반복하중에 의한 비등방정규압밀 점토의 거동

김팔규,김경진,송전섭,김명우 충남대학교 공업교육연구소 1989 論文集 Vol.12 No.1

The objective of this paper is to study experimentally anisotropically consolidated clay which are subjected to repeated loading, and to include in this experimentally study the measurement of pore water pressures, stress - strain, pore water pressure - strain and equilibrium line. For this study the undrained triaxial test is performed by using compression failure, cycled at failure, 2-WAY, non-failure equilibrium test.

압축성 모의 압밀에 대한 수치해석 -다층토를 중심으로-

김팔규,송용희,이환기,Kim, Pal-Gyu,Song, Yong-Hui,Lee, Hwan-Gi 한국지반공학회 1985 대한토질공학회지 Vol.1 No.1

압축성 흙에 대한 천밀침하의 수치해석 연구는 이제까지 Terzaghi의 정밀론을 간단히 확장하여 사용해 왔다. 그러나 비선형 응력-변형관계, 다층토, 큰 변형의 문제를 고려한 보다 복잡한 문제를 탄밀론에 적응한 예는 거의 없었다. 본 연구의 목적은 압축성 흙에서도 다층토를 중심으로 시간과 위치에 따른 추밀도와 과잉간극수압을 보다 실제적인 조건에 부합되도록 하기 위하여 유한차분법을 사용한 수치해석을 근거로 유용한 컴퓨터 알고리즘을 개발하는 데 있다. 압밀식을 해석하는 Explicit Scheme이 전체 깊이에 대한 최적분할 깊이율과 아울러 Operator의 변화에 따른 안정조건과 수고의 관점에서 연구되었다. 침하의 예측에 대해 전통적인 대석과 수식해법이 기초를 둔 개발된 알고리즘으로부터 새로운 알고리즘은 압축성 흙에 있어 전통적인 이론보다 우수한 것으로 판명되었다. Ocassionally it is used for simple extensions of Terzahgi's theory to account for time-depend- tint loading but there is little evidence of application in more complicated consolidation theories that take into account such effects as nonlinear stress.strain, layered systems or large strains. The purpose of this paper provides an efficient computer algorthm based on numerical analysis using finite difference method which account for multi-layered soils to determine the degree of consolidation and excess pore pressures relative to time and positions more realistically. The explicitly scheme of solving the consolidation equations has been investigated from the point of view of the stability conditions and the convergence with variance of the operator as well as to obtain an optimal divided depth ratios of total depth. A comparison of the settlement predictions with both the classical analysis and the algorithm based on numerical analysis indicates that the new algorithm scheme is found to be superior to the classical theory in the layered soils.

일정변형률 압밀시험에 있어서 속도기준과 물성인자와의 상관관계에 관한 연구

김팔규,류권일,최명진,고영헌 忠南大學校 産業技術硏究所 2002 산업기술연구논문집 Vol.17 No.2

Even though STD test based on Terzaghi's 1-D consolidation theory is extensively used to estimate the consolidation constant of soft-clay, it takes too much to perform the test in addition to the problem in estimation of C_v and preconsolidation pressure. To overcome these defects, several types of rapid consolidation test, e.g., constant rate of strain test (CRS) an controlled gradient (CG), are proposed. Because consolidation characteristics obtained from the results of CRS test depend on the rate of strain, it is required to determine the variation rate on the basis of the physical and structural characteristic in a building site, and then perform the test. Several methods determining the rate of strain, e.g., ASTM standard, Smith and Wahls' equation in 1969 and Armour and Drnevich's equation in 1986, have been researched. However, the rules about consolidation rates described in ASTM consider only summary of the rate rules as a trial and error an its criterion also depends only on LL value.

內陸工業團地 造成을 爲한 河川沿岸 開發計劃에 關한 硏究 : 금강유역 문평지구를 중심으로 an Interior Industrial District along the Geum River

金八圭,朴承範 충남대학교 공업기술개발연구소 1974 工業技術開發硏究所論文集 Vol.1 No.1

If we will construct a long dike to avoid flooding along the Geum river at Moon Pyong Ri in Choongnam province and have this idle, large, wet land, be banked, we would have an important interior industrial district which would bring us a great deal of wealth. Before manufacturing an industrial site, the authors have annually whether this is suitable for development planning with reviews of weather, geology, eco-nomics and hydraulics in this paper.

Strip Area의 水平應力을 考慮한 深度別 壓密沈下

金八圭,林熙大 충남대학교 공업교육연구소 1980 論文集 Vol.3 No.2

This paper develops new equation for predicting in-situ consolidation settlement at any depth of a Strip Area subject to a Uniform Pressure and describes the laboratory procedures used to validate the equation. In order to calculate consolidation settlement at any depth, the depth of clay layer was divided into n equal parts of thickness Δz and the vertical stress was determined, based on the Boussinesq solution. Prediction of consolidation settlement is normally based on the results of one -dimensional Oedometer tests using representative samples of the clay. Due to the confining ring the net lateral strain in the test specimen is zero but in many practical situations, however, appreciable lateral strain will occur and the initial excess pore pressure will depend on the in -situ stress conditions. Applying the Bussinesq solution and the Skempton -Bjerrum method which took the lateral strain into account, a new equation was derived that can be used to calculate consolidation settlement at any depth for a Strip Area carrying a Uniform Pressure. The equation proved to predict the consolidation settlement at any depth more closely to the actual field conditions than have previously known equation.

土木工學敎育科 敎育改善에 關한 硏究

金八圭,鄭海駿,權五憲,姜準默,林熙大 충남대학교 공업교육연구소 1981 論文集 Vol.4 No.1

Korea enters a new era of industrial modernization, spurred by her successive five-year economic development plans. The labor-intensive light industry that led the nation's economy in the past decades is undergoing a gradual shift to the technology-intensive heavy and chemical industry. The demand for industry-minded young technician is thereby ever mounting in number in various industrial sectors, which in turn creates many challenging issues on Civil Engineering Education. Among them, this paper deals exclusively with the curriculum of the Department of Civil Engineering Education. As the results of a trade analysis for graduates from technical high schools, it was realized that current curriculum were somewhat isolated from outside environment and found too rigid to meet the changing requirements. Needless to mention, teachers play a vital roles in the technician education. Accordingly the teacher must be qualified well not only in knowledge on the major subjects but also in practices. The improvement of current curriculum is strongly recommended to produce qualified teachers, taking into account the changing social demands. This study is very limited in terms of finance, time allowance and manpower. Accordingly the model curriculum was based on the trade analysis, social requirements and the current curriculum, and its justification was not verified by tests and broad reviews.

이달의 논제 : 소도읍기능화전략

김팔규 대한지방행정공제회 1977 地方行政 Vol.26 No.289

반복하중을 받는 등방정친압밀점토의 거동 및 한계반복응력

김팔규,송전섭 한국지반공학회 1988 대한토질공학회지 Vol.4 No.3

반복하중을 받는 정토의 거동은 단일하중에 의한 결과와 매우 상리하게 나타나며, 그중에서도 특히 간극수려의 거동은 상당히 중요하다. 본 연구는 반복하중 하에서의 점토에 대한 응력-변형 특성을 규명하기 위한 실험적 연구로서 하 중을 가하는 동안에 발생하는 간극수려에 대하여도 언급하였다. 시료는 삼축용기 안에서 24시간동안 등방려밀시켰으며, 삼축시험은 비배수상태 하에서 재성형된 시료에 때하여 압축파괴, 파괴반복, 비파괴 평형시험을 변형제어방법으로 수행하였다. 이에 따라 어느 특정한 시료의 거동을 뚜렷하게 서로 다른 두가지 양상으로 구분하는 반복응력의 한계치가 존재 함을 확인할 수 있었다. The behavior of clays subjected to Repeated loading has been shown to be very different from the behavior under a single load application. Especially the behavior of pore water pressure is Qf considerable importance. The objective of this work is to experimentally study the stress-strain characteristics of clays, and this study includes the pore water pressure which is built up during the load repetition. For this study, the samples were consolidated isotropically in the triaxial cell during 24 hours, .and monotonic strain controlled triaxial test is carried out by uslng the tests of Compression failure, Cycled at failure, and Nonfailure equilibrium on remoulded samples under undrained .condition . Consequently there exists a critical level of repeated loading which seperates the behavior of a particular sample into two distinctly different patterns.

CRS 압밀시험속도 산정에 관한 연구

김팔규,류권일,최명진,고영헌 충남대학교 공업교육연구소 2002 論文集 Vol.25 No.1

Even though STD test based on Terzaghi's 1-D consolidation theory is extensively used to estimate the consolidation constant of soft-clay, it takes too much time to perform the test in addition to the problem in estimation of C_v and preconsolidation pressure. To overcome these defects, several types of rapid consolidation test, e.g., Constant Rate of Strain Test (CRS) and Controlled Gradient (CG), are proposed. Because consolidation characteristics obtained from the results of CRS test depend on the rate of rate of strain, it is repuired to determine the variation rate on the basis of the physical and structural characteristic in a building site, and then perform the test. Several methods determining the rate of strain, e.g., ASTM standard, Smith and Wahls' equation in 1969 and Armour and Drnevich's equation in 1986, have been researched. However, the rules about consolidation rates described in ASTM consider only the summary of the rate rules as a trial and error and its criterion also depends only on LL value. In this thesis, the test rate and parameters related in addition to LL value considered on ASTM basis are esamined in many fidlds of view ane the corresponding rate criterion is proposed.

1次元 壓密에 대한 硏究

金八圭 충남대학교 공업교육연구소 1982 論文集 Vol.5 No.2

The purposes of this paper are to point out a method of using finite difference to solve one-dimensional consolidation problems more realistically, to compare finite difference and classical analysis and to apply the finite difference method to some actual problems. The results obtained from the new scheme were in good agreement with the measured values of a trial embankment constructed on the alluvium of four-layered soils, and a comparison of the settlement predictions indicates that the new scheme is found to be superior to on other scheme.