필댐의 필터設計規準에 관한 硏究

박인호,임희대 忠南大學校 産業技術硏究所 2001 산업기술연구논문집 Vol.16 No.2

Filters are provided in earthfill and rockfill dams to control erosion of soil in the dam embankment. Therefore, It is very important for dam design to select proper filter criteria. In korea, most of design methods for filter are based on the Terzaghi's and U.S.B.R.'s criteria. In many cases, these criteria have proven to be satisfactory. But, they are deemed conservative in the case of a filter to protect clay. The primary objective of this paper is to suggest suitable filter criteria. Thus, Many a filter criteria that have been proposed until now have investigated and compared each other. The results of this paper are summarized as follows: ①In some cases, Terzaghi's and U.S.B.R.'s criteria did not give good results. ②For widely graded base soils the 'Perfect Filter' can be adopted through checking of its practicability. ③the function of filter can be improved through layered filter design. ④For the internal stability, filter and base materials should be checked by LoweⅢ and Kenney & Lau' method.

光彈性 實驗에 의한 Stress Intensity Factor의 決定法에 關한 硏究

朴熙代,權在度 영남이공대학 1974 論文集 Vol.3 No.-

The mathematical and experimental solutions in regard to the crack tip stress intensity factors has been increased recently in terms of both quality and quantity. The determination of stress intensity factors by stess analysis through photoelastic method often provides the criterion available to the actual design problems. In this paper, the very mehhod was applied to the determination of stress intensity factor around the crack tip in a plane which was subjected under combined shear and tension. For the distribution of stress around the crack tip which has root radius of p=0.25mm, the theoretical formula was determined by shear difference method and confirmed that the formula has slightest difference in value compared with that of experiment.

편측 Crack을 가진 有限板에서 Notch가 應力擴大係數에 미치는 영향

朴熙代 영남이공대학 1985 論文集 Vol.14 No.-

In this paper, by using photoclastic experiment, for the case of a rectangular plate of width W, with crack and notch both sides respectively, is subjected to a uniform tensile stress σ. The stress intensity factors which are affected by depth and radius of notch has been studied. The results can be summerized as follows. In the range between b/w=0.3 and 0.4, the stress intensity factor K_(Ⅰ), equal to about one-third of that of edge cracked plate without having notch and effects of R/W on the stress intensity factor are small.

應力集中部에서의 破壞進路

朴熙代,金鍾周,曺相鳳 영남이공대학 1981 論文集 Vol.10 No.-

It was known by photoelastic and fracture experiments that the theory of fracture path of crack problems, fracture grows to the direction which the maximum shearing stresses arc minimum at the vicinity of crack tip, could be applied to the general stress concentration problems. That is the theory is like this, fracture initiation occurs at the maximum stress concentrated point and frature grows to the direction which the maxi-mum shearing stresses are minimum at the stress concentrated field.

오픈케이슨기초의 침하촉진을 위한 AIR-JET 공법의 적용성 분석

박진원,류제천,임희대 忠南大學校 産業技術硏究所 2003 산업기술연구논문집 Vol.18 No.2

By air jet method, settlement time was much decreased and settlement was reached even to the depth which conventional method could not. The friction reduction increased more than 20 to 30%. In addition to this merits, air jet method can make caisson settlement without separating loading or increasing dead loads. By this method, size of caisson sections can be reduced for resulting in tremendous cost reduction. Also, caisson damage by blasting can be prevented with this method.

周邊圓空의 有限板의 偏側균열에 미치는 影響

조상봉,박희대 영남이공대학 1979 論文集 Vol.8 No.-

Determination of the stress intensity factors was studied by many scientists. There are several methods in this. Up to now, what is the most useful method is Irwin's two parameter method by measuring the maximum distance, direction and the order of a fringe loop. But, in this paper, the stress intensity factors were determined by new method measuring the initial direction. in which the maximum shearing stress is minimum and distance and number of fringe loop in arbitarary direction. In this result, we have several concuiusions. 1) Determination of the stress intensity factor by this new method than conventional method is easy and has small error. 2) When the finite width strip with a oneside crack and a pair of symmetrical near hole is under the uniaxial tension, there is only the stress intensity factor of opening mode and stresses near the crack are increasing as the hole is closed to the crack tip. In particular, when the hole is in the direction of 60°, stresses near the crack are very large 3) In case of unsymmetrical hole, the initial direction in which the maximum shearing stress is minimum is not zero degree but turned. 4) When the distance between hole and crack tip is larger than 3 times of the hole diameter, stresses in the vicinity of crack is not effected by the hole.

Notch을 가진 圓孔을 포함하는 有限錫의 應力集中에 關한 硏究

朴熙代 영남이공대학 1980 論文集 Vol.9 No.-

It is well known that a notch of a circular hole circumference causes a high stress concentration at the end of the notch in a plate. This paper, considering variations of notch length and the angle of notch position investigated the stress concentration on a strip, when subjected to uniaxial load, containing a circular hole with U type notch, by the photoelastic apparatus. As a result of the experiment, it can be concluded that the low part of a curved line in figure'8'indicated that the stress concentration at the end of north lessened than the stress concentration of the same circular hole without notch.

土木工學敎育科 學生의 現場實習 改善方案

林熙大,鄭海駿,金八圭,朴承範 충남대학교 공업교육연구소 1983 論文集 Vol.6 No.2(A)

Education is the process of acquiring or transferring knowledge from our existing body of tyeory and experience. The educational process must provide the Civil Engineers with ability to comprehend and adapt to the continuing changes in the practice of their profession. During the past several years, many practice-oriented educational programs and researchoriented programs have developed for students, but most of them are related to the improvement of curriculum. This paper deals exclusively with the spot-practice of civil engineering students. As the results of an analysis for the spot-practice, it is realized that the past spot-practice was somewhat isolated from outside environment and found too rigid to meet the changing requirements. The improvement of the spot-practice for civil engineering students is strongly recommended to produce qualified teachers, taking into account the changing social demands.

다짐점토의 간극수압 모델에 관한 연구

임희대,박수용 忠南大學校 産業技術硏究所 1995 산업기술연구논문집 Vol.10 No.1

The behavior of an unsaturated soil tested under undrained loading conditions depends on the magnitude of the pore-air and pore-water pressure developed. This paper derives pore pressure parameters that can be utilized in determining the pore pressure response of the compacted clayey materials. Pore pressure parameter expressions are also derived for the pore-water pressures induced as a result of isotropic stress changes and deviator stress changes during undrained loading. The parameters required to computation in the proposed model can be readily determined from the conventional triaxial compression tests. To examine the degree to which the proposed pore pressure model reflects the results of triaxial tests, The back analyses carried out, It is shown from the examination that agreements are generally satisfactory.

ABUTMENT의 경사가 CORE의 응력-변형률에 미치는 영향

임희대,박수용,우원재 忠南大學校 産業技術硏究所 1995 산업기술연구논문집 Vol.10 No.1

Cracking of core presents a serious hazard resulting in possible leakage and failure. For a realistic evaluation of cracking of core one must take into account irregular steep abutment. The present paper is concerned with the most dangerous transverse movements in the embankment which result from non-uniform settlement along the abutments. In this study, the effect of steepness of abutment has been analyzed for 100m high central trapezodial cores with abutment slopes of 1:0.25, 1:0.5, 1:0.75, and 1:1 respectively. Numerical analysis of longitndinal sections of the embankment has been carried out by the application of finite element method. The nonlinear and stress-dependent stress-strain properties of soil is approximated by using a hyperbolic model. The results of the analyses indicate that there is a decrease of vertical stress due to arching action. This decrease is more for steeper slope than for flatter slope.