T. Kokusho, H. Hazarika, T. Ishizawa, S. Ishibashi, Katsuya Ogo
In two recent earthquakes in Hokkaido, Japan, liquefied sand unusually flowed underground in very gentle man-made fill slopes, creating large ground surface depressions. In both cases, a significant amount of non-plastic fines was present in the loose fine sands. When tested in undrained triaxial tests, these sands were found far more contractive and easier to flow than sand of the same density without fines. This strongly suggested that the high fines content was the major cause of the strange flow failures because it made the sand flowable on the contractive side of the steady state line. Another series of cyclic torsional simple shear tests on contractive sands with fines under initial shear stress indicated that the flow failure can initiate even in a gentle slope. This is when the effective stress path comes across a straight yield line drawn from the origin on τ−σ c ’ diagram uniquely defined irrespective of stress paths. A scenario to replicate the unusual flow failures was developed based on the observations.
在日本北海道最近发生的两次地震中，液化的沙子异常地在非常平缓的人造填充物斜坡上流入地下，造成了大面积的地表凹陷。在这两种情况下，松散的细砂中都存在大量的非塑性细粒。在不排水的三轴试验中，这些砂比相同密度的无细粒砂更容易收缩和流动。这强烈表明，高细粒含量是导致奇怪的流动破坏的主要原因，因为它使砂在稳态线的收缩侧可流动。另一系列初始剪应力作用下含细粒收缩砂的循环扭转单剪试验表明，即使在缓坡中也可能发生流动破坏。这是当有效应力路径遇到一条从τ−σ c '图上的原点绘制的直线屈服线时，而不考虑应力路径。根据观察结果，开发了一个模拟异常流动故障的场景。
{"title":"Understanding Liquefaction Flow of Gentle Slopes Containing Non-Plastic Fines","authors":"T. Kokusho, H. Hazarika, T. Ishizawa, S. Ishibashi, Katsuya Ogo","doi":"10.1680/jfoen.21.00019","DOIUrl":"https://doi.org/10.1680/jfoen.21.00019","url":null,"abstract":"In two recent earthquakes in Hokkaido, Japan, liquefied sand unusually flowed underground in very gentle man-made fill slopes, creating large ground surface depressions. In both cases, a significant amount of non-plastic fines was present in the loose fine sands. When tested in undrained triaxial tests, these sands were found far more contractive and easier to flow than sand of the same density without fines. This strongly suggested that the high fines content was the major cause of the strange flow failures because it made the sand flowable on the contractive side of the steady state line. Another series of cyclic torsional simple shear tests on contractive sands with fines under initial shear stress indicated that the flow failure can initiate even in a gentle slope. This is when the effective stress path comes across a straight yield line drawn from the origin on τ−σ c ’ diagram uniquely defined irrespective of stress paths. A scenario to replicate the unusual flow failures was developed based on the observations.","PeriodicalId":42902,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Forensic Engineering","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90498135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Mohammadhasani, A. Beitollahi, Mohammed Jameel, Mahdi Bameri
Niavaran Complex features a mix of architectural styles with the elements from modernism and traditional Iranian architecture and is situated in the northern part of Tehran. The Sahebqaraniyeh Heritage Palace from the time of Naser al-Din Shah of the Qajar dynasty is located in this complex (1846-1896). Based on the initial investigation done by Iran’s Cultural Heritage Handicrafts and Tourism Organization (ICHHTO), significant damages and cracking were observed in structural elements of the palace (walls and roofs). To this end, since early 2014, the monument is closed to the public and in-depth assessment has been carried out. The study includes seismicity of the Niavaran fault, soil liquefaction, landslides, land subsidence, and historical aspects, such as the removal of stabilizing walls about half a century ago and the reduction in underground water level. The detailed field investigation and experimental testing were performed by the Building and Housing Research Center (BHRC) of Iran. One of the main investigations has been the influence of deep excavations downstream in the south part of the palace. The outcome of structural, geotechnical, geophysical, and other related investigations indicated that the Niavaran Cultural/Historic Complex has been damaged significantly in the last decades and is in urgent need of retrofitting/strengthening.
{"title":"Investigating the possible structural damage scenarios of Niavaran Cultural / Historic Complex","authors":"M. Mohammadhasani, A. Beitollahi, Mohammed Jameel, Mahdi Bameri","doi":"10.1680/jfoen.21.00023","DOIUrl":"https://doi.org/10.1680/jfoen.21.00023","url":null,"abstract":"Niavaran Complex features a mix of architectural styles with the elements from modernism and traditional Iranian architecture and is situated in the northern part of Tehran. The Sahebqaraniyeh Heritage Palace from the time of Naser al-Din Shah of the Qajar dynasty is located in this complex (1846-1896). Based on the initial investigation done by Iran’s Cultural Heritage Handicrafts and Tourism Organization (ICHHTO), significant damages and cracking were observed in structural elements of the palace (walls and roofs). To this end, since early 2014, the monument is closed to the public and in-depth assessment has been carried out. The study includes seismicity of the Niavaran fault, soil liquefaction, landslides, land subsidence, and historical aspects, such as the removal of stabilizing walls about half a century ago and the reduction in underground water level. The detailed field investigation and experimental testing were performed by the Building and Housing Research Center (BHRC) of Iran. One of the main investigations has been the influence of deep excavations downstream in the south part of the palace. The outcome of structural, geotechnical, geophysical, and other related investigations indicated that the Niavaran Cultural/Historic Complex has been damaged significantly in the last decades and is in urgent need of retrofitting/strengthening.","PeriodicalId":42902,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Forensic Engineering","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91227312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Mohammadhasani, Behnaz Sheykh Shariati Kermani, Mohammed Jameel, S. Hakim
Increased exploitation of underground resources compared is one of the main reasons for subsidence. Subsidence causes infrastructure damage and ultimately leads to increased risk to society and the economy. In some areas of Iran recently, buildings, runways, bridges, tunnels, streets, railways and roads have been severely damaged. In this study, the amount of land subsidence was analysed in the western region of Kerman city using interferometry of radar images of Sentinel-1 satellite data from 2014 to 2020 in Sentinel’s Application Platform software. Results show that the subsidence rate in the area changed between 3.3 cm to 13.2 cm, confirms a significant increase. Field studies indicate that increased utilisation of groundwater resources, compaction due to ground drainage and imposition of heavy loads can all cause subsidence, which in turn rate leads to huge damage to infrastructure.
{"title":"Estimation of land subsidence hazard using interferometry of satellite radar images","authors":"M. Mohammadhasani, Behnaz Sheykh Shariati Kermani, Mohammed Jameel, S. Hakim","doi":"10.1680/jfoen.21.00013","DOIUrl":"https://doi.org/10.1680/jfoen.21.00013","url":null,"abstract":"Increased exploitation of underground resources compared is one of the main reasons for subsidence. Subsidence causes infrastructure damage and ultimately leads to increased risk to society and the economy. In some areas of Iran recently, buildings, runways, bridges, tunnels, streets, railways and roads have been severely damaged. In this study, the amount of land subsidence was analysed in the western region of Kerman city using interferometry of radar images of Sentinel-1 satellite data from 2014 to 2020 in Sentinel’s Application Platform software. Results show that the subsidence rate in the area changed between 3.3 cm to 13.2 cm, confirms a significant increase. Field studies indicate that increased utilisation of groundwater resources, compaction due to ground drainage and imposition of heavy loads can all cause subsidence, which in turn rate leads to huge damage to infrastructure.","PeriodicalId":42902,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Forensic Engineering","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76409527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Earth-fill dam failure and landsliding during heavy rainfall and flooding is a common problem observed all over the world. This paper examines and discusses the causes of landsliding due to rainfall and flooding. Climatic rainfall data are interconnected with rainfall precipitation and its effect on the increase in pore water pressure inside soil slopes. Various soil slopes with different geometries and material properties are analysed, and the variation in pore water pressure and the slope factors of safety (FSs) are calculated. Correlations between the groundwater level (GWL) and slope FS are developed in both seismic and non-seismic situations. Correlations between shear strength (τ), shear stress (σ) and FS are also developed. The Kotkai landslide in Pakistan is considered a case study for cross-checking the correctness of the developed correlations. These correlations can be applied to design a safe soil slope in intense flood and rainfall areas.
{"title":"Correlating groundwater level and shear strength: Kotkai Pakistan landslide as case study","authors":"Muhammad Israr Khan, Shuhong Wang","doi":"10.1680/jfoen.21.00035","DOIUrl":"https://doi.org/10.1680/jfoen.21.00035","url":null,"abstract":"Earth-fill dam failure and landsliding during heavy rainfall and flooding is a common problem observed all over the world. This paper examines and discusses the causes of landsliding due to rainfall and flooding. Climatic rainfall data are interconnected with rainfall precipitation and its effect on the increase in pore water pressure inside soil slopes. Various soil slopes with different geometries and material properties are analysed, and the variation in pore water pressure and the slope factors of safety (FSs) are calculated. Correlations between the groundwater level (GWL) and slope FS are developed in both seismic and non-seismic situations. Correlations between shear strength (τ), shear stress (σ) and FS are also developed. The Kotkai landslide in Pakistan is considered a case study for cross-checking the correctness of the developed correlations. These correlations can be applied to design a safe soil slope in intense flood and rainfall areas.","PeriodicalId":42902,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Forensic Engineering","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89204537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohammad Bavandi, A. S. Moghadam, M. Mansoori, A. Aziminejad
Recently developed steel self-centring moment-resisting frames have been analytically and experimentally validated as having the potential to eliminate structural damage under a design basis earthquake and restore their original vertical position following a major earthquake. In this study, the repairability index of post-tensioned self-centring frame for near-field earthquake has been developed. According to the six models of the studied building, a building that can be repaired, the maximum rotation in its connection after the earthquake does not exceed the rotation of the immediate occupancy performance. Based on this, the output data of incremental dynamic analysis analyses were drawn according to the connection of relative rotation and spectral acceleration. According to the predicted performance levels for each acceleration level, the value of the connection opening is divided by the opening of the design-basis earthquake level. The resulting curve shows the repairability index according to spectral acceleration, which if less than one, the repairability target is achieved. To evaluate the damage, the angle failure probability of post-tensioned self-centring frame for near-field earthquake has been developed. This index equation is determined according to the fragility curve and the intensity of damage in each building.
{"title":"Computation of the repairability index of short buildings with rocking connections","authors":"Mohammad Bavandi, A. S. Moghadam, M. Mansoori, A. Aziminejad","doi":"10.1680/jfoen.21.00007","DOIUrl":"https://doi.org/10.1680/jfoen.21.00007","url":null,"abstract":"Recently developed steel self-centring moment-resisting frames have been analytically and experimentally validated as having the potential to eliminate structural damage under a design basis earthquake and restore their original vertical position following a major earthquake. In this study, the repairability index of post-tensioned self-centring frame for near-field earthquake has been developed. According to the six models of the studied building, a building that can be repaired, the maximum rotation in its connection after the earthquake does not exceed the rotation of the immediate occupancy performance. Based on this, the output data of incremental dynamic analysis analyses were drawn according to the connection of relative rotation and spectral acceleration. According to the predicted performance levels for each acceleration level, the value of the connection opening is divided by the opening of the design-basis earthquake level. The resulting curve shows the repairability index according to spectral acceleration, which if less than one, the repairability target is achieved. To evaluate the damage, the angle failure probability of post-tensioned self-centring frame for near-field earthquake has been developed. This index equation is determined according to the fragility curve and the intensity of damage in each building.","PeriodicalId":42902,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Forensic Engineering","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81143804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the construction industry, fall accidents are a critical form of accident. This research examines fall accidents in formwork operations that occurred between 1995 and 2015. This study examines the different dimensions of fall incidents, such as the level of severity of formwork activities, fall height and causes of falls using the 205 construction industry accidents reported in the Occupational Safety and Health Administration (OSHA) database, a regulatory agency in the USA. The findings revealed that most fall incidents occur at the height of less than 9.1 m (30 ft), mostly due to unprotected or unguarded edges or floor covering. Furthermore, erection and stripping activities were found to have severe risks to carpenters and moreso to the general workers who tend to have more chances of meeting such accidents; additionally, human error can also be observed. These results are intended to alert safety authorities of the need to examine the existing state of fall incidents and formulate strategies to minimise them in the future. Since OSHA does not provide in-depth information for each incident, it was impossible to ascertain the exact situation and formwork type in use at the event.
{"title":"Analysis of workers’ fall accidents due to formwork operations","authors":"V. Chellappa, U. Salve","doi":"10.1680/jfoen.21.00006","DOIUrl":"https://doi.org/10.1680/jfoen.21.00006","url":null,"abstract":"In the construction industry, fall accidents are a critical form of accident. This research examines fall accidents in formwork operations that occurred between 1995 and 2015. This study examines the different dimensions of fall incidents, such as the level of severity of formwork activities, fall height and causes of falls using the 205 construction industry accidents reported in the Occupational Safety and Health Administration (OSHA) database, a regulatory agency in the USA. The findings revealed that most fall incidents occur at the height of less than 9.1 m (30 ft), mostly due to unprotected or unguarded edges or floor covering. Furthermore, erection and stripping activities were found to have severe risks to carpenters and moreso to the general workers who tend to have more chances of meeting such accidents; additionally, human error can also be observed. These results are intended to alert safety authorities of the need to examine the existing state of fall incidents and formulate strategies to minimise them in the future. Since OSHA does not provide in-depth information for each incident, it was impossible to ascertain the exact situation and formwork type in use at the event.","PeriodicalId":42902,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Forensic Engineering","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90361233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
It has been more than 20 years since the Metro Danshui Line of Taipei City was put into commercial operation and, the tunnels and underground metro stations experience structural aging along with p...
台北市地铁淡水线投入商业运营已逾20年，隧道与地下车站随著城市的变迁而经历结构老化。
{"title":"Rectification of Ground Water Leakage During Metro Tunnel Operation","authors":"Wen-Jen Chang, C. H. Chan, H. M. Shang","doi":"10.1680/jfoen.21.00017","DOIUrl":"https://doi.org/10.1680/jfoen.21.00017","url":null,"abstract":"It has been more than 20 years since the Metro Danshui Line of Taipei City was put into commercial operation and, the tunnels and underground metro stations experience structural aging along with p...","PeriodicalId":42902,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Forensic Engineering","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77575760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Failure analysis of a landslide along the Mangla reservoir rim near Khaliqabad, Pakistan","authors":"Fatima Mehmood, K. Farooq","doi":"10.1680/jfoen.20.00011","DOIUrl":"https://doi.org/10.1680/jfoen.20.00011","url":null,"abstract":"","PeriodicalId":42902,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Forensic Engineering","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73088219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Temporary Works Forum was founded to give a place for professionals to come together and share their experience and learning about temporary works. 2019 marked its 10th anniversary. In this art...
{"title":"Briefing: Temporary Works Forum: how history and narrative shaped a major safety initiative","authors":"Bill Hewlett","doi":"10.1680/JFOEN.20.00001","DOIUrl":"https://doi.org/10.1680/JFOEN.20.00001","url":null,"abstract":"The Temporary Works Forum was founded to give a place for professionals to come together and share their experience and learning about temporary works. 2019 marked its 10th anniversary. In this art...","PeriodicalId":42902,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Forensic Engineering","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72918040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper reports on an evaluation of failures of non-engineered earthen buildings, timber-framed buildings with bamboo matting, unreinforced load-bearing masonry buildings and framed reinforced-c...
本文报道了非工程土建建筑、竹垫木结构建筑、无加筋承重砌体建筑和框架加筋混凝土建筑的失效评估。
{"title":"Failure analysis of earthen, masonry and concrete buildings during the 2017 Tripura earthquake","authors":"D. Tripura, Sangketa Sangma","doi":"10.1680/jfoen.19.00017","DOIUrl":"https://doi.org/10.1680/jfoen.19.00017","url":null,"abstract":"This paper reports on an evaluation of failures of non-engineered earthen buildings, timber-framed buildings with bamboo matting, unreinforced load-bearing masonry buildings and framed reinforced-c...","PeriodicalId":42902,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Forensic Engineering","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76464270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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