According to the recently revised seismic design standards, seismic design of underground structures is required. Concrete underground outer walls are installed separately from temporary earth retaining walls as permanent underground outer walls. This raises issues of constructability, economy, and space narrowness. Therefore, a steel underground continuous wall is developed to promote construction efficiency, safety, and economy by introducing the off-site construction (OSC) method of underground structures. The steel underground continuous wall will be used as a permanent underground continuous wall along with the temporary earth retaining wall. To this end, it must satisfy structural performance equivalent to or higher than the concrete underground outer wall. The integrity and in-plane shear resistance performance between single panel members must be satisfied to be used as a permanent wall. The interlocking effect through geometric bonding is intended to enhance the bonding effect between these members. Therefore, trapezoidal members were developed, and bending performance tests and analyses of each member were performed to confirm the structural bending performance of these members. The bending performance improvement effect of the combined multiple members was confirmed. As a result, it was confirmed that the integration of members and structural performance was improved due to the interlocking effect of the absence of joints. The seismic design analysis of the demonstration site was performed with these developed members, and it was confirmed that the structural performance was equivalent to or higher than that of the existing RC underground continuous wall. As a result, it was confirmed that the steel underground continuous wall can be used as a permanent underground wall together with the temporary earth retaining wall.
본 글의 문제의식은 위성정당 출현의 재발을 막기 위해 선거법에 대한 여야합의처리의 중요성을 강조하는 것이다. 본 글의 목적은 선거법 개정 방향의 대안을 모색하기 위해 여야합의가 깨진 상황에서 민주당의 다수 결주의에 따른 졸속적인 준연동형 비례제 선거법의 강행처리가 어떻게 위성정당을 제도화하고 21대 총선에서 양당제 효과를 구축하였는지를 인 과론적으로 살펴보는 데 있다. 당연한 결과이지만 이런 위성정당의 출현 과 제도화는 소수정당의 정치적 진출을 활성화하여 다당체제 구축 효과 를 기대했던 준연동형 비례제 선거법의 취지를 무력화하였다는 점에서, 졸속적인 선거법 논의과정과 다수결주의에 따른 강행처리의 문제점을 근 본적으로 시정해야 한다는 것을 강조하였다. 본 글에서는 “독일식 연동형 비례대표제” 대신 “한국식 병립형 비례대표제”로의 전환을 제언하고 있다.
PURPOSES: This study aims to evaluate the performance of interlocking block pavement system for low speed highway. METHODS: Through on-site monitoring, environmental impact assessment of interlocking block pavement such as heat island reduction, traffic safety, noise pollution were evaluated as compared with asphalt pavement. Also the pavement condition and roughness were evaluated according to performance period. RESULTS: Surface temperature of interlocking block pavement was about 7 degree lower than asphalt pavement in midsummer. Compared to asphalt pavement, vehicle speed reduction effect of interlocking block pavement was about 2kph. For low speed driving, the noise pollution was measured at a similar level for both asphalt and interlocking block pavement. After 42month service period, the breakage of block was only 0.24% for the whole surveyed area. IRI of interlock block pavement was estimated within the range of 5~8m/km. CONCLUSIONS : Depending on the performance monitoring results such as heat island reduction, providing traffic safety and keeping a good pavement condition for a long service period, it assures that interlocking block pavement was applicable for low speed road.
PURPOSES: In this study the influence factors related to abrasion resistance of interlocking concrete block have been evaluated, and comparisons between various domestic and foreign abrasion test methods was also accomplished. METHODS: The modified rotational cutting method suggested in ASTM C 944 was applied. Surface materials with different types of fine aggregate such as crushed sand, sea sand, and mixture of crushed and sea sand were tested to compare the aggregate effect for abrasion resistance. RESULTS: The different surface mixtures with various W/C ratios, mortar and fly ash ratios have been investigated for functional and economical considerations. CONCLUSIONS: This study had obtained reliable results by changing diamond blade of rotating cutter. Therefore, in order to improve the abrasion resistance of interlocking concrete block for road, a new mix design was proposed.
이 연구의 목적은 결합원형띠철근을 갖는 철근콘크리트 교각의 내진성능을 파악하는데 있다. 3개의 인터락킹 교각 실험체에 일정 축하중 하에서 횡방향 반복하중을 가하는 준정적 실험을 수행하였다. 사용된 프로그램은 철근콘크리트 구조물의 해석을 위한 RCAHEST이다. 사용된 해석기법은 조사된 실험체에 대하여 하중단계에 따라 성능을 비교적 정확하게 예측하였다. 실험적, 해석적 결과로부터 결합원형띠철근을 갖는 철근콘크리트 교각의 설계와 시공 실무를 향상하기 위한 상세를 제시하였다.
In this study, it was developed geopolymer concrete of alkali-activated using the mixed fly ash and blast furnace slag. and it was developed the interlocking block using the developed geopolymer concrete. In addition, the bending strength and water absorption rate of the interlocking block was tested by KS standard. The test results were as follows. The water adsorption ratio of the BSF4 specimen was under 10%, and the flexural strength of that was over 5MPa
In this study, it was developed geopolymer concrete of alkali-activated using the mixed fly ash and blast furnace slag. and it was developed the interlocking block using the developed geopolymer concrete. In addition, the bending strength and water absorption rate of the interlocking block was tested by KS standard. The test results were as follows. The water adsorption ratio of the BSF4 specimen was under 10%, and the flexural strength of that was over 5MPa.