• Title/Summary/Keyword: Diaphragm wall

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Development of Analytical Model to Predict the Inelastic Moment Capacity of Reinforced Concrete and Masonry Shear Wall (전단벽 구조물의 모멘트 저항능력에 관한 비탄성 해석모델개발)

  • 홍원기;이호범;변근주
    • Magazine of the Korea Concrete Institute
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    • v.5 no.4
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    • pp.123-134
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    • 1993
  • A rapid progress has been made over last decade in the state-of-the-art earthquake structura1 engineering towards a better understanding of both the earthqauke ground motion and structural response. These efforts seek to ensure that there will be no serious injury or loss of life in the event of earthquake, and that structures can be built at minimum cost. The design of structures in general, concrete structures in particular, to resist strong ground input motions is not a simple matter, and analytical models for such structures must be developed from a design perspective that accounts for the complexities of the structural responses. The primary obj ective of earthquake structural engineering research is to ensure the safety of structures by understanding and improving a design methodology. Ideally, this would require the development of an analytical model related to a design methodology that ensures a ductile performance. For the accurate assessment of the adequacy of analytically developed model, experiments conducted to study the inplane inelastic cyclic behavior of structures should verify the analytical approach. The fundamental goal of this paper is to present and demonstrate experimentally verified analytical methods that provide the adequate degree of safety and confidience in the behavior of reinforced concrete structural components. This study further attempts to extend the developed modeling techruque for use by practicing structural engineers for both the analysis and design.Plication of the relaxed diaphragm through left thoracotomy was done and result was excellent as seen on Fig. 5. Cause of eventration of the left hemidiaphragm was due to paralysis of the left phrenic nerve which was tested during thoracotomy.

The Estimation of Appropriate Mixing Amount of Cement-Bentonite Cutoff Walls for Repair and Reinforcement of Reservoir Embankments (저수지 제체의 보수·보강용 Cement-Bentonite 벽체의 적정혼합량 산정)

  • Kim, Taeyeon;Lee, Bongjik
    • Journal of the Korean GEO-environmental Society
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    • v.22 no.6
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    • pp.27-32
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    • 2021
  • Due to heavy rainfall and typhoons caused by climate change, it has become common to witness heavy rain that exceeds the design frequency of agricultural reservoirs. This has brought greater attention to the safety of irrigation facilities including agricultural reservoirs. Out of approximately 17,740 reservoirs available in Korea, 83.87% were built before 1970. To ensure the safety of these old reservoirs, their embankments are being repaired and reinforced using various techniques. Among these techniques, using the cement-bentonite cutoff wall makes it possible to construct diaphragm walls with slurry composed of cement and bentonite, while excavation. The advantages of this technique include that it is simple and fast, and ensures the uniformity of cutoff walls by enabling the immediate application of the replacement method to excavation areas; thus excellent performance is guaranteed. However, despite these advantages, the technique is not commonly used in Korea. Thus, this study investigated the changes in strength and permeability by varying the mix ratio of cement and bentonite. As a major experimental results, when the cement of 200 kg/m3 and the bentonite of 60 to 80 kg/m3 is most suitable for the repair and reinforcement of the reservoir embankments.

A Study on the Utilization Method in the SCW Method using Supplementary Cementitious Materials (시멘트 대체재료를 활용한 SCW공법에서의 활용 방안에 대한 연구)

  • Kwang-Wu Lee;Jae-Hyun Park;Young-Won Lee;Dae-Sung Cho
    • Journal of the Korean Geosynthetics Society
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    • v.22 no.3
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    • pp.87-95
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    • 2023
  • Recently, redevelopment of the original downtown area is underway, the necessity of construction in adjacent location is increasing. However, excavations in dense urban areas are prone to ground problems due to various causes, so it is necessary to use materials and methods that can minimize such problems. As a general earth retaining method, various methods such as diaphragm wall and CIP method are applied using cement. However, since a large amount of cement is used for the installation of earth retaining method, it is necessary to conduct research on the development of new cement substitute materials to significantly reduce greenhouse gas emissions. In this study, we utilized the hardening reaction of blast furnace slag powder, desulfurized gypsum and high calcium fly ash by alkali activation and applied it to the SCW method. As a result, it was analyzed that the compressive strength of solidified soil using development solidification material was 96.2 ~ 106.3% of OPC at 28 days of curing. In addition, the strength increment ratio was 2.06 for sandy soil and 2.41 for clayey soil, which was higher than 1.85 of OPC. It seems an advantageous in terms of long-term strength. In addition, from the environmental point of view, it was analyzed that there is no elution of heavy metals and that greenhouse gas emissions can be dramatically reduced. Therefore, if further studies are conducted, it can be applied to the SCW method.

Imaging Findings of Pneumothorax Caused by Bronchial Cartilage Hypoplasia in a Dog (개에서 기관지 연골 저형성에 의해 발생한 기흉의 영상학적 진단 증례)

  • Kim, Su-yeon;Kim, Seong-soo;Lee, Jeo-soon;Yun, Soo-kyung;Oh, Hyun-jung;Shon, Jung-min;Kim, Bo-eun;Kim, Wan-hee;Yoon, Jung-hee;Choi, Min-cheol
    • Journal of Veterinary Clinics
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    • v.32 no.5
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    • pp.469-472
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    • 2015
  • A 10-year-old, castrated poodle dog presented with a cough for 2 weeks, and the cough initially developed since very young age. On radiographs, pneumothorax was noticed by characteristics of radiolucent area without pulmonary markings along the thoracic wall and diaphragm, retracted lung lobes from the thoracic wall and severely decreased volume of the left cranial lung lobe with disconnected bronchus. Computed tomography (CT) findings identified several pulmonary air-filled cysts and collapsed lung with abnormal shape and non-tapered end of bronchus, bronchioles at the accessory lobe and left cranial lobe. Also, pneumothorax, pneumomediastinum and subcutaneous emphysema were found. Imaging diagnosis was the spontaneous pneumothorax caused by ruptured emphysematous bullae associated with congenital bronchial cartilage abnormality or bronchial tree malformation. On surgery, hypoplasia of the left cranial lobe, right middle lobe, and accessory lobe with a bulla where air was leaking was identified. The accessory lobe was partially resected and bronchial cartilage hypoplasia was confirmed by histopathologic examination.

Korean Clinical Imaging Guidelines for the Appropriate Use of Chest MRI (한국형 흉부 MRI 영상 진단 정당성 권고안)

  • Jiyoung Song;Bo Da Nam;Soon Ho Yoon;Jin Young Yoo;Yeon Joo Jeong;Chang Dong Yeo;Seong Yong Lim;Sung Yong Lee;Hyun Koo Kim;Byoung Hyuck Kim;Kwang Nam Jin;Hwan Seok Yong
    • Journal of the Korean Society of Radiology
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    • v.82 no.3
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    • pp.562-574
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    • 2021
  • MRI has the advantages of having excellent soft-tissue contrast and providing functional information without any harmful ionizing radiation. Although previous technical limitations restricted the use of chest MRI, recent technological advances and expansion of insurance coverage are increasing the demand for chest MRI. Recognizing the need for guidelines on appropriate use of chest MRI in Korean clinical settings, the Korean Society of Radiology has composed a development committee, working committee, and advisory committee to develop Korean chest MRI justification guidelines. Five key questions were selected and recommendations have been made with the evidence-based clinical imaging guideline adaptation methodology. Recommendations are as follows. Chest MRI can be considered in the following circumstances: for patients with incidentally found anterior mediastinal masses to exclude non-neoplastic conditions, for pneumoconiosis patients with lung masses to differentiate progressive massive fibrosis from lung cancer, and when invasion of the chest wall, vertebrae, diaphragm, or major vessels by malignant pleural mesothelioma or non-small cell lung cancer is suspected. Chest MRI without contrast enhancement or with minimal dose low-risk contrast media can be considered for pregnant women with suspected pulmonary embolism. Lastly, chest MRI is recommended for patients with pancoast tumors planned for radical surgery.