http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
이봉직,윤준식,이종규 한국지반환경공학회 2005 한국지반환경공학회논문집 Vol.6 No.3
Dynamic compaction is a ground improvement technique which is particularly effective for loose granular soils. It has also been used successfully to the cohesive soils with high void ratio, and wastes and fills. For the design of dynamic compaction method, prediction of depth of improvement is very important. The depth of improvement is influenced not only by compaction energy but also by many parameters such as grid spacing, soil property, degree of saturation and site conditions. Based on the test results, the depth of improvement were evaluated with considering compaction energy, soil type and ground water level. 동다짐공법은 느슨한 지반의 개량에 주로 사용되는 공법으로 점착성 토사나 폐기물과 성토지반에도 성공적으로 적용되고 있다. 동다짐공법의 설계에 있어 지반개량심도의 결정은 중요한 요소이다. 그러나 개량심도는 다짐에너지 뿐만 아니라 다짐간격, 대상토질 특성, 포화정도 및 현장여건 등에 영향을 받고 있다. 본 연구에서는 개량심도 예측을 위하여 현장실험결과를 이용하였으며 다짐에너지, 토질특성 및 포화정도에 따른 개량심도를 평가하였다.
이봉직,김조순,이종규 한국지반환경공학회 2007 한국지반환경공학회논문집 Vol.8 No.4
In this study, several pullout tests were carried out under various field conditions to evaluate the pullout force of the end fixed nails. Pullout resistance force, displacement and friction force between the grouting and nail were measured in end fixed nails installed in soft rock, weathered rock and weathered soil. Furthermore, the field test were also carried out under the same condition using the conventional type nails. Based on the test results, it is concluded that the end fixed nails showed larger ultimate resistance force compared with conventional types nails, approximately two times in weathered soil and 1.6 times of weathered rock, respectively. The skin friction is also increased in end fixed type about 1.8~3.0 times. Finally, it is concluded in the base of the force transfer properties that using the end fixed nails could decrease the displacement and show a uniform resistance in entire length of nails. 양단정착형 네일의 인발력을 평가하기 위하여 여러 조건에 대한 현장실험을 실시하였다. 현장인발시험은 연암, 풍화암 및 토사지반를 대상으로 인발력, 변위 및 그라우트와 네일의 마찰력 등을 측정하였으며, 이의 결과를 동일 조건에서 실시된 일반네일의 시험결과와 비교하였다. 시험결과 한계인발력은 양단정착형네일이 일반네일에 비하여 토사지반에서는 2배 이상, 풍화암에서는 약 1.6배 큰 것으로 분석되었으며, 단위길이당 주면마찰력도 양단정착형네일이 일반네일에 비하여 약 1.8~3배정도 증대되는 효과가 있는 것으로 분석되었다. 또한, 네일종류에 따른 하중전이특성 분석결과 양단정착형네일의 경우에는 변위는 작고, 네일 전 길이에 걸쳐 하중을 균등하게 부담함을 알 수 있다.
이봉직 忠州大學校 1999 한국교통대학교 논문집 Vol.34 No.2
Since elasto-plastic model is presented by Drucker et al in the latter of 1950s, then Cam-clay model is proposed by the Roscoe et al and constitutive model of Cap model etc. that founded on continuous failure concept of soil has been proposed. Elasto-plastic constitutive model proposed by Lade is new elasto-plastic work hardening model with two yield surface containing work hardening rule and plastic potential surface that is presented by yield surface and hardening softening process upon plastic compression. Sample soil is weathered granite soil that be foundation at cheong-ju district. To determine soil parameter, isotropic consolidation tests and cylinderical triaxial compression tests are carried out. Basis physical properties is determined by geotechnical tests, and for application of constitutive model with multiple intersecting yield surface. it keep constant compaction energy and then determind soil parameters(14). And predicted value of stress-strain behavior was compared with measured value.
Kaolinite 에 근입된 앵커에서 흡입력이 미치는 영향
이봉직,이준대 한국산업안전학회 1997 한국안전학회지 Vol.12 No.4
Plate anchors are primarily used in the foundation construction of earth-supported and earth-retaining structures. In order to estimate uplift capacity as well as suction force of clay, model tests were performed with respect. to various embedment depths and two different moisture contents in the prepared saturated kaolinite. Further, suction effects on the ultimate uplift capacity, at the various embedment depths of anchor, were also taken into account. Test results show that, ultimate uplift capacity including suction force increases from 4.2㎏ at H/D=1 upto 11.6㎏ at H/D=5 in K1 and from 2.3㎏ at H/D=1 upto 7.3㎏ at H/D=5 in K2 respectively. The ratio of F_s/Q_n decreases along with the increases in the embedment ratio. In general, mud suction force under the ultimate uplift capacity in kaolinite decreases or become constant along with the increase of the embedment ratio.