데이터베이스를 이용한 폐기물매립지의 거동 및 침하특성 연구 = (A) Study on behavior and settlement characteristics of waste landfill using database

다국어 초록 (Multilingual Abstract)

The analysis of the engineering characteristics of waste landfills including the settlement is important to design landfills and to use the closed landfills as construction areas. The settlement of waste landfill depends not only on its mechanical properties but also on the biological decomposition of wastes, which is distinguished from the behavior of typical soils. Therefore, prediction and analysis of long-term settlement of the waste landfill is difficult and its detailed mechanism has not been fully cleared yet. In addition, the analysis of settlement of the foundation soil is necessary for the domestic landfills, because many domestic waste landfill are constructed on soft soils near seashore.
In this thesis, a database system for a waste landfill is developed to manage the stability of the landfill as the measurement data of the waste landfill is obtained. The behavior of No. 1 Gimpo metropolitan waste landfill, which was represented domestic waste landfills, is analyzed from its field measurement data, and the analyses of settlement characteristics of the foundation soil as well as the disposed wastes are carried out.
From the database analyses, it was found that the leachate level to the fourth stage of waste disposal was increased with the increase in waste height and converged to 12∼15m. After fourth stage of waste disposal, the settlement of the landfill increased significantly due to the increased effective stress. A waste density analyzed from the measurement data of earth pressure gauge was found as 0.9∼1.2 t/㎥, which was in the range of the density of the compacted waste. The data of surface index mark from the Q block showed that upward vertical and outward horizontal displacements were developed rapidly after the fourth stage of waste disposal. This was the sign of potential instability of the waste fill filling and the further disposal of waste is prohibited. These results shows the usefulness of the database system for detecting instability and damage protection of the landfill.
From the settlement data of the foundation soil of the landfill, the void ratio and the compression index are back calculated and the geostatistics analysis is used to estimate the values where the measurement data are not available. The field void ratio was decreased as the stages of waste fill increases and the subsurface clay under the landfill showed the characteristics of over-consolidated clay.
Variation of field compression index using the back-calculated void ratio was 0.05∼0.7. At the initial stage of waste disposal, the compression index of the subsurface clay was very small, because effective stress increased by the waste load was negligible. However, with the increase of waste disposal after fourth stage, the increase of the effective stress was significant and the compression index in clay foundation was also increased significantly. It was found that the pre-consolidation pressure is located around the fourth stage of waste loading.
The characteristics of the settlement for multi-staged waste fill are studied after the equation of Sower's(1973). The primary and secondary compression index of the waste, which reflects the mechanical and biochemical characteristics of waste, respectively, are calculated from the back analysis of the settlement data. The model verification is performed by comparing the predicted settlement with the measured settlement.
Primary compression index(C_(c)) at the initial stage of waste disposal had wide range of value as 0.103∼1.517. It was converged to 0.5 as the height of waste increases and the value was close to the average of primary compression indexes of total stages of waste. Domestic metropolitan waste had significant composition of papers and textiles. Since these types of waste decomposes slowly, secondary compression index(C_(α)) of the initial stage of disposal was very low and increased significantly after 2∼6 years of waste disposal.
Model settlements predicted using back-calculated primary and secondary compression index was well compared with field settlement data. Using the average values of the settlement properties, the model also predicted the settlement of the other block in the studied area very well.

목차 (Table of Contents)

• 목차 = iv
• 제1장 서론 = 1
• 1.1 연구배경 및 목적 = 1
• 1.2 연구내용 = 3
• 제2장 문헌고찰 = 5
• 2.1 데이터베이스 = 5
• 2.2 지구통계학적 기법의 토목환경 분야에의 응용 = 12
• 2.3 폐기물 매립지의 침하특성 = 24
• 제3장 데이터베이스를 이용한 폐기물 매립지 관리시스템 및 거동분석 = 31
• 3.1 개요 = 31
• 3.2 데이터베이스의 구조설계 = 32
• 3.2.1 데이터베이스 구조 = 32
• 3.2.2 데이터베이스 구조 설계 = 34
• 3.3 폐기물 매립지 관리를 위한 데이터베이스 설계 = 39
• 3.3.1 매립지반 데이터베이스 = 39
• 3.3.2 매립현황 데이터베이스 = 40
• 3.3.3 계측자료 데이터베이스 = 42
• 3.3.4 데이터베이스의 통합 = 42
• 3.4 폐기물 매립지 관리시스템 = 45
• 3.4.1 폐기물 매립지 관리시스템 개발을 위한 응용프로그램의 선정 = 45
• 3.4.2 사용자 인터페이스 = 46
• 3.4.3 매립현황 = 48
• 3.4.4 계측자료 입력창 = 49
• 3.4.5 계측자료 분석창 = 50
• 3.5 매립지 관리시스템을 이용한 매립지의 거동분석 = 52
• 3.5.1 수도권 매립지 1공구의 현장조건 = 52
• 3.5.2 매립지 계측자료별 분석 = 56
• 3.6 요약 = 64
• 제4장 지구통계학적 기법 및 적용 = 66
• 4.1 개요 = 66
• 4.2 크리깅 기법 = 66
• 4.3 Variogram = 67
• 4.3.1 Experimental Variogram = 68
• 4.3.2 Theoretical Variogram = 69
• 4.4 크리깅의 종류 = 74
• 4.4.1 Ordinary Kriging = 74
• 4.4.2 Simple Kriging = 80
• 4.4.3 Universal Kriging = 81
• 제5장 지구통계학적 기법을 이용한 매립지 기초지반의 침하특성 = 83
• 5.1 개요 = 83
• 5.2 대상매립지의 매립현황 및 실내시험결과 = 83
• 5.2.1 대상매립지의 매립현황 = 83
• 5.2.2 실내시험 및 현장시험 결과 분석 = 86
• 5.3 크리깅을 이용한 점토층 두께분포 추정 = 91
• 5.3.1 Variogram 계산 및 검정 = 92
• 5.3.2 점토층 두께 평면분포 = 94
• 5.4 현장 계측치를 이용한 간극비, 압축지수의 역산 = 96
• 5.4.1 현장 계측치를 이용한 간극비 역산 = 96
• 5.4.2 현장 계측치를 이용한 압축지수 역산 = 100
• 5.5 매립지 기초지반에 대한 경과 년도별 침하량 = 104
• 5.5.1 1997년도 매립지 기초지반 침하현황 = 104
• 5.5.2 추정값을 이용한 년도별 침하량 비교 = 109
• 5.6 요약 = 111
• 제6장 매립지 폐기물의 침하특성 = 113
• 6.1 개요 = 113
• 6.2 매립지 폐기물의 침하메카니즘 = 113
• 6.3 기존 침하량 산정식과 응용 = 114
• 6.4 매립지 폐기물의 침하 현황 = 116
• 6.4.1 E 블록의 매립고에 따른 시간-침하현황 = 116
• 6.4.2 M 블록의 매립고에 따른 시간-침하현황 = 119
• 6.5 매립지 폐기물의 침하특성 = 120
• 6.5.1 매립지 폐기물의 역학적 일차 침하특성 = 120
• 6.5.2 매립지 폐기물의 생화학적 이차 침하특성 = 129
• 6.5.3 실측 침하량과 계산 침하량의 비교 = 139
• 6.6 요약 = 141
• 제7장 결론 = 144
• 참고문헌 = 148
• 부록 = 155
• 부록 A. 데이터베이스 속성정보 = 155
• 부록 B. 계측자료 입력창 = 158
• 부록 C. 매립지 관리 시스템 프로그램 사용자 설명서 = 160
• 부록 D. 매립지 관리시스템 프로그램 Source = 171
• 부록 E. 크리깅 추정분산 계산 = 177
• 부록 F. Lagrange Technique = 181
• 부록 G. 연도별 추정 간극비와 압축지수 = 185
• ABSTRACT = 191