simulation. Finally, the sensitivity of the characteristic parameters is studied, the evolution law of the equivalent head is revealed, and the influence mechanism is discussed. The research shows that the error between the calculated value of tunnel water inflow and the field measured value can be reduced from 16.1% to 8.9%, which improves the prediction accuracy of tunnel water inflow to a certain extent.
{"title":"Analysis of the impact of groundwater level decrease caused by drainage on tunnel water inflow","authors":"Pengtao An, Maoxiang Li, Helin Fu","doi":"10.1144/qjegh2023-019","DOIUrl":"https://doi.org/10.1144/qjegh2023-019","url":null,"abstract":"Affected by the excavation, the phenomenon of groundwater level drop around mountain tunnels is widespread, resulting in poor accuracy of the existing water inflow calculation formula derived when the groundwater level is fixed. Based on this, a simplified calculation model of tunnel water inflow is constructed when considering drainage, and the tunnel water inflow is calculated according to the Dupuit assumption and conformal transformation. The law of conservation of fluid mass is used to solve the equivalent water head around the tunnel after drainage, and the Taylor formula is used for degradation analysis, and the rationality of the model construction and the correctness of the formula derivation are verified through the tunnel under construction and numerical simulation. Finally, the sensitivity of the characteristic parameters is studied, the evolution law of the equivalent head is revealed, and the influence mechanism is discussed. The research shows that the error between the calculated value of tunnel water inflow and the field measured value can be reduced from 16.1% to 8.9%, which improves the prediction accuracy of tunnel water inflow to a certain extent.","PeriodicalId":20937,"journal":{"name":"Quarterly Journal of Engineering Geology and Hydrogeology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46074886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Synthetic Aperture Radar (SAR) is traditionally used in the identification, mapping, and analysis of petroleum slicks, regardless of their origin. On SAR images, oil slicks appear as dark patches that contrast with the brightness of the surrounding sea surface. This distinction allows for automated detection algorithms to be designed using computer vision methods for objective oil slick identification. Nevertheless, efficient interpretation of the SAR imagery by statistical analysis can be diminished due to the speckle effect present on SAR images, a granular artefact associated with the coherent nature of SAR, which visually degrades the image quality. In this study, a quantitative and qualitative assessment of common SAR image despeckling methods is presented, analyzing their performance when applied to images containing natural oil slicks. The assessment is performed on Copernicus Sentinel-1 images acquired with various temporal and environmental conditions. The assessment covers a diverse area of filters that employ Bayesian and non-linear statistics in the spatial, transform and wavelet domains, focusing on their demonstrated performance and capabilities for edge and texture retention. In summary, the results reveal that filters using local statistics in the spatial domain produce consistent desired effects. The novel SAR-BM3D algorithm can be used effectively, albeit with a higher computational demand. Supplementary material: Implementations of the speckle filters used in this paper are made available at: https://github.com/cavrinceanu/specklefilters under an MIT license. Image statistics data is available for Tables 3-11 at: https://doi.org/10.6084/m9.figshare.13010405 Thematic collection: This article is part of the Remote sensing for site investigations on Earth and other planets collection available at: https://www.lyellcollection.org/cc/remote-sensing-for-site-investigations-on-earth-and-other-planets
{"title":"The performance of speckle filters on Copernicus Sentinel-1 SAR images containing natural oil slicks","authors":"C. Vrinceanu, S. Grebby, S. Marsh","doi":"10.1144/qjegh2022-046","DOIUrl":"https://doi.org/10.1144/qjegh2022-046","url":null,"abstract":"Synthetic Aperture Radar (SAR) is traditionally used in the identification, mapping, and analysis of petroleum slicks, regardless of their origin. On SAR images, oil slicks appear as dark patches that contrast with the brightness of the surrounding sea surface. This distinction allows for automated detection algorithms to be designed using computer vision methods for objective oil slick identification. Nevertheless, efficient interpretation of the SAR imagery by statistical analysis can be diminished due to the speckle effect present on SAR images, a granular artefact associated with the coherent nature of SAR, which visually degrades the image quality. In this study, a quantitative and qualitative assessment of common SAR image despeckling methods is presented, analyzing their performance when applied to images containing natural oil slicks. The assessment is performed on Copernicus Sentinel-1 images acquired with various temporal and environmental conditions. The assessment covers a diverse area of filters that employ Bayesian and non-linear statistics in the spatial, transform and wavelet domains, focusing on their demonstrated performance and capabilities for edge and texture retention. In summary, the results reveal that filters using local statistics in the spatial domain produce consistent desired effects. The novel SAR-BM3D algorithm can be used effectively, albeit with a higher computational demand.\u0000 \u0000 Supplementary material:\u0000 Implementations of the speckle filters used in this paper are made available at:\u0000 https://github.com/cavrinceanu/specklefilters\u0000 under an MIT license. Image statistics data is available for Tables 3-11 at:\u0000 https://doi.org/10.6084/m9.figshare.13010405\u0000 \u0000 \u0000 Thematic collection:\u0000 This article is part of the Remote sensing for site investigations on Earth and other planets collection available at:\u0000 https://www.lyellcollection.org/cc/remote-sensing-for-site-investigations-on-earth-and-other-planets\u0000","PeriodicalId":20937,"journal":{"name":"Quarterly Journal of Engineering Geology and Hydrogeology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47669263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
With the rapid development of transportation in China, the number of tunnels, as the main control project, is also increasing. However, tunnels may suffer from fire accidents during operation, and the surrounding rock of tunnels will be irreparably damaged by high temperature. To investigate the influence of temperature on the physical and mechanical properties of red sandstone, physical properties as well as Brazilian splitting test were conducted on red sandstone after thermal treatment from 25 ℃ to 600 ℃. The results show that with the increasing temperature, the apparent color of red sandstone is gradually deepened. The P-wave velocity and Leeb hardness decreased with the increase of temperature, and typical temperature threshold (300 ℃) was identified. The tensile strength of red sandstone decreasing quickly from 25 ℃ to 300 ℃ and then decreases slowly from 300 ℃ to 600 ℃. The acoustic emission (AE) signal has a high degree of consistency with the stress time curve. As the temperature increased, the AE became more active, when red sandstone is near to failure, the AE signal increases sharply. The failure mode of sandstone is mainly composed of a through main crack and a secondary crack, and the crack width also grows gradually. Moreover, we observe that the number of fractures in the sandstone also increase as the temperature rise by polarized light microscopy images. The variation of physical and mechanical properties of red sandstone is closely related to microstructure. These findings demonstrate that temperature has an obvious weakening effect on the physical and mechanical properties of sandstone, and provide theoretical guidance and engineering significance for tunnel fire restoration. Thematic collection: This article is part of the Engineering Geology and Hydrogeology of the Anthropocene collection available at: https://www.lyellcollection.org/topic/collections/engineering-geology-and-hydrogeology-of-the-anthropocene
{"title":"Experimental investigation of temperature on the physical and mechanical properties of red sandstone","authors":"Yun Wu, Longxiang Deng, Zhen Huang, Li-Ning Yang","doi":"10.1144/qjegh2021-086","DOIUrl":"https://doi.org/10.1144/qjegh2021-086","url":null,"abstract":"With the rapid development of transportation in China, the number of tunnels, as the main control project, is also increasing. However, tunnels may suffer from fire accidents during operation, and the surrounding rock of tunnels will be irreparably damaged by high temperature. To investigate the influence of temperature on the physical and mechanical properties of red sandstone, physical properties as well as Brazilian splitting test were conducted on red sandstone after thermal treatment from 25 ℃ to 600 ℃. The results show that with the increasing temperature, the apparent color of red sandstone is gradually deepened. The P-wave velocity and Leeb hardness decreased with the increase of temperature, and typical temperature threshold (300 ℃) was identified. The tensile strength of red sandstone decreasing quickly from 25 ℃ to 300 ℃ and then decreases slowly from 300 ℃ to 600 ℃. The acoustic emission (AE) signal has a high degree of consistency with the stress time curve. As the temperature increased, the AE became more active, when red sandstone is near to failure, the AE signal increases sharply. The failure mode of sandstone is mainly composed of a through main crack and a secondary crack, and the crack width also grows gradually. Moreover, we observe that the number of fractures in the sandstone also increase as the temperature rise by polarized light microscopy images. The variation of physical and mechanical properties of red sandstone is closely related to microstructure. These findings demonstrate that temperature has an obvious weakening effect on the physical and mechanical properties of sandstone, and provide theoretical guidance and engineering significance for tunnel fire restoration.\u0000 \u0000 Thematic collection:\u0000 This article is part of the Engineering Geology and Hydrogeology of the Anthropocene collection available at:\u0000 https://www.lyellcollection.org/topic/collections/engineering-geology-and-hydrogeology-of-the-anthropocene\u0000","PeriodicalId":20937,"journal":{"name":"Quarterly Journal of Engineering Geology and Hydrogeology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43527008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. C. Katchkin, J. Thomson, R. Mcconnell, R. Fitzgerald, R. Moore
In 2017 two landslides resulted in temporary closure of the main access road to Scrabster Harbour, located in the north of the Scottish mainland. A slope stability assessment was commissioned to investigate the occurrence, causes and mechanisms of historical landslides and their associated consequences to inform future landslide hazard potential. Within Scotland, most slope stability studies are undertaken using qualitative rather than quantitative methods, largely due to insufficient historical data. This paper presents a case study where a semi-quantitative risk assessment was used to assess the stability of coastal slopes above the A9 Trunk Road at Scrabster Harbour. A database of historical landslides and slope characteristics was compiled and used in a semi-quantitative risk assessment to provide the client with targeted information on which areas of the slope can be stabilised most effectively. This was based on ranking the slopes in terms of relative risk, thus providing the road operator and maintenance contractor with an indication of those slopes presenting a higher risk so that these areas could be prioritised for remedial works. The analysis showed that surface water drainage intersecting the slopes and locally over-steepened slopes were primary controls for the observed landslides.
{"title":"Slope Stability Assessment of a Major Trunk Road at Scrabster Harbour, Scotland, UK","authors":"M. C. Katchkin, J. Thomson, R. Mcconnell, R. Fitzgerald, R. Moore","doi":"10.1144/qjegh2021-187","DOIUrl":"https://doi.org/10.1144/qjegh2021-187","url":null,"abstract":"In 2017 two landslides resulted in temporary closure of the main access road to Scrabster Harbour, located in the north of the Scottish mainland. A slope stability assessment was commissioned to investigate the occurrence, causes and mechanisms of historical landslides and their associated consequences to inform future landslide hazard potential.\u0000 Within Scotland, most slope stability studies are undertaken using qualitative rather than quantitative methods, largely due to insufficient historical data. This paper presents a case study where a semi-quantitative risk assessment was used to assess the stability of coastal slopes above the A9 Trunk Road at Scrabster Harbour.\u0000 A database of historical landslides and slope characteristics was compiled and used in a semi-quantitative risk assessment to provide the client with targeted information on which areas of the slope can be stabilised most effectively. This was based on ranking the slopes in terms of relative risk, thus providing the road operator and maintenance contractor with an indication of those slopes presenting a higher risk so that these areas could be prioritised for remedial works. The analysis showed that surface water drainage intersecting the slopes and locally over-steepened slopes were primary controls for the observed landslides.","PeriodicalId":20937,"journal":{"name":"Quarterly Journal of Engineering Geology and Hydrogeology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47831945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tunnels are underground structures that are widely used in geology, mining, and other related fields. Given the fact that many severe underground structure instabilities are found to be closely associated with fault systems present nearby, an integrated fault identification method, namely the 3M method, is proposed based on analyzing the macrostructure, mineral characteristics, and microstructural of rock masses in the tunnel. This method comprises three steps, and each step corresponds to one “M”: macrostructure identification, mineral analysis, and microstructure identification. First, the macrostructure is investigated to determine whether there is a fault-related feature in the tunnel, e.g., a slickenside. Second, mineral analysis infers the spatial extent of the fault from changes to the types and compositions of minerals. Third, the microstructure is investigated to determine the fault-related deformation mechanism in the tunnel, e.g., deformation twinning. Adopting the proposed method reduces the subjective influence of geological engineers and improves the accuracy of fault identification via traditional geological analysis. The results of this study provide new insight into tunnel excavation and support design.
{"title":"Integrated Fault Identification in Granite Tunnel Based on the Analysis of Structural and Mineral Characteristics of Rock Masses: A Case Study","authors":"P. Lin, R. Shao, Zhen-hao Xu, T. Yu","doi":"10.1144/qjegh2022-053","DOIUrl":"https://doi.org/10.1144/qjegh2022-053","url":null,"abstract":"Tunnels are underground structures that are widely used in geology, mining, and other related fields. Given the fact that many severe underground structure instabilities are found to be closely associated with fault systems present nearby, an integrated fault identification method, namely the 3M method, is proposed based on analyzing the macrostructure, mineral characteristics, and microstructural of rock masses in the tunnel. This method comprises three steps, and each step corresponds to one “M”: macrostructure identification, mineral analysis, and microstructure identification. First, the macrostructure is investigated to determine whether there is a fault-related feature in the tunnel, e.g., a slickenside. Second, mineral analysis infers the spatial extent of the fault from changes to the types and compositions of minerals. Third, the microstructure is investigated to determine the fault-related deformation mechanism in the tunnel, e.g., deformation twinning. Adopting the proposed method reduces the subjective influence of geological engineers and improves the accuracy of fault identification via traditional geological analysis. The results of this study provide new insight into tunnel excavation and support design.","PeriodicalId":20937,"journal":{"name":"Quarterly Journal of Engineering Geology and Hydrogeology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42142465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fanghua Zhu, Zhifeng Zhang, W. Tao, Fanfan Li, Tianyu Wei
As one of the extensively used gasoline additives, MTBE can leak into the subsurface, which will not only deteriorate the ecological environment, but also affect the geotechnical characteristics of the soil. In this study, the geotechnical properties of MTBE-contaminated soil consisting of the basic physical properties, strength, compressibility, hydraulic conductivity, leachability, electrical resistivity and microstructural characteristics are comprehensively investigated. The results show that the Atterberg limits consistently decrease with increasing MTBE content in the soil. As the MTBE content increases from 0% to 10%, the specific surface area of the soil decreases by 28%, the sand content increases by 22%, the clay and silt contents decreases by 3% and 18%, respectively. The soil compression index, hydraulic conductivity, leached MTBE concentration and electrical resistivity increase, while the UCS decreases with increasing the MTBE content. Microstructural analysis shows that increasing MTBE content would result in mineralogical alterations that decrease the illite and kaolinite content in the soil. The aggregation and flocculated structures could be detected with an increase in the number and size of the inter-aggregate pores. Additionally, electrical resistivity of the contaminated soil is adopted to assess the geotechnical properties of MTBE-contaminated soil based on the well-established empirical relations.
{"title":"Changes in geotechnical properties of soil contaminated by methyl tertiary butyl ether (MTBE)","authors":"Fanghua Zhu, Zhifeng Zhang, W. Tao, Fanfan Li, Tianyu Wei","doi":"10.1144/qjegh2022-095","DOIUrl":"https://doi.org/10.1144/qjegh2022-095","url":null,"abstract":"As one of the extensively used gasoline additives, MTBE can leak into the subsurface, which will not only deteriorate the ecological environment, but also affect the geotechnical characteristics of the soil. In this study, the geotechnical properties of MTBE-contaminated soil consisting of the basic physical properties, strength, compressibility, hydraulic conductivity, leachability, electrical resistivity and microstructural characteristics are comprehensively investigated. The results show that the Atterberg limits consistently decrease with increasing MTBE content in the soil. As the MTBE content increases from 0% to 10%, the specific surface area of the soil decreases by 28%, the sand content increases by 22%, the clay and silt contents decreases by 3% and 18%, respectively. The soil compression index, hydraulic conductivity, leached MTBE concentration and electrical resistivity increase, while the UCS decreases with increasing the MTBE content. Microstructural analysis shows that increasing MTBE content would result in mineralogical alterations that decrease the illite and kaolinite content in the soil. The aggregation and flocculated structures could be detected with an increase in the number and size of the inter-aggregate pores. Additionally, electrical resistivity of the contaminated soil is adopted to assess the geotechnical properties of MTBE-contaminated soil based on the well-established empirical relations.","PeriodicalId":20937,"journal":{"name":"Quarterly Journal of Engineering Geology and Hydrogeology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44094819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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