Pile Driving에 의한 지반진동 측정 및 진동 영향 평가

박선주,박연수,강성후 東新大學校 工業技術硏究所 1998 工業技術硏究 Vol.4 No.-

In this paper, the ground vibrations have been measured. These were induced during pile driving using vibratory hammer at construction field of the 1st subway line in Gwangju. The measurement of ground vibrations was divided by four step to pile driving processing, auger in reclaimed layer, casing, auger in soft rock layer and H-pile driving. The measured data were analyzed by reliability index to determination the vibration equations and the allowable isolate distance for vibration criteria. These equations and allowable isolate distance were suggested with division of ultimate limit state(β=0), serviceability limit state(β=1.28), safety state(β=3), respectively. These equations can be used to predict the peak vibration values where soil conditions are similar to this test site. From this paper, analysis method for vibrations inference using reliability index was estabilished and the attenuation of the ground vibration induced during pile driving using vibratory hammer(T4W) are suggested.

지진하중을 받는 5경간씩 연속인 10경간 강상자형교의 거더간 충돌 분석

박선준,강성후,이정용 東新大學校 工業技術硏究所 2004 工業技術硏究 Vol.10 No.-

The present study determined whether there is collision between girders due to difference in natural period between neighboring vibration systems when a designed earthquake load is applied to a 3-lane 10-span steel box girder bridge with 5-span continuity, which are equipped with friction pot bearings that receive earthquake load, and examined the stability of a formula that calculates the shift of the sliding bearings, which is used in expansion joint design. In addition, this study developed a simple collision evaluation formula directly applicable in determining the possibility of collision.

Hybridization에 의한 반수체 재조합 효모균주의 전분 발효능 증진

박선영,김근,이창후 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.6

Hybridization을 통하여 α-amylase와 glucoamylase를 동시에 분비하는 재조합 단수체 효모균주 Saccharomyces diastaticus K114의 전분분해력, 에탄올내성, 당내성, 고온내성등의 발효특성을 증진시키고자 하였다. 이 단수체 효모균주와 glucoamylase의 활성이 좋고 여러가지 발효능이 우수한 단수체 효모균주 S. diastaticus 1177과의 hybridization 결과 얻어진 hybrid HH64주는 에탄올내성, 고온과 당내성이 증진되었으며, 특히 4%의 전분으로부터 1.6%(w/v)의 에탄올을 생산하여, 1.30%(w/v)의 에탄올을 생산한 재조합균주 S. diastaticus K114보다 전분으로부터 에탄올 생성능이 크게 증진되었다. 한편 이 HH64균주의 전분발효에 있어서의 최적온도 및 pH는 각각 30℃와 5이어다. 개발된 hybrid 효모 HH64sms 20%의 전분으로부터 7.5(w/v)의 에탄올을 직접 생산하였다. To improve the fermentation characteristics(such as starch-degradability, ethanol tolerance, sugar and high-temperature tolerance) of recombinant haploid yeast Saccharomyces diastaticus K114, hybridization technique was used. The hybridization partner was S. diastaticus 1177 which had good glucoamylase activity and fermentability. The best hybrid HH64 showed improved ethanol tolerance, sugar and high-temperature tolerance. Especially, the starch-fermentability was significantly improved, since the hybrid produced 1.60% (w/v) ethanol from 4% (w/v) starch, while the recombinant haploid K114 produced 1.30% (w/v) ethanol. The optimum temperature and pH for the starch-fermentation by the hybrid HH64 was 30℃ and 5, respectively. The hybrid yeast HH64 produced 7.5% (w/v) ethanol directly from 20% (w/v) starch.

유한요소법을 이용한 고성능 콘크리트의 파괴거동

강성후,박선준,박상균 東新大學校 1999 論文集 Vol.11 No.-

As structures made of concrete are getting more high-rise and large-sized, it is necessary to fortify the concrete, the basic material of construction. Concrete's degree of strength is getting more improved due to these basic needs and researches on the subject are actively under way. This study is to predict mechanical behavior and fracture behaviors of high performance concrete. For that purpose, The writer fixed water-cementitious ratio at 33% and used finite element method based upon results of three-point bending tests by having six different types of test pieces with varying mixture ratio of silica fume, water reducer, and superplasticizer. With the finite element method, The writer compared the result of three-point bending test with fracture parameters which was acquired from nonlinear fracture analysis, from which mechanical behavior and fracture behavior of high performance concrete were predicted and usefulness of applied programs was verified.

3경간 연속 중로식 강아치교의 내풍안정성을 고려한 라이즈 비 특성

강성후,박선준,최명기 東新大學校 工業技術硏究所 2004 工業技術硏究 Vol.10 No.-

The most important element is a rise ratio when regarding beauty and economics of arch bridges. Only the effect of dead load has been considered to decide the rise ratio. In this study, when going over the rise ratio of arch bridges, examined the problems, that the determination of the rise ratio by the dead load has, by adding the factor of a determination of optimum rise ratio, which is not only the effect of the dead load that has been currently considered but also the problem with respect to wind resistant dynamic stability that is now taken seriously. Synthetically, when deciding rise ratio that is investigated in basic step of design, it is not necessary to consider the evaluation wind resistant dynamic stability. Therefore the result of this research can be summarized as followes ; If it is identify oneself with rise ratio that the divided ratio due to the tie girder of the 3 continuous spans half-through steel arch bridges cannot cause a big effect in stability the wind resistant dynamic stability. If it is identify oneself with the relative stiffness ratio and girder depth ratio of the 3 continuous spans half-through steel arch bridges that the rise ratio proposes that it uses 0.10~0.30, divided ratio due to tie girder proposes that it uses 1.0~2.5 because of the wind resistant dynamic stability and the stress of the hanger. The rise ratio proposes that it uses 0.16~0.18 is given by the Japanese bridge construction association to obtained in investigation equation between an arch span length and the rise, using 0.1~0.2 at the basic design phase and the divided ratio which using 1.5 due to tie girder generally has been employed to main results and very well agrees with a research accomplishment results.

강박스 거더교 콘크리트 바닥판에 발생하는 크리이프와 건조수축에 관한 연구

강성후,박선준,김현일 東新大學校 工業技術硏究所 2002 工業技術硏究 Vol.8 No.-

It studies the non-structural crack factors that are produced in Steel Box Girder Bridge concrete floor plate using analytical method. It mainly studies humidity and design standard of concrete strength. It used MIDAS CIVIL Ver 5.4.0, a general structure analysis program that applies drying shrinkage rate of domestic road bridge design standard and standard value of creep coefficient, CEF-FIP standard equation and ACI standard equation from the aspect of creep, drying shrinkage and hydration heat to see the effect of the two factors on concrete crack and found the following result. The analytical results of this study showed that the initial stress, which was obtained by ACI standard, exceeds the allowable tensile stress between 5 to 18 days. This result means that even if a bridge is designed and constructed according to design standard, the bridge can have cracks due to various variables such as drying shrinkage, hydration heat and creep that produce stress in slab.

휨부재의 인장철근비 변화에 따른 섬유보강에폭시 판넬의 보강효과평가

강성후,박선준,송영국 東新大學校 工業技術硏究所 2003 工業技術硏究 Vol.9 No.-

FREP is a stiffener that is increasingly used in construction fields today. Concerning it, however, the mechanical characteristics of structures reinforced with it, reinforcement design methods, etc. have not been systematically established yet. The present study evaluated the mechanical characteristics of FREP such as fracture behavior, bending stress enhancement, etc. through a bending test using as variables steel ratio of RC beams reinforced with FREP and the thickness of FREP reinforcement. The RC Beams used in the test showed two types of fraction, which were bending tension fraction and edge stripping fracture, and when the ratio of steel ratio (ρ) to FREP ratio (ρ_(F)) is larger than 1.8, it showed edge stripping fracture. Under same reinforcement condition, if steel ratio is relatively low, reinforcement effect appeared to be high. In addition, if reinforcement thickness increases, the flexural rigidity rises and, as a result, the maximum load also increases, but an excessive increase of reinforcement thickness makes stress concentrate on the reinforced end and cause unexpected brittle fracture (edge stripping fracture) even at a light load.

3경간 중로식 아치교량의 풍하중에 대한 동적안전성

강성후,박선준,정철호 東新大學校 工業技術硏究所 2003 工業技術硏究 Vol.9 No.-

Recently, bridges have been momentous as not only regarding function but also concerning aesthetics. However, when beauty is considered in the design, it is also essential that stability and economics be considered. Moreover, when considering stability, an arch bridge is one of the most stable structures. The most important element is a rise ratio when regarding beauty and economics of arch bridges. Only the effect of dead load has been considered to decide the rise ratio. Therefore, in this study, when going over the rise ratio of 3-Span half through type arch bridges, I examined the problems, that the determination of the rise ratio by the dead load has, by adding the factor of a determination of optimum rise ratio, which is not only the effect of the dead load that has been currently considered but also the problem with respect to wind-resistant dynamic stability that is now taken seriously.

노천 발파패턴에 따른 발파상수의 정량적 평가

강성후,박선준 東新大學校 工業技術硏究所 2002 工業技術硏究 Vol.8 No.-

The actual ground vibrations due to prism cut and trench cut blasting at power plant field have been measured, and the data were analyzed using reliability index(β) to the blast constants and attenuation coefficients. In this study, blast vibrations were suggested with wave component parts of ground vibration to the blast patterns, and were suggested with the division of ultimate limit state(,8 =0), serviceability limit state(β=1.28) and safety state(β =3) respectively. The reliability index 0 means 50% data line obtained by the least squares best-fit line. The reliability index 1.28 and 3 represent bounds below 90%, and 99.9% of the data, respectively. The vibration constants K(particle velocity) for prism cut were evaluated to 333, 619, 1419, respectively and the attenuation coefficients of vibrations was -1.94. From this study, inference and analysis methods of vibration equations using reliability theory were established.

파괴에너지를 고려한 콘크리트 배합설계 프로그램

강성후,박선준,노호현 東新大學校 工業技術硏究所 2001 工業技術硏究 Vol.7 No.-

In the concrete structure, there are many possibilities existing cracks that are produced and developed from the infinitesimal crack in the member, fatigue or corrosion being not existing in the early period. Also, it is not enough to explain the fracutre behavior using the strength theory. Because the concrete reach to the shear due to main cracking after developing infinitesimal crack when it is received the tension stress. But it is hard to solve the structural problem of concrete, because current analysis and design methods of structure are based on the strength of concrete. Hence the subject of this thesis is programming the design of automatic mix design program to do automatic concrete mix design and to consider fracutre energy depending on mix condition.