• Title/Summary/Keyword: Cut-off wall

Search Result 60, Processing Time 0.023 seconds

Experimental Study on Enhanced Jet Grouting by Cavitation Theory (공동현상 이론을 고압분사주입공법에 적용하기 위한 실험적 연구)

  • Lee Sang-Ik;Kim Chang-Jong;Oh Se-Hun;Kim Young-Uk
    • Journal of the Korean Geotechnical Society
    • /
    • v.21 no.1
    • /
    • pp.43-50
    • /
    • 2005
  • Jet grouting method is widely being used in many geotechnical problems, especially for the purpose of reinforcement of clayey ground and cut-off wall of sandy ground. However, its design depends on highly empirical method, in which many researches have been undertaken. This study investigated the effect of cavitation on jet grouting. Small-scaled model tests were carried out using specially designed and fabricated device to analyze the effect of cavitation on jet grouting with various test conditions including ground condition, injection pressure, and injection time. The test results show that cavitation has a significant effect on jet grouting, and it has a potential for engineering application.

The Structural Characteristics of the Temporary Cofferdam in Accordance with the Shape and Size Obtained from Numerical Analysis (유한요소 해석을 통한 형상 및 크기에 따른 가물막이 특성 검토)

  • Kim, Hyun-Joo;Choi, Jin-O;Gwon, Yun-Ho
    • Journal of the Korean Geotechnical Society
    • /
    • v.36 no.1
    • /
    • pp.29-38
    • /
    • 2020
  • These days the circular cross section cofferdam has been frequently used for the earth retaining structures or cut off wall such as ventilating opening, intake tower in cofferdam, shaft for emergency. By the arching effect, the circular cross section type cofferdam has more advantage than a polygon cofferdam in terms of the structural forces and moment. This paper shows the proper approach to analyze the circular cross section cofferdam using 2D Finite Element Method (FEM) for the circular stiffener (ring beam) evaluation. Besides, the various shapes of cofferdam indluding circular cross section have modeled the 3D Finite Element Mothod (FEM). The circular cross section cofferdam shows the minimum reaction force compared with the other shapes of cofferdam.

Basic study for construction methods of salino water protection for Estuary barrier. (하구언의 담수침투방지공법에 관한 연구)

  • 최영박;임병조
    • Water for future
    • /
    • v.9 no.1
    • /
    • pp.55-69
    • /
    • 1976
  • The purpose of this paper is to provide basic data for construction methods of leakage pretaction for estuary barrien which is constructed to in take restoration water from irigative use and a river flow in its ultimate dsicharge to ward to sea, The water, accordingly, has reviewed the discrepancis between theories and experiments based on the hydraulic analysis of ground water through a series of sourveys on equi-patential line of seepage flow and a series of some experiments. apparently, however, the research results herein might reflect in some part not more than inference since those experiments are not conducted in a real foundation but from an indoor experiment or calculation, conclusion in brief are itemized here-under. 1. small-scale barrier require cut-off wall, which should reach the complete impereable layer, 2. Duplication barrier is provided effective in protection saline water seepage. 3. a barrier with broad crest might enable protection of massive seepage by fresh water lens formed from precipitation.

  • PDF

Strength of Improved Soil on the Work-conditions of Deep Mixing Method (시공조건에 따른 심층혼합처리 개량체의 강도에 관한 연구)

  • Lee, Kwang-Yeol;Yoon, Sung-Tai;Kim, Sung-Moo;Han, Woo-Sun
    • Journal of the Korean Geotechnical Society
    • /
    • v.23 no.7
    • /
    • pp.99-104
    • /
    • 2007
  • The deep soil mixing, on ground modification technique, has been used for many diverse applications including building and bridge foundations, port and harbor foundations, retaining structures, liquefaction mitigation, temporary support of excavation and water control. This method has the basic objective of finding the most efficient and economical method for mixing cement with soil to secure settlements through improvement of stability on soft ground. In this research, the experiments were conducted on a laboratory scale with the various test conditions of mixing method; the angle of mixing wing, mixing speed. Strength and shapes of improved soil of these test conditions of deep mixing method were analysed. From the study, it was found that the mixing conditions affect remarkably to the strength and shapes of improved soils.

Seepage Characteristics of Domestic Bed Sediments Mixed with Good-quality Soil as Levee Fill Material (양질토와 혼합처리된 국내 하상토의 제체재료로서의 침투특성)

  • Choi, Bong-Hyuck;Kim, Kyung-Min;Kim, Jin-Man;Lee, Dae-Yeong
    • Journal of the Korean Geotechnical Society
    • /
    • v.24 no.10
    • /
    • pp.105-111
    • /
    • 2008
  • To improve the stability of levee structure, it is required to use good quality fill materials, intensive management, appropriate hydraulic structure and construction of cut-off wall. In particular, the most important factor of levee construction technology is to use bed sediment for its safety. In this study, seepage model test and numerical analysis were performed based on a standard section of levee recommended in the river design standard of korea (2005). The results of test and analysis show that most of the bed soil is a sand (SP in USCS), which does not satisfy the permeability criteria for levee materials ($< k=10^{-3}cm/sec$), thus for the safety of levee it is required to adopt a stabilizing method such as good quality soil mixing, water content control.

Studies on the Applicability of Various Antigen Preparations in the Immunoblot Diagnosis of Cysticercosis (Immunoblot법을 이용한 낭미충증(囊尾蟲症)진단에 있어서 각종 항원(抗原)의 적용가능성(適用可能性) 검토(檢討)에 관한 연구(硏究))

  • Koh, Young-Tae;Joo, Kyoung-Hwan;Chung, Myung-Sook;Rim, Han-Jong
    • Journal of agricultural medicine and community health
    • /
    • v.16 no.1
    • /
    • pp.79-89
    • /
    • 1991
  • A systematic study was conducted to identify and isolate a serologically pertinent antigen with high specific activity and low cross reactivity from Cysticercus parenchymal antigen. Differential centrifugation of the homogenate yield three particulate and one soluble fractions ; the $480{\times}G$ pellets($CyL_2$), the $7650{\times}G$ pellet($CyL_3$), the $100000{\times}G$ pellet($CyL_4$), and $100000{\times}G$ supernatant($CyL_6$). We compared antigenicity of these antigens to that or cystic fluid antigens($CyF_1$), saline extract of cystic wall($CyL_1$), and n-butanol treated $GyL_4$ antigen ($CyL_6$) based on SDS-PAGE and immunoblot techniques. The data obtained were as follows : 1) The ratio of O.D. value of ELISA against cysticercosis positive pool sera to that of negative pool sera was highest when using $CyF_1$ as antigen. However the ratio was relatively low in case of $CyL_{3.4}$ and $CyL_5$. 2) We have noted in previous paper that most strong antigenic activities are present in 63Kd band with low cross reactivities. An effective serologic reagent must contain components that are recognized by most infected sera. 63Kd band met this criteria and could be considered as a reliable band for the diagnosis of cysticercosis. As far as 63Kd band concern, $CyL_5$ showed most strong activities without disturbance of cross reaction by EITB in spite of low applicability to microplate ELISA. 3) $CyL_5$ could detect the serum antibody of cysticercosis even in very low titers, around cut-off values of microplate ELISA, by immunoblot. It also could detect the cross reactivities of Echinococcus species, which showed high absorbance value in micro plate ELISA and some sparganosis cases. Further purification of this antigen will be able to represents a antigen that can be used in the diagnosis of cysticercosis.

  • PDF

Analysis on Change of Construction Type for the Non-national Forest Road in Jeollabuk-do (전라북도 민유임도의 시기별 공종변화에 관한 연구)

  • Son, Jae-Ho;Park, Chong-Min;Lee, Joon-Woo
    • Journal of Korean Society of Forest Science
    • /
    • v.96 no.6
    • /
    • pp.652-660
    • /
    • 2007
  • The study was intended to investigate the changes of construction types of 216 non-national forest roads, which were completed between 1989 and 2005 in Jeollabuk-do, by analyzing their drawing and specification. It was found that the mean length of yearly construction has been significantly reduced after the Policy of Green Forest Roads compared with before the policy. Soil cut-off of earth work was changed from bulldozer to a combination of bulldozer and excavator. Soils were transported by truck in all design, but establishment of spoil-bank was not designed at all. The design of slope revegetation works was developed from turfing and Bastard indigo planting to seed spray, combination of seed spray and belt-sodding, and mulching with coir net and rice straw. In design of the culvert, the average interval of culvert installation was reduced to 92m in step 3, the dimension of culverts was expanded to over 600 mm after step 2, and all drainpipes were corrugated steel pipes. The design length of concrete pavement increased from 40 m/km of step 1 to 240 m/km of step 3. Thanks to the enormously increased amount of concrete pavement, the stability and functionality of forest roads could be improved. Stone masonry was the main work drawn for slope stability, and concrete retaining wall and gabion have been drawn for same object since 1999.

Surgical Repair of Single Ventricle (Type III C solitus) (단심실 -III C Solitus 형의 수술치험-)

  • naf
    • Journal of Chest Surgery
    • /
    • v.12 no.3
    • /
    • pp.281-288
    • /
    • 1979
  • For years, physicians and anatomists have been interested in the heart that has one functioning ventricle. Various terms have been suggested for this entity including single ventricle, common ventricle, double-inlet left ventricle, cor biatriatum triloculare, and primitive ventricle. In this report, the term "single ventricle" is utilized as suggested by Van Praagh, and is defined as that congenital cardiac anomaly in which a common or separate atrioventricular valves open into a ventricular chamber from which both great arterial trunks emerge. An outlet chamber, or infundibulum, may or may not be present and give rise to the origin of either of the great arteries. This definition excludes the entity of mitral and tricuspid atresia. An 11 year old cyanotic boy was admitted chief complaints of exertional dyspnea and frequent upper respiratory infection since 2 weeks after birth. He was diagnosed as inoperable cyanotic congenital heart disease, and remained without any corrective treatment up to his age of 11 year when he suffered from aggravation of symptoms and signs of congestive heart failure for 2 months before this admission. On 22nd of May 1979, he was admitted for total corrective operation under the impression of tricuspid atresia suggested by a pediatrician. Physical check revealed deep cyanosis with finger and toe clubbing, and grade V systolic ejection murmur with single second heart sound was audible at the left 3rd intercostal space. Development was moderate in height [135 cm] and weight[28Kg]. Routine lab findings were normal except increased hemoglobin [21.1gm%], hematocrit [64 %], and left axis deviation with left ventricular hypertrophy on EKG. Cardiac catheterization and angiography revealed 1-transposition of aorta, pulmonic valvular stenosis, double inlet of a single ventricle with d-loop, and normal atriovisceral relationship [Type III C solitus according to the classification of Van Praagh]. At operation, longitudinal incision at the outflow tract of right ventricle in between the right coronary artery and its branch [LAD from RCA] revealed high far anterior aortic valve which had fibrous continuity with mitral annulus, and pulmonic valve was stenotic up to 4 mm in diameter positioned posterolaterally to the aorta. Ventricular septum was totally defective, and one markedly hypertrophied moderator band originated from crista supraventricularis was connected down to the imaginary septum of the ventricular cavity as a pseudoseptum of the ventricle. Size of the defect was 3X3 cm2 in total. Patch closure of the defect with a Teflon felt of 3.5 x 4 cm2 was done with interrupted multiple sutures after cut off of the moderator band, which was resutured to the artificial septum after reconstruction of the ventricular septum. Pulmonic valvotomy was done from 4 mm to 11 mm in diameter thru another pulmonary arteriotomy incision, and right ventriculotomy wound was closed reconstructing the right ventricular outflow tract with pericardial autograft of 3 x 4 cm2. Atrial septal defect of 2 cm in diameter was closed with 3-0 Erdeck suture, and atrial wall was sutured also when rectal temperature reached from 24`C to 35.5`C. Complete A-V block was managed with temporary external pacemaker with a pacing rate of 110/min. thru myocardial wire, and arterial blood pressure of 80/50 mmHg was maintained with Isuprel or Dopamine dripping under the CVP of 25-cm saline. Consciousness was recovered one hour after the operation when his blood pressure reached 100 /70 mmHg, but vital signs were not stable, and bleeding from the pericardial drainage and complete anuria were persisted until his heart could not capture the pacemaker impulse, and patient died of low output syndrome 320 min after the operation.

  • PDF

Surgical Repair for Ebstein's Anomaly (Ebstein 기형의 수술 -2례 보고-)

  • naf
    • Journal of Chest Surgery
    • /
    • v.12 no.3
    • /
    • pp.289-296
    • /
    • 1979
  • For years, physicians and anatomists have been interested in the heart that has one functioning ventricle. Various terms have been suggested for this entity including single ventricle, common ventricle, double-inlet left ventricle, cor biatriatum triloculare, and primitive ventricle. In this report, the term "single ventricle" is utilized as suggested by Van Praagh, and is defined as that congenital cardiac anomaly in which a common or separate atrioventricular valves open into a ventricular chamber from which both great arterial trunks emerge. An outlet chamber, or infundibulum, may or may not be present and give rise to the origin of either of the great arteries. This definition excludes the entity of mitral and tricuspid atresia. An 11 year old cyanotic boy was admitted chief complaints of exertional dyspnea and frequent upper respiratory infection since 2 weeks after birth. He was diagnosed as inoperable cyanotic congenital heart disease, and remained without any corrective treatment up to his age of 11 year when he suffered from aggravation of symptoms and signs of congestive heart failure for 2 months before this admission. On 22nd of May 1979, he was admitted for total corrective operation under the impression of tricuspid atresia suggested by a pediatrician. Physical check revealed deep cyanosis with finger and toe clubbing, and grade V systolic ejection murmur with single second heart sound was audible at the left 3rd intercostal space. Development was moderate in height [135 cm] and weight[28Kg]. Routine lab findings were normal except increased hemoglobin [21.1gm%], hematocrit [64 %], and left axis deviation with left ventricular hypertrophy on EKG. Cardiac catheterization and angiography revealed 1-transposition of aorta, pulmonic valvular stenosis, double inlet of a single ventricle with d-loop, and normal atriovisceral relationship [Type III C solitus according to the classification of Van Praagh]. At operation, longitudinal incision at the outflow tract of right ventricle in between the right coronary artery and its branch [LAD from RCA] revealed high far anterior aortic valve which had fibrous continuity with mitral annulus, and pulmonic valve was stenotic up to 4 mm in diameter positioned posterolaterally to the aorta. Ventricular septum was totally defective, and one markedly hypertrophied moderator band originated from crista supraventricularis was connected down to the imaginary septum of the ventricular cavity as a pseudoseptum of the ventricle. Size of the defect was 3X3 cm2 in total. Patch closure of the defect with a Teflon felt of 3.5 x 4 cm2 was done with interrupted multiple sutures after cut off of the moderator band, which was resutured to the artificial septum after reconstruction of the ventricular septum. Pulmonic valvotomy was done from 4 mm to 11 mm in diameter thru another pulmonary arteriotomy incision, and right ventriculotomy wound was closed reconstructing the right ventricular outflow tract with pericardial autograft of 3 x 4 cm2. Atrial septal defect of 2 cm in diameter was closed with 3-0 Erdeck suture, and atrial wall was sutured also when rectal temperature reached from 24`C to 35.5`C. Complete A-V block was managed with temporary external pacemaker with a pacing rate of 110/min. thru myocardial wire, and arterial blood pressure of 80/50 mmHg was maintained with Isuprel or Dopamine dripping under the CVP of 25-cm saline. Consciousness was recovered one hour after the operation when his blood pressure reached 100 /70 mmHg, but vital signs were not stable, and bleeding from the pericardial drainage and complete anuria were persisted until his heart could not capture the pacemaker impulse, and patient died of low output syndrome 320 min after the operation.

  • PDF

A Comparative Considerations of the Moat at the East and West (동.서양 해자(垓字)의 비교 고찰)

  • Jung, Yong-Jo;Park, Joo-Sung;Sim, Woo-Kyung
    • Journal of the Korean Institute of Traditional Landscape Architecture
    • /
    • v.28 no.3
    • /
    • pp.29-38
    • /
    • 2010
  • A moat is a pond or waterway paved on the outside of a fortress that is one of the facilities to prevent enemy from approaching the fortress wall or classify it as the boundary space, and this study was undertaken to find out the characteristics of the moat that was existed in the East and the West from ancient time to medieval time with the following result. First, the moat in the East was installed of natural moat and artificial moat at the same time while the moat in the West had the fortress built in naturally advantageous site to use natural most substantially more. Second, the moats of Korea were smaller in scale compared to other countries (Japan, China and the Western countries). Third, the fortresses in the East were built to protect towns or royal palace while the West had the fortress to protect the residence of kings, lords, great wealthy persons and the like, and they were used jointly with the natural moat and artificial moat to defend against the infiltration of enemy. Fourth, the Pungsujiri in the Orient is one of the numerous ideologies forming the supplementary ideologic system of Korean people that could not be denied as the perception that influences on Korean people after the Silla Dynasty, and this Pungsujiri was considered when determining the location of the castle. The moat surrounding the castle had the role to keep the good energy in the castle from escaping away. Fifth, the Ha-Ha technique in the west was designed to prevent the external power from infiltration by digging the ditch on the place applicable to the boundary of the garden site, rather than the fence. While walking around along the water-side path without knowing the existence of this ditch, when the road is discovered with the cut off in the ditch, people had the exclamation without actually recognizing such astonishment. It was originally the dike for military purpose during the medieval time that was designed to look into the garden without physical boundary surrounded with the vertical fence in the garden that by having the deep ditch like shape on the boundary line of the garden which was designed to form the farm by preventing various types of cattle from coming inside the garden and bring in the garden element for farms, forestry, agricultural land and the like.