• Title/Summary/Keyword: Foundation work

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Assessment the effect of pile intervals on settlement and bending moment raft analysis of piled raft foundations

  • Ghiasi, Vahed;Moradi, Mobin
    • Geomechanics and Engineering
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    • v.16 no.2
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    • pp.187-194
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    • 2018
  • Application the pile group foundation to reduce overall settlement of the foundation and also avoid a very fruitful settlement of foundations, inconsistent was carried out. In such a case, in event that the Foundation, not as a mere pile group, which as a system consisting of a broad foundation with pile Group, economic design criteria will be provided in spite of high safety. A new approach in the design of the Foundation can be introduced as the piles are just a tool to improve the parameters of soil hardness; that it can work with detachable piles from raft. Centralized arrangement of piles as the most optimal layout of piles in reducing inconsistent settlement, which is the lowest value of resulting layout in this differential settlement. Using the combination of piles connected and disconnected to form the raft, bending moment created in the raft is reduced. It also concentrated arrangements have greatest effect in reducing amount of moment applied to the raft.

Seismic isolation of nuclear power plant based on layered periodic foundation

  • Mi Zhao;Qun Chen;Junqi Zhang;Xiuli Du
    • Earthquakes and Structures
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    • v.24 no.4
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    • pp.259-274
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    • 2023
  • In this paper, mechanical properties of periodic foundation made of concrete and rubber are investigated by a parametric study using the finite element method (FEM). Periodic foundation is a special type of seismic isolation foundation used in civil engineering, which is inspired by the meso-scale structure of phononic crystals in solid-state physics. This type of foundation is capable of reducing the seismic wave propagating though the foundation, therefore providing additional protection for the structures. In the FEM analysis, layered periodic foundation is frequently modelled due to its simplicity in numerical modeling. However, the isolation effect of periodic foundation on nuclear power plant has not been fully discussed to the best knowledge of authors. In this work, we construct four numerical models of nuclear power plant with different foundations to investigate the seismic isolation effects of periodic foundations. The results show that the layered periodic foundation can increase the natural period of the nuclear power plant like traditional base isolation systems, which is beneficial to the structures. In addition, the seismic response of the nuclear power plant can also be effectively reduced in both vertical and horizontal directions when the frequencies of the incident waves fall into some specific frequency bandgaps of the periodic foundation. Furthermore, it is demonstrated that the layered periodic foundation can reduce the amplitude of the floor response spectrum, which plays an important role in the protection of the equipment.

Importance of an Integrated Assessment of Functional Disability and Work Ability in Workers Affected by Low Back Pain

  • Fabrizio Russo;Cristina Di Tecco;Simone Russo;Giorgia Petrucci;Gianluca Vadala;Vincenzo Denaro;Sergio Iavicoli
    • Safety and Health at Work
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    • v.15 no.1
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    • pp.66-72
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    • 2024
  • Background: This study examines the relationship between functional disability and work ability in workers affected by low back pain (LBP) through an analysis of correlations between the Oswestry Disability Index (ODI) and Work Ability Index (WAI). The role of personal and work factors on functional disability/work ability levels has also been studied. LBP is the most common musculoskeletal problem and a major disabling health problem worldwide. Its etiology is multifactorial. Multidisciplinary approaches may help reduce the burden of pain and disability and improve job continuity and reintegration at work. Methods: A cohort of 264 patients affected by LBP from an Italian outpatient clinic were included in a clinical diagnostic/therapeutic trial aiming at rehabilitation and return to work through an integrated investigation protocol. Data were collected during the first medical examination using anamnestic and clinical tools. The final sample is composed of 252 patients, 57.1% man, 44.0 % blue collars, 46.4% with the high school degree, 45.6% married. Results: WAI and ODI reported a negative and fair correlation (r = -0.454; p = .000). Workers with acute LBP symptoms have a higher probability of severe disability than those with chronic LBP symptoms. White collars without depressive symptoms reported higher work ability - even in chronic disability conditions-than those with depressive symptoms. Conclusion: The study found that ODI and WAI have a convergent validity and this suggests that the two tools measure capture distinctive aspects of disability related to personal, environmental, and occupational characteristics. The most important and modifiable prognostic factors found for ODI and WAI were depressive symptoms, workday absence, and intensity of back pain. The study also found a mild association between age and ODI. The study's findings highlight the importance of using a multidisciplinary approach to manage and prevent disability due to LBP.

Evaluation of Convenience Equipment for Improve Work Efficiency and Preventing of Farm Work-Related Musculoskeletal Disorders (농작업자의 근골격계질환 예방과 작업 효율성 향상을 위한 농작업 편이장비의 평가)

  • Lee, Kyung-Suk;Kim, Kwan-Woo;Choi, Hae-Sun;Kim, Chang-Han;Nam, So-Young;Lee, Kyoung-Mi;Choi, Youn-Woo;Park, Keun-Sang
    • Journal of the Ergonomics Society of Korea
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    • v.29 no.4
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    • pp.495-503
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    • 2010
  • The packing and sorting processes of grape are required repetitive movements to need considerable physical load for a long time. And thereby, there is strong possibility to cause musculoskeletal disorders. In this study, ergonomically designed convenience equipments of worktable and handcart are introduced for improvement of the working movements and less physical load to increase the work efficiency. For objective analysis of the movements and the workload between the ones before and after the improvement, we measured heart rate, OWAS, RULA, REBA, LMM, moving Line and work time. Also, we used a checklist of physical fatigue regions to confirm the subjective evaluation of physical load of workers. As the result of study, it showed lower heart rate, value of Working Postures (OWAS, RULA, REBA) and LMM in the work after introduction of those convenient equipments than the work of before the introduction. The work time and moving Line were shortened and the number of grape boxes packed within the same work time was increased, too. Also the overall load as the subjective evaluation was reduced.

The Activities of Childhood Cancer Foundation in Taiwan (대만 어린이암재단의 활동)

  • Lee ChungHsiang
    • Korean Journal of Hospice Care
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    • v.2 no.1
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    • pp.182-192
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    • 2002
  • Childhood Cancer Foundation of ROC(CCFROC) has been founded since 1982. Its goal is to provide comprehensive care for cancer children and their families. And in turn, under the provision of good and complete care, they can be back to the school and society. To achieve this goal, it needs to get every body's effort of the society together. The foundation has been founder under this concept and tried to fulfil this task. The first step is to educate the public to know that childhood cancer can be cured and the process of treatment is long and expensive. In order to reach this life-saving procedure, campaigns for raising money is most important thing. Then, pediatric hematologists / oncologists try to organize study group, named Taiwan Pediatric Qncology Goupp(TPOG), to make treatment protocols for childhood cancers. Its primary purpose is to increase the cure rate to prove the earlier the diagnosis and treatment, the better the prognosis. The second step is to provide full support of medical expenses and further to give help for emergent need to living. Through the varieties of active exercises of cancer children or families, foundation provides opportunities for them to share the experience during the different periods of diseases. The third step is to extend the scope of training activities for many kinds of personnel who devote to the care for cancer children. On the other hand, it promotes the cooperation or communication with international organizations and sets up recreation playing ground in the communities. The aim is to provide a comprehensive and integrated care for cancer children during their education, breeding and even accomplishment period. Besides the financial support of medical care, it provides social services to give psychological support for children and their families, to strengthen doctor-patients or doctor-families relationship. The foundation provides the mourning religious activities to cherish the memory of their children who passed away and to comfort their sadness. Since the childhood cancer is curable, its treatment should be active, comprehensive and it needs to provide to all cancer children without exception. Indeed, the work of CCFROC should be changed according to the environment and different time period. But, it needs the full support from the society. We hope the scope and content of the work will be more extended and its achievement will be better than now in the future.

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Design and 3D-printing of titanium bone implants: brief review of approach and clinical cases

  • Popov Jr, Vladimir V.;Muller-Kamskii, Gary;Kovalevsky, Aleksey;Dzhenzhera, Georgy;Strokin, Evgeny;Kolomiets, Anastasia;Ramon, Jean
    • Biomedical Engineering Letters
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    • v.8 no.4
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    • pp.337-344
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    • 2018
  • Additive manufacturing (AM) is an alternative metal fabrication technology. The outstanding advantage of AM (3D-printing, direct manufacturing), is the ability to form shapes that cannot be formed with any other traditional technology. 3D-printing began as a new method of prototyping in plastics. Nowadays, AM in metals allows to realize not only net-shape geometry, but also high fatigue strength and corrosion resistant parts. This success of AM in metals enables new applications of the technology in important fields, such as production of medical implants. The 3D-printing of medical implants is an extremely rapidly developing application. The success of this development lies in the fact that patient-specific implants can promote patient recovery, as often it is the only alternative to amputation. The production of AM implants provides a relatively fast and effective solution for complex surgical cases. However, there are still numerous challenging open issues in medical 3D-printing. The goal of the current research review is to explain the whole technological and design chain of bio-medical bone implant production from the computed tomography that is performed by the surgeon, to conversion to a computer aided drawing file, to production of implants, including the necessary post-processing procedures and certification. The current work presents examples that were produced by joint work of Polygon Medical Engineering, Russia and by TechMed, the AM Center of Israel Institute of Metals. Polygon provided 3D-planning and 3D-modelling specifically for the implants production. TechMed were in charge of the optimization of models and they manufactured the implants by Electron-Beam Melting ($EBM^{(R)}$), using an Arcam $EBM^{(R)}$ A2X machine.

Dynamic instability and free vibration behavior of three-layered soft-cored sandwich beams on nonlinear elastic foundations

  • Asgari, Gholamreza;Payganeh, Gholamhassan;Fard, Keramat Malekzadeh
    • Structural Engineering and Mechanics
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    • v.72 no.4
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    • pp.525-540
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    • 2019
  • The purpose of the present work was to study the dynamic instability of a three-layered, symmetric sandwich beam subjected to a periodic axial load resting on nonlinear elastic foundation. A higher-order theory was used for analysis of sandwich beams with soft core on elastic foundations. In the higher-order theory, the Reddy's third-order theory was used for the face sheets and quadratic and cubic functions were assumed for transverse and in-plane displacements of the core, respectively. The elastic foundation was modeled as nonlinear's type. The dynamic instability regions and free vibration were investigated for simply supported conditions by Bolotin's method. The results showed that the responses of the dynamic instability of the system were influenced by the excitation frequency, the coefficients of foundation, the core thickness, the dynamic and static load factor. Comparison of the present results with the published results in the literature for the special case confirmed the accuracy of the proposed theory.

Stability of EG cylindrical shells with shear stresses on a Pasternak foundation

  • Najafov, A.M.;Sofiyev, A.H.;Hui, D.;Karaca, Z.;Kalpakci, V.;Ozcelik, M.
    • Steel and Composite Structures
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    • v.17 no.4
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    • pp.453-470
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    • 2014
  • This article is the result of an investigation on the influence of a Pasternak elastic foundation on the stability of exponentially graded (EG) cylindrical shells under hydrostatic pressure, based on the first-order shear deformation theory (FOSDT) considering the shear stresses. The shear stresses shape function is distributed parabolic manner through the shell thickness. The governing equations of EG orthotropic cylindrical shells resting on the Pasternak elastic foundation on the basis of FOSDT are derived in the framework of Donnell-type shell theory. The novelty of present work is to achieve closed-form solutions for critical hydrostatic pressures of EG orthotropic cylindrical shells resting on Pasternak elastic foundation based on FOSDT. The expressions for critical hydrostatic pressures of EG orthotropic cylindrical shells with and without an elastic foundation based on CST are obtained, in special cases. Finally, the effects of Pasternak foundation, shear stresses, orthotropy and heterogeneity on critical hydrostatic pressures, based on FOSDT are investigated.

Analysis of load-settlement behaviour of shallow foundations in saturated clays based on CPT and DPT tests

  • Mir, Mouna;Bouafia, Ali;Rahmani, Khaled;Aouali, Nawel
    • Geomechanics and Engineering
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    • v.13 no.1
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    • pp.119-139
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    • 2017
  • Static Penetration Test (CPT) and Dynamic Penetration Test (DPT) are commonly used in-situ tests in a routine geotechnical investigation. Besides their use for qualitative investigation (lithology, homogeneity and spatial variability), they are used as practical tools of geotechnical characterization (resistance to the penetration, soil rigidity) and modern foundation design as well. The paper aims at presenting the results of an extensive research work on the evaluation of the 1D primary consolidation settlement of saturated clayey soils on the basis of the CPT or DPT tests. The work is based on an analysis of the correlations between the tip resistance to penetration measured in these tests and the parameters of compressibility measured by the compressibility oedometer test, through a local geotechnical database in the northern Algeria. Such an analysis led to the proposal of two methods of calculation of the settlement, one based on the CPT test and the other one on the DPT. The comparison between the predicted settlements and those computed on the basis of the oedometer test showed a good agreement which demonstrate the possbility to use the CPT and DPT tests as reliable tools of computation of foundation settlements in clayey soils.