폐기물매립지 선별토사의 재활용을 위한 흙 시멘트 효과에 대한 역학적 특성

김영묵,김원주 한밭대학교 건설안전기술연구소 2004 건설안전기술논문집 Vol.4 No.-

To recycle used wasted disposal fill, it is most important that selected waste soil effectively be used. In the many case of used wasted disposal fill, ordinary soil is occupying more than 50% of wasted disposal fill usually, and that selected waste soil utilizes by cover materials is applied actually. It is essential for use as construction material to recycle selected waste soil. This study performed characteristics of geotechnical engineering characteristics in considering soil-cement effect to utilize fill materials in selected waste soil. Wished to get basis data to use to fill materials on the basis of analysis result executing a basis physical experiment and unconfined compressive test of soil cement, direct shear test etc., and the results of this summary as follow. The results of unconfined compressive strength, was increased until 7 days after curing rapidly. In the case of 7 days curing, the unconfined strength was appeared averagely 90% of 28 day curing. When direct shear test, the cohesion was increased rapidly at curing early but after small increased. In the case of 3 day cohesion, about 70% appear of 28 day cohesion. For shear strength of selected waste soil, soil-cement effect was appeared to cohesion enlargement mainly, but there was small change of angle of internal friction. When increasing of cement content was induced to do large cohesion of soil, but angle of internal friction was showed small increasing rate relatively. 우리나라의 과거 폐기물 최종 처분방식은 도심지 주변지역에 단순투기방식을 통한 매립에 의존하여 왔다. 1999년을 기준으로 하여 우리나라에서는 전체 폐기물의 25%, 생활폐기물의 52%를 매립에 의존하고 있는데 이러한 매립비율은 1996년의 전체 폐기물의 40%, 생활폐기물의 68% 와 비교해 볼 때 매립 율이 다소 감소하였으나, 과거의 폐기물처분방식은 단순매립에 높은 비중을 차지하고 있음을 알 수 있다. 최근 급격한 도시화와 인구증가에 따른 도시의 확장으로 인하여 활용 용지의 필요성이 더욱 대두됨에 따라 도시 주변에 대한 개발과 더불어 기존의 사용 종료된 매립지를 재이용하려는 방안이 검토되고 있다. 이에 대한 대책으로 매립지 부지를 굴착하여 재이용하려는 매립지의 굴착 자원화 기술, 즉 landfill mining 이 관심의 대상이 되고 있으며 관련 연구가 발표되고 있다. 본 연구는 폐기물 선별토사를 성토재로 활용하는 방안이 중요한 선별토사의 재활용에 중요한 방안이 될 수 있으므로 이에 관련하여 선별토사의 흙 시멘트 효과에 대한 토질공학적 특성을 파악하고자 하였다. 폐기물 매립장의 물리적 조성을 알기 위하여 채취한 선별전 시료로부터 11 가지의 종류별로 분류하여 물리적 조성 및 삼성분을 조사하였으며, 폐기물 매립장의 토양조사를 실시하여 토양 오염도를 분석하였다. 또한 폐기물 채취시료를 선별한 후 선별토사의 물성시험은 한국산업규격을 기준으로 하여 비중시험, 함수비시험 및 입도분석시험 등을 실시하였다. 또한, 선별토사의 다짐시험은 일반 성토부의 다짐기준인 A다짐시험 (KS F 2312)을 실시하여 최적함수비 및 최대건조단위중량을 구하였다. 선별토사를 시벤트와 혼합하여 최적함수비 조건에서 공시체를 제조한 후 일축압축강도 시험을 실시 하였으며, 이때 선별토사에 대한 시벤트의 혼합비율이 0, 3, 6, 9, 12%가 되도록 시료를 조성하였다. 성토 후 전단강도 정수를 구하기 위한 흙 시멘트 의 직접전단시험은 선별토사에 대한 시멘트의 혼합비율이 0, 1.5, 3.0, 4.5, 6.0% 가 되도록 시료를 조성하여 시험을 실시하여 그 결과를 분석하였다.

河川에서 橋梁의 橋脚設置로 인한 洗掘에 관한 硏究

李榮基,李大澈 한밭대학교 건설안전기술연구소 2003 건설안전기술논문집 Vol.3 No.-

본 연구에서는 하천에서 교량의 교각 설치로 인한 하상세굴을 흐름특성 및 하상 형상의 횡 방향을 고려한 교각주위의 국부적인 하상세굴을 규명하는 것을 목적으로 충청북도 옥천군 준용 하천인 소옥천과 소옥천의 지류인 이백세천을 횡단하는 옥각교, 서정교, 이백교, 3개의 교량에서 발생하는 하상세굴 형상, 수축세굴, 국부세굴, 현장측정치를 프로그램을 이용하여 얻은 결과와 세굴심 예측식과 비교 검토를 한 결과 국부세굴심은 옥각교에서 4.94m~5.89m, 서정교에서 4.73m~5.99m, 이백교에서 4.llm~5.46m로 나타났으며 총세굴심의 발생위치는 기초하부 아래로 0.12m-4.23m까지 발생하는 것으로 계산되었다. 그러나 최대세굴심 산정결과를 비교할 때 충적층까지는 세굴이 급속히 진행된 것으로 판단되었으며, CSU공식을 이용한 계산세굴심이 암 반층보가 깊게 계산된 경우에는 암반층에서 세굴이 멈출 것으로 판단되고 따라서 최대세굴심의 연속적인 변화는 현장측정치를 범용프로그램을 이용하여 얻은 결과와 세굴심 예측치를 비교검토를 한 결과 총세굴심 산정에 있어서 국부세굴에 의한 영향이 가장 큰 것으로 나타났으며 교량안전을 위하여는 세굴방지공을 설치하여야 할 것으로 판단되며 지속적으로 세굴에 관한 연구가 이루어져야 할 것으로 사료된다.

건설엔지니어링 해외진출 지원조직 비교분석

박희성,박환표 한밭대학교 건설안전기술연구소 2004 건설안전기술논문집 Vol.4 No.-

This paper aiIDS to derive and analysis for rational hydrograph and design flood discharge by relating of the rainfall-runoff model and flooding routing at small watershed in urban region. HEC-HMS (Hydrologic Modeling System) was applied to study area as a derived devices of the optimum design discharge from precipitation-runoff model through small urban catchment of the SIWHA reservoir upper drainages. Rational analysis of rainfall-runoff and flood routing that must be determined and selected in order to design for exactly hydraulic structural as the conditions precedent a optimal design-rainfall and a precipitation-runoff model and a rainfall-distribution pattern. This study area also were applied to determine the optimized design discharge for rationa1 countermeasure on flood and draught control of reservoir as the drainage area with a inf10w from around catchment of the SIWHA reservoir. Cumulative rainfall-distributions in duration were examined with the analysis methods as well as the distribution chara teristics using a long term data by the precipitation measured stations. As a result, the optimal pattem for cumulative rainfall-distribution in duration was determined by the HUFF method have got maximum precipitation. And rational design flood discharge also can be calculated for the cumulative rainfall of duration by carrying out to a runoff-analysis and a flood routing in study drainage.

畜産廢水 Sludge의 有機物 除去를 위한 嫌氣性 處理에 관한 硏究

이종각,이동윤 한밭대학교 건설안전기술연구소 2003 건설안전기술논문집 Vol.3 No.-

Importance of livestock wastewater productions contain only 1% from total occurrence quantities in our country, it should be prepared the provisions expeditiously because the pollutant loading rate is very high as 9% from total pollutant loading of BOD. In the characteristics of the piggery wastewater, it has become main sources of pollution, which is resulted eutrophication from rivers and lakes, as both organic and nitrogen concentrations are high. In this treatise, it should be considered as follows: first, the design parameters for effective treatment derives from observation of the physical-chemical characteristics of piggery wastewater and the concentration variation depends on seasonal change, second, the organics in the digestion tank during the digestion time of anaerobic digestion for the organic removal of high concentrations in the primary sedimentation tanks of piggery wastewater and the conduct if nutrient. It should be also considered methane which is product of anaerobic digestion. The BOD removal of the digestion process about 12days in organics is 72%, resulted COD removal is 36%. Ammonia nitrogen removal of the digestion process of 20day 57%, according to the increase of ammonia nitrogen, one of the digestion process of 40day is 47%, therefore, removal efficiency is decreased. It is considered that the difference of minimized point is wide range, according to mixing, difference of velocity reaches to maximum gas production is, however, narrow. As the water use which is used in combined piggery enters to the primary sedimentation tank, pH of piggery wastewater is reported from 7.14 to 8.86.

비틂 불균형 구조물의 지진응답에 미치는 지반-구조물 상호작용효과에 관한 연구

송기범,이남호 한밭대학교 건설안전기술연구소 2003 건설안전기술논문집 Vol.3 No.-

For many structures the severity of an earthquake may be lowered dramatically by considering the flexibility of the supporting subgrade medium. For a torsionally unbalanced structure, when a transverse mode is coupled to a rotational mode, dynamic amplification of the torsional component will dominate the seismic response because of structural asymmetry and low damping. A seismic Soil-Structure Interaction(SSI) of a typical nuclear power plant building with a moderate torsional unbalance will be analyzed to demonstrate that by taking into account the flexibility of soil underneath the structure, the response peak at floors due to the coupling of transverse mode and torsion mode will be flattened or even eliminated.

忠南地域 小河川의 計劃河幅 算定에 關한 硏究

南光鉉,李大澈 한밭대학교 건설안전기술연구소 2003 건설안전기술논문집 Vol.3 No.-

This study is to determine the formula for river width of small streams in Sabgyo River Basin by looking into hydrological and topographical characteristic factors. This study also is to examine the feasibility of the formula for the actual practice comparing with the existing formulas. The design flood discharge, drainage area and stream length for the small streams in the Sabgyo River basin are shown the relationships as L=3.116+0,130*A and Q=623.087+192.648*A. The formulas for the design-width of small streams in Sabgyo River basin are suggested, on the basis of the flood discharge, drainage area, and bed slope, as B_(Q)=20.723+0.005(Q/√(I)) and B_(A)=30.747+0.035(A/√(I)), respectively. The newly set-up-formula in this study is more accurate and applicable in deciding the flood discharge and drainage than the existing formulas. Therefore, I argue that this equation can be applied to determine the design-width of small streams in fluvial river basin.

파쇄석이 혼합된 뒷채움재 보강토 옹벽의 변위거동에 대한 사례분석

김영묵,전인근 한밭대학교 건설안전기술연구소 2003 건설안전기술논문집 Vol.3 No.-

In order to assess the behavior characteristics and stability of the ribbed steel strip reinforced soil retaining wall using the granite soil included crushed stone as backfill material, a series of the field test construction and monitoring were conducted. Displacement gauges were installed on two site of the reinforced earth wall of the 7.5m height, to obtain displacements of the wall facing during and after construction. For the reinforced earth wall of the 15m height strain gauges were installed in 7 steps to measure displacement of the wall. A step of the reinforcements and the displacement of the reinforce earth body. In the results of monitoring, face horizontal displacements were measured by very small, and its measures were presented to satisfy the allowable criterion for that. From the results of this study, the increment of face displacement and reinforcements strain was measured very little after construction, and it was found that the most of deformations of wall and reinforcements were occurred during construction due to compaction work for backfills. The reason of the satisfied strain behavior in this test site is thought due to the good compaction control for the granite soil with crushed stone that has good friction property.

폐콘크리트를 굵은골재로 사용한 콘크리트의 강도 특성

김옥형,이형준 한밭대학교 건설안전기술연구소 2003 건설안전기술논문집 Vol.3 No.-

Sources of good quality aggregate are rapidly becoming depleted. Also, the production of construction waste due to demolition of old concrete structures cause to environmental problem. Resue of concrete as aggregate is a process whose time has arrived. In this paper the experimental study was conducted to verify the effects of the recycled coarse aggregate on the fresh concrete and harden concrete properties. The recycled coarse aggregate was producted by crushing the concrete with different strength(18MPa, 24MPa and 50MPa). The workability, air content and strength characteristics of concrete produced from the recycled aggregate was depend on the strength of the original concrete. The compressive strength of concrete produced from high-strength recycled coarse aggregate was greater than that of concrete produced from low-strength recycled coarse aggregate. Also, The compressive strength of the concrete from recycled aggregate was about 23% lower than that of the concrete produced from natural coarse aggregate. The compressive strength of blended concrete of 70% natural and 30% recycled coarse aggregate was about 6% lower than natural coarse aggregate concrete.

Correction Factor for Depth-Averaged Velocity

Lee, Jong-Seok,Julien, Pierre Y. 한밭대학교 건설안전기술연구소 2003 건설안전기술논문집 Vol.3 No.-

본 연구에서 수심평균유속 환산계수로 느린 유속과 갈수시를 제외한 평균 흐름에서는 0.83, 빠른 유속의 홍수시에는 0.88이 수공실무에 활용될 수 있을 것이다. 이 값들을 이용함으로써 홍수시 전자파 표면 유속계에 의한 실시간적 유량측정이 가능할 것이다. 또한 수공실무에 실용화 하기 위해 비접촉성 유속계인 전자파 표면 유속계의 실험실 및 현장시험을 실시함으로써 기기 조작의 최적조건을 결정하였다. 최적조건으로 수직각과 편각은 0.30~2.O0m/s 유속범위에서 θ≒30˚, Φ=10~13˚로 각각 나타났다. 이 결과는 현장 및 실험치와의 비교에서 아주 잘 일치하는 것으로 나타났다.

개착식 가시설물의 거동 분석 및 평가

김영묵,박준식 한밭대학교 건설안전기술연구소 2001 건설안전기술논문집 Vol.1 No.-

To utilize more effectively underground space many deep excavation have been practiced in constructing of building or subway in urban area, recently. In doing such underground excavations, the analysis of design factors and construction information through the field measuring are very important value for the safety control of braced cut. In this study the estimation for design is compared with field measuring in the construction of urban subway, those are the earth pressure distribution, horizontal displacement, underground water table and so on. The results of this study are summarized as follows. The lateral displacement at the design is larger than the value of observation in the anchored and strut retention walls. The lateral displacement is influenced in the ground water table in the behind of retaining wall, the prevention of seepage is effected in the control of wall displacement. The lateral earth pressure distribution of anchored and strut retention walls are showed trapezoidal distribution. The maximum lateral earth pressure in the strut retention is 0.52K_aH and 0.57K_aH in the anchored retention. The values of maximum lateral earth pressure is some smaller than the empirical earth pressure proposed by Terzaghi and Peck