structural solution
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2022 ◽  
Author(s):  
Martin Wiedemann ◽  
Camil Badrya ◽  
Adarsh Prasannakumar ◽  
Lennart Lobitz ◽  
Hendrik Traub ◽  
...  

Author(s):  
Jean-Paul Faguet ◽  
Mahvish Shami

AbstractInstitutional reforms are structural changes in the rules and norms of authority, with effects that are long-term and unpredictable on government, politics, and society. But leaders may undertake them to solve unrelated, discrete, short-term political problems. Understanding the latter is key to understanding the characteristics of many real reforms, and hence their fate. We introduce the concept of instrumental incoherence and use it to construct a theory of decentralization where reform is motivated by orthogonal objectives. We show that reformers’ incentives map onto the specifics of reform design via their side effects, not their main effects, which in turn lead to the medium- and long-term consequences eventually realized. We characterize downwardly accountable decentralization, which ties the hands of the center to empower local voters, vs. upwardly accountable decentralization, which ties the hands of local government to empower the center. We use these ideas to explain highly divergent outcomes in two extreme cases, Bolivia and Pakistan, using detailed, original evidence. Our analysis likely extends to a broader class of reforms where the incentives of agents pursuing a change, and the effects of that change, are highly asymmetric in time and dimension.


2021 ◽  
Vol 12 (2) ◽  
pp. 61-66
Author(s):  
Tatjana Grigorjeva ◽  
Ainars Paeglitis

Suspension bridges are characterized by exceptional architectural expressions and excellent technical and economic properties. However, despite all advantages, suspension bridges have a few negative features. Suspension bridges with flexible cables share excessive deformation caused by the displacement of kinematic origin. In order to increase the stiffness of suspension bridges, an innovative structural solution refers to rigid cables used instead of the flexible ones. The paper describes a methodology for calculating an asymmetric single-pylon suspension bridge with rigid cables considering installation features. Also, the article presents the numerical simulation of the bridge and determines the accuracy of the proposed methodology.


2021 ◽  
Author(s):  
Jiří Stráský ◽  
Tomas Romportl ◽  
Pavel Kaláb ◽  
Leonard Šopík

<p>Four arch pedestrian and cyclist bridges built in the USA, Slovakia and in the Czech Republic are described in terms of their architectural and structural solution, static and dynamic behaviour, and technology of their construction. The bridges with span length up to 104 m have slender decks which are suspended on arches of a butterfly arrangement. The dynamic analysis proved that all structures are comfortable to users. The footbridges are structurally efficient, they are light and transparent, correspond to the scale of the landscape and all structural members have human dimensions.</p>


2021 ◽  
Author(s):  
Jiří Stráský ◽  
Pavel Sliwka ◽  
Pavel Kaláb ◽  
Lenka Zapletalova

<p>Three suspension pedestrian and cyclist bridges built in Sweden and in the Czech Republic are described in terms of their architectural and structural solution, static and dynamic behaviour, and technology of their construction. The bridges with span length up to 179 m have slender decks which are fix connected with suspension cables. The dynamic analysis proved that all structures are comfortable to users and they have a sufficient aerodynamic stability. The footbridges are structurally efficient, they are light and transparent, correspond to the scale of the landscape and the structural members have human dimensions.</p>


Author(s):  
И. Л. Кузнецов ◽  
Р. Г. Гайнетдинов

Постановка задачи. В скатных фермах из стальных тонкостенных холодногнутых и стеклопластиковых профилей, где элементы соединяются непосредственно на болтах с помощью листовых фасонок, основной проблемой является недостаточная жесткость центрального узла верхнего пояса, что существенно влияет на устойчивость фермы в процессе транспортировки, монтажа и ее эксплуатации. В связи с этим предлагается рассмотреть новое узловое соединение верхнего пояса двускатной фермы. Результаты. Установлено, что предлагаемое новое решение центрального узла верхнего пояса скатной фермы позволяет повысить жесткость узла из плоскости. Отмечается, что конструктивное решение может найти применение при изготовлении решетчатых конструкций из стальных тонкостенных холодногнутых и стеклопластиковых профилей. Выводы. Рассмотрено новое узловое соединение центрального узла верхнего пояса двускатной фермы. Доказано, что решение позволяет увеличить момент сопротивления сечения из плоскости. Узловое соединение обеспечивает устойчивость из плоскости фермы на стадии транспортировки, монтажа и ее эксплуатации. Statement of the problem. In pitched trusses made of steel thin-walled cold-formed and fiberglass plastic profiles, where the elements are connected directly on bolts using sheet gusset, the main problem is the lack of rigidity of the central node of the upper belt, which significantly affects the stability of the farm during installation and operation. Therefore, it is suggested that a new node connection of the upper belt of the pitched truss is considered. Results. It is established that the suggested new solution of the central node of the upper belt of the pitched truss allows the rigidity of the node to be increased. It is noted that the structural solution can be employed in manufacturing lattice structures of steel thin-walled cold-formed and fiberglass plastic profiles. Conclusions. The new node connection of the central node of the upper belt of the pitched truss is considered, it is proved that the solution enables an increase in the moment of resistance of the section from the plane. The node connection allows stability to be provided from the plane of the truss at the stage of installation and its operation.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wayne D. Harshbarger ◽  
Derrick Deming ◽  
Gordon J. Lockbaum ◽  
Nattapol Attatippaholkun ◽  
Maliwan Kamkaew ◽  
...  

AbstractBroadly neutralizing antibodies (bnAbs) targeting conserved influenza A virus (IAV) hemagglutinin (HA) epitopes can provide valuable information for accelerating universal vaccine designs. Here, we report structural details for heterosubtypic recognition of HA from circulating and emerging IAVs by the human antibody 3I14. Somatic hypermutations play a critical role in shaping the HCDR3, which alone and uniquely among VH3-30 derived antibodies, forms contacts with five sub-pockets within the HA-stem hydrophobic groove. 3I14 light-chain interactions are also key for binding HA and contribute a large buried surface area spanning two HA protomers. Comparison of 3I14 to bnAbs from several defined classes provide insights to the bias selection of VH3-30 antibodies and reveals that 3I14 represents a novel structural solution within the VH3-30 repertoire. The structures reported here improve our understanding of cross-group heterosubtypic binding activity, providing the basis for advancing immunogen designs aimed at eliciting a broadly protective response to IAV.


Buildings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 24
Author(s):  
Arianna Pavia ◽  
Fabrizio Scozzese ◽  
Enrica Petrucci ◽  
Alessandro Zona

Masonry towers are part of a valuable architectural heritage characterizing the landscape of many historical areas. These towers are vulnerable structures that are prone to earthquake damage. Hence, the design of effective seismic upgrading interventions is an important task for preserving such architectural forms for future generations. In view of that, the objective of this study is to contribute a possible addition to the portfolio of available approaches for seismic upgrading of masonry towers. This goal was pursued by exploring an innovative structural solution that does not alter the external appearance of the tower and its static scheme under gravity loads, yet is able to increase its capacity to withstand seismic actions through added damping. Specifically, the proposed solution consists of a steel structure internal to the masonry tower that incorporates fluid viscous dampers. In order to evaluate its potentialities, a real case study was taken as a testbed structure, historic analysis as well as geometric and architectural surveys were undertaken, an initial design for the upgrading was made, and numerical simulations were performed. The obtained results, although preliminary, highlight the potentialities of the proposed structural solution for the seismic upgrading of masonry towers and might open the way to future developments and applications.


2021 ◽  
Vol 274 ◽  
pp. 03017
Author(s):  
Juliya Mironova

Despite the widespread use of monolithic construction, precast concrete remains in demand in the construction of residential and administrative buildings. Regardless of the advantages in technology and the quality of work, it is necessary and appropriate to modernize the existing design solutions, which allows you to simplify and speed up the technological operations during construction. Moreover, in the construction of complex nodes and joints, the qualification of workers is important, so simplifying the work without losing the quality of construction and ensuring strength, stability and durability is an important task. This problem can be solved by using modern embedded parts in the joints that do not require welding and other complex technological operations. In this paper, a constructive solution of the horizontal joint of the floor slabs located in the zone of action of minimal forces is proposed on the example of a girderless frame. The purpose of the study is to determine the stress-strain state of the proposed structural solution of the horizontal joint of floor slabs using loopshaped embedded parts «PFEIFER» and to develop recommendations for determining the shear compliance. Based on the analysis of the results of numerical modeling, the features of the stress-strain state of the joint during shear operation are revealed. The results obtained can be used in the design of buildings with precast-monolithic ringless frames, in the modernization of existing standard solutions of precast-monolithic frames, as well as other load-bearing systems made of precast concrete.


Author(s):  
S. G. Golovina ◽  

The article deals with the process of forming the structural solution of the buildings in St. Petersburg in the 1703-1730-s. St. Petersburg has established its own sustainable architectural and structural system, which remained virtually unchanged until the beginning of the XX century. This system began to be formed during the reign of Emperor Peter I, by borrowing and mastering the Western European experience, combining the advanced innovations of that time and Russian traditions. Generalization of the experience of creating a structural system will allow assessing the evolution of the construction skills in St. Petersburg, identifying and preserving the structural elements of the historical buildings of the city center.


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