Pub Date : 2014-10-31DOI: 10.7474/TUS.2014.24.5.373
I. Yang, Nam-Soo Choi, Chul-Soo Jeon, Sang-eun Lee, Dongju Shin
Hydraulic filling methods are widely applied to suppress the land subsidence recently. But the research on high-efficiency hydraulic filling to protect the land subsidence is rare. In this study, field experiments to improve the efficiency of the hydraulic filling method are performed by changing the property, specification of the filling material and injection pipe. The filling amounts using vertical injection pipe, reducing tee (ø100 mm) pipe, reducing tee (ø80 mm) pipe and reducing tee (ø50 mm) pipe showed 28.84 ton, 42.62 ton, 53.33 ton, and 63.33 ton respectively. The filling rates using reducing tee (ø100 mm) pipe, reducing tee (ø80 mm) pipe and reducing tee (ø50 mm) pipe showed 47.8%, 84.9% and 119.6% respectively. Filling efficiency can be incresed by using reducing tee. This study shows that simply changing the type of injection pipe is expected to increase the hydraulic filling rate.
{"title":"Study on High-efficiency Hydraulic Filling Field Experiment for Subsidence Protection","authors":"I. Yang, Nam-Soo Choi, Chul-Soo Jeon, Sang-eun Lee, Dongju Shin","doi":"10.7474/TUS.2014.24.5.373","DOIUrl":"https://doi.org/10.7474/TUS.2014.24.5.373","url":null,"abstract":"Hydraulic filling methods are widely applied to suppress the land subsidence recently. But the research on high-efficiency hydraulic filling to protect the land subsidence is rare. In this study, field experiments to improve the efficiency of the hydraulic filling method are performed by changing the property, specification of the filling material and injection pipe. The filling amounts using vertical injection pipe, reducing tee (ø100 mm) pipe, reducing tee (ø80 mm) pipe and reducing tee (ø50 mm) pipe showed 28.84 ton, 42.62 ton, 53.33 ton, and 63.33 ton respectively. The filling rates using reducing tee (ø100 mm) pipe, reducing tee (ø80 mm) pipe and reducing tee (ø50 mm) pipe showed 47.8%, 84.9% and 119.6% respectively. Filling efficiency can be incresed by using reducing tee. This study shows that simply changing the type of injection pipe is expected to increase the hydraulic filling rate.","PeriodicalId":437780,"journal":{"name":"Journal of Korean Society for Rock Mechanics","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128338484","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}
Pub Date : 2014-10-31DOI: 10.7474/TUS.2014.24.5.354
Jun Kyoung Kim
Abstract The horizontal response spectra using the observed ground motions from 15 Fukuoka earthquake series, including main earthquake (2005/03/20; Mw=6.5), were analysed and then were compared to both the seismic design response spectra (Regulatory Guide 1.60), applied to the domestic nuclear power plants, and the Korean Standard Design Response Spectrum for general structures and buildings (1997). 178 horizontal ground motions, without considering soil types, were used for normalization with respect to the peak acceleration value of each ground motion. The results showed that response spectrum have strong dependency on epicentral distance. The results also showed that the horizontal response spectra revealed higher values for frequency bands at two frequency bands (about 8 – 10 and 16- 20 Hz) than Regulatory Guide 1.60. The results were also compared to the Korean Standard Building Design Spectrum for the 3 different soil types and showed that thehorizontal response spectra revealed higher values for almost all period bands than the Korean Standard Response Spectrum (500 yrs; Return Period; Seismic province 1; SE soil conditions). Through the qualitative improvements and quantitative enhancement of the observed ground motions, the diversity of the observed ground motions should be considered more significantly to improve the certainty of response spectrum.
{"title":"Analysis of Characteristics of Horizontal Response Spectrum of Ground Motions from Fukuoka Earthquakes Series","authors":"Jun Kyoung Kim","doi":"10.7474/TUS.2014.24.5.354","DOIUrl":"https://doi.org/10.7474/TUS.2014.24.5.354","url":null,"abstract":"Abstract The horizontal response spectra using the observed ground motions from 15 Fukuoka earthquake series, including main earthquake (2005/03/20; Mw=6.5), were analysed and then were compared to both the seismic design response spectra (Regulatory Guide 1.60), applied to the domestic nuclear power plants, and the Korean Standard Design Response Spectrum for general structures and buildings (1997). 178 horizontal ground motions, without considering soil types, were used for normalization with respect to the peak acceleration value of each ground motion. The results showed that response spectrum have strong dependency on epicentral distance. The results also showed that the horizontal response spectra revealed higher values for frequency bands at two frequency bands (about 8 – 10 and 16- 20 Hz) than Regulatory Guide 1.60. The results were also compared to the Korean Standard Building Design Spectrum for the 3 different soil types and showed that thehorizontal response spectra revealed higher values for almost all period bands than the Korean Standard Response Spectrum (500 yrs; Return Period; Seismic province 1; SE soil conditions). Through the qualitative improvements and quantitative enhancement of the observed ground motions, the diversity of the observed ground motions should be considered more significantly to improve the certainty of response spectrum.","PeriodicalId":437780,"journal":{"name":"Journal of Korean Society for Rock Mechanics","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123652942","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}
Pub Date : 2014-10-31DOI: 10.7474/TUS.2014.24.5.335
Soo-Ho Chang, Chulho Lee, Soon-Ju Choi, Jinsuk Hur, J. Hwang
Room-and-pillar mining method is one of the most popular underground mining method in the world. If the room-and-pillar mining method is able to be adopted in civil works, it would be highly probable to reduce underground construction costs and to expand a underground structure in use. Therefore, this study aims to analyze the design procedure of unsupported rock pillars which are indispensable to ensure the stability of a room-and-pillar underground structure. Parametric studies on their key design parameters are also carried out for 125 different kinds of design conditions. From the study, the width of a rock pillar is found to show a linear relationship with its corresponding safety factor. The safety factor of a unsupported rock pillar decreased drastically like a negative exponential function as the ratio of room width to pillar width increases in the same rock strength condition. Based on the parametric studies, a design chart to simply evaluate the geometric design parameters of a unsupported rock pillar satisfying a design safety factor is also proposed in this study.
{"title":"Design of Unsupported Rock Pillars in a Room-and-Pillar Underground Structure by the Tributary Area Method and the Pillar Strength Estimation","authors":"Soo-Ho Chang, Chulho Lee, Soon-Ju Choi, Jinsuk Hur, J. Hwang","doi":"10.7474/TUS.2014.24.5.335","DOIUrl":"https://doi.org/10.7474/TUS.2014.24.5.335","url":null,"abstract":"Room-and-pillar mining method is one of the most popular underground mining method in the world. If the room-and-pillar mining method is able to be adopted in civil works, it would be highly probable to reduce underground construction costs and to expand a underground structure in use. Therefore, this study aims to analyze the design procedure of unsupported rock pillars which are indispensable to ensure the stability of a room-and-pillar underground structure. Parametric studies on their key design parameters are also carried out for 125 different kinds of design conditions. From the study, the width of a rock pillar is found to show a linear relationship with its corresponding safety factor. The safety factor of a unsupported rock pillar decreased drastically like a negative exponential function as the ratio of room width to pillar width increases in the same rock strength condition. Based on the parametric studies, a design chart to simply evaluate the geometric design parameters of a unsupported rock pillar satisfying a design safety factor is also proposed in this study.","PeriodicalId":437780,"journal":{"name":"Journal of Korean Society for Rock Mechanics","volume":"47 11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125712876","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}
Pub Date : 2014-10-31DOI: 10.7474/TUS.2014.24.5.366
Youn-Kyou Lee
The generalized Hoek-Brown (H-B) function provides a unique failure condition for a jointed rock mass, in which the strength parameters of rock mass are deduced from the intact values by use of the GSI value. Since it is actually the only failure criterion which accounts for the rock mass conditions in a systematic manner, the generalized H-B criterion finds many applications to the various rock engineering projects. Its nonlinear character, however, limits more active usage of this criterion. Accordingly, many attempts have been made to understand the generalized H-B condition in the framework of the M-C function. This study presents the closed-form expression relating the tangential cohesion to the tangential friction angle, which is derived by the non-dimensional stress transformation of the generalized H-B criterion. By use of the derived equation, it is investigated how the relationship between the tangential cohesion and friction angle of the generalized H-B criterion varies with the quality of rock masses. When only the variation of GSI value is considered, it is found that the tangential friction angle decreases with the increase of GSI, while the tangential cohesion increases with GSI value.
{"title":"Relationship between Tangential Cohesion and Friction Angle Implied in the Generalized Hoek-Brown Failure Criterion","authors":"Youn-Kyou Lee","doi":"10.7474/TUS.2014.24.5.366","DOIUrl":"https://doi.org/10.7474/TUS.2014.24.5.366","url":null,"abstract":"The generalized Hoek-Brown (H-B) function provides a unique failure condition for a jointed rock mass, in which the strength parameters of rock mass are deduced from the intact values by use of the GSI value. Since it is actually the only failure criterion which accounts for the rock mass conditions in a systematic manner, the generalized H-B criterion finds many applications to the various rock engineering projects. Its nonlinear character, however, limits more active usage of this criterion. Accordingly, many attempts have been made to understand the generalized H-B condition in the framework of the M-C function. This study presents the closed-form expression relating the tangential cohesion to the tangential friction angle, which is derived by the non-dimensional stress transformation of the generalized H-B criterion. By use of the derived equation, it is investigated how the relationship between the tangential cohesion and friction angle of the generalized H-B criterion varies with the quality of rock masses. When only the variation of GSI value is considered, it is found that the tangential friction angle decreases with the increase of GSI, while the tangential cohesion increases with GSI value.","PeriodicalId":437780,"journal":{"name":"Journal of Korean Society for Rock Mechanics","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123904681","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}
Pub Date : 2014-08-31DOI: 10.7474/TUS.2014.24.4.255
Sang-eun Lee, Hak-Sung Kim, Yoon-Ho Jang
The target of this study is large scale rock slope collapsed by around 7 pm on August, 2012, which is located at ○○ limestone quarries of Gangneung city, Gangwondo. The slope prior to the collapse is formed as the height of about 200 m and the average inclination of 45°. The estimated amount of the collapse is about 1,500,000 m 3 with respect to the slope after the collapse. Geotechnical and field investigations such as boring, geophysical prospecting, surface geological survey, geological lineaments, borehole imaging, metric 3D imaging, experimental and field test, mining work by year, and daily rainfall were performed to find the cause of rock slope failure. Various analyzes using slope mass rating, stereonet projection, limit equilibrium method, continuum and non-continuum model were conducted to check of the stability of the slope. It is expected that the cause of slope failure from the results of various analysis and survey is due to the combined factors such as topography, rainfall, rock type and quality, discontinuities, geo-structural characteristics as the limestone cavity and fault zones, but the failure of slope in case of the analysis without the limestone cavity is not occurred. Safe factor of 0.66 was obtained from continuum analysis of the slope considering the limestone cavity, so the ultimate causes of slope failure is considered to be due to the influence of limestone cavity developed along fault zone.
{"title":"A Study on the Failure Cause of Large Scale Rock Slope in Limestone Quarries","authors":"Sang-eun Lee, Hak-Sung Kim, Yoon-Ho Jang","doi":"10.7474/TUS.2014.24.4.255","DOIUrl":"https://doi.org/10.7474/TUS.2014.24.4.255","url":null,"abstract":"The target of this study is large scale rock slope collapsed by around 7 pm on August, 2012, which is located at ○○ limestone quarries of Gangneung city, Gangwondo. The slope prior to the collapse is formed as the height of about 200 m and the average inclination of 45°. The estimated amount of the collapse is about 1,500,000 m 3 with respect to the slope after the collapse. Geotechnical and field investigations such as boring, geophysical prospecting, surface geological survey, geological lineaments, borehole imaging, metric 3D imaging, experimental and field test, mining work by year, and daily rainfall were performed to find the cause of rock slope failure. Various analyzes using slope mass rating, stereonet projection, limit equilibrium method, continuum and non-continuum model were conducted to check of the stability of the slope. It is expected that the cause of slope failure from the results of various analysis and survey is due to the combined factors such as topography, rainfall, rock type and quality, discontinuities, geo-structural characteristics as the limestone cavity and fault zones, but the failure of slope in case of the analysis without the limestone cavity is not occurred. Safe factor of 0.66 was obtained from continuum analysis of the slope considering the limestone cavity, so the ultimate causes of slope failure is considered to be due to the influence of limestone cavity developed along fault zone.","PeriodicalId":437780,"journal":{"name":"Journal of Korean Society for Rock Mechanics","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132376446","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}
Pub Date : 2014-08-31DOI: 10.7474/TUS.2014.24.4.308
Sung Ryong Lee
Abstract In this study, reduced scale experiments were carried out to evaluate the effect of external wind in a road tunnel fire. Experiments were conducted in a 1.1 m × 0.5 m × 50.4 m tunnel. 4.5 litter gasoline was used as a fuel. Temperature, oxygen and carbon monoxide concentration were measured. Smoke reaching time to the tunnel exit was affected by the external wind. When a fire was fully developed, wind effect is reduced compared with the early stage of a fire. CO concentration was reached at more than 1,500 ppm. Key words Road Tunnel, Wind Effect, Smoke movement, Toxic gas, Reduced scale experiment초 록 본 연구에서는 도로터널 화재 시 외부 바람에 의한 영향을 평가하기 위하여 축소모형 실험을 실시하였다 . 1.1 m × 0.5 m × 50.4 m 모형 터널에서 휘발유 4.5리터를 사용하여 실험을 실시하였다 . 터널 내부의 온도, 산소와 일산화탄소 농도를 측정하였다. 외부 바람의 영향에 따라 연기의 출구 도달 시간에 차이를 보였다 . 최성기 이후에는 외부 바람의 영향이 초기에 비하여 작은 것을 확인할 수 있었다 . 화재로 인하여 발생한 일산화탄소가 1,500 ppm 이상 도달하여 피난자에게 치명적인 위해를 가할 수 있다 .핵심어 도로터널, 바람영향, 연기거동, 유독가스, 축소모형실험 1. 서 론 2012년 기준 총 1,578개소의 도로터널이 운영 중에 있으며, 총연장은 1,148.9 km이다. 이 중 775개소가 고속국도에 건설되어 있으며 총 연장은 606 km이고 일반국도에는 421개소가 설치 운영 중이다 . 대부분의 터널은 1 km 미만이지만, 도로 터널 중 38개소가 1 km 이상인 장대터널이며 최근 건설되는 터널들은 점차 장대화되고 있는 추세이다
Abstract In this study, reduced scale experiments were carried out to evaluate the effect of external wind In a road tunnel fire。Experiments were conducted in a 1.1 m × 0.5 m × 50.4 m tunnel。4.5 litter gasoline was used as a fuel。Temperature, oxygen and carbon monoxide concentration were measured。Smoke reaching time to the tunnel exit was affected by the external wind。When a fire was fully developed, wind effect is reduced compared with the early stage of a fire。CO concentration was reached at more than 1,500 ppm。“Key words Road Tunnel”、“Wind Effect”、“Smoke movement”、“Toxic gas”、“Reduced scale experiment”超绿化本研究中，为评价道路隧道火灾时外部风的影响，进行了缩小模型实验。在1.1 m × 0.5 m × 50.4 m模型隧道中使用汽油4.5升进行实验。测定了隧道内部的温度，氧气和一氧化碳浓度。由于外部风的影响，烟气到达出口的时间有所不同。在鼎盛时期以后，可以确认外部风的影响比初期小。火灾产生的一氧化碳达到1500 ppm以上，对逃难者造成致命危害。关键词道路隧道，风影响，烟气行为，有毒气体，缩小模型实验1。截至2012年，共有1578条公路隧道正在运行，总长148.9公里。其中775个建设在高速国道上，总长为606公里，在普通国道上设置运营421个。大部分隧道都不到1公里，但道路隧道中有38个是1公里以上的长台隧道，最近建设的隧道呈逐渐长大化的趋势
{"title":"An Experimental Study on Smoke Movement by the External Wind in Road Tunnel Fires","authors":"Sung Ryong Lee","doi":"10.7474/TUS.2014.24.4.308","DOIUrl":"https://doi.org/10.7474/TUS.2014.24.4.308","url":null,"abstract":"Abstract In this study, reduced scale experiments were carried out to evaluate the effect of external wind in a road tunnel fire. Experiments were conducted in a 1.1 m × 0.5 m × 50.4 m tunnel. 4.5 litter gasoline was used as a fuel. Temperature, oxygen and carbon monoxide concentration were measured. Smoke reaching time to the tunnel exit was affected by the external wind. When a fire was fully developed, wind effect is reduced compared with the early stage of a fire. CO concentration was reached at more than 1,500 ppm. Key words Road Tunnel, Wind Effect, Smoke movement, Toxic gas, Reduced scale experiment초 록 본 연구에서는 도로터널 화재 시 외부 바람에 의한 영향을 평가하기 위하여 축소모형 실험을 실시하였다 . 1.1 m × 0.5 m × 50.4 m 모형 터널에서 휘발유 4.5리터를 사용하여 실험을 실시하였다 . 터널 내부의 온도, 산소와 일산화탄소 농도를 측정하였다. 외부 바람의 영향에 따라 연기의 출구 도달 시간에 차이를 보였다 . 최성기 이후에는 외부 바람의 영향이 초기에 비하여 작은 것을 확인할 수 있었다 . 화재로 인하여 발생한 일산화탄소가 1,500 ppm 이상 도달하여 피난자에게 치명적인 위해를 가할 수 있다 .핵심어 도로터널, 바람영향, 연기거동, 유독가스, 축소모형실험 1. 서 론 2012년 기준 총 1,578개소의 도로터널이 운영 중에 있으며, 총연장은 1,148.9 km이다. 이 중 775개소가 고속국도에 건설되어 있으며 총 연장은 606 km이고 일반국도에는 421개소가 설치 운영 중이다 . 대부분의 터널은 1 km 미만이지만, 도로 터널 중 38개소가 1 km 이상인 장대터널이며 최근 건설되는 터널들은 점차 장대화되고 있는 추세이다","PeriodicalId":437780,"journal":{"name":"Journal of Korean Society for Rock Mechanics","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116783065","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}
Pub Date : 2014-08-31DOI: 10.7474/TUS.2014.24.4.297
Hyunwoo Kim, Dohyun Park, E. Park, C. Sunwoo
Cavern Thermal Energy Storage system stores thermal energy in caverns to recover industrial waste heat or avoid the sporadic characteristics of renewable-energy resources, and its advantages include high injectionand-extraction powers and the flexibility in selecting a storage medium. In the present study, the structural stability of rock mass pillar between these silo-type storage caverns was assessed using a coupled thermal-mechanical model in FLAC. The results of numerical simulations showed that thermal stresses due to long-term storage depended on pillar width and had significant effect on the pillar stability. A sensitivity analysis of main factors indicated that the influence on the pillar stability increased in the order cavern depth < pillar width < in situ condition. It was suggested that two identical caverns should be separated by at least one diameter of the cavern and small-diameter shaft neighboring the cavern should be separated by more than half of the cavern diameter. Meanwhile, when the line of centers of two caverns was parallel to the direction of maximum horizontal principal stress, the shielding effect of the caverns could minimize an adverse effect caused by a large horizontal stress.
{"title":"Stability Analysis of Multiple Thermal Energy Storage Caverns Using a Coupled Thermal-Mechanical Model","authors":"Hyunwoo Kim, Dohyun Park, E. Park, C. Sunwoo","doi":"10.7474/TUS.2014.24.4.297","DOIUrl":"https://doi.org/10.7474/TUS.2014.24.4.297","url":null,"abstract":"Cavern Thermal Energy Storage system stores thermal energy in caverns to recover industrial waste heat or avoid the sporadic characteristics of renewable-energy resources, and its advantages include high injectionand-extraction powers and the flexibility in selecting a storage medium. In the present study, the structural stability of rock mass pillar between these silo-type storage caverns was assessed using a coupled thermal-mechanical model in FLAC. The results of numerical simulations showed that thermal stresses due to long-term storage depended on pillar width and had significant effect on the pillar stability. A sensitivity analysis of main factors indicated that the influence on the pillar stability increased in the order cavern depth < pillar width < in situ condition. It was suggested that two identical caverns should be separated by at least one diameter of the cavern and small-diameter shaft neighboring the cavern should be separated by more than half of the cavern diameter. Meanwhile, when the line of centers of two caverns was parallel to the direction of maximum horizontal principal stress, the shielding effect of the caverns could minimize an adverse effect caused by a large horizontal stress.","PeriodicalId":437780,"journal":{"name":"Journal of Korean Society for Rock Mechanics","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129205948","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}
Pub Date : 2014-08-31DOI: 10.7474/TUS.2014.24.4.282
Hyong Doo Jang, Hyung-sik Yang
Abstract Stoping method has been acknowledged as one of the typical metalliferous underground mining methods. Notwithstanding with the popularity of the method, the majority of stoping mines are suffering from excessive unplanned dilution which often becomes as the main cause of mine closure. Thus a reliable unplanned dilution management system is imperatively needed. In this study, reliable unplanned dilution prediction system is introduced by adopting artificial neural network (ANN) based on data investigated from one underground stoping mine in Western Australia. In addition, contributions of input parameters were analysed by connection weight algorithm (CWA). To validate the reliability of the proposed ANN, correlation coefficient (R) was calculated in the training and test stage which shown relatively high correlation of 0.9641 in training and 0.7933 in test stage. As results of CWA application, BHL (Length of blast hole) and SFJ (Safety factor of Joint orientation) show comparatively high contribution of 18.78% and 19.77% which imply that these are somewhat critical influential parameter of unplanned dilution.
{"title":"A Case Study of Prediction and Analysis of Unplanned Dilution in an Underground Stoping Mine using Artificial Neural Network","authors":"Hyong Doo Jang, Hyung-sik Yang","doi":"10.7474/TUS.2014.24.4.282","DOIUrl":"https://doi.org/10.7474/TUS.2014.24.4.282","url":null,"abstract":"Abstract Stoping method has been acknowledged as one of the typical metalliferous underground mining methods. Notwithstanding with the popularity of the method, the majority of stoping mines are suffering from excessive unplanned dilution which often becomes as the main cause of mine closure. Thus a reliable unplanned dilution management system is imperatively needed. In this study, reliable unplanned dilution prediction system is introduced by adopting artificial neural network (ANN) based on data investigated from one underground stoping mine in Western Australia. In addition, contributions of input parameters were analysed by connection weight algorithm (CWA). To validate the reliability of the proposed ANN, correlation coefficient (R) was calculated in the training and test stage which shown relatively high correlation of 0.9641 in training and 0.7933 in test stage. As results of CWA application, BHL (Length of blast hole) and SFJ (Safety factor of Joint orientation) show comparatively high contribution of 18.78% and 19.77% which imply that these are somewhat critical influential parameter of unplanned dilution.","PeriodicalId":437780,"journal":{"name":"Journal of Korean Society for Rock Mechanics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114333671","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}
Pub Date : 2014-08-31DOI: 10.7474/TUS.2014.24.4.289
Hyung-mok Kim
Abstract A simple analytical approach for stability assessment of underground storage caverns against ground uplift of overburden rock above the rock caverns for high pressurized fluid such as compressed air energy storage (CAES) and compressed natural gas (CNG) was developed. In the developed approach, we assumed that failure plane of the overburden is straight upward to ground surface, and factor of safety can be calculated from a limit equilibrium analysis in terms of this cylindrical shape failure model. The frictional resisting force on the failure plane was estimated by Hoek-Brown strength criterion which replaces with Mohr-Coulomb criterion such that both intact rock strength and rock mass conditions can be considered in the current approach. We carried out a parametric sensitivity analysis of strength parameters under various rock mass conditions and demonstrated that the factor of safety againt ground uplift was more sensitive to Mohr-Coulomb strength criterion rather than Hoek-Brown criterion.
{"title":"Stability Analysis for Ground Uplift in Underground Storage Caverns for High Pressurized Gas using Hoek-Brown Strength Criterion and Geological Strength Index (GSI)","authors":"Hyung-mok Kim","doi":"10.7474/TUS.2014.24.4.289","DOIUrl":"https://doi.org/10.7474/TUS.2014.24.4.289","url":null,"abstract":"Abstract A simple analytical approach for stability assessment of underground storage caverns against ground uplift of overburden rock above the rock caverns for high pressurized fluid such as compressed air energy storage (CAES) and compressed natural gas (CNG) was developed. In the developed approach, we assumed that failure plane of the overburden is straight upward to ground surface, and factor of safety can be calculated from a limit equilibrium analysis in terms of this cylindrical shape failure model. The frictional resisting force on the failure plane was estimated by Hoek-Brown strength criterion which replaces with Mohr-Coulomb criterion such that both intact rock strength and rock mass conditions can be considered in the current approach. We carried out a parametric sensitivity analysis of strength parameters under various rock mass conditions and demonstrated that the factor of safety againt ground uplift was more sensitive to Mohr-Coulomb strength criterion rather than Hoek-Brown criterion.","PeriodicalId":437780,"journal":{"name":"Journal of Korean Society for Rock Mechanics","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128424029","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}
Pub Date : 2014-08-31DOI: 10.7474/TUS.2014.24.4.316
Y. Choi, C. Yoon, Hyun-Ah Kim, H. Choi
In the underground 500 m depth, the high level radioactive waste disposal system is made by boring the tunnel in the base rock and putting the high level waste disposal canister that is the surrounding form with the buffer material. According to the many statistics, it is the tendency that the earthquake increases in the Korean peninsula every year. In case that the earthquake is generated, the disposal canister in the rock mass can be broken due to the shearing force in the underground. Furthermore, a major environmental problems can be caused by the radioactive harmful substances. In this study, the earthquake-proof type buffer material was developed with the protection method safely on the earthquake. The main parameter having an effect on the earthquake-resistant performance was analyzed and the earthquake-proof type buffer material was designed. The shear analysis model was developed and the performance of the earthquake-proof type buffer material was evaluated by using ABAQUS.
{"title":"Development of an Earthquake-Resistant Model for a High-Level Waste Disposal Canister","authors":"Y. Choi, C. Yoon, Hyun-Ah Kim, H. Choi","doi":"10.7474/TUS.2014.24.4.316","DOIUrl":"https://doi.org/10.7474/TUS.2014.24.4.316","url":null,"abstract":"In the underground 500 m depth, the high level radioactive waste disposal system is made by boring the tunnel in the base rock and putting the high level waste disposal canister that is the surrounding form with the buffer material. According to the many statistics, it is the tendency that the earthquake increases in the Korean peninsula every year. In case that the earthquake is generated, the disposal canister in the rock mass can be broken due to the shearing force in the underground. Furthermore, a major environmental problems can be caused by the radioactive harmful substances. In this study, the earthquake-proof type buffer material was developed with the protection method safely on the earthquake. The main parameter having an effect on the earthquake-resistant performance was analyzed and the earthquake-proof type buffer material was designed. The shear analysis model was developed and the performance of the earthquake-proof type buffer material was evaluated by using ABAQUS.","PeriodicalId":437780,"journal":{"name":"Journal of Korean Society for Rock Mechanics","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127941519","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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