변위벡터방향성을 이용한 터널 전방 단층대 예측에 관한 연구

김광염 ( Kwang Yeom Kim ),임성빈 ( Sung Bin Yim ),김장겸 ( Jang Kyeom Kim ),서용석 ( Yong Seok Seo ),김진웅 ( Jin Woung Kim ) 대한지질공학회 2010 지질공학 Vol.20 No.4

본 연구에서는 3차원 유한요소해석을 통해 터널 굴착 전방에 위치한 단층대를 내공변위 계측결과를 이용하여 예측하기 위한 방안을 고찰하였다. 이를 위하여 터널과 단층대의 기하학적 위치변화에 따른 수치해석 모델을 구성하였다. 단층대의 경사는 각각 90°, 터널 진행 반대방향 45°, 터널 진행방향 45°의 3가지로 구분하였으며, 각 경사별로 주향을 15° 간격으로 변화시켜 총 15개의 해석 모델에 대하여 분석하였다. 각 모델별 내공변위의 변화양상은 천단부와 측벽부에서의 벡터 방향성을 이용하여 분석하였다. 최종적으로, 총 9가지 조건의 단층대 분포 특성에 해당하는 굴착면 전방 예측 경향선을 도시화 하였으며, 이를 기반으로 일상 계측 데이터 분석을 통한 전방 단층대 출현 및 배향의 예측 방안을 제시하였다. A three-dimensional finite element analysis was performed to predict the location of a fault zone ahead of a tunnel face based on convergence displacement. Geometrical models for the numerical analysis were developed based on the possible geometric intersection between the fault zone and the tunnel. Fifteen fault models were generated from combinations of faults with five different strikes (at 15° intervals) and three dips (vertical, 45° and -45°) relative to the tunnel route. The displacements on the crown and side walls were calculated and analyzed using a vector orientation approach. As a result, nine representative prediction charts were developed, showing location and orientation of the fault zone based on convergence displacement.

주파수 영역 탄성파 완전파형역산을 위한 변위벡터 목적함수의 적용

곽상민 ( Sang Min Kwak ),편석준 ( Suk Joon Pyun ),민동주 ( Dong Joo Min ) 한국지구물리·물리탐사학회 2011 지구물리와 물리탐사 Vol.14 No.3

In the elastic wave equations, both horizontal and vertical displacements are defined. Since we can measure both the horizontal and vertical displacements in field acquisition, these displacements compose a displacement vector. In this study, we propose a frequency-domain elastic waveform inversion technique taking advantage of the magnitudes of displacement vectors to define objective function. When we apply this displacement-vector objective function to the frequency-domain waveform inversion, the inversion process naturally incorporates the back-propagation algorithm. Through the inversion examples with the Marmousi model and the SEG/EAGE salt model, we could note that the RMS error of the solution obtained by our algorithm decreased more stably than that of the conventional method. Particularly, the density of the Marmousi model and the low-velocity sub-salt zone of the SEG/EAGE salt model were successfully recovered. Since the gradient direction obtained from the proposed objective function is numerically unstable, we need additional study to stabilize the gradient direction. In order to perform the waveform inversion using the displacementvector objective function, it is necessary to acquire multi-component data. Hence, more rigorous study should be continued for the multi-component land acquisition or OBC (Ocean Bottom Cable) multi-component survey.

Damage detection using both energy and displacement damage index on the ASCE benchmark problem

Mohammad Javad Khosraviani,Omid Bahar,Seyed Hooman Ghasemi 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.77 No.2

This paper aims to present a novelty damage detection method to identify damage locations by the simultaneous use of both the energy and displacement damage indices. Using this novelty method, the damaged location and even the damaged floor are accurately detected. As a first method, a combination of the instantaneous frequency energy index (EDI) and the structural acceleration responses are used. To evaluate the first method and also present a rapid assessment method, the Displacement Damage Index (DDI), which consists of the error reliability (β) and Normal Probability Density Function (NPDF) indices, are introduced. The innovation of this method is the simultaneous use of displacement-acceleration responses during one process, which is more effective in the rapid evaluation of damage patterns with velocity vectors. In order to evaluate the effectiveness of the proposed method, various damage scenarios of the ASCE benchmark problem, and the effects of measurement noise were studied numerically. Extensive analyses show that the rapid proposed method is capable of accurately detecting the location of sparse damages through the building. Finally, the proposed method was validated by experimental studies of a six‐story steel building structure with single and multiple damage cases.

등방 및 이방성 암반 터널 전방의 연약대 예측을 위한 수치해석적 연구

박창섭,문현구 한국자원공학회 2009 한국자원공학회지 Vol.46 No.3

The concept of displacement vector orientation, defined as the ratio of longitudinal displacement to vertical displacement, is originally suggested in Austria. The field displacement monitoring in the vicinity of a weakness zone has shown a large longitudinal displacement in the direction of the tunnel axis. Such increase of longitudinal displacement observed as the tunnel face approaches a weakness zone can be used to predict the presence of the weakness zone. This study presents the results of predicting the weakness zone ahead of the tunnel face in various ground conditions such as the weakness zones of various thickness and elastic moduli. The weakness zone can be predicted at one to two times the tunnel diameter ahead of the tunnel face. The same procedure is applied to the transversely isotropic ground conditions. The weakness zone can be predicted at the tunnel diameter ahead of the tunnel face. 변위벡터방향의 개념은 터널계측에서 수직방향 변위에 대한 종방향 변위의 비로 정의되는데, 최초로 오스트리아에서의 터널 계측 시 막장면이 연약대에 근접함에 따라 큰 종방향 변위가 계측됨으로써 제안되었다. 이는 막장면이 연약대에 근접함에 따라 증가양상을 보여 연약대 예측에 이용될 가능성이 제기되었다. 본 연구에서는 등방성 암반에서 연약대의 두께와 강성이 변화하는 조건으로 두고 변위벡터방향을 이용하여 이 연약대를 예측하였다. 이때 연약대가 예측되는 막장면의 위치는 연약대 후방으로 터널 직경의 1~2배의 거리 내에 있음을 확인하였다. 또한 평면이방성 암반에서 변위벡터방향을 이용해 연약대 예측을 수행한 결과, 연약대 후방으로 터널 직경의 1배의 거리에 막장면이 도달할 때부터 전방의 연약대를 예측할 수 있었다.

Landslide Displacement Prediction Affected by the Periodic Precipitation, Reservoir Level and Groundwater Level Fluctuations

Fu Ren,Xueling Wu 보안공학연구지원센터 2014 International Journal of u- and e- Service, Scienc Vol.7 No.5

Since the initial impoundment of the Three Gorges Reservoir in June 2003 and approximately 30 m of reservoir level fluctuation, numerous preexisting landslides have been reactivated. To mitigate disastrous landslides, the Baishuihe landslide in the Three Gorges region was selected as a case study in predicting such displacement using the monitoring dataand a radial basis function-support vector machine (RBF-SVM) model.The landslide displacement was strongly influenced by periodic precipitation, reservoir level and groundwater level fluctuations. Primary landslide influencing factors were used as independent variables to predict the displacement using several kernel function types including sigmoid function, polynomial function, and RBF based on SVM model.Prediction results demonstrated that the RBF-SVM with the optimal parameters c, ε and r of 170, 0.05 and 0.04 can provide the best predictive accuracy, with the maximum and minimum absolute error values of 9.84 and 0.47 mm, respectively.

직접측정법과 벡터 CTD해석을 통한 샤시 프레임용 강재의 하중작용각도 변화에 따른 피로균열 전파거동

서기정(Kijeong Seo),송삼홍(Samhong Song) 한국자동차공학회 2004 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

Occuring on fatigue crack surface crack closure effect is a major cause of crack growth rate decreasing. For fatigue crack propagations, especially under mixed-mode loading one is closely difficult to estimate without crack closure effect. Single mode acting only tensile loading component and mixed-mode acting tensile loading component at the same time shear loading component must be analyzed differently the crack closure effect. To measurement crack opening displacement by tensile loading component and crack sliding by shear loading component under mixed-mode loading we used the direct measuring method. Data through direct measuring method was studied using the vector crack tip displacement method. In result, we can correct Paris's equation considering crack closure effect under mixed-mode loading.

코드와 변위 벡터를 이용한 프랙탈 변형

한영덕(Yeong-Deok Han),김기옥(Gi-Ok Kim) 한국콘텐츠학회 2007 한국콘텐츠학회논문지 Vol.7 No.12

프랙탈의 특성에 알맞은 변형 방법을 고려하였다. IFS 프랙탈에서 점의 위치 특성은 공간적 좌표뿐만 아니라 코드에 의해서도 표현된다. 코드는 프랙탈 내에서의 점의 주소로 볼 수 있는데, 코드값을 바꾸어 생기는 점의 이동에 프랙탈적 특성이 있으므로, 코드의 정보를 이용한 세 가지 변형 방법을 제안하였다. 즉, 한점의 이동에 사용될 벡터로서 1) 코드 변환을 통해 얻어지는 다른 점에서의 벡터장 값을 이용하는 방법과 2) 코드 정보를 활용하여 변위 벡터를 정하는 방법을 구현하여 본 결과, 연속적 변형의 특징과 프랙탈적 특징을 모두 갖는 변형을 얻을 수 있었다. 또한 3) 변형이 가해질 영역을 코드를 활용하여 제한함으로써, 고사리의 경우, 보다 자연물에 적합한 변형을 얻을 수 있었다. We consider a deformation method suitable for fractal. In IFS fractal, the position of a point is characterized by its code as well as by its coordinates. Code has a meaning of address for fractal. If we move a point by changing its code, the resulting movement shows fractal behavior. We propose three deformation methods based on code information. For the deformation vector of a point in fractal, 1) we use the vector of a given vector field at the point obtained by code transformation, 2) we use the vector constructed by adding predefined displacement vectors according to the code information of the point. Both methods show a fractal-like character as well as an ordinary continuous deformation character. Also, 3) we can deform fern-fractal more naturally by restricting its deforming region using code form.

듀얼 영 벡터 모드를 갖는 2상 RCD-PWM기법에 의한 유도 모터의 스위칭 소음저감

오승열,위석오,정영국 전력전자학회 2004 전력전자학회 논문지 Vol.9 No.6

In this paper, a two-phase DZRCD(Dual Zero Vector Modes RCD) technique is proposed to develope the problem of a conventional two-phase RCD-PWM (Random Centered Distribution PWM) which gives the power spectra of narrow band range in the high modulation index (M). In the proposed DZRCD technique, the zero vector V0 is selected as V0(111) for M 0.8. Also, V0 is selected as V0(000) for the modulation indices < 0.8. For the implementation of the proposed method, a 16-bit micro-controller C167 was used and the experiments were conducted with the 1.5kw induction motor under no load condition. The experimental results show that the voltage / current spectra is spread to a wide band range, and the switching noise of motor is reduced by the proposed method compared to the conventional random operation. 본 연구에서는 높은 변조지수 M 영역에서는 소음 및 고조파 스펙트럼의 광대역화 효과가 저하되는 2상 RCD-PWM(Random Centered Distribution PWM)기법의 문제점을 개선하고자, 듀얼 영 벡터 모드를 갖는 2상 RCD(Dual Zero Vector Modes RCD : DZRCD)기법을 제안하였다. 제안된 2상 DZRCD기법은 변조지수 M=0.8을 기준으로 하여 M이 0.8보다 큰 영역에서는 영 벡터로 V0(111)를 선택하고, 0.8보다 작은 영역에서는 V0(000)를 선택한다. 제안된 방법을 16비트 마이크로 콘트롤러인 C-167기반의 유도 모터 구동 시스템에 적용해 본 결과, M이 0.8이상인 영역에서 모터의 전압 / 전류 및 스위칭 소음 스펙트럼의 광대역화 특성이 종전의 방법과 비하여 우수함을 확인할 수 있었다.

Moving Pixel Displacement Detection using Correlation Functions on CIS Image

Ryu, Kwang-Ryol,Kim, Young-Bin The Korea Institute of Information and Commucation 2010 Journal of information and communication convergen Vol.8 No.4

Moving pixel displacement detection algorithm using correlation functions for making panorama image on the continuous images is presented in this paper. The input images get from a CMOS image sensor (CIS). The camera is maintained by constant brightness and uniform sensing area in test input pattern. For simple navigation and capture image has to 70% overlapped region. A correlation rate in two image data is evaluated by using reference image with first captures, and compare image with next captures. The displacement of the two images are expressed to second order function of x, y and solved with finding the coefficient in second order function. That results in the change in the peak correlation displacement from the reference to the compare image, is moving to pixel length. The navigating error is reduced by varying the path because the error is shown in the difference of the positioning vector between the true pixel position and the navigated pixel position. The algorithm performance is evaluated to be different from the error vector to vary the navigating path grid.

Nonlinear Prediction Study of Pile Top Displacement Considering the Structural Characteristics of Sliding Bed Rock Mass

( Zihao Sun ),( Liangqing Wang ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

The structural characteristics of the sliding bed rock mass, such as occurrence and thickness, could significantly influence the effectiveness of anti-slide piles. Aimed at the problem that the structural characteristics of the sliding bed rock mass are rarely studied and just remain at the single factor sensitivity analysis level, thus a pile top displacement nonlinear prediction method considering multiple factors of the sliding bedrock mass structural characteristics was proposed. Firstly, influencing rules of structural characteristics of the sliding bed rock mass on anti-slide pile top displacement were quantitatively analyzed through 3DEC numerical test. Secondly, in order to study the comprehensive effects of rock mass structure characteristic on pile top displacement, a database consisting of varied rock mass structure characteristics and corresponding pile top displacements was established by orthogonal test and 3DEC numerical test. Based on this database, a nonlinear prediction model for pile top displacement was established by PSO-SVR method. Finally, the prediction model was verified by in-site measured data from Majiagou landslide, the results showed the high accuracy with a relative error of 5.6% for pile top displacement predicted by the established model. This work provides reference for similar engineering practice and is worthy of promotion.