콘크리트포장 줄눈부의 평가에 관한 기법연구

박제선,이주형,홍창우,이정호,Park, Je-Seon,Lee, Joo-Hyung,Hong, Chang-Woo,Lee, Jung-Ho 강원대학교 산업기술연구소 1999 産業技術硏究 Vol.19 No.-

The joint in the concrete pavement provides a control against transverse or longitudinal cracking at slab, which may be caused by temperature or moisture variation during or after hydration. Without control of cracking, random crack may cause more serious distresses and result in structural or functional failure of pavement system. Sometimes, joint itself, purposed to control crack, may cause a distresses in joint due to its inherent weakness in structural integrity. Thus, the load transfer capacity in joint is very important for serviceability and durability. The purpose of this dissertation was to develop an evaluation system at joints of jointed concrete pavement using finite element analysis was performed using ILLI-SLAB program with a selected variables which might affect fairly to on the performance of transverse joints. The most significant variables were selected from precise analysis. It was concluded that the variables which most significantly affect to pavement deflections are the modulus of subgrade reaction(K) and the modulus of dowel/concrete interaction(G), and limiting criteria on the performance of joints at JCP at 300pci, 500,000 lb/in. respectively.

강구조물(鋼構造物) 맞대기 용접연결부(鎔接連結部)의 피로파괴거동(疲勞破壞擧動)에 관한 연구(硏究)

박제선,정영화,김정태,Park, Je Seon,Chung, Yeong Wha,Kim, Jeong Tae 대한토목학회 1986 대한토목학회논문집 Vol.6 No.3

소재시험편(素材試驗片)과 맞대기 용접시험편(鎔接試驗片)을 대상(對象)으로 피로시험(疲勞試驗)을 행(行)하여 작용최대응력(作用最大應力)-피로수명(疲勞壽命)(S-N)선도(線圖), 소성변형율(塑性變形率)-하중반복회수(荷重反復回數)(${\varepsilon}_p$-N)선도(線圖), 초기균열발생시(初期龜裂發生時)의 소성변형율(塑性變形率)-피로수명(疲勞壽命)(${\varepsilon}_p-N_c$)선도(線圖) 및 균열성장율(龜裂成長率)-응력확대계수변동범위(應力擴大係數變動範圍)(da/dN-${\Delta}K$)선도(線圖)를 그려서 강구조물(鋼構造物) 용접부(鎔接部)에서의 여러가지 피로거동(疲勞擧動)을 검토(檢討)하였다. 본(本) 연구(硏究)에서 얻어진 결과(結果)를 요약(要約)하면 다음과 같다. 하중반복회수(荷重反復回數) $2{\times}10^6$ cycle에서의 피로강도(疲勞强度)는 용접부(鎔接部)가 소재부(素材部)의 약(約) 60%였으며 강복응력(降伏應力)에 대한 피로강도(疲勞强度)의 비(比)는 소재부(素材部)와 용접부(鎔接部)가 각각(各各) 0.72, 0.65로 나타났다. 용접시험편(鎔接試驗片)의 S-N 선도(線圖)는 피로강도(疲勞强度)의 감소(減少)가 완만(緩慢)한 구간(區間)과 피로강도(疲勞强度)의 감소(減少)가 큰 구간(區間)으로 분류(分類)되어 작용최대응력(作用最大應力)이 작을 수록 피로강도(疲勞强度)의 감소(減少)가 커지는 현상(現象)을 보였다. 두 구간(區間)으로 구분(區分)되지 않은 S-N 선도(線圖)에 의한 피로강도(疲勞强度)에 비(比)해 $2{\times}10^6$ cycle에서의 피로강도(疲勞强度)가 약(約) 83%에 해당(該當)하였다. 이는 낮은 응력(應力)에서 용접부(鎔接部) 내부결함(內部缺陷)의 영향(影響)이 크게 작용(作用)하는 때문이 아닌가 생각된다. 용접시험편(鎔接試驗片)의 경우(境遇) 소재시험편(素材試驗片)에 비(比)해, 또 작용최대응력(作用最大應力)이 클수록 초기균열발생(初期龜裂發生)이 빠르고 균열발생직전(龜裂發生直前)의 소성변형율(塑性變形率)의 증가(增加)가 급격(急激)한 것을 알 수 있었다. 소재시험편(素材試驗片)에서 ${\varepsilon}_p-N_c$ 관계식(關係式)의 상수(常數) ${\alpha}$값이 0.42 로 Manson, Coffin의 연구결과(硏究結果)와 거의 일치(一致)하였고 용접시험편(鎔接試驗片)에서는 이 값이 0.28 로 이들의 연구결과(硏究結果)와 큰 차이(差異)를 나타내었는데, 이는 피로(疲勞)에 의한 용접부(鎔接部) 소성변형(塑性變形)의 급격(急激)한 변화(變化)와 내부결함(內部缺陷)의 영향(影響)이 작용(作用)했기 때문이 아닌가 생각된다. 이와 같은 결과(結果)로 볼 때 기존(旣存)의 강구조물(鋼構造物) 및 향후(向後) 신설(新設)될 강구조물(鋼構造物) 용접부(鎔接部)의 품질(品質) 및 피로(疲勞)에 대한 안전성(安全性)에 적절(適切)한 대책(對策)이 요망(要望)되며, 이 분야(分野)에 관한 더 많은 연구(硏究)가 행(行)해져야 되리라고 사료(思料)된다. For the research on the fatigue fracture behavior in the welded joints of steel structures, base metal specimens and welded ones were selected, and the direct fatigue tests were carried out. Thereafter, fatigue-life (S-N) curves, plastic strain-number of cycles (${\varepsilon}_p$-N) curve, the extrapolated fatigue-life (${\varepsilon}_p$-$N_c$) curve, and da/dN-${\Delta}K$ curves were plotted. By these results the followings were obtained. It was shown that the ratio of fatigue strength at $2{\times}10^6$ cycles of the welded specimen to that of the base metal one was 0.6, and that 0.72 for the base metal and 0.65 for the welded one were the ratio of fatigue strength at $2{\times}10^6$ cycles to yielding stress. The S-N curve for the welded specimen was separated into two sections, the low gradient section and the steep section. As this result, it was shown that the more stress became to reduce, the more the reduction of fatigue strength became to be great. It was shown that fatigue strength at $2{\times}10^6$ cycles from this case was about 83 % of that from the S-N curve plotted with one section. It was thought that the reason was that weld flaw acted greatly on the fatigue strength within the low stress range. It was shown that at the instart of crack initiation plastic strain increased abrupt1y in the case of the welded specimen more than the case of the base metal specimen, and increased abruptly in the upper stress range in both cases. It was shown that the experimental constant ${\alpha}$, 0.42, in the base metal nearly accorded with Manson-Coffin's result, but this made a great difference with the case in the welded specimen. It was thought that it was due to the abrupt change of plastic strain and the influence of weld flaw.

강구조물(鋼構造物)의 용접연결부(鎔接連結部)의 피로강도(疲勞强度)에 관한 연구(?究)(I)

박제선,장동일,정영화,Park, Je Seon,Chang, Dong Il,Chung, Yeong Wha 대한토목학회 1985 대한토목학회논문집 Vol.5 No.3

판항교(鈑桁橋)의 덮개 판(板), 수직보강재(垂直補强材) 및 연결판(連結板) 등의 용접연결부(鎔接連結部)를 포함하는 실물(實物)을 modeling 하여 직접(直接) 피로시험(疲勞試驗)을 행하지 않고서도 계산 program에 의해 S-N 선도(線圖)를 그리는 방안을 정립하여 서울의 수동대교(水東大橋), 제(第) 3 한강교(漢江橋) 및 춘천(春川)의 강촌교(江村橋) 등에 적용해 보았다. 이에 앞서, SS 41, SS 50, SWS 50, SWS 58 등의 구조강(構造鋼)으로서 소재(素材), 균열방향에 평행용정, 균열방향에 직각 용접의 compact tension 시험편을 제작 피로시험을 행하여 계산 program 중의 data로 쓰여질 재료상수(材料常數) c 및 m 값을 구하였다. 이 결과 다음과 같은 결과들을 얻었다. 덮개판(板)의 경우 다른 두 부분보다 피로강도(疲勞强度)가 매우 낮았다. 덮개판(板)의 경우 두께가 커지면 피로강도(疲勞强度)가 상당히 낮아지는 외에는 치수에 그다지 큰 영향을 받지 않으며, c 및 m 값에는 매우 민감한 영향을 받음을 알 수 있었다. c 값 및 m 값이 적어질수록 피로강도(疲勞强度)가 상당히 커지며, m 값이 적어지면 S-N 곡신의 경사가 매우 급해짐을 알 수 있었다. 이와 같은 연구가 계속되어 더 많은 data가 집적(集積)되면 앞으로 설계(設計)될 판항교(鈑桁橋)의 피로설계지침(疲勞設計指針)을 마련하고, 또 기존(旣存) 판항교(鈑桁橋)의 피로(疲勞)에 대한 내용년한(耐用年限)을 추정(推定)할 수 있는 기본(基本) pattern이 제공(提供)할 수 있으리라 사료된다. The simplified method drawing the S-N curves in welding joints of the cover plates, the transverse stiffners and the gusset plates of the plate girders by calculation and its computer program without the direct fatigue tests, was established. And the method was applied to the Young- Dong Great Bridge, the 3 th Han River Bridge and the Kang Chon Bridge. Before this, SS 41, SS 50, SWS 50 and SWS 58 were selected, then the compact tension specimens were made by the use of these materials, the things welded by these materials transversely and the ones longitudinally to the crack propagation direction. The fatigue tests were performed by the use of these 'specimens, and the values of material constants c and m were obtained. By these results the followings were obtained. It was showed that the fatigue: strength in the case of the cover plates was much lower than in the case of other two cases. It was showed that, in the case of the cover plates with the cover plates thicker the fatigue strength was lower, but besides this the fatigue strength was not much influenced by the size of specimens. It was showed that in the difference from this the fatigue strength was sensitively influenced by the values of c and m. It was showed that in accordance with the lower values of c and m the fatigue strength was fairly higher, in accordance with the lower values of m the gradient of the S-N curves was abrupter. It was considered that if such data were accumulated continuously, in the near future the basic pattern used availably in providing the indicater of the fatigue design of the plate girders, and presuming the life-proof of the existing plate girders.

강구조물(鋼構造物)의 용접연결부(鎔接連結部)의 피로강도(疲勞强度)에 관한 연구(?究)(II)

박제선,정영화,장동일,Park, Je Seon,Chung, Yeong Wha,Chang, Dong Il 대한토목학회 1986 대한토목학회논문집 Vol.6 No.1

강구조물(鋼構造物)의 girder중(中) 중요형식(重要形式)인 판항(板桁)에서 덮개판(板) 및 수직보강재(垂直補剛材)와 판항(板桁)이나 상자항(箱子桁)의 격점부(格點部)에 사용도는 연결판(連結板) 등의 용접연결부(鎔接連結部)를 포함하는 실물(實物)을 modeling하여 직접 피로시험(疲勞試驗)을 행하지 않고서도 계산에 의하여 S-N 선도(線圖)를 그려서 피로강도(疲勞强度)를 추정(推定)할 수 있는 계산식 및 program을 정립하였다. 또, 실물시험편(實物試驗片)에 대한 피로시험(疲勞試驗)을 행하여 계산에 의한 S-N 선도상(線圖上)에 plot하여 서로 비교 검토하였다. 이로써 다음과 같은 결과를 얻었다. 계산에 의한 피로강도(疲勞强度)가 실험(實驗)에 의한 실제 피로강도(疲勞强度)보다 다소 낮게 나타났다. 계산에 의한 방법은 초기균열(初忌龜裂) $a_i$가 발생한 다음부터 파단시(破斷時)까지의 피로수명(疲勞壽命) $N_p$에 대한 것임에 비해 실험(實驗)에 의한 것은 초기균열(初忌龜裂) $a_i$의 발생수명(發生壽命) $N_c$까지를 포함한 총(總) 피로수명(疲勞壽命) $N=N_c+N_p$에 대한 것이므로 오히려 당연한 결과라 생각된다. 그 차이가 그다지 크지 않으며, 구조물(構造物)의 안전성(安全性)을 생각할 때 계산(計算)에 의한 결과가 안전측(安全側)에 해당하므로 실제 구조물(構造物)의 피로설계(疲勞設計) 시(時) 그대로 적용하여도 무방할 것으로 생각된다. 참고로 저강도강(低强度鋼)인 SS 41 시험편(試驗片)을 각 경우 3개씩 제작하여 같은 피로시험(疲勞試驗)을 행하여 비교해 보았다. 덮개판(板)의 경우 시험최대응력(試驗最大應力) $14kg/mm^2$ 정도 이상(以上)에서 서서히, 수직보강재(垂直補剛材)의 경우 실험최대응력(實驗最大應力) $31kg/mm^2$ 정도 이하(以下)에서 급격(急激)히, 고강도강(高强度鋼)인 SWS 50 시험편(試驗片)의 경우보다 피로강도(疲勞强度)가 더 커진 경향을 나타내고 있다. 이는 저강도강(低强度鋼)에서 피로강도(疲勞强度)가 낮을 것이라는 상식적(常識的)인 기대와는 다른 특징(特徵)이지만 시험편(試驗片) 3개씩만의 결과이므로 확정적(確定的)인 결론이라고 단언(斷言)할 수는 없겠으며, 앞으로 더 많은 실험(實驗)을 행하여 확인해 보아야 할 것이라 생각된다. Welded connectors of the cover plates, the transverse stiffeners of the plate girders, and the gusset plates of the plates girders or box girders, were selected as studying objects. A simplified method of drawing the S-N curves in these welded joints by a computer program without the direct fatigue tests was established. The plots on the S-N curve using the values from the practical fatigue tests were compared with the results from the method of the computer programming. The results of these studies are as follows. It appeared that the fatigue life by calculation method was a little less than the practical fatigue life from the actual tests. The latter values included both life $N_c$ of occurrence of initial crack $a_i$ and the life $N_p$ of propagation of critical crack. On the other hand, the former values included only the life $N_p$. Therefore, these results should be considered as justifiable ones. Since the difference between the two results was not significant, the results by calculation method should be in the conservation side when the safety of the structures was considered. Consequently, the results by calculation method should be applicable to the fracture fatigue design of structure. For reference, the same fatigue tests were performed with the specimens of 3 pieces in each case made of the low-strength steel, SS 41. The results went unexpected showing that the fatigue strength was lower in the case of low-strength steel. That is, in the case of the cover plate, the fatigue strength became slowly higher than the case of high-strength steel, SWS 50. That was observed when the maximum testing stress was higher than $14kg/mm^2$. In addition, in the case of the transverse stiffener, the fatique strength became rapidly higher than the case of SWS 50. That was observed when the maximum testing stress was lower than $31kg/mm^2$. It was thought that more such fatigue tests should be performed for more reliable results.

첨가질량이 존재하는 변단면 4변고정 적층복합판의 진동해석

박제선,김경진,원치문,심도식,Park, Je-seon,Kim, Kyeong-jin,Won, Chi-moon,Shim, Do-sik 강원대학교 산업기술연구소 1995 産業技術硏究 Vol.15 No.-

A method of calculating the natural frequency corresponding to the first mode of vibration of beams and tower structures, with irregular cross-sections and with arbitrary boundary conditions was developed and reported by D. H. Kim in 1974. This method has been developed for two-dimensional problems including the laminated composite plates and was proved to be very effective for the plates with arbitrary boundary conditions and irregular sections. In this paper, the result of application of this method to the clamped composite plates with non-uniform cross-section and with attached point mass/masses is presented.

줄눈콘크리트포장의 하중응력분포 해석

박제선(Park Je Seon),이주형(Lee Joo Hyung),김태경(Kim Tea Kyung),윤경구(Yun Kyung Ku) 강원대학교 산업기술연구소 1998 産業技術硏究 Vol.18 No.-

This study focused on the development of an alternative stress estimation procedure to instantly calculate the critical stresses bonded concrete pavement. Closed form analysis is commonly used to analyze pavement structures. This type of analysis assumes linearelastic material properties and static loading conditions. The well-known ILLI-SLAB finite element program was used for the analysis. Bonded concrete overlay analyzed the stress distribution, behavior and load carrying capacity under track load is made evaluation standard of bonded concrete overlay. In the study, the following results were derived ; The properties of strength is that compress and 3-point bending strength of existing pavement is deteriorated with 184 kg/㎠, 59 kg/㎠ but compress and splitting tensile strength of overlay is satisfied with 465 kg/㎠, 45 kg/㎠. Load transfers is happen at adjacent slab by interlocking under track load. The stress distribution under interior, corner and edge load is described high loading position surrounding then loading position.

새만금을 통일 전진 기지로

박제선(Je-Seon Park) 대한토목학회 2009 대한토목학회지 Vol.57 No.7

지식기반사회가요구하는 창의적인인재

박제선(Je-Seon Park) 한국콘크리트학회 2012 콘크리트학회지 Vol.24 No.2

프로그램 하중을 받는 철도 레일용 강의 피로균열성장거동

박제선(Je Seon Park),정영화(Yeong Wha Chung),이종영(Jong Yeong Lee),윤경구(Kyong Ku Yun) 한국강구조학회 1991 韓國鋼構造學會誌 Vol.3 No.3

PC에서 퍼지?을 이용한 아스팔트 포장의 기능수행가능성 추정

김광우,박제선,이성남,Kim, Kwang Woo,Park, Je Seon,Lee, Seong Nam 대한토목학회 1993 대한토목학회논문집 Vol.13 No.5

본 연구는 퍼지?이론을 도로포장(道路鋪裝)의 공용성(共用性) 평가에 응용하기 위하여 수행되었다. 포장의 견실도(堅實度)와 포장에 가해지는 외력 및 포장의 현재상태에 근거하여 포장을 평가하는 모델을 개발하였다. 퍼지 종합평가를 위하여 설정된 거리등급지수(Gd)의 값이 가장 적절히 균형을 이루도록 5등급의 등급퍼지?과 3등급의 경중(輕重)퍼지?을 설정하였다. 또한 평가기준과 그에 상응하는 퍼지등급척도를 제시하였으며 설정된 평가기준에 준하여 공용성을 평가하는 컴퓨터 프로그램을 개발하였다. 이 프로그램은 각 항목에 대한 Input 값을 질의 문답식으로 화면을 통하여 문의하고 자판을 통하여 사용자가 넣어 주어 수행되도록 작성되었다. 본 연구에서 제시된 퍼지이론에 근거한 포장공용성(鋪裝共用性) 추정기법을 실제 data를 이용하여 수행하여 본 결과 일정도로의 미래 기능수행가능성 추정과, 시범구간의 Gd 값과의 비교 수치를 사용한다면 그 실용가능성이 높음을 알 수 있었다. This study was deviced to apply fuzzy concepts to pavement serviceability evaluation. An evaluation model was developed based on workmanship of pavement during construction, external load on pavement and current distress level. Five rating fuzzy sets, three weight fuzzy sets were developed based on the concept that the most appropriate balance was achieved in Gd which was established for grading the fuzzy overall rating results. Evaluation criteria and corresponding fuzzy rating scale were suggested. A computer program for evaluating serviceability based on the criteria was developed. The program was operated by simply typing in input data on each question and producing output as Gd on the screen. lt was possible to estimate the pavement serviceability level well using this fuzzy-set-based approach.