초록 ▼

1. 현장조사, 현장 및 실내시험1) 현장암반 물성측정 시험 및 실험실 시험2) 갱도 및 채광장의 불연속면 조사3) 해석의 입력자료를 위한 초기지압측정2. 시험대상 석회석 광산에 대한 안정성 평가1) 기존의 암반분류법개선을 통한 광산적용 가능한 암반분류법의 개발2) 암반분류법을 통한 갱도 안정성의 평가3) GSI 암반분류법에 의한 암반특성의 추정4) 새로운 분류법 개발을 위한 요소 평가3. 갱도 및 채광장의 안정성에 영향을 미칠 수 있는 암반공학적 요소 검토1) 수치해석2) 암반분류법을 통한 현지 암반물성의 특성치의 추정식 개발3)

1. 현장조사, 현장 및 실내시험1) 현장암반 물성측정 시험 및 실험실 시험2) 갱도 및 채광장의 불연속면 조사3) 해석의 입력자료를 위한 초기지압측정2. 시험대상 석회석 광산에 대한 안정성 평가1) 기존의 암반분류법개선을 통한 광산적용 가능한 암반분류법의 개발2) 암반분류법을 통한 갱도 안정성의 평가3) GSI 암반분류법에 의한 암반특성의 추정4) 새로운 분류법 개발을 위한 요소 평가3. 갱도 및 채광장의 안정성에 영향을 미칠 수 있는 암반공학적 요소 검토1) 수치해석2) 암반분류법을 통한 현지 암반물성의 특성치의 추정식 개발3) 채광장을 중신으로 한 3차원 수치해석4. 갱내환경개선을 갱내통기 조사 및 분석

Abstract ▼

Underground limestone mmes were investigated based on geotechnical logging of sites, laboratory tests of rock samples and using the numerical analysis technique for ensuring the safety of underground openings. A series of geotechnical tests and investigations on the underground limestone mines enabl

Underground limestone mmes were investigated based on geotechnical logging of sites, laboratory tests of rock samples and using the numerical analysis technique for ensuring the safety of underground openings. A series of geotechnical tests and investigations on the underground limestone mines enabled to develop a new rock mass classification system suitable for the underground mine openings.The stability of the underground openings was analyzed with numerical simulations by taking into consideration the mechanical properties obtained from the geotechnical investigations and in-situ stresses determined from the hydraulic fracturing method. Ventilation surveying of the roadways and working faces were also conducted simultaneously. The results of these studies of the second year are summarized belows:1) Most of the small-scale Korean limestone mines need a technical assistance from the government, because the productivity of the underground mines is generally lower than that of the open pit mines.2) Relying on the experience of the mining engineers, underground openings are excavated without taking into account the rock mechanical properties which can differ from place to place. Based on the RMR and Q values obtained from test mines, a modified rock mass classification is developed and can be applied to the stability analysis of mine openings. The application of new technique is suggested in this study. It provides a good correlation with the actual status of mine openings in two those selected of limestone mines. In this study the new classification system was applied only to the selected limestone mines. Once it is validated hereafter for other mines, a general criterion will be recommended for the evaluation of the stability of limestone mine openings. The deformational modulus of rock mass is usually determined from the RMR and Q system, however these two classifications do not always provide appropriate design parameters. It is found that GSI is more useful for the determination of the mechanical properties and the design parameters of the 3) The results of numerical analysis of the underground openings of Daesung mine showed that the yielding zone and rock falling would take place only at a limited roof of the opening. Stresses are concentrated mainly on the pillars. In the Choongmu mine, the failure zone of the underground openings wasn′t observed and the deformation converged to a stable state. The major principal stress acting on the pillar is about 10MPa, which equals to one tenths of the compressive strength of the intact rock.The parametric study showed that the order of excavation process is not important for the stability. But the large opening by sublevel caving will take place the unstable condition.BEM technique is an alternative of FEM or FDM to solve a three dimensional problems of a complicated underground mine structure. Analysis by Map 3D, a BEM solution showed that a systematic support would be necessary to guarantee the stability of the pillars susceptible to a maximum deformation. A true three dimensional analysis will be carried out by taking into consideration the site specific geotechnical parameters.4) The ventilation study suggests that underground limestone mmes does not have a systematic network with proper intake and return paths. necessary to study on the leakage flow along the natural caves.