• 제목/요약/키워드: Stability chart

검색결과 89건 처리시간 0.024초

역학적으로 엄밀한 사면안정도표의 제안 (Proposal of a Mechanically Rigorous Slope Stability Chart)

  • 김종민
    • 한국지반공학회논문집
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    • 제20권1호
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    • pp.121-129
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    • 2004
  • 본 연구에서는 균질 단순사면의 안정검토 시 간편하게 이용할 수 있는 사면안정도표를 제안하였다. 기존의 사면안정도표는 대부분 한계평형해석에 근거하고 있으나 잘 알려진 바와 같이 한계평형해석은 역학적으로 엄밀한 해석기법이 아니다. 반면 가상일방정식과 소성이론의 경계정리를 이용한 한계해석은 계산이 간단하면서도 역학적 엄밀성이 보장되어 사면과 같은 지반구조물의 안정해석에 적합한 해석기 법이다. 특히 유한요소와 최적화기법을 적용한 수치한계해석은 다양한 사면조건을 반영할 수 있을 뿐 만 아니라 안정해의 최적값을 효율적으로 산정할 수 있는 장점이 있다. 본 연구에서는 유효응력 개념의 수치한계해석기법을 개발하고 다양한 사면조건에 대한 해석을 수행하여 역학적으로 엄밀한 사면안정도표를 제안하였다. 유효응력해석을 위한 간극수압의 영향은 기존의 사면안정도표와 같이 간극 수압비를 적용하여 고려하였다. 제안된 안정도표와 Spencer 안정도표를 비교한 결과 Spence. 안정도표를 적용하여 사면설계를 수행할 경우 안전측 설계가 됨을 알 수 있었다.

Strain Analysis of Crust at the Stabilization Stage Using and Applied Statistical Analysis

  • Kim, Hyeong-Sin;Yun, Hyun-Seok;Chae, Byung-Gon;Choi, Jung-Hae;Seo, Yong-Seok
    • 지질공학
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    • 제25권1호
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    • pp.9-20
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    • 2015
  • A strainmeter goes through a period of instability immediately after installation. To determine the stability of strainmeters installed around the Andong fault zone, South Korea, an x-MR control chart analysis and a T2 control chart analysis were conducted. The x-MR control chart analysis used an empirically determined 3σ control limit line to identify abnormal data in recently installed strain gauges. In the T2 control chart analysis, the control limit line was set at a confidence of 95%. A comparison of the early stage of measurement with the terminal stage of measurement for three months after installation indicates that stabilization depends on the location and direction of each strain gauge in x-MR control chart analysis. In the T2 control chart analysis, the number of values exceeding the control limit line decreased as the terminal stage was approached. Based on these results, it is suggested that the 3σ control limit line of an x-MR control chart can be used as a standard for single gauge stability, and that the 95% confidence limit of a T2 control chart analysis could be used as the standard for the stability of multi-gauge strainmeters.

드릴링 M/C의 Chatter 해석과 동적안정성에 관한 연구 (A Study on the Chatter Analysis & Dynamic Stability of Drilling Mchine)

  • 박종권;이후상
    • 한국정밀공학회지
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    • 제6권2호
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    • pp.77-87
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    • 1989
  • This study is carried out to estimate the influence of cutting speed on the dynamic stability of a drilling machine. The theoretical stabilityu chart is constructed by using the measurd dynamic characteristics of the drilling machine. The critical cutting width and speed predicted from the stability chart show excellent agreements with those measured. Therefore it is confirmed that the analysis technique used in this study is useful for the prediction of the dynamic instability and improvement of the dynamic characteristics of drilling machines.

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프로그램과 도표에 의한 사면안정해석의 비교연구 (A comparative study on slope stability by program and stability cahrt)

  • 주경훈;김주철;이종규
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 1994년도 가을 학술발표회 논문집
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    • pp.253-258
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    • 1994
  • Recently, computer technique for the analysis of slope stability enable to reduce a considerable time and efforts. And also, stability problems can be approached by using stablility chart which was basically developed to handle the problems under simple conditions only. Most of the conventional slope stability computer programs and stability chart are still based on the general limit equilibrium method. 16 types of sample slopes and 2 types of failure slope were compared and analysed by stability charts and programs. This research work intend to apply 4 types of conventional computer programs based on the same theoretical backgroung and 7 types of stability charts for solving the same stability problems and the results and compared and analysed in order to justify their reliability.

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터널천단변위와 암석 또는 암반의 일축압축강도를 이용한 시공 중인 터널의 예비 안정성 평가 (The Pre-Evaluation of Stability during Tunnel Excavation using Unconfined Compression Strength of Intact Rock or Rock Mass and Crown Settlement Data)

  • 박영화;문홍득;하만복
    • 한국도로학회논문집
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    • 제17권6호
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    • pp.27-32
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    • 2015
  • PURPOSES : It is difficult to estimate tunnel stability because of lack of timely information during tunnel excavation. Tunnel deformability refers to the capacity of rock to strain under applied loads or unloads during tunnel excavation. This study was conducted to analyze a methods of pre-evaluation of stability during tunnel construction using the critical strain concept, which is applied to the results of tunnel settlement data and unconfined compression strength of intact rock or rock mass at the tunnel construction site. METHODS : Based on the critical strain concept, the pre-evaluation of stability of a tunnel was performed in the Daegu region, at a tunnel through andesite and granite rock. The critical strain concept is a method of predicting tunnel behavior from tunnel crown settlement data using the critical strain chart that is obtained from the relationship between strain and the unconfined compression strength of intact rock in a laboratory. RESULTS : In a pre-evaluation of stability of a tunnel, only actually measured crown settlement data is plotted on the lower position of the critical strain chart, to be compared with the total displacement of crown settlement, including precedent settlement and displacement data from before the settlement measurement. However, both cases show almost the same tunnel behavior. In an evaluation using rock mass instead of intact rock, the data for the rock mass strength is plotted on the lower portion of the critical strain chart, as a way to compare to the data for intact rock strength. CONCLUSIONS : From the results of the pre-evaluation of stability of the tunnel using the critical strain chart, we reaffirmed that it is possible to promptly evaluate the stability of a tunnel under construction. Moreover, this research shows that a safety evaluation using the actual instrumented crown settlement data with the unconfined compression strength of intact rock, rather than with the unconfined compression strength of a rock mass in the tunnel working face, is more conservative.

Soil Nailing 공법을 적용하기 위한 사면보강 설계도표에 관한 연구 (A Study of Reinforced Design Chart for Soil Nailing Slopes)

  • 서진원;김학문;장경준
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2009년도 춘계 학술발표회
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    • pp.1009-1019
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    • 2009
  • Soil nailing method is widely used in reinforcing slopes and excavating earth. The analysis of nail-reinforced slopes, in order to determine the economical length ratio and nail angle, complicated analytical need to be applied by means of computer programs. Therefor this suggested Soil stability Chart for nailed slopes which may be very useful for pre-design, rapidly design, and final check. Three slope types, three nail length and three nail angles are selected for the stability analysis by using limit equilibrium method of Bishop and French Method. From the above results, this study propose the slope reinforced design charts for dry season and rainy season. This proposed reinforced design charts can check dry season as well as rainy season, also these charts can provide reinforcing requirement, soil nail's economical length ratio and nail angle as well.

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An investigation into the motion and stability behaviour of a RO-RO vessel

  • Mohan, Poonam;Shashikala, A.P.
    • Ocean Systems Engineering
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    • 제9권2호
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    • pp.157-177
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    • 2019
  • Studies on motion response of a vessel is of great interest to researchers, since a long time. But intensive researches on stability of vessel during motion under dynamic conditions are few. A numerical model of vessel is developed and responses are analyzed in head, beam and quartering sea conditions. Variation of response amplitude operator (RAO) of vessel based on Strip Theory for different wave heights is plotted. Validation of results was done experimentally and numerical results was considered to obtain effect of damping on vessel stability. A scale model ratio of 1:125 was used which is suitable for dimensions of wave flume at National Institute of Technology Calicut. Stability chart are developed based on Mathieu's equation of stability. Ince-Strutt chart developed can help to capture variations of stability with damping.

한계평형해석을 사용한 Soil Nailing보강사면의 설계도표의 제안 (The Design Charts for Soil Nailing Slopes Through Limit Equilibrium Method)

  • 김학문;장경준;서진원
    • 한국산학기술학회논문지
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    • 제10권10호
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    • pp.2794-2802
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    • 2009
  • Soil Nailing 공법은 사면보강과 지반굴착시 많이 사용되고 있는 공법이다. 일반적인 Soil Nailing의 해석은 복잡한 컴퓨터해석을 필요로 하지만 본 연구에서는 한계평형 해석을 이용하여 단순사면에 Soil Nailing 보강검토시 간편하게 사용할 수 있는 설계도표를 제안하였다. 3가지 사면형태와 네일의 길이비, 입사각을 선택하여 한계평형해석에 근거한 Bishop법과 French Method를 적용하여 해석하였으며 신속한 설계가 요구되는 경우나 예비설계단계, 그리고 설계에 대한 최종 검토시 간편하게 사용할 수 있는 안정도표로 정리하였다. 본 연구에서 제안한 도표를 Taylor의 도표와 비교한 결과 유사한 안전율을 계산할 수 있었으며 Soil Nailing 보강도표를 네일의 길이비와 입사각의 선택시 활용한다면 해석에 따른 시간을 많이 줄일 수 있을 것으로 판단된다.

한계해석을 이용한 토사면의 항복지진계수 산정도표 제안 연구 (A Study on the Development of a Stability Chart for Yield Seismic Coefficient of Soil Slope Using Limit Analysis)

  • 최상호;김종민
    • 한국지반공학회논문집
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    • 제26권3호
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    • pp.47-57
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    • 2010
  • Newmark 활동블록법을 이용하여 지진시 토사면의 영구변위를 산정할 경우 항복지진계수의 결정은 매우 중요하다. 그러나 기존에 제안된 항복지진계수는 일반적으로 한계평형해석에 기초하고 있어 역학적조건 중 평형조건만을 만족하므로 역학적으로 엄밀하지 못하다. 따라서 기 제안된 항복지진계수를 이용하여 토사면의 영구변위를 산정할 경우 문제점를 야기할 수 있다. 한계해석은 역학적으로 엄밀한 해의 범위를 산정하는 해석기법으로 항복지진계수의 역학적 엄밀성을 판단하는데 유용하다. 본 연구에서는 안정수, 사면경사, 지반물성 등에 따른 다양한 해석조건을 고려하여 실무적용에 유용한 항복지진계수 산정도표를 제안하였다.