Journal of Korean Society for Rock Mechanics最新文献_第3页

Pattern of Shear-induced Fracture Development in en Echelon Array : Discrete-element Approach en Echelon阵列剪切裂缝发育模式:离散元方法

Journal of Korean Society for Rock Mechanics Pub Date : 2015-08-31 DOI: 10.7474/TUS.2015.25.4.359

Soondal Kwon, Seungwan You, Sanghoon Kwon, Ki-Seog Kim

{"title":"Pattern of Shear-induced Fracture Development in en Echelon Array : Discrete-element Approach","authors":"Soondal Kwon, Seungwan You, Sanghoon Kwon, Ki-Seog Kim","doi":"10.7474/TUS.2015.25.4.359","DOIUrl":"https://doi.org/10.7474/TUS.2015.25.4.359","url":null,"abstract":"Abstract Rock masses include various rock discontinuities such as faults, joints, and bedding planes. These discontinuities appear as complex structures in geometry. In this study, growth patterns of fractures between two stepping shear fracture tips are numerically modeled using PFC2D (Particle Flow Code). The numerical model showed not only incipient growth of fractures at the tips of preexisting fractures but also subsequent growth of the new fractures. It is observed from all of the experiments that the incipient fractures are tensile cracks developed at 30～57° to the preexisting fractures and the subsequent growth of these fractures were at low angles to the preexisting fractures this study.Key words Shear fracture, Discrete-element code, PFC, Numerical experiment, Fracture growthoints set초 록 암반에는 단층, 절리, 층리 등의 불연속면이 많이 포함되어 있다 . 이러한 불연속면은 기하학적 복합성에 의해 복잡한 구조로 나타난다 . 이 연구는 스텝으로 배열된 두 전단균열의 끝에서 나타나는 구조 발달을 수치 해석적으로 연구하였다 . 이 연구에서는 PFC2D(Particle Flow Code) 프로그램을 이용하여 두 전단균열의 끝에서 형성되는 초기균열(incipient fracture)뿐만 아니라 초기균열에서 덧자라는 균열의 성장과정을 살펴보았으며 , 균열발생 시 나타나는 주변응력상태를 관찰하였다 . 모든 실험 결과에서는 균열 끝에서 발생한 초기 균열 대부분이 인장균열에 의한 것으로 나타났으며 , 균열의 전파각은 초기에 30～57°에서 실험이 더 진행되면 저각으로 발달하는 것으로 나타났다.핵심어 전단균열, 개별요소법, PFC, 수치실험, 균열성장","PeriodicalId":437780,"journal":{"name":"Journal of Korean Society for Rock Mechanics","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125187533","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}

引用次数: 0

A Case Study of Site Investigation and Ground Stability Analysis for Diagnosis of Subsidence Occurrence in Limestone Mine 石灰石矿山沉陷发生诊断的现场调查与地面稳定性分析实例研究

Journal of Korean Society for Rock Mechanics Pub Date : 2015-08-31 DOI: 10.7474/TUS.2015.25.4.332

Seung-Joong Lee, Byung-ryeol Kim, Sung O. Choi, Seokhoon Oh

引用次数: 0

Case Study on Groß Schönebeck EGS Project Research in Germany 德国Groß Schönebeck EGS项目研究案例分析

Journal of Korean Society for Rock Mechanics Pub Date : 2015-08-31 DOI: 10.7474/TUS.2015.25.4.320

K. Min, Sehyeok Park, G. Zimmermann

{"title":"Case Study on Groß Schönebeck EGS Project Research in Germany","authors":"K. Min, Sehyeok Park, G. Zimmermann","doi":"10.7474/TUS.2015.25.4.320","DOIUrl":"https://doi.org/10.7474/TUS.2015.25.4.320","url":null,"abstract":"This paper presents a case study of an enhanced geothermal system(EGS) demonstration project conducted in Gros Schonebeck, Northerm Germany, focusing on hydraulic stimulation. The project was conducted with doublet system in sandstone and volcanic formations at 4 - 4.4 km depth. Under normal faulting to strike-slip faulting stress regime, hydraulic stimulations were conducted at injection and production wells by massive waterfrac and gel-proppant fracturing. Injectivity index increased from 0.97 m 3 /(hr*MPa) to 7.5 m 3 /(hr*MPa) and productivity index increased from 2.4 m 3 /(hr*MPa) to 10.1 m 3 /(hr*MPa) by a series of hydraulic stimulations at both wells. After circulation tests through injection and production wells, however, productivity index decreased from 8.9 m 3 /(hr*MPa) to 0.6 m 3 /(hr*MPa) in two years. Slip tendency analysis for the stimulation in volcanic layer estimated the required pressure for shear slip and its preferred orientations and it showed reasonable match with actual stimulation results. Through the microseismicity observation for the stimulation of volcanic formation, only 80 seismic events with its moment magnitudes in -1.8","PeriodicalId":437780,"journal":{"name":"Journal of Korean Society for Rock Mechanics","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124869255","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}

引用次数: 1

Risk Of Buildings Damage Due To Subsidence During Tunnelling Under The Buildings In Sand-Gravel Layer 砂砾层建筑物下隧道施工沉陷破坏建筑物的风险

Journal of Korean Society for Rock Mechanics Pub Date : 2015-08-31 DOI: 10.7474/TUS.2015.25.4.383

Cheehwan Kim

{"title":"Risk Of Buildings Damage Due To Subsidence During Tunnelling Under The Buildings In Sand-Gravel Layer","authors":"Cheehwan Kim","doi":"10.7474/TUS.2015.25.4.383","DOIUrl":"https://doi.org/10.7474/TUS.2015.25.4.383","url":null,"abstract":"Abstract It is analyzed the risk of building damage due to ground surface subsidence occurred during constructing a tunnel below buildings in sand-gravel layer. The overburden and the thickness of sand-gravel layer is about 20m and the width and the height of the tunnel are 12m and 8.6m, respectively. The tunnel is pre-reinforced by umbrella method with three rows of long steel pipes and grouting. Surface subsidence is measured at 36 points surrounding buildings and measured data are used to calculate optimized three dimensional subsidence surface. Depending on the building location, deflection ratio and horizontal strain are calculated to evaluate the risk of building damage. No damage occurs at the buildings because of both the small deflection ratios involved 1~4mm subsidence and compressive horizontal strains.Key words Sand gravel layer, Multi stage grouting through large diameter steel pipe, Ground surface subsidence, Risk of damage to building초 록 모래자갈층에서 터널굴착 시 발생하는 지표침하에 의해 지상빌딩에 발생하는 손상도를 분석하였다 . 모래자갈층의 두께와 터널까지의 심도는 약 20m이고 터널의 폭과 높이는 각각 12m, 8.6m이다. 터널은 막장전방을 3열의 강관다단그라우팅으로 보강하면서 시공하였다. 터널시공 중에 빌딩주변 36개소에서 지표침하를 계측하였고 이를 이용하여 3차원 지표침하면을 구하고 빌딩의 위치에 따라 처짐비와 수평변형율로 빌딩의 손상도를 평가하였다. 시공 중 계측된 지표침하는 약 1~4mm로 작았고 빌딩은 수평압축변형을 받는 상태가 되어 빌딩에 손상이 발생하지 않았다.핵심어 모래자갈층, 강관다단그라우팅, 지표침하, 빌딩손상도","PeriodicalId":437780,"journal":{"name":"Journal of Korean Society for Rock Mechanics","volume":"178 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132677494","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}

引用次数: 1

Applicability Study of Geotextile Mesh Soil Nail on Slope Reinforcement Using Numerical Analysis 土工布网土钉在边坡加固中的适用性数值分析

Journal of Korean Society for Rock Mechanics Pub Date : 2015-06-30 DOI: 10.7474/TUS.2015.25.3.264

K. You, Y. Jung, Jiwon Ha

{"title":"Applicability Study of Geotextile Mesh Soil Nail on Slope Reinforcement Using Numerical Analysis","authors":"K. You, Y. Jung, Jiwon Ha","doi":"10.7474/TUS.2015.25.3.264","DOIUrl":"https://doi.org/10.7474/TUS.2015.25.3.264","url":null,"abstract":"In this study, the applicability of geotextile mesh soil nails on slopes was evaluated by numerical analysis to reduce environmental problems which a general soil nailing might produce and to improve its economical efficiency and construction convenience. To this end, in situ pull-out tests were conducted for both general soil nail and geotextile mesh soil nail and their pull-out characteristics were analyzed. Also, finite difference method was used to verify the suitability of numerical simulation. Parameters for nail and ground conditions were selected and sensitivity analysis was performed for the evaluation of slope stability. In addition, analysis was performed by limit equilibrium method which is widely used for slope stability analysis in practice. As a result, if the nail diameter was same, there is no big difference between geotextile mesh soil nails and general soil nails in terms of slope stability. Therefore it can be expected that geotextile mesh soil nails could be effective for slope reinforcement since they could keep a slope as stable as general soil nails and give better economical efficiency and construction convenience than general soil nails.","PeriodicalId":437780,"journal":{"name":"Journal of Korean Society for Rock Mechanics","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123894746","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}

引用次数: 1

Effects of Input Parameters in Numerical Modelling of Dynamic Ground Motion under Blasting Impact 爆破冲击下动力地面运动数值模拟中输入参数的影响

Journal of Korean Society for Rock Mechanics Pub Date : 2015-06-30 DOI: 10.7474/TUS.2015.25.3.255

C. Ryu, Byung-Hee Choi, Hyung-Su Jang, Myoung-Soo Kang

引用次数: 0

Estimation of Equivalent Friction Angle and Cohesion of Near-Surface Rock Mass Using the Upper-Bound Solution for Bearing Capacity of Strip Footing 基于条形基础承载力上限解的近地表岩体等效摩擦角和黏聚力估算

Journal of Korean Society for Rock Mechanics Pub Date : 2015-06-30 DOI: 10.7474/TUS.2015.25.3.284

Youn-Kyou Lee

{"title":"Estimation of Equivalent Friction Angle and Cohesion of Near-Surface Rock Mass Using the Upper-Bound Solution for Bearing Capacity of Strip Footing","authors":"Youn-Kyou Lee","doi":"10.7474/TUS.2015.25.3.284","DOIUrl":"https://doi.org/10.7474/TUS.2015.25.3.284","url":null,"abstract":"The generalized Hoek-Brown failure criterion, the strength parameters of which are determined by using the GSI index, is an empirical nonlinear failure criterion of rock mass and has been widely employed in various rock engineering practices. Many rock engineering practitioners, however, are still familiar with the description of the strength of rock mass in terms of friction angle and cohesion. In addition, almost all rock mechanics softwares incorporate the simple linear Mohr-Coulomb function. Therefore, it is necessary to provide a tool to implement the Hoek-Brown function in the framework of the Mohr-Coulomb criterion. In this study, the use of upper-bound solution of limit analysis for bearing capacity of a strip footing resting on the ground surface is proposed for the estimation of the equivalent friction angle and cohesion of rock mass incorporating the generalized Hoek-Brown failure criterion. The upper-bound bearing capacity is expressed in terms of friction angle by use of the relationship between tangential friction angle and tangential cohesion implied in the generalized Hoek-Brown function. The friction angle minimizing the upper-bound bearing capacity is taken as the equivalent friction angle. Through the illustrative implementations of the proposed method, the influences of GSI,  and D on the equivalent friction angle and cohesion are investigated.","PeriodicalId":437780,"journal":{"name":"Journal of Korean Society for Rock Mechanics","volume":"130 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126320564","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}

引用次数: 2

Development and Utilization of Mine Management Software: A Review 矿山管理软件的开发与利用综述

Journal of Korean Society for Rock Mechanics Pub Date : 2015-06-30 DOI: 10.7474/TUS.2015.25.3.221

Sebeom Park, Yosoon Choi

引用次数: 3

A Study on the Upper Ground Reinforcement Effect in Underground Cavern 地下洞室上部地面加固效应研究

Journal of Korean Society for Rock Mechanics Pub Date : 2015-06-30 DOI: 10.7474/TUS.2015.25.3.275

Ki Ho Kim, Jong-Se Lim, Won-Yil Jang

引用次数: 0

Development of a Powder-type Thin Spray-on Liner and Its Performance Evaluation at Different Curing Ages 粉末型薄型喷涂衬板的研制及其不同龄期固化性能评价

Journal of Korean Society for Rock Mechanics Pub Date : 2015-06-30 DOI: 10.7474/TUS.2015.25.3.293

Soo-Ho Chang, Gyu-Phil Lee, Jin-Tae Han, Soon-Ju Choi, Gwi-Sung Hwang, Myung-Sik Choi

引用次数: 8