榮山江 下流地域 軟弱地盤의 特性 및 計測을 통한 沈下管理 = Soft ground special quality to Youngsan-river area of the downstream and settlement administration through the measurement

다국어 초록 (Multilingual Abstract)

The need for both industrial and residential land has been gradually getting increased with economic development, however, it becomes difficult to acquire commercial site having decent ground condition. In order to develop the land in a efficient and ballanced manners, it is in progress to develop soft ground land as well as firm ground one. Thus, it is needed to have active methods to manage soft ground lands which are of poor ground characteristics and development conditions. A soft ground land has the complex characteristics in terms of engineering properties. Especially when its strength is low and its depth is deep, it is highly likely to get deformed like a settlement. Therefore, all necessary methodes for this should be implemented by accurately analyzing engineering properties of the soft ground land, when improved, in order to design and menage them economically.
When we prepare the land on the soft ground and build buildings on it, precise techniques for design, construction and maintenance and repair are needed to gurentee its stability. Unfortunately, there are still many problems for establishiments in applying for countermeasure construction method for the soft ground, sufficient effort of expedite of a compaction, related theories and experience, precise construction, etc. Therefore, there are many cases which spend much maintenace and repair cost in order to take care of these problems after the constructions is completed. It is necessary to resolve technical problems on the soft ground issue by identifying engineering characteristics of the domestic soft ground by suggesting its countermeasures, which can be done through indoor test on the soft ground, its field measurement and corresponding numerical analysis studies.
Therefore, the purpose of this paper is to improve soft ground at the downstream of Young-san River efficiently through expedient analysis of a compaction on the overall soft ground in that area. The analysis includes precise field mesurements of settlements in that area and comparison between designed and measured values. So far, it shows that the measured values are smaller than the predicted one in the entire range under the completion of 70% preloading. It is believed that this result is very useful when the soft ground in this region is improved.

다국어 초록 (Multilingual Abstract)

The objective of the study was to analyze longterm temporal trends of water chemistry and spatial heterogeneity for 10 sampling sites of the Yeongsan-River watershed using water quality dataset during 1995-2004 (obtained from the Ministry of Environment, Korea). The water quality, based on multi-parameters of biological oxygen demand (BOD), chemical oxygen demand (COD), conductivity, dissolved oxygen (DO), total phosphorus (TP), total nitrogen (TN) and total suspended solids (TSS), largely varied depending on the sampling sites, seasons and years. Largest seasonal variabilities in most parameters occurred during the two months of July to August and these were closely associated with large spate of summmer monsoon rain. Conductivity, used as a key indicator for a ionic dilution during rainy season, and nutrients of TN and TP had an inverse function of precipitation (absolute r values＞0.32, p＜0.01, n=119), whereas BOD and COD had no significant relations (p＞0.05, n=119) with rainfall. Minimum values in conductivity, TN, and TP were observed during the summer monsoon, indicating an ionic and nutrient dilution of river water by the rainwater. In contrast, major inputs of total suspended solids (TSS) occurred during the period of summer monsoon. BOD values varied with seasons and the values was closely associated (r=0.592, p＜0.01) with COD, while variations of TN were had high correlations (r=0.529, p＜0.01) with TP. Seasonal fluctuations of DO showed that maximum values were in the cold winter season and minimum values were in the summer seasons, indicating an inverse relation with water temperature. The spatial trend analyses of TP, TN, BOD, COD and TSS, except for conductivity, showed that the values were greater in the mid-river reach than in the headwater and down-river reaches. Conductivity was greater in the down-river sites than any other sites. Overall data of BOD, COD, and nutrients (TN, TP) showed that water quality was worst in the Site 4, compared to those of others sites. This was due to continuous effluents from the wastewater treatment plants within the urban area of Gwangju city. Based on the overall dataset, efficient water quality management is required in the urban area for better water quality.

목차 (Table of Contents)

• 목차 = ⅰ
• 표목차 = ⅳ
• 그림목차 = ⅵ
• 제1장 서론 = 1
• 1.1 연구목적 = 1
• 1.2 연구동향 = 1
• 1.3 연구 내용 및 범위 = 2
• 제2장 침하 및 안정관리 = 3
• 2.1 침하관리 = 3
• 2.2 안정관리 = 5
• 2.2.1 정성적 방법 = 5
• 2.2.2 정량적 방법 = 6
• 제3장 침하량 산정 = 7
• 3.1 개요 = 7
• 3.2 연약지반 설계 기준안 = 7
• 3.2.1 허용잔류침하량 = 7
• 3.2.2 공용하중 기준 = 9
• 3.2.3 연약지반 개량 목표 = 10
• 3.2.4 절·성토사면 설계기준 = 10
• 3.3 연약지반 침하량 산정 = 12
• 3.3.1 연약지반 구역(zone) 구분 = 12
• 3.3.2 연약지반 토질정수 = 17
• 3.3.3 지반 침하특성 = 17
• 3.3.4 배수조건 구역 구분 = 22
• 3.3.5 침하 및 압밀특성 검토 결과 = 23
• 제4장 계측 = 26
• 4.1 계측 개요 = 26
• 4.1.1 계측의 목적 = 26
• 4.1.2 계측범위 = 26
• 4.1.3 계측기 설치기준 = 27
• 4.1.4 대상범위별 계측기 배치기준 = 28
• 4.1.5 계측기 설치 현황 = 28
• 4.1.6 계측지구 지층현황 = 29
• 4.2 계측기 매설 = 30
• 4.2.1 계측기 매설 관리기준 = 30
• 4.2.2 계측기 선정 = 33
• 4.2.3 계측기 매설계획 = 33
• 제5장 계측결과 및 분석 = 41
• 5.1 계측결과 분석 = 41
• 5.1.1 시공현황 = 41
• 5.1.2 침하결과 = 41
• 5.1.3 간극수압 결과 = 45
• 5.2.4 지하수위 결과 = 49
• 5.1.5 침하재해석 및 거동분석 = 51
• 5.2.6 계측결과에 따른 고찰 = 52
• 제6장 결론 = 54
• 참고문헌 = 55
• Abstract = 58