국내 노상토의 M_R특성 분석을 위한 실험적 연구

문홍득,신영철 진주산업대학교 1997 산업과학기술연구소보 Vol.- No.4

The deflection and deterioration of road surfaces are largely related to the deformation of underlying soils. The American Association of State Highways and Transportation Officials(AASHTO) has adopted use of resilient modulus in the pavement design to represent the deformational characteristics of pavement materials due to repeated loading. Because of the recent interest in the use of resilient modulus for pavement design, it is needed to evaluate on the effects of moisture, soil type, and stress state on resilient modulus. In this paper, resilient characteristics are investigated for subgrade soils gained from road construction sites in Korea. The experimental technique basically follows the method suggested in this study.

터널해석에 있어서 적정 하중분담율의 결정 연구

문홍득,설진성 진주산업대학교 1999 산업과학기술연구소보 Vol.- No.6

3-D structure is created at the tunnel face in all tunnelling. Accordingly, the ground around the tunnel under construction shows three dimensions deformational behavior due to the transverse and longitudinal arching effects. In order to obtain the realistic results of these the tunnel behavior from the numerical analysis, actual construction measures and their sequence must be taken into account. In particular, the excavation and installation of support and lining are important tunnel construction parameters. Despite these three dimensionalities encountered in tunnelling, a three-dimensional analysis is often not necessary. Instead, a two-dimensional model can be substituted because of the size and complexity associated with a 3-D model and calculation times to perform a 3-D analysis. The simulation of 3-D conditions by a 2-D model requires experience and the understanding of the relationship between theses two models. Load distribution ratio is used to the 2-D analysis for the consideration of the effects of the tunnel advance in three dimensions in Korea. However, constant load distribution ratios have been assigned for 2-D analysis even if the conditions for tunnel design are different. This paper presents the results of the evaluation of load distribution ratios through a three-dimensional tunnel analysis for the different ground formation and compares the cases of load distribution ratios applied actual tunnel design in Korea.

평균 및 위너 필터를 사용한 영상 복원에 관한 연구

문홍득,강경덕,배상범,김남호,Moon Hong-Deuk,Kang Kyeong-Deog,Bae Sang-Bum,Kim Nam-Ho 한국정보통신학회 2004 한국정보통신학회논문지 Vol.8 No.7

영상은 획득, 저장 그리고 전송 등의 처리과정에서 다양한 원인에 의해 훼손되며, 이러한 영상을 복원하기 위한 많은 연구가 이루어지고 있다. 일반적으로 AWGN(additive white gaussian noise)에 의해 훼손된 영상을 복원하는 방법으로 평균 필터와 위너 필터가 있으며, 특히 평탄한 영역에서의 노이즈 제거에 평균 필터가 우수하다. 그러나 평균 필터는 영상의 특징을 고려하지 않으므로 에지 성분이 왜곡되어 평활화되는 단점이 있다. 따라서 본 논문에서는 평균 필터와 함께 에지 성분을 보존하면서 대조도 개선에 강한 위너 필터를 사용하여 각각 필터링한 후, 처리된 영상에 가중치를 설정하여 병렬처리하는 영상 복원 방법을 제안하였다. Image is degraded by several causes such as the process of acquisition, storage and transmission. To restore those images, many researches have been continued. Centrally methods to restore degraded image by AWGN(additive white gaussian noise) a.e mean filter and wiener filter. Especially, mean filter is superior in noise reduction of area that is a small change of luminosity. But mean filter brings about the effect smoothing edge components of the image, because it does'nt consider characteristics of the image. So in this paper we propose an image restoration method compounding respective images adding established weights, after filtering with mean filter and powerful wiener filter in both improvement of contrast and preservation of edge components.

현장계측에 의한 터널 지보재에 작용하는 지반하중 평가 연구

문홍득 진주산업대학교 1998 論文集 Vol.37 No.-

NATN(New Austrian Tunnelling Method) uses a support system of shotcrete, rockbolt, and steel support, which are installed after tunnel excavation. Among these support system, a steel support is used for reinforcement of a unsupported ground, redistribution of the rock load applied to shotcrete, and resistance of the earth pressure until the strength of shotcrete and rockbolt is fully developed. Recently, a H-shaped steel set is reported to have some problems in installation. So, a Lattice girder was developed to replace a problematic H-shaped steel set in Switzerland and German. Lattice girder is a triangular shape welded with steel rods. Lattice girder is a light-weight support system which enables fast installation. The major advantage of lattice girder is the good bonding with shotcrete. To evaluate the applicability of a lattice girder to tunnelling in Korea, field test was performed at a high speed railway tunnelling site with a large section and was compared with the feature of a H-shaped steel set. This paper especially presents the evaluation of the percentage of the rock load distributed to shotcrete and a steel support system(lattice girder and H-shaped steel set) which were investigated in this study. Field tests proved that a lattice girder fully supported the initial earth pressure developed right after tunnelling and therefore limited ground deformation effectively.

안정처리 되지 않은 지반 상에 건설되는 농로의 안정성 평가

문홍득,박순철 진주산업대학교 산업과학기술연구소 2007 산업과학기술연구소보 Vol.- No.14

Recently, many road construction is being performed in country side to wide the existing small agricultural road. In this case, the road is designed without the exact site investigation because of financial reason of regional government. So in some case, the road is designed on soft soils and has many problems in the process of construction. Especially agricultural road which needs to wide the existing small road overlying on the untreated soft soil is planned without the site investigation. In this case, the enlarged road will have the problems such as excess settlement or shear failure of road. In the process of designing and constructing structures on soft soils, we need to consider whether the soil properties can be economically improved. In this study, a case study was performed for the stability analysis of agricultural road overlying on the untreated soft soil. Soil tests were performed to investigate soft soil properties and plate bearing test was performed to find the bearing capacity of subbase and subgrade. Numerical analysis was also performed to evaluate the stability of new planning road overlying on the untreated soft soil using commercial soft ware which is used to analyze the consolidation settlement. We found that the new planning road overlying on the untreated soft soil has consolidation settlement in excess of the allowable settlement criteria. After evaluating the several methods available for the improvement of the engineering properties of soft clays of this site, the replacement method as safe and economical method was selected and analysed. We conclude that in case of designing new road to wide the existing small agricultural road, site investigation should be necessary and then road have to be designed rationally in according to the site soil conditions.

수치해석에 의한 암반내 초기응력의 영향인자 분석 연구

문홍득 진주산업대학교 2000 산업과학기술연구소보 Vol.- No.7

Reliable evaluation of initial stress in rock mass is an important step in the analysis and design of underground excavations, particularly for analysing the stability of underground structures to prevent failure or collapse of underground openings. This initial stress rolates primary with depth, rock properties, rock conditions and surrounding circumstances etc. In this study the influence factors on initial stress were analysed by numerical experiment, especially with past stress history, topography, formation and joint of rocks, geological structure(fault).

현장시험에 의한 이방향 병용천공 발파공법의 평가

문홍득 진주산업대학교 건설기술연구소 1998 건설기술연구소보 Vol.1 No.-

Currently in Korea, the tunnel enlargement process uses the combined method of TBM/NATM with the conventional method. So, it is difficult to get advantages which involved in the combined method. In this study, the new drilling and blasting enlargement excavation method was developed which drills charge holes in a radial direction inside the pilot tunnel. Then holes are drilled in the outer portion of the tunnel section in the same direction as the tunnel axis to prevent overbreak. Next, all charged holes are blasted simultaneously (to be called the "bidirectional method"). This paper presents an evaluation of new drill and method with two different drilling directions for pilot tunnel enlargement through experimental field tests performed on a road tunnel construction site in Seoul area. To evaluate the efficiency of new tunnel enlargement method, field test results were compared with those of conventional drill and blast method.

터널지보용 격자지보의 시공성 평가 연구

문홍득 진주산업대학교 건설기술연구소 1998 건설기술연구소보 Vol.1 No.-

Recently, a lattice girder is used in tunnelling as a tunnel support. A lattice girder is a new steel support developed in Europe for the replacement of an existing H-shaped steel set, which is reported to have some problems in installation. In this study, to evaluate the workability of a lattice girder in tunnelling in Korea, field observations were performed at a subway tunnel construction site with a small section. Also, features of lattice girder in field observations were compared with those of a H-shaped steel set respectively.

현장계측 자료분석을 통한 암반내 초기응력의 평가

문홍득 진주산업대학교 2000 산업과학기술연구소보 Vol.- No.7

Although a number of techniques have been proposed and developed to determine initial stress in rock mass, the determination of initial stress is not an easy task and all suffer from deficiencies and limitations. The main deficiency of established techniques such as over coring method or hydraulic fracturing method which is currently used in Korea is that they are usually expensive and time consuming. This paper presents a guide to determine the resonable initial stress for tunnel design through the analysis of field instrumentation data measured in Korea.

폐콘크리트 순환골재의 단입자 파쇄 특성

문홍득,박성식,김상중 한국지반공학회 2016 한국지반공학회논문집 Vol.32 No.12

A single particle crushing test was carried out for recycled aggregates from waste concrete while demolishing variousstructures. When the recycled aggregates were used for backfill or road subbase materials, load-displacement and crushingcharacteristics were analyzed. The recycled aggregates with hydrates and aggregates were sorted into 40 mm size (75-40mm) and 20 mm size (40-20 mm). At initial loading, their irregular surface was closed to and then crushed by loadingplate. Such first crushing stage was called ‘Surface crushing’. Further loading, some hydrate was crushed and detachedfrom aggregate, and such process repeated several times. This state is called ‘hydrate crushing’. The final state is called‘aggregate crushing’ in which aggregate crushed and following load suddenly dropped down. As the load increased,such crushing cycle is repeated several times. The shapes of aggregates are round or square, and triangle or long shaped. Depending on their shapes and surface conditions, they crushed in different ways. The 63% of aggregates showed morethan 50% load reduction due to aggregate crushing. The 90% load reduction occurred at 15% of aggregates. The 40mm aggregate crushed at maximum load between 3.05-4.38 kN and 70% of crushed aggregates were less than 20 mm.