Supporting method of a Temporary retaining wall for underground excavation project are adopted by systems of strut, anchor, nail, raker, etc. Strut system and Raker system of these methods are mostly used preloading jack to minimize deformations of retaining wall. We determinate efficient preloading to analysis these strut-preloadings, deformations of retaining wall, axial forces, and etc.. This study is analysed that preloading applied 0%, 10%, 20%, 30%, ...., 100% for strut and raker installed by CIP temporary retaining wall. This study results that adequate preloadings were determined to analysis correlations of preloading, deformations of wall, maximum bending moment, axial force of strut, and displacement of surrounding.

Top-Down Construction Method has been considered as the steadiest and the most reasonable method of construction since 1984 when it was applied to LG Da-Dong building and its usage in the field construction has since grown rapidly. With increased cases, engineers not only pursue their studies of R & D continuously but also develop various technical methods based on Top-Down Construction in an era of rapid technological change to adopt them to the field construction. Top-Down Construction meets the needs of these challenging points, such as reduction and eliminates of temporary equipment for supporting permanent structures on the ground, improved method of construction, shortening construction periods, cost reduction, and allows for minimal environmental impact.

Since timbering of a cut in association with underground excavtion work is introduced to domestic, in spite of limitation of special quality in this method, time change, variety of construction, Strut Method is still considered with general methods. Experts have developed methods which is improved in limitation of special quality by continuous studies of normal strut method in basic, and it has been applied to construction site Consequently, this study introduced improved Strut Method to help experts when they select resonable methods with regard to construction site, conditions

The ground anchoring has been utilized over 40 years. It is growing the application of the removal ground anchor with tension force for holding earth retaining constructions in the city. It transmits tension stress of prestressed steel wire through grouting to fixed the ground that is of great advantage adjacent ground stability. Nowadays, we can find the compression dispersion anchor on many site. But, it has some problems in behavior of anchors because of impossible to tense p.c strand uniformly under the existing equipment due to different length of p c strand. Hence, motive of this research was to study the application of the newly developed tension system, that analyze and compare with the current anchoring method build on the data of in-site test and laboratory test. As a result, in case of auto back tension system, it became clear that tension pressure was equally distributed among the steal wires but the existing tension system showed sign of instability by indicating stress deflection of about 30% compare with design load. This can cause an ultimate failure of the concentrated p.c strand and a shear failure of ground.

The project comprised the construction of the new oil pier and associated topside facilities and demolition of exiting south pier. The site is located approximately 33km south of Kuwait city at MAA refinery. The approach trestle and berth structures of the new oil pier were designed to be supported by steel tubular piles Total 2,480 numbers of piles(795 piles at Approach Trestle, 1187 piles at Berth 1 -4 and 498 piles at Berth 5-6) had to be driven through the calcareous silty sand In this study, the design procedures for offshore steel pipe piles, evaluation for the compression and tension capacities by static and dynamic load test and effective driving criteria by the final set values are discussed

The single drilled shaft foundation has been used in the other countries, but has not used in South Korea at all This foundation is very effective and economic method in South Korea which is easy to meet a good rock mass within 50m depth from the ground We have many experiences to construct 1.52 5m drilled shaft foundations and ability to construct 30m drilled shaft foundation without special efforts The soil behavior is nonlinear, but it can be proposed in linear in practical purpose on bridges. The elastic modulus of soil can be rationally obtained by the method of Road Bridge Design Manual in South Korea using the Schmertmann(1970)'s proposal, and the elastic modulus of rock can be obtained by the field test. In seismic design the column and drilled shaft must be restricted to the elastic design because the behavior of this foundation is flexible and the arrangement of the rebars makes the various defect In this paper the design criteria is compared with FHWA design criteria, and the design criteria is proposed in consistent with Road Bridge Design Manual in South Korea. The single drilled shaft foundation of a test bridge was constructed in the Iksan-Jangsoo highway, and we checked its stability, workability and economy

본 글은 부산-김해간 경량전찰 건설공사의 기초설계시 현장타설말뚝 기초의 지지층을 모래자갈층으로 적용한 사례이다. 낙동강 유역은 퇴적층이 발달하여 풍화암 이상의 기반암층이 지표하 60~80m 이후에서 출현하며, 40m 이상의 심도에서 매우 조밀한 상태의 모래자갈층이 10-20m 두께로 분포하고 있어, 모래자갈층을 관통하여 기반암에 말뚝기초를 지지할 경우 기초공사에 상당한 기간이 소요될 뿐만 아니라, 시공성과 경제적인 측면에서 매우 불리하다. 이에 대한 개선방안으로 대구경 현장타설말뚝을 N치 50 이상의 조밀한 상태의 모래자갈층에 지지하였으며, 인근현장의 적용사례, 기초 구조물 안전성 검토 및 현장재하시험 등의 비교분석을 통하여 모래자갈 지지층의 적정성을 확인하였다. 따라서, 풍화암 이상의 지지지반 출현심도가 60m 이상으로 매우 깊고, 지지지반 상부에 모래자갈층이 두껍게 분포하는 경우에는 모래자갈층을 말뚝기초의 지지층으로 활용하는 방안이 시공성 및 경제성 측면에서 합리적이라 판단된다.

Soil nailing systems are generally many used in underground excavations and reinforcements of slopes since the first construction as a temporary retaining wall in 1993, Korea. In recently, they are many attempts to expand the permanent reinforcements of slopes However, experimental studies related to soil nailing systems are insufficient Specially, there are no researches related in the large scaled load tests of soil nailed walls in Korea In this study, a case study on the large scaled load tests of soil nailed walls is introduced and the behavior characteristic of them is investigated Also, they are proposed allowable deformation corresponding to the serviceability limit of soil nail walls and ultimate deformation corresponding to the collapse state of the walls. These results can be applied to the maintenance management of soil nailed walls And analysis on the required minimum factor of safety of soil nailed walls using the relation curve of load ratio and deformation ratio are carried out

2006년도 집중호우에 의해 발생된 강원도지역의 수해에 대하여 자료를 수집, 분석하였으며 수해의 발생기구 및 유형에 따른 피해정도와 저감방안에 대한 고찰을 실시하였다. 2006년 7월 15일-17일 사이의 집중적인 호우는 강원도 지역에 많은 피해를 주었는데, 특히 강원도 인제, 양양, 평창지역에서의 피해로 수십명의 인명피해와 재산피해를 발생시켰다. 최근 들어 발생되는 집중호우로 인한 피해 중 토석류에 의한 피해가 많은 이유 중에는 지구온난화로 인한 100mm에 가까운 시간당 강우량을 보이고 있어 국내에서 산악지가 형성된 구간에서는 어느 지역이나 토석류가 발생될 가능성을 지니고 있다고 할 수 있다. 그러므로 본 연구에서는 2006년 7월에 발생된 강원도 인제, 양양지역을 중심으로 토석류 피해에 대하여 자료를 수집, 분석하였으며 토석류 발생기구 및 유형에 따른 피해정도와 저감방안에 대한 고찰을 실시하였다. 앞으로 빈번해지는 토석류에 대한 관리체계의 확립 및 보완대책과 토목 공사시에 반영될 수 있는 방안 등을 모색해야 할 것이다.

Recently, construction of soil-reinforced segmental retaining walls which used geosynthetics are being increased day by day due to its construction efficiency, economic efficiency, and its aesthetic view. The conventional reinforced earth retaining wall has the connector system to fix the reinforcement and block However, this system may cause the crack of block and the rupture of reinforcement due to the stress concentration near the face of reinforced earth retaining wall In this study, the new connector system, which is able to allow the settlement of reinforcement, was applied to analyze the effect of connector system of reinforced earth retaining wall The connection strength tests and centrifugal tests for both the conventional reinforced earth retaining wall and the settlement reinforced earth retaining wall were performed to compare the results

Segmental Grid Retaining Wall is one of the segmental grid retaining walls using headers and stretchers to establish the framework of the wall In this method, grids formed by the intersection of headers and stretchers are generally filled with the gravel to maintain the weight of the wall Therefore, the construction can be carried out with higher speed and much economically when compared with the concrete retaining wall Furthermore, it has high drain capacity, and environmentally friendly aspects also have been pointed out because the possibility of the planting at the front of the wall However, in the segmental grid retaining wall method, the relative movement between the individual headers and stretchers was generally recognized, and stress redistribution in the gravel filling was also observed when subjected to the external loading and self-weight of filling Therefore, it has been thought that the distribution of the earth pressure in the segmental grid retaining wall system differ from that of the concrete retaining wall In this study, the surcharge tests using the scaled model segmental grid retaining wall was carried out to observe the distribution of the earth pressure in the segmental grid retaining wall The earth pressure was measured in the six specified height of wall, and the distribution of the pressure was analyzed. Furthermore, the earth pressure by computation or by the test using the concrete retaining wall was also considered to make comparison

In this study the case of ground improvement by CGS as injection method were analyzed in order to find out effect of behavior of sandy soil and the application of this method as ground improvement. The study were analyzed N value after CGS work of sandy soil by many sites test. Considering that increase of N value, CGS can be considered as an effective method to increase the bear capacity as well as constrain the settlement of soft ground From the results of this study, N value after CGS work of sandy soil were closed to N value of ground and relative density(Dr), improvement ratio(As) of grouting and the study will be done continuously for finding out relation of them

서울지하철 0호선 000 공구 000 정거장 구간은 버팀보 7단, 어스앵커 2단, 그리고 록볼트 3단의 개착식 가시설로 설계되어 있다. 버팀보 및 앵커 축력 계측을 위해 변형률계 및 하중계를 설치하고 연속계측 중, 4~6단 버팀보 수 개소에서 5월부터 하중이 급격히 증가하엿다. 따라서 굴착작업을 즉시 중단하고 관리기준치를 초과하는 하중이 계측된 STA.9k+750~800 구간의 5, 6단 버팀보 위치에 격간으로 총 20본(10본${\times}$2단), 그리고 STA.9k+900~920 구간의 7단 버팀보 위치에 격간으로 총 9본(9본${\times}$1단)의 버팀보를 추가적으로 설치 완료하였다. 이 때, 추가 버팀보는 선행하중잭을 이용하여 10ton의 선행하중을 재하하였으며, 향후 추가 보강 필요시 재하하중 증가가 가능하도록 조치하였다. 또한, 추가 설치된 버팀보, 그리고 이상하중이 발생된 버팀보에 계측기를 추가 설치하여 지속적으로 계측중이며, 띠장의 변위발생 구간은 스티프너 및 앵글 등을 응급조치하였다. 본 사례 연구에서는 보강 전.후의 계측결과 및 수치해석적 분석을 이용하여 가시설 굴착시 버팀보의 하중증가 원인 및 보강 효과를 규명하고, 향후 추가 굴착시의 안정성 여부를 검토해 보고자 하였다. 계측값 분석 결과, 추가버팀보 보강 후의 기존버팀보 축력 계측 결과 보강 직후 기존버팀보의 축력이 어느정도 감소하였으며, 이후 시간이 지남에 따라 축력이 더 이상 증가하지 않고 일정한 값에 수렴하는 경향을 보였다. 또한 수치해석 결과 온도 증가가 버팀보 축력증가에 미치는 영향은 버팀보 위치의 지반강성이 클수록 크며, 축력증가는 온도증가에 대체적으로 비례하였고, 추가버팀보의 보강 효과는 선행하중의 크기에 비례하는 것으로 나타났으며, 잔여굴착은 전반적으로 기존 버팀보의 축력 증가에 영향을 미치는 것으로 나타났다. 따라서 추가굴착시 지속적인 계측을 수행하며, 급격한 축력증가가 관찰될 경우 현재 보강된 버팀보의 선행하중 추가 재하, 굴착에 가장 큰 영향을 받는 최하단 버팀보의 추가보강 등의 대책방안을 제시하였다.

현재 연약지반의 개량 및 구조물기초 지반의 보강을 위하여 약액주입공법 및 고압분사주입공법 등의 주입공법이 널리 행해지고 있는 실정이다. 이에 본 연구에서는 00교 교대 전면 옹벽기초 하부지반을 고압분사주입공법을 이용해 보강한 사례로서 설계 및 시공, 시험 자료를 분석하고, 보강작업에 따른 지반의 개량효과를 분석하였다. 개량효과학인을 위한 시추조사와 시추공영상 촬영 이미지 관찰결과에서는 고압분사에 의해 양호한 상태의 고결체(토사 + 시멘트 페이스트)가 형성되었음을 확인 할 수 있었으며, 고결체와 원지반의 복합지반상에서 실시한 평판재하시험 결과 및 시추조사시 채취된 고결체 Core에 대해 실시한 일축압축강도시험 결과에서도 설계시 가정한 값을 모두 만족하는 것으로 나타나 연약지반의 강도가 개량되어 안정성을 확보한 것으로 확인되었다.

Debris flows are a natural hazard which looks like a combination of flood, land and rock slide. Large rainfall in July 2006 produced several large scale debris flows and many small debris flows that resulted in loss of life and considerable property and highway damage, as was widely reported in the national media. The hazard "debris flow" is still insufficiently researched Furthermore debris flows are very hard to predict. In this paper, a general over view of the debris flow problems along the highway, a generic way for the design and dimensioning of flexible barrier systems will be presented. A brief description of the various unique barrier types will be provided, too. The future for these barrier concepts looks promising because these barriers represent the state of art for such applications and are superior to many other available options.

A ground treatment work for Hongkong container terminal yard is reported as a case study of site formation work with full dredging and replacement method. Ground treatment work adopting surcharge and deep compaction (vibroflotation) were applied to improve the sand creep potential. The sand creep parameter of 0 25% was assumed in design stage and improved up to 0.05% and 0.02% after surcharge and deep compaction respectively

광양항 3단계 1차 컨테이너터미널 부지 연약지반개량의 경우 광양지역의 특성상 재하용 토사확보 곤란, 시공기간 단축 및 환경훼손 최소화를 위해 진공압밀공법이 적용되었다. 본 사례연구에서는 진공압밀공법의 시공에 따른 문제점 및 개선사항을 제시하였고, 현장계측 및 진공 압밀완료 후에 실시된 지반조사 결과 등을 분석하여 준설매립지반에서의 진공압밀공법의 적용성을 평가하였다.

최근 피조콘시험은 과거 일반적으로 사용되었던 표준관입시험과 함께 연약지반의 특성을 평가하기 위해 빈번히 사용되고 있다. 본 연구에서는 하부지반의 지층상태를 파악하고 설계를 위한 연약지반 심도 결정 및 시공시 수직배수재 타설심도 결정시 그 신뢰도를 향상시키기 위해서 표준관입시험결과(N치), 선행압밀하중(pc), 수직배수재 타설시 관입에너지와 피조콘시험을 통한 콘 관입저항치($q_c$)와의 관계를 분석하였다. 대상 지역별로 일정한 표준관입저항치를 기준으로 평균 연약지반심도를 결정하여, 동일한 심도에서 피조콘관입저항치를 값을 분석한 결과 $q_c$=(1.09~1.63)N, 선행압밀하중을 고려한 결과 $q_c$=(1.21~1.98)N의 관계를 나타내었다. 또한 수직배수재 타설시 관입에너지와 피조콘시험을 통한 콘 관입저항치($q_c$)와의 관계를 분석한 결과 평균적으로 피조콘 관입저항치 10kgf/$cm^2$의 경우 수직배수재 타설 시 관입저항치는 약 65~70.0kgf/$cm^2$의 값을 나타내였다.

영산강 하구지역은 현재 신도시개발이 한창 진행되고 있으며, 연약한 해성퇴적층이 15~25cm로 존재하고 있다. 연약지반 개량설계는 불교란시료를 채취하고 각종 실내시험을 통하여 지반의 토질정수를 결정한다. 본 고찰은 압밀관련 지반정수인 선행압밀하중(Pc), 압축지수(Cc), 재압축지수(Cr)를 재해석하기 위해 침하계측 결과를 이용 실내시험의 압밀 곡선과 비교 분석하였다.

This study shows decision-making process for selection of cutoff wall on a wastewater treatment project. There are 10 different cut-off wall methods So, we examine the site to gather information for find appropriate methods. After using that information, 10 cutoff wall methods are reviewed for analysis. Through brainstorming, four alternatives are selected for design VE item. Following the standard VE process, we established performance criteria and evaluated function score(F) using questionnaire. The questionnaires, brainstorming and AHP method for weighting on performance criteria and evaluate function score increased the reliability of this selection process. Water Jet method, one of four methods, has the best function score(F=92.71) and the lease construction cost(as cost index 1,000). The value score also highest as 92.7, so we select the method. The result is value innovation type In addition, the authors try to calculate the environmental burden in selection process using LCA. We cannot conduct the full LCA as defined ISO, so perform Simple LCA In LCA result, the cut-off grouting has the least environmental burden as index 9.09E+01 and Water Jet method has following as the second. To selection best method to specific area and purpose, design VE/LCG process used as useful tool and it is needed to develop integrated method that evaluate VEILCC and LCA as one-set process.

국내 건설산업은 현재 기술보다는 수주위주의 경쟁이 치열함으로서 종합기술 수준은 세계 25위권, 기획.설계 능력은 선진국의 70% 수준에 불과한 취약한 기술경쟁 기반과 시공 중심의 생산구조를 갖고 있다. 이러한 건설부문의 문제점을 극복하고자 정부는 2015년까지 건설 기술력 수준을 선진국의 90%까지 끌어올리기 위해 건설 분야의 연구개발 투자규모 확대 등 다양한 계획을 추진 중에 있다. 본 고에서는 상기와 같은 상황 속에서 장차 미래사회에 있어 건설교통 분야의 기술발전을 이끌 도시성장, 인구변화, 에너지 및 자원 고갈, 기후변화 등 대응기술에 대한 연구개발사업계획을 소개하고, 국내 건설기술의 재도약의 일환으로 2006년을 기점으로 시작된 R&D 혁신로드맵의 체제와 그 의미를 소개하였다.

This study researched N-Value, strength of clayey soil and preconsolidation pressure m order to variety application of standard Penetration test. We compared it makes on analysis of the relationship of the N-value and $q_u$ with relation formula is presented in existing, presented the estimated preconsolidation pressure by using the predicted undrained shear strength.

Artesian Pressure exists in Hwa Jeon Project Site of Nakdong Delta Area. Maxium value of the pressure ranges between 06 tonf/m2 and 1 3 tonf/m2 in the design site. This paper presents a design case study considering the Artesian Pressure to calculate the consolidation settlement of the deep marine clay.

In this test, there was two dimensional model loading test implemented for analysis with respect to the problem of evaluating bearing capacity and the application range on the dredged and reclaimed ground. It was got following conclusion through comparison of button's and Brown&Meyerhof"s equation with experimental result that was obtained by 2 dimensions model loading test. For the difference between average undrained shear strength by 2/3B of loading board width and under 2/3B is more than ${\pm}$ 50%, application of Nc(coefficient of bearing capacity was used in that case $\phi$=0 analysis is considered in the single layer) was declined. Brown&Meyerhof(1969)'s equation was underestimated comparing with loading test result, while Button(1953)'s equation was overestimated comparing with loading test result applied dividing as double layers of upper dessication layer and lower soft layer about dredged and reclaimed ground. Also, bearing capacity factors, Nc that was calculated by using button's equation was estimated greatly about 1.7 times more than bearing capacity factors, Nc that was calculated by using Brown&Meyerhof's equation. Bearing capacity factors, Nc that was calcuated by using Brown&Meyerhof's and Button's equation was evaluated each 2.3-3.6 times, 1.3-2.1 times smaller than bearing capacity factors, Nc5.14 that was calcuated by using Meyerhof's equation in case of unit layer.

터널 설계시 일반적으로 지반조사와 물리탐사를 시행하여 지층에 따른 적절한 터널 지보패턴을 설정하고 있으나, 다양한 지반 및 지질특성과 설계단계에서 미쳐 발견되지 못한 단층등의 연약대로 인하여 시공시 터널내에서 종종 붕락사고가 발생하고 있다. 터널 굴착시 발생하는 붕락은 터널의 안정성 저하 및 공기 지연 등의 큰 문제점들을 발생시키므로 조기에 적절한 보강방안이 요구된다. 본 논문에서는 터널 굴착시 발생한 두개의 붕락사고에 대해서 붕락원인과 붕괴유형을 파악하고 현장 여건에 맞는 신속한 보강대책을 제시하고 시공한 보강사례이다. 향 후 본 사례와 유사한 터널붕락사고가 발생할 경우 보강설계 및 보강방안을 계획.수립하는데 유용한 참고자료가 될 것이다.

The Tunnel portal is designed on temporary support system which is composed by 28m height H-Pile method and Ground Anchor method. The tunnel has excavated about 30m from the portal, but some deformation is found on the surface ground just above the tunnel face. It was investigated very carefully to find out the causes of deformation. By the observation and study, two main causes of deformation are found out. The one is earth pressure increase compared with classical earth pressure theory. That was due to the direction of ground rock mass's discontinuities. It causes the increase of earth pressure that are activated by the direction of discontinuity. The other one is that present design method neglect the transferred force by removal of temporary support members and ground anchor within the tunnel contour line as the tunnel excavation proceeds As the result of removals of the member and anchor, some force transferred from removed systems to remaining supporting systems. In designing the portal support systems, lt must be considered the discontiunity of ground mass and the transfered force due to excation.

최근 기상이변에 따른 이상홍수가 빈번하고, 댐 설계홍수량 설계기준이 가능최대홍수량(PMF)으로 강화되었으며, 최근의 주요 호우사상을 고려하여 산정한 임하댐 유역의 가능최대강수량(P.M.P)이 설계 당시보다 증가됨에 따라 가능최대홍수량(PMF) 유입시 댐 안정성 확보가 필요한 것으로 검토되었다. 따라서, 본 과업은 “댐의 수문학적 안정성검토 및 치수능력증대 기본계획 수립, 2004. 9. 건설교통부/한국수자원공사”에 의거하여, 최근의 태풍 ‘RUSA’(’02) 및 ‘MAEMI’(’03)와 같은 이상호우에 대한 댐 및 여수로의 안정성을 확보함으로써 국민의 생명과 재산을 보호할 수 있도록 비상여수로를 계획하였다. 비상여수로는 수문학적 안정성을 검토한 후, 가능최대홍수량(PMF)과 같은 홍수유입시 댐의 안전을 위하여 신속히 홍수를 배제시킬 수 있는 수리적.구조적인 안정성 확보가 가능하고, 시공성, 경제성 및 환경성 측면을 고려하여 댐우안 300m 지점에 터널규모 D15m${\times}$3련 ${\times}$L1,262m (L1=379m, L2=421m, L3=462m)의 월류형 터널식으로 계획하였다.