세미 오픈컷 역타공법의 현장적용에 관한 연구

소광호,Sho, Kwang-Ho 한국공간구조학회 2011 한국공간구조학회지 Vol.11 No.2

지하공사는 상부층의 구조물과 연계된 시공순서에 따라 Bottom-Up공법, Up-Up공법 그리고 Top-Down 공법으로 대별할 수 있다. 탑다운 공법을 사용하면 건물의 본구조를 흙막이지보공으로 이용하면서 상층에서 하층으로 굴착과 구체구축을 반복하여 시공함으로써 인접구조물이나 주변 지반의 변위를 극소화 시킬 수 있다. 이는 토류벽의 안정성이 높으며, 각층의 바닥슬래브를 작업공간으로 사용하여 도심지 공사에서 작업장 확보가 용이하다. 그러나 굴토작업이 슬래브 하부에서 진행되므로 작업 능률 및 작업환경이 저하되고, 어스앵커 공법보다 경제성이 없다는 이유로 다소 회피하는 경우가 종종있다. 따라서 본 논문에서는 터파기 공사는 세미오픈컷 공법을 적용하고 흙막이 공법에는 지하연속벽(슬러리월)을 그리고 지보공으로는 C.W.S공법을 적용한 역타공법으로 대상현장을 중심으로 기존 역타공법과 경제성, 공사기간 및 작업성 등을 분석 제시하였다. 토사운반 및 철골설치공사 작업의 용이성과 PRD 공사의 정밀도 향상 등의 품질관리가 우수하며, 공기단축이 가능하였다. Construction methods for underground structure are classified as bottom-up, up-up, and top-down methods depending on the procedure of construction related to a superstructure. In top-down construction methods, building's main structure is built from the ground level downwards by sequentially alternating ground excavation and structure construction. In the mean time, the main structure is also used as supporting structure for earth-retaining wall, which results in the increased stability of the earth-retaining wall due to the minimized deformation in adjacent structures and surrounding grounds. In addition, the method makes it easy to secure a field for construction work in the downtown area by using each floor slabs as working spaces. However top-down construction method is often avoided since an excavation under the slab has low efficiency and difficult environment for work, and high cost compared with earth anchor method. This paper proposes a combined construction method where semi-open cut is selected as excavation work, slurry as earth -retaining wall and CWS as top-down construction method. In the case study targeted for an actual construction project, the proposed method is compared with existing top-down construction method in terms of economic feasibility, construction period and work efficiency. The proposed construction method results in increased work efficiency in the transportation of earth and sand, and steel frame erection, better quality management in PHD construction, and reduced construction period.

한글창제의 오류

소광호(Sho, Kwang Ho) 대한건축학회 2019 建築 Vol.63 No.10

부순모래를 다량 사용한 고강도콘크리트의 유동성 및 역학적 특성에 관한 연구

소광호(Sho Kwang-Ho),박상준(Park Sang-Joon) 대한건축학회 2009 大韓建築學會論文集 : 構造系 Vol.25 No.6

The purpose of this study is to put to practical use high-strength concrete in which over-added crushed sand is used. An indoor mixing test as to crushed sand substitution rates 0∼100% was implemented, and based on its results, the productivity evaluation of the batcher plant followed. First, the compressive strength of the indoor mixing test showed somewhat different results according to the water-binder ratio. That is, when the water-binder ratio was 0.25, the compressive strength in the 28th increased slightly as the crushed sand mixing ratio was getting higher. However, when the water-binder ratio was 0.30 and 0.35, the crushed sand mixing ratio increased up to 50%; but it was found to decrease gradually in the higher crushed sand mixing ratio than that(0.30, 0.35). As to the modulus of elasticity, the result of this study was estimated to be 9.57% lower than that of the current concrete standard specification. As to the heat of hydration in the batcher plant mixing test, the highest temperature decreased by about 11℃ and the highest temperature rose by about 9℃ as the water-binder ratio increased by 0.1. The compressive strength of the specimen for the structure management was 7% higher than the standard cure specimen in the case of the on-site sealing cure, and 2.7% in the case of the on-site underwater cure. In conclusion, as a result of mixing at the rate of 1(50%) to 1(50%)crushed sand, which had somewhat improper quality to be used as concrete aggregate with 3.98 of fineness modulus and 52.7% of solid volume percentage for shape determination; and sea sand, which had relatively excellent quality and the fineness modulus of 2.8(the fineness modulus : 3.23), it was proven that there was no significant problem in manufacturing high strength concrete with the specified compressive strength around 40∼70㎫.

유ㆍ무기 복합 나노실리카를 혼합한 시멘트 모르타르의 염화물 확산 특성에 관한 연구

소광호(Sho, Kwang-Ho),이건철(Lee, Gun-Cheol),박상준(Park, Sang-Joon) 대한건축학회 2011 大韓建築學會論文集 : 構造系 Vol.27 No.12

This study investigates the effect of organic/inorganic nano-hybrid silica on the chloride penetration of cement mortar. This nano-hybrid silica was produced by using a starting material of sodium silicate, instead of using tetraethyorthosilicate or tetramethyl orthosilicate that is expensive, but still commonly used in the literature. Three mortar types (namely, control cement, slag cement and ternary cement) were prepared for this investigation. Blast furnace slag of 40 % was used for the slag cement, and blast furnace slag of 40 % and fly ash of 30 % were used for the ternary cement. Test results showed that the cement mortar with the proposed nano-hybrid silica improved compressive strength around 20 % higher than the control cement, 38 % higher than the slag cement and 19 % higher than the ternary cement. In addition, this study found that by replacing cement with this nano-hybrid cement of only 3% by volume, the percentage of chloride penetration was reduced to 30 %, compared to other specimens without the nano-hybrid silica, and the watertightness was improved to 24 %, compared to the ternary cement. In particular, the use of the nano-hybrid silica significantly reduced the porosity of cement ranging from 0.06 to 3.00 ㎛.

열병합 플라이애시 기반 현장타설 바닥 난방용 마감모르타르의 공학적 특성

소광호(Sho, Kwang-Ho),박상준(Park, Sang-Joon) 대한건축학회 2012 大韓建築學會論文集 : 構造系 Vol.28 No.11

In this study, the applicability of eco-friendly floor finishing mortar for heating was investigated when high amount of byproducts was used as a binder without cement. Fly ash, was produced in combined heat power plant and had much amount of free CaO, was mainly used by 35~5%, and ground granulated blast-furnace slag and paper sludge ash were added. As a result of the study, the fludity of mortar decreased when water-mortar ratio was low and addition of paper sludge ash was high. The setting time of mortar was delayed when water-mortar ratio was high and, especially, it’s final setting time was delayed three times more than that of plain mortar. Length of mortar specimen was expanded up to 180~290 μ at age of 1 day and it was shown that this mortar had an advantage of the reduction of crack. Also, hydration properties of this mortar was similar to that of ordinary portland cementㆍhydration products such as monosulphate, Ca(OH)₂, and ettringite etc. were formed at early ages and much CSH(Ⅰ,Ⅱ.Ⅲ) was formed at age of 28 days.

초고층 기둥축소량 보정을 위한 측량기법에 관한 연구

소광호(Sho Kwang-Ho),정동환(Jung Dong-Whan),양극영(Yang Keek-Young) 대한건축학회 2003 大韓建築學會論文集 : 構造系 Vol.19 No.5

Since the end of 20th century, the construction of high-rise buildings is greatly increased. The column of tall buildings is inherently vertically shortened and it causes several serviceability problems such as tilting of slab, crack within partition wall, deformation of curtain wall. Therefore, the column shortening has to be compensated at construction stage. To make sure the accurate compensation of column shortening, advanced and additional survey method is required. In this study, the basic survey method for tall building construction is briefly addressed. And the survey methods for the KLCC, TELEKOM H/Q, Plaza Rakyat projects are analytically examined. It could be concluded that vertical and horizontal levels has to be surveyed by the higher resolution equipment and combination of small and large zone survey is required.

시공성 향상을 위한 초고층 건물의 기둥 축소량 보정법에 관한 연구

소광호(Sho Kwang-Ho),양극영(Yang Keek-Young) 대한건축학회 2003 大韓建築學會論文集 : 構造系 Vol.19 No.11

Column shortening in the cores and columns of tall concrete buildings requires special attention to ensure proper behavior for strength of the structure and the nonstructural element. The effects of column shortening, both elastic and inelastic, take on added significance and need special consideration in design and construction with increased height of structures. The compensation differ from reinforced concrete and steel reinforced concrete members. In this paper, the compensation methods of column shortening are presented and analyzed according to the material characteristics. It could be concluded that suitable compensation methods according to the reinforced concrete or steel members are significant factors for the accurate compensation of column shortening.

미립자시멘트를 이용한 조강형 콘크리트의 현장 실용화에 관한 연구

소광호(Sho Kwang-Ho),김경민(Kim Kyoung-Min) 대한건축학회 2009 大韓建築學會論文集 : 構造系 Vol.25 No.6

Currently, there is limited to demonstrate the demanding technology for high early strength, and the cost of construction is increased. Therefore, the technology for high early strength is the most important on the cement, so the improvement of high early strength should take precedence over the others on the cement. Therefore, this study investigates the technology for high early strength using fine particle cement which is generated from separator bag filter for the practical application to the construct field and batcher plant. For results, there is not significant difference on the fresh, however the compressive strength when fine particle cement was used is increased about 164~203%, and the time to 5 ㎫ could be reduced about 1 day and 7 hours.

병행순타공법의 현장적용에 관한 연구

소광호(Sho Kwang-Ho),양극영(Yang Keek-Young) 대한건축학회 2009 大韓建築學會論文集 : 構造系 Vol.25 No.9

Top-down method is divided into Up-down method which is digging underground from earth level and making underground structure and slab at the same time and Double-up method, advanced technology compared to Up-down, which is making underground structure and ground structure coincidently. Double-up method is making underground and ground structure after excavation, constructing from underground bottom to first floor slab and then from first floor to ground structure simultaneously. Up-down method, one of the Top-down methods, has been studied a lot by the academic world recently. It is broadly used by construction site in urban areas but there are few studies about Double-up method. So this thesis came to the conclusion as followings by applying Double-up method in real construction site. First, Double-up method could reduce construction term over 40%. Second, Core preceding method is effective for Double-up method to reduce construction term. Double-up method costs 8 percent more than conventional method, but the entire construction cost has no big difference in case of considering overheads. If the research and development for the technology to apply Double-up method is completed, Double-up method will be used effectively on the construction site.

마이크로 필러 혼화재를 이용한 조강콘크리트 현장적용

소광호(Kwang-Ho Sho),김경민(Kyoung-Min Kim) 한국콘크리트학회 2012 콘크리트학회지 Vol.24 No.2