Experimental Evaluation of Tension and Shear Capacities of New Headed Cast-in Specialty Inserts in Cracked Concrete

정상덕,오창수,이창환 한국콘크리트학회 2023 International Journal of Concrete Structures and M Vol.17 No.5

Headed cast-in specialty inserts are often developed and employed for their improved constructability and time-saving benefits over traditional cast-in and post-installed anchors. Their acceptance criteria (AC 446) were established by The International Code Council Evaluation Service. However, previous research on the behavioral characteristics of headed specialty inserts is rare. This study investigates the performance of a newly developed insert anchor for use as an earthquake-resistant anchor for fire protection systems and suspended lightweight piping. Firstly, three cyclic tension tests of the specialty insert with a threaded rod were conducted in accordance with AC 446. These tests resulted in all experimental subjects achieving the target strength without defects. Subsequently, monotonic tension and shear tests of the insert anchor in cracked concrete were performed five times each to assess the tensile and shear capacities of the new insert anchor. The results were compared with the nominal strength determined by the anchor design equation provided by the ACI 318 for cast-in headed anchors, finding that the latter adequately approximates the concrete breakout strength of the new insert anchor in tension but underestimates the concrete pryout strength in shear. Based on the measured breakout failure surface angles, a projected area of the failure cone of the corresponding anchor with a relatively large head size is proposed.

음나무 삽목 번석에 관한 연구

정상덕,성정숙,허만규,Jung Sang Duk,Sung Jung Sook,Huh Man Kyu 한국생명과학회 2005 생명과학회지 Vol.15 No.1

음나무 근삽의 연령별 발근율 및 근삽의 길이별 조제 방법이 발근율에 미치는 영향과 식물생장 촉진제인 IBA처리의 발근율의 효과에 대한 음나무 삽목상에서 사용가치 여부를 규명하기 위하여 음나무를 공시 수종으로 선정하여 발근율 조사를 실시한 결과, 다음과 같은 결론을 얻었다. 1. 근삽의 채취 연령별 평균 발근율은 1년생 근삽 $92\%$가 가장 발근율이 높았으며, 연령이 오래된 근삽일수록 발근율이 낮아지는 경향이었다. 2. 1년생 기준으로 근삽의 길이별 평균 발근율은 근삽길이 10cm, 15cm 두 처리구는 발근율이 비슷하였으나, 근삽길이 5cm 처리구는 발근율이 매우 낮은 것으로 나타났다. 3. 근삽의 호르몬 처리별 평균 발근율은 IBA처리구가 무처리구보다 약간 발근율이 높았으나 유의차는 나타나지 않았다. 4. 삽목에 의해 생육된 개체가 실생법의 의한 개체보다 전반적으로 생육이 양호하였다. This study officially selected Kalopanax pictus. The root cutting and investigation conducted how the production process of the rooting ratio according to its age and its length gives some influence to the rooting ratio and what is the usage value in the effect of rooting ratio of an accelerant of plant growth and IBA treatment. The ages and ratio of rooting are one year $92.0\%$, two years $80.0\%$, and three years $67.0\%$. As shown above, one year cutting showed the highest growth. The rooting ratio by the length of the cutting-tree is $75.0\%$ in 5cm, $92.0\%$ in 10cm and $89.0\%$ in 15cm. There is a little differences according to the result of each analysis in the rooting ratio by the length of the cutting tree. Two groups having the length 10cm and 15cm showed the similar rooting ratio, while the group having the length 5cm showed that the rooting ratio is very low. The rooting ratio treated by the hormone, IBA showed that the treated group was $94\%$ and the untreated group was $92\%$. Although the treated group showed a little high rooting growth ratio, there was no significant difference. Thus, it is said that the treatment of IBA in the cutting tree is insignificant.

Ecological relationship between environmental factors and Pacific cod (Gadus macrocephalus) catch in the southern East/Japan Sea

정상덕,강수경,김수암 한국통합생물학회 2013 Animal cells and systems Vol.17 No.5

The habitat characteristics of Pacific cod (Gadus macrocephalus) and the ecological relationship between Pacific cod catch and environmental parameters in the southern East/Japan Sea were investigated. Pacific cod is sexually matured at age of 4–5. The highest catch of Pacific cod off the eastern Korean Peninsula occurred in seawater temperature range of 0–4°C and salinity range of 33.8–34.2 practical salinity unit at 100 m. The Cross-Correlation Function analysis showed that there was a significant negative correlation between Pacific cod catch and February seawater temperature at 75 m nearby spawning area with a time lag of 5 years in Korean waters (r = –0.360, p < 0.05). The annual catch of Pacific cod also had a significant correlation (p < 0.05) with zooplankton biomass in coastal nursery areas with a time lag, i.e., the highest ones, r = 0.432 and r = 0.452, for total zooplankton biomass in June of 5 years ago, and for euphausiids abundance in February of 4 years ago from the period when Pacific cod was caught, respectively. Furthermore, total catches of Pacific cod in the southern East/Japan Sea (i.e., sum of Korean and Japanese catches) were negatively correlated with winter Arctic Oscillation Index, and the highest negative correlation (r = –0.364, p < 0.05) was shown with a time lag of 4 years. Considering sexual maturation at ages 4–5, such statistical analyses imply that biotic and abiotic environmental factors during the early life stages of Pacific cod have a significant influence on recruitment after 4–5 years of spawning.

한국인의 치태, 치석, 치주낭 깊이, 치은퇴축 및 출혈의 상호관계에 대한 역학적 연구

정상덕,Chung, Sang-Duk 대한치주과학회 1987 Journal of Periodontal & Implant Science Vol.17 No.1

佛敎와 꽃에 對한 考察

鄭常德(정상덕) 동국대학교 석림회 1978 석림 Vol.12 No.-

반복하중을 받는 경량 배관 서포트 시스템에 대한 실험적 성능 평가

정상덕,오창수,박민재,이창환 한국공간구조학회 2023 한국공간구조학회지 Vol.23 No.3

Damage to gas and fire protection piping systems can lead to secondary disasters after an earthquake, so their seismic design is crucial. Accordingly, various types of seismic restraint installations are being devised, and a new suspended piping trapeze restraint installation has also recently been developed in Korea. In this study, a cyclic loading test was performed on the developed trapeze support system, and its performance was evaluated according to ASHRAE 171, the standard for seismic and wind restraint design established by the American Society of Refrigeration and Air Conditioning Engineers (ASHRAE). The three support system specimens did not break or fracture, causing only insignificant deformations until the end of the experiment. Based on the experimentally rated strength and displacement performance, this trapeze support system is expected to control the seismic movement of piping during an earthquake

반복하중 패턴에 따른 균열 콘크리트에 매입된 선설치 인서트 앵커의 전단성능 평가

정상덕,오창수,이창환 한국공간구조학회 2023 한국공간구조학회지 Vol.23 No.2

Recently, a novel cast-in specialty insert was developed in Korea as an anchor for lightweight pipe supports, including fire-protection pipes. As these pipe supports and anchors play a critical role in transferring loads of fire-protection pipes to structural members, it is crucial to evaluate their seismic performance before applying the newly developed insert. In this study, the seismic shear performance of the insert anchors was evaluated through cyclic loading tests based on the loading protocols of ACI 355.2 and FEMA 461. Initially, five monotonic loading tests were conducted on the insert anchors in cracked concrete, followed by cyclic loading tests based on the monotonic test results. The findings revealed that the insert anchors exhibited negligible decrease in shear strength even after cyclic loading. Furthermore, a comparison of the maximum load and displacement of the insert anchors obtained under the loading protocols of ACI 355.2 and FEMA 461 was performed to investigate the applicability of the FEMA 461 loading protocol for anchor performance evaluation. Recently, a novel cast-in specialty insert was developed in Korea as an anchor for lightweight pipe supports, including fire-protection pipes. As these pipe supports and anchors play a critical role in transferring loads of fire-protection pipes to structural members, it is crucial to evaluate their seismic performance before applying the newly developed insert. In this study, the seismic shear performance of the insert anchors was evaluated through cyclic loading tests based on the loading protocols of ACI 355.2 and FEMA 461. Initially, five monotonic loading tests were conducted on the insert anchors in cracked concrete, followed by cyclic loading tests based on the monotonic test results. The findings revealed that the insert anchors exhibited negligible decrease in shear strength even after cyclic loading. Furthermore, a comparison of the maximum load and displacement of the insert anchors obtained under the loading protocols of ACI 355.2 and FEMA 461 was performed to investigate the applicability of the FEMA 461 loading protocol for anchor performance evaluation.Recently, a novel cast-in specialty insert was developed in Korea as an anchor for lightweight pipe supports, including fire-protection pipes. As these pipe supports and anchors play a critical role in transferring loads of fire-protection pipes to structural members, it is crucial to evaluate their seismic performance before applying the newly developed insert. In this study, the seismic shear performance of the insert anchors was evaluated through cyclic loading tests based on the loading protocols of ACI 355.2 and FEMA 461. Initially, five monotonic loading tests were conducted on the insert anchors in cracked concrete, followed by cyclic loading tests based on the monotonic test results. The findings revealed that the insert anchors exhibited negligible decrease in shear strength even after cyclic loading. Furthermore, a comparison of the maximum load and displacement of the insert anchors obtained under the loading protocols of ACI 355.2 and FEMA 461 was performed to investigate the applicability of the FEMA 461 loading protocol for anchor performance evaluation.

균열콘크리트에 매입된 선설치 인서트 앵커에 대한 모의지진 인장실험

정상덕(Jeong, Sang-Deock),오창수(Oh, Chang-Soo),이창환(Lee, Chang-Hwan) 한국콘크리트학회 2022 한국콘크리트학회 학술대회 논문집 Vol.34 No.2

울릉도해역에서 삼중자망에 의한 어획물의 종조성

정상덕 ( Sangdeok Chung ),차형기 ( Hyung Kee Cha ),이재봉 ( Jae Bong Lee ),이해원 ( Hae Won Lee ),양재형 ( Jae Hyeong Yang ) 한국어업기술학회 2015 수산해양기술연구 Vol.51 No.4

Species composition in the coastal waters off Ulleungdo of Korea were examined based on catches bimonthly collected by trammel net in 2013. A total of 711 individuals and 181.9 Kg were caught and catches were composed of 4 classes 15 orders 27 families 52 species including 44 Pisces, 4 Gastropoda, 3 Cephalopoda, and 1 Echinodermata. The dominant species in biomass were File fish (Thamnaconus modestus), Atka mackerel (Pleurogrammus azonus), and Greenling (Hexagrammos otakii). Data were summarized using hierarchical cluster analysis (HCA) and detrended correspondence analysis (DCA) to examine similarity in species composition for each month, and community structure in Ulleungdo was divided into two groups. Community structures in February, April and December with low temperature and well-mixed surface water were distinguished from those in June, August and October with high temperature and strong stratification, which could be attributed to temporal changes in dominant species. Atka mackerel and Spear squid mainly caught in February and April, disappearing in June, August and October, and File fish outburst was shown in October. Because the water off Ulleungdo has been under low human pressure, it could be a good case study to elucidate effects of climate change on community structure and ecosystem in the East sea. Continuous surveys and further studies are required to demonstrate migration route and distribution of dominant species and long-term changes in community structure in the water of Ulleungdo.

모의지진실험을 통한 선설치 인서트 앵커의 인장강도 평가

정상덕(Jeong, Sang-Deock),오창수(Oh, Chang-Soo),이창환(Lee, Chang-Hwan) 대한건축학회 2023 대한건축학회 학술발표대회 논문집 Vol.43 No.1