• Title/Summary/Keyword: Strut Support

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Strut Support with Tricortical Iliac Allografts in Unstable Proximal Humerus Fractures: Surgical Indication and New Definition of Poor Medial Column Support

  • Lee, Seung-Jin;Hyun, Yoon-Suk;Baek, Seung-Ha
    • Clinics in Shoulder and Elbow
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    • v.22 no.1
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    • pp.29-36
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    • 2019
  • Background: The execution of fibular allograft augmentation in unstable proximal humerus fractures (PHFs) was technically demanding. In this study, the authors evaluated the clinical and radiographic outcomes after tricortical iliac allograft (TIA) augmentation in PHFs. Methods: We retrospectively assessed 38 PHF patients treated with locking-plate fixation and TIA augmentation. Insertion of a TIA was indicated when an unstable PHF showed a large cavitary defect and poor medial column support after open reduction, regardless of the presence of medial cortical comminution in preoperative images. Radiographic imaging parameters (humeral head height, HHH; humeral neck-shaft angle, HNSA; head mediolateral offset, HMLO; and status of the union), Constant score, and range of motion were evaluated. Patients were grouped according to whether the medial column support after open reduction was poor or not (groups A and B, respectively); clinical outcomes were compared for all parameters. Results: All fractures healed radiologically (average duration to complete union, 5.8 months). At final evaluation, the average Constant score was 73 points and the mean active forward flexion was $148^{\circ}$. Based on the Paavolainen assessment method, 33 patients had good results and 5 patients showed fair results. The mean loss of reduction was 1.32 mm in HHH and 5.02% in HMLO. None of the parameters evaluated showed a statistically significant difference between the two groups (poor and not poor medial column support). Conclusions: In unstable PHFs, TIA augmentation can provide good clinical and radiological results when there are poor medial column support and a large cavitary defect after open reduction.

Numerical Analysis of Retaining Wall Considering Supporting Load of Adjacent Retaining Wall (인접 흙막이 구조물의 지보재 하중을 고려한 가시설의 수치해석)

  • Yoo, Chanho;You, Jaemin;Lee, Seungjoo;Hwang, Jungsoon;Baek, Seungcheol
    • Journal of the Korean GEO-environmental Society
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    • v.19 no.1
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    • pp.31-36
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    • 2018
  • Recently, as the building construction works have been activated, the environment in which the excavation work is proceeding in parallel with the existing structure and the adjacent excavation work is increasing. However, there is not a lot of research on this. In this study, numerical analysis was carried out for interaction analysis between former excavation construction and follow-up excavation on two excavation retaining structures in parallel with excavation. As a result of numerical analysis, if the supporting load of strut is not considered, it was analyzed that the displacement distribution in the structure can be underestimated and acting stress of strut is overestimated. It was analyzed that the support stress causes by the former excavation should be considered in order to simulate the actual behavior characteristic.

An Numerical Analysis of the Preloading Effect of IPS Retaining Wall through Earth Horizontal Displacement Measuring (IPS 흙막이 가시설의 수평 변위 계측을 통한 선행하중 효과 수치해석적 분석)

  • Lee, Chiho;Lee, Jonghwi;Lee, Changki;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.5
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    • pp.25-33
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    • 2012
  • In this study, gathered measuring data at fields constructed by IPS(Innovative Prestressed Support) system controls the ground displacement and improves the constructability of earth work and structure work greatly, and compared with horizontal displacement calculated by Elasto-plastic analysis program(EXCAV/W). As the result, displacement of calculated by pre-loading data is reduced 13.2% average of general method, and measuring displacement is also reduced 26.7% average of general method. Therefore that IPS system is more safe than conventional strut method in contrast to displacement of underground wall. In addition, horizontal displacement is reduced through the pre-loading effect used by IPS system.

Prosthetic reconstruction with an obturator using swing-lock attachment for a patient underwent maxillectomy: A clinical report

  • Seong, Dong-Jae;Hong, Seoung-Jin;Ha, Seung-Ryong;Hong, Young-Gi;Kim, Hyo-Won
    • The Journal of Advanced Prosthodontics
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    • v.8 no.5
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    • pp.411-416
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    • 2016
  • Patients who underwent resection of maxilla due to benign or malignant tumor, or accident will have defect in palatal area. They get retention, support and stability from remaining tissues which are hardly optimal. The advantage of swing-lock attachment design is having multiple contacts on labial and lingual side of the abutment teeth by retentive strut and palatal bracing component. Because the force is distributed equally to abutment teeth, abutment teeth of poor prognosis can be benefited from it. It is also more advantageous to cover soft tissue defects which are hard to reach with conventional prosthesis. A 56-year-old female patient who had undergone a maxillectomy due to malignant melanoma complaining of loose and unstable surgical obturator. Surveyed crowns were placed on #12, 26, and 27. Teeth #11, 21, 22, and 23 had lingual rest seat and #24 had mesial rest seat to improve stability and support of the obturator. This clinical report presents the prosthetic management of a patient treated with obturator on the maxilla using swing-lock attachment to the remaining teeth.

A Study on the Structural Performance of Reinforced Concrete Shear Walls with An Opening (개구부가 있는 전단벽의 구조성능 평가)

  • Choi, Hyun-Ki;Choi, Youn-Cheul;Choi, Chang-Sik;Lee, Li-Hyung
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05a
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    • pp.102-105
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    • 2006
  • Nowadays, increase of demands on efficient utilization of resources while construction process stimulates structural engineers to select remodeling to improve old buildings. To analyze the effects of openings that may be installed in the course of remodeling old buildings, an experimental research was carried out using four approximately half scale of specimens subjected to constant axial forces, and cyclic loading to simulate seismic conditions. Consequently, the existence of opening was verified to induce different observed damages, which caused by reduction of compression strut support formed on the surface of wall. Especially, the maximum force was revealed to decrease approximately 35% as openings were existed. As this tendency was appeared with stiffness and energy dissipation capacity.

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Artificial Intelligence Image Segmentation for Extracting Construction Formwork Elements (거푸집 부재 인식을 위한 인공지능 이미지 분할)

  • Ayesha Munira, Chowdhury;Moon, Sung-Woo
    • Journal of KIBIM
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    • v.12 no.1
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    • pp.1-9
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    • 2022
  • Concrete formwork is a crucial component for any construction project. Artificial intelligence offers great potential to automate formwork design by offering various design options and under different criteria depending on the requirements. This study applied image segmentation in 2D formwork drawings to extract sheathing, strut and pipe support formwork elements. The proposed artificial intelligence model can recognize, classify, and extract formwork elements from 2D CAD drawing image and training and test results confirmed the model performed very well at formwork element recognition with average precision and recall better than 80%. Recognition systems for each formwork element can be implemented later to generate 3D BIM models.

Structural Stability Study on the Location and Installation form of H-beam Backfill Applied to Top-Down Construction Method (역타공법에 적용되는 뒷채움재 위치 및 설치 형태에 대한 구조 안정성 연구)

  • Shim, Hak-Bo;Jeon, Hyun-Soo;Seok, Won-Kyun;Park, Soon-Jeon
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.05a
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    • pp.179-179
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    • 2021
  • Top-Down construction method is a method of connecting a beam to a column and using a strut to support earth retaining walls. This method has the advantage of reducing the process of underground construction by reducing the work of installation. Recently, there are a lot of cases of damage and defect occurring in H-beam backfill applied to Top-Down construction method and the concrete slab supporting H-beam backfill. For this, appropriate methods were suggested through finite element analysis of the position and installation form of the H-beam backfill.

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Sublabial Autologous Ear Cartilage Grafting for Increasing the Nasolabial Angle

  • Toncic, Rajko;Toncic, Dinko
    • Archives of Plastic Surgery
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    • v.43 no.1
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    • pp.46-52
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    • 2016
  • Background The loss of nasal tip support is caused by many factors and eventually results in the collapse and eventual dropping of the nasal tip. This reduces the nasolabial (NL) angle and negatively affects respiratory functions and one's appearance. Methods The aim of this retrospective study, which was conducted on 52 patients, was to present and popularize a simple and effective method for the reconstruction of a weakened columella by inserting an autologous ear cartilage graft using a sublabial approach. Results Of all the patients, three patients experienced transplant rejection. The period of follow-up observation was one to five years (mean, 27 months). The results were objectively evaluated by measuring the NL angle in standardized photos before and after the procedure at different time intervals over the follow-up period. We observed a significant increase of the NL angle (mean, $20^{\circ}$), and found these results to be durable over the long term. Of the 52 patients included in this study observed patients, three were dissatisfied (due to immediate infection and shifting of the strut), 28 were satisfied, and 21 were very satisfied. Conclusions The surgical method described here is simple and can be learned quickly. It has very good results with few complications, and is our method of choice for complex and serious cases seen in everyday rhinosurgical practice.

Static behavior of Kiewitt6 suspendome

  • Li, Kena;Huang, Dahai
    • Structural Engineering and Mechanics
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    • v.37 no.3
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    • pp.309-320
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    • 2011
  • As a new type of large-span space structure, suspendome is composited of the upper single-layer reticulated shell and the lower cable-strut system. It has better mechanical properties compared to single-layer reticulated shell, and the overall stiffness of suspendome structure increases greatly due to the prestress of cable. Consequently, it can cross a larger span reasonably, economically and grandly with high rigidity, good stability and simple construction. For a better assessment of the advantages of mechanical characteristic of suspendome quantitatively, the static behavior of Kiewitt6 suspendome was studied by using finite element method, and ADINA was the software application to implement the analysis. By studying a certain suspendome, the internal forces, deformation and support constrained forces of the structure were obtained in this paper. Furthermore, the influences of parameters including prestress, stay bar length, cross-sectional area and rise-to-span ratio were also discussed. The results show that the increase of prestress and vertical stay bar length can improve the stiffness of suspendome; Cross-sectional area has nearly no impact on the static behavior, and the rise-to-span ratio is the most sensitive parameter.

Consideration of Failure Type on the Ground Excavation (지하굴착에 따른 붕괴유형에 대한 고찰)

  • Lee, Jung-Jae;Jung, Kyung-Sik;Lee, Chang-No
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.09a
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    • pp.660-670
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    • 2009
  • Neighboring construction becomes mainstream of Ground excavation in downtown area. This causes the displacement, deformation, stress condition, etc of the ground surroundings. Therefore Neighboring construction have an effect on Neighboring structure. All these years a lot of Neighboring construction carried out, and the accumulation of technology also get accomplished. But earth retaining structure collapse happens yet. Types of earth retaining structure collapse are 12. 1. Failure of anchor or strut system, 2. Insufficiency of penetration, 3. H-pile Failure on excessive bending moment, 4. Slope sliding failure, 5. Excessive settlement of the back, 6. Deflection of H-pile, 7. Joint failure of coupled H-pile, 8. Rock failure when H-pile penetration is rock mass, 9. Plane arrangement of support systems are mechanically weak, 10. Boiling, 11. Heaving, 12. Over excavation. But field collapses are difficult for classification according to the type, because collapse process are complex with various types. When we consider the 12 collapse field, insufficient recognition of ground condition is 4 case. Thorough construction management prevents from fault construction. For limitations of soil survey, It is difficult to estimate ground condition exactly. Therefore, it should estimate the safety of earth retaining system, plan for necessary reinforcement, according to measurement and observation continuously.

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