Journal of the Korean GEO-environmental Society (한국지반환경공학회 논문집)

Korean Geo-Environmental Society (한국지반환경공학회)
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Effect of the Height of the Slope on the Topology Optimization of Soilnail

비탈면의 높이가 쏘일네일 위상최적화에 미치는 영향

  • Received : 2018.10.19
  • Accepted : 2018.11.19
  • Published : 2019.01.01
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Abstract

In this paper, we introduced phase optimization techniques in the Soil-Nail design to optimize the reinforcement required for each grade level. The optimal design results at the maximum slope height were further amplified to allow for phase optimization of the horizontal spacing of the Nail in accordance with the change in the height of the slope. The limit equilibrium analysis was performed by step-by-step sloping height, and the safety factor exceeded when the horizontal spacing of four days was fixed. The process of optimization was effectively carried out by densifying the required reinforcement depending on the slope elevation. Also limited to reflect the axial force of the nail into the reinforcement details.Using the method, the members' strength was reflected. When phase optimization technique is applied for each slope height by calculating the stiffening precision, it is judged that it will be more economical to optimize horizontal intervals by effectively reducing the repeated reinterpretation process that satisfies the reference safety ratio for each slope height.

본 논문에서는 쏘일네일 설계에 위상최적화 기법을 도입하여 비탈면 높이별로 필요로 하는 보강력을 최적화하였다. 최대 비탈면 높이에서의 최적설계 결과를 보강형상밀도화하여 비탈면의 높이 변화에 따라 적용 시 쏘일네일의 수평간격의 위상최적화가 가능하였다. 단계별로 비탈면 높이를 달리하여 한계평형해석을 수행하고 쏘일네일의 수평간격이 고정값일 때 초과되는 안전율을 확인하였다. 비탈면 높이에 따른 필요 보강력을 밀도화 함으로써 최적화의 과정을 효율적으로 수행할 수 있었다. 또한 쏘일네일의 축력을 보강형상밀도에 반영하기 위하여 유한요소법을 이용하여 부재력을 반영하였다. 보강형상밀도를 산정하여 비탈면 높이별로 위상최적기법을 적용 시 비탈면 높이마다 기준안전율을 만족하는 반복적인 재해석과정을 효과적으로 감소시킬 수 있어 수평간격을 위상 최적화하는 방법이 경제적인 설계에 활용도가 높을 것으로 판단된다.

Keywords

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Fig. 1. Topology optimization process for a structure with equivalent material properties (Bendsoe & Sigmund, 2004)

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Fig. 2. Concept of shape density (MIDAS IT, 2013)

HJHGC7_2019_v20n1_43_f0003.png 이미지

Fig. 3. Factor of safety by LEM (Bishop)

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Fig. 4. Analysis results of slope height changes

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Fig. 5. Shape density with slope height

Table 1. Types of optimum design

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Table 2. Soil parameters by analysis application

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Table 3. Model slope case

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Table 4. Dimensions of reinforcement

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Table 5. Factor of safety by LEM

HJHGC7_2019_v20n1_43_t0005.png 이미지

Table 6. Shape density with slope height

HJHGC7_2019_v20n1_43_t0006.png 이미지

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