• Earthquakes and Structures
• /
• 제21권6호
• /
• pp.641-652
• /
• 2021

Digging well foundation has been widely used in railway bridges due to its good economy and reliability. In other instances, bridges with digging well foundation still have damage risks during earthquakes. In this study, a new type of digging well foundation with prefabricated roots was proposed to reduce earthquake damage of these bridges. Quasi-static tests were conducted to investigate the failure mechanism of the root digging well foundation, and then to analyze seismic behaviors of the new type well foundation. The testing results indicated that these prefabricated roots could effectively limit the rotation and uplift of the digging well foundation and increase the lateral bearing capacity of the digging well foundation. The elastic critical load and ultimate load can be increased by 69% and 36% if prefabricated roots were added in the digging well foundation. The prefabricated roots drived more soil around the foundation to participate in working, the stiffness of the bridge pier with root digging well foundation was improved. Moreover, the root participation could improve the energy dissipation capacity of soil-foundation-pier interaction system. The conclusions obtained in this paper had important guiding significance for the popularization and application of the digging well foundation with prefabricated roots in earthquake-prone zones.

• Agricultural and Biosystems Engineering
• /
• 제5권2호
• /
• pp.40-44
• /
• 2004

This study was conducted to solve the problem of spinach harvesting done by manpower at the outdoor field during the cold winter season. Prototype spinach harvester was designed to dig, pick-up, and collect in a continuous operation for harvesting outdoor field-planted crawling type spinach. In the field test, two types of blades (Type A : angle of $150^{\circ}$, Type B : straight) were used for measuring the cutting loads of spinach and chain conveyor with lugs was used for picking up the root cut spinach. Prototype's vibrating blade reduced the digging power of the fixed blade by $46\%$. The loss was also very little ($0.7\%$) with a digging depth of 4 cm, an oscillation frequency of 748 rpm, and an oscillation distance of 33 mm. The working performance of the prototype spinach harvester was 38 hour/ha resulting to $96\%$ labor cost reduction compared to the conventional harvesting.

• Journal of Biosystems Engineering
• /
• 제27권4호
• /
• pp.311-316
• /
• 2002

This study was carried out to investigate the optimum operating conditions of the air injection type onion peeling device which could be attached to a prototype onion peeler. An onion, stem and root was cut and some vertical line was dug in 1 mm depth on the skin, was put on the two parallel rollers. The diameters of the rollers were 105 mm and the ratio of peripheral velocity was 3:2, and moved by a geared motor. Air from the nozzle with high pressure and velocity was jetted to the rotating onion on the revolving rollers, and then the skin of the onion was stripped. On the test, the rolling characteristics of the experimental materials were measured. The effective peeling conditions were, the number of digging line on the skin of the onion was 4, and the air jet pressure was above 392.3 kPa(4.0 kg/$\textrm{cm}^2$) when the peripheral velocity was at 2.4 m/s. On these conditions, time requirement to peel an onion was less than 2 sec.

• 고려인삼학회:학술대회논문집
• /
• 고려인삼학회 1993년도 학술대회지
• /
• pp.155-163
• /
• 1993

An American ginseng(Panax quillquefolium L) industry has emerged in British Columbia, Canada over the past ten years. Interest has grown very rapidly and with this development, attention is now moving away from field production issues and emphasis is being directed to enhancements in ginseng storage, drying and processing. There is a dearth of knowledge on these aspects even though they are crucial to international competitiveness. Enhancement dicatates the application of a systems approach to optimizing the harvest and post - harvest production system(crop digging, pre - washing cold storage. washing, drying and post - drying storage). Research in British Columbia to date has focussed on drying and storage issues and has resulted in the design of an enhanced commercial drying system. The role of dryer management, loading rates, airflow rates and pre - drying cold storage on American ginseng root drying rates and root quality were examined. From the dryer management experiments, there are distinct advantages to size sorting root to yield optimum drying rates. If unsorted root is used, efficiency is increased if the trays are systematically rotated. Loading rate experiments illustrate that increasing rates above those currently used in commercial dryers are possible without any sacrifice in quality. This has significant implications for commercial drying. Pre - drying cold storage is a most significant tool for managing drying operations. Over a period of six weeks, no discernable decrease in quality was found as a consequence of cold storage. Further, the moisture loss and the associated root surface changes(loss of surface soil in storage for example) provide new challenges for root quality management. Continued research and technological innovation will be crucial in addressing the demanding challenges of the future.

• 한국조경학회지
• /
• 제30권4호
• /
• pp.92-104
• /
• 2002

This study investigates, analyzes, and summarizes Dansplantation techniques and methods through practical methodology centering on fieldwork in order to present effective planting methods for large trees that have important significance. The conclusions are as follows : 1. The transplantation process of a large tree generally consists of the stages of digging up a tree, manufacturing a carrier frame, loading the tee on a vehicle, transporting, transplanting the tree, installing a strut and maintaining and managing the new transplant. In addition, planting a tree on a mounted place includes the primary procedures of trimming out the root, and preparing for transplanting the tree on a mounted place, as well as the secondary work of trimming out the root, transplanting a tree on a mounted place, maintenance and management. 2. In order to decide on a transplantation method for a large-sized tree, a structure calculation has to be performed first. That is, one must calculate the weight of the tree and the allowable stress of the strut (H-beam, etc.) fhst and then decide on the upper method through computer modeling based upon this structural calculation. 3. As a result of the analysis of a transplanted tree using the life soil method, it was confirmed that large quantities of feeder roots had developed around the root within a short time after the transplantation. The life soil method has proven to be very effective for transplantation of large-sized trees. 4. As for the production method of an H-beam strut frame, it was found that the manufacturing process and disassembly process were simple and proper; therefore, the H-beam frame is an appropriate structure to be used in the transplantation of large trees. 5. The concavo-convex method, which consists of filling the life soil in the concavo-convex area around the root, was found to be a method that promotes the growth of feeder roots within a short period of time and saves the supply of water at the same time.

• 한국환경생태학회지
• /
• 제18권1호
• /
• pp.7-17
• /
• 2004

폐기물로 처리되고 있는 자생수목 그루터기를 재활용하여 에코녹화공법을 개발하기 위하여 전남 함평군 월야면에 위치한 호남대학교 부속농장에 모니터링 시험구를 2001년 11월에 설치하였다. 시험기간은 2001년 11월부터 2003년 10월까지였으며, 모니터링 시험구 조사는 2002년 10월, 2003년 9월, 총 2회 실시하였다. 모니터링 시험에서 그루터기의 맹아우세수종 선발 수간 절지길이 차이 및 방부처리 유무에 따른 생장량 변화, 식재시기 및 식재본수에 따른 활착율을 조사하였다. 자생수목 그루터기 모니터링 시험결과는 다음과 같다. 90% 이상 활착율을 나타낸 수종은 공시수종 총 20종 중 10종으로 느티나무, 때죽나무, 비목나무, 산딸나무, 상수리나무, 야광나무, 참느릅나무, 털야광나무, 팽나무, 장구밥나무 였다. 수간절지길이에 따른 생장량은 수간길이 10cm처리구보다 35cm처리구에서 우세하게 나타났고, 근원직경에 대한 뿌리규격에 따른 생장량은 3배(폭)${\times}$5배(깊이)와 5배(폭)${\times}$5배(깊이)에서 우세하게 나타났다. 수간절지부 방부처리 유무에 따른 생장량은 방부처리구의 수종에서 우세하게 나타났고, 식재시기에 따른 공시수종의 생장량은 생리휴면기인 늦가을(11월)에 식재한 그루터기에서 우세하게 나타났으며, 다음으로 초봄(3월), 늦봄(5월) 식재 순이었다.

• 한국환경생태학회지
• /
• 제27권5호
• /
• pp.571-578
• /
• 2013

본 연구는 도시의 주요 상록 조경수종인 소나무와 잣나무를 대상으로, 직접수확법을 통해 탄소저장 및 흡수를 용이하게 추정하는 회귀모델을 제시하고 도시수목의 탄소저감 효과를 계량화하는데 필요한 기반정보를 구축하였다. 수종별로 유목에서 성목에 이르는 일정 간격의 흉고직경 크기를 고려하여 개방 생장하는 조경수목을 구입한 후, 근굴취를 포함하는 직접수확법에 의해 개체당 부위별 및 전체 생체량을 측정하고 탄소저장량을 산출하였다. 또한, 흉고 부위의 수간원판을 채취하여 직경생장을 분석하고 탄소흡수량을 산정하였다. 흉고직경을 독립변수로 생장에 따른 수종별 단목의 탄소저장 및 흡수를 계량화하는 활용 용이한 회귀모델을 유도하였다. 이들 회귀식의 $r^2$는 0.98 이상으로서 적합도가 상당히 높았다. 동일 직경의 탄소저장 및 흡수량은 유목의 경우 소나무가 잣나무보다 더 많았으나, 20cm 이상 성목의 경우 생장량 차이에 기인하여 그 반대인 경향을 보였다. 흉고직경 25cm인 소나무와 잣나무는 각각 115.6kg, 130.0kg의 탄소를 저장하고, 연간 9.4kg, 14.6kg의 탄소를 흡수하는 것으로 나타났다. 본 연구는 조경수목의 직접 벌목 및 근굴취의 난이성에 기인하여, 생체량 확장계수, 지하부/지상부 비율, 직경생장 등 산림수목의 계수를 대용하여 대상수종의 탄소저감을 계량화한 기존 연구의 한계성을 극복할 새로운 초석을 마련하였다.

• 한국환경생태학회지
• /
• 제23권4호
• /
• pp.302-308
• /
• 2009

합리적 주목 관리의 기초자료를 얻고자 강원도 정선군 하이원 스키장 건설지역에 분포하는 주목 323개체(이식된 57 체 포함)에 대하여 수고, 근원경, 흉고직경, 줄기상태, 동공의 크기, 초두부 상태, 가지고사율, 엽생육상태, 신초생장, 2년생엽 탈락율, 뿌리상태 및 수형을 조사하였다. 조사항목들을 생육상태가 나쁠수록 높은 점수가 되도록 등급화하였다. 조사대상지에 생육 중인 주목은 주로 해발고가 높은 능선부나 북사면에서 자라고 있었다. 백운산 주목의 생육상태는 국내 다른 아고산지대의 주목과 구상나무의 생육상태에 비하여 상대적으로 양호한 것으로 판단된다. 피해주목들은 이식작업에서 뿌리제거, 잔존 목으로 슬로프 공사 시 복토, 터파기로 인한 뿌리 손상 등이 대부분이었다. 주목보존을 위한 몇 가지 방안이 제시되었다.

• Journal of Biosystems Engineering
• /
• 제34권6호
• /
• pp.397-403
• /
• 2009

This study was carried out to investigate the present status of subsoil compaction, and subsoil compaction management in orchard as a basic study for developing a self-propelled explosive subsoiler. Subsoil compaction was evaluated using the soil penetration resistance. Soil cone index was measured using the DIK 5520 type cone penetrometer in several fruit farms such as apple, pear, peach and grapes during growing seasons of these fruit in Jecheon, Gamgok, Choongju, Cheonan and Hwasung areas. Most of the subsoil managing machinery were either explosive type or digging type attached to the tractor or power tiller and turning radius of this machine was more than 3-5 m. Many of the farmers wanted to use the subsoiler which can put lime into soil and rupture soil at the same time. For most of the orchard fields, soil penetration resistance in vehicle traffic area was increased quickly and reached about 1.0 MPa in 5 cm soil depth. As the soil depth increased to 15-20 cm, cone penetration resistance reached about 2.0-2.5 MPa which restricted root growth seriously. Thus it was concluded that one of the main reason for increasing the soil compaction in orchard fields is agricultural vehicle traffic. In the vicinity of fruit trees, compaction is not so serious compared to that of the vehicle traffic area, but as the soil depth increased to 20-25 cm, in most of the orchard fields soil penetration resistance reached about 2.0-2.5 MPa which is the root growth-limiting value. Considering the rooting depth of fruit trees which ranged 30-60 cm for apple, pear and peach, and 20-30 cm for grape, it is necessary to loosen the subosoil and improve the subsoil conditions using subsoiler.

• 한국조경학회지
• /
• 제37권1호
• /
• pp.131-138
• /
• 2009

본 연구는 1962년부터 2007년까지 약 45년간 제정된 토목공사 표준품셈 공종에 속해 있는 조경공사 표준품셈을 대상으로 시대별 표준품셈의 변화의 흐름을 파악하여, 그 특성을 밝혀 향후 조경공사 표준품셈의 발전 방안에 대한 기초자료를 제시하고자 하였다. 연구의 결과는 다음과 같다. 조경공사 표준품셈이 속해 있는 공종 명칭과 관련해서 최초에는 '토공사'에서 1974년에 '토공 및 조경공사' 그리고 1984년에는 '조경공사'로 명칭이 개정되었으나, 현재까지도 조경공사 표준품셈은 토목공사 표준품셈에 조경공사라는 공종으로 되어 있다. 그리고 1972년에 조경공사와 관련해서 '식재'와 '전정작업' 품셈이 최초로 제정된 이후 현재는 '떼붙임 및 초류파종', '굴취', '식재', '뿌리돌림', '유지관리', '정원석 쌓기 및 놓기', '암 절개면 보호식재공' 등 총 7개 대공종과 29개 소공종으로 조경공사 표준품셈이 구성되어 있다. 시대별 특성을 10년 단위로 살펴보면 조경공사 표준품셈은 1960년대($1962{\sim}1969$)는 '잔디' 분야, 1970년대($1970{\sim}1979$)는 '수목식재' 분야, 1980년대($1980{\sim}1989$)는 '유지관리' 분야, 1990년대($1990{\sim}1909$)는 '절개면 보호' 분야 그리고 2000년대($2000{\sim}$현재)는 '신소재 및 신공법'과 '유지관리' 분야 위주로 조경공사 표준품셈이 제정되었다. 본 연구의 결과를 바탕으로 향후 조경공사 표준품셈의 발전 방안을 제시하여 보면, '신소재 및 신공법' 품셈의 제정과 '유지관리' 분야의 품셈들이 더욱 세분화된 방향으로 발전할 것으로 판단된다.