Floating-bending tensile-integrity structures

Abstract This is a conceptual work about the form-finding of a hybrid tensegrity structure. The structure was obtained from the combination of arch-supported membrane systems and diamond-type tensegrity systems. By combining these two types of structures, the resulting system features the “tensile-integrity” property of cables and membrane together with what we call “floating-bending” of the arches, a term which is intended to recall the words “floating-compression” introduced by Kenneth Snelson, the father of tensegrities. Two approaches in the form-finding calculations were followed, the Matlab implementation of a simple model comprising standard constant-stress membrane/cable elements together with the so-called stick-and-spring elements for the arches, and the analysis with the commercial software WinTess, used in conjunction with Rhino and Grasshopper. The case study of a T3 floating-bending tensile-integrity structure was explored, a structure that features a much larger enclosed volume in comparison to conventional tensegrity prisms. The structural design of an outdoor pavilion of 6 m in height was carried out considering ultimate and service limit states. This study shows that floating-bending structures are feasible, opening the way to the introduction of suitable analysis and optimization procedures for this type of structures.

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Effects of corrosion on a steel bowstring bridge in marine environment: A case-study of assessment and retrofit

Bridge Structures ◽

10.3233/brs-200178 ◽

2021 ◽

Vol 16 (4) ◽

pp. 121-137

Author(s):

Michele Fabio Granata

Keyword(s):

Corrosion Protection ◽

Marine Environment ◽

Spray Coating ◽

Thermal Spray Coating ◽

In Situ Tests ◽

Limit States ◽

Intervention Measures ◽

Near Future

The case-study of a steel bowstring bridge set in a marine environment and highly damaged by corrosion is presented. The bridge was built in 2004 and was repainted for corrosion protection in 2010. Despite the recent construction and the maintenance interventions, many structural elements like hangers are highly damaged by corrosion with decreasing performance in terms of serviceability and ultimate limit states. A deep investigation was carried out in order to assess the bridge and to establish the necessary retrofit actions to be carried out in the near future. In-situ tests reveal the reduced performance of the original steel in terms of strength and corrosion protection, together with the inefficiency of the successive maintenance interventions. The paper presents assessment of the bridge and retrofit measures, including replacement of the hangers and galvanization through thermal spray coating technology, in order to increase its service life. The results of the investigations and the intervention measures are outlined and discussed.

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Errors in documenting the subsoil and their impact on the investment implementation: Case study

Open Engineering ◽

10.1515/eng-2021-0074 ◽

2021 ◽

Vol 11 (1) ◽

pp. 744-754

Author(s):

Marzena Lendo-Siwicka ◽

Grzegorz Wrzesiński ◽

Katarzyna Pawluk

Keyword(s):

Construction Projects ◽

Organic Soils ◽

Cohesive Soils ◽

Engineering Model ◽

Limit States ◽

Uplift Pressure ◽

Geological Engineering ◽

Jet Grouting ◽

Geotechnical Category

Abstract Improper recognition of the subsoil is the most common cause of problems in the implementation of construction projects and construction facilities failures. Most often, their direct cause is the mismatch of the scope of geotechnical diagnosis to the appropriate geotechnical category, or substantive errors, including incomplete or incorrect interpretation in the creation of a geological-engineering model and often overlooked hydrogeological conditions. In many cases, insufficient recognition and documentation of geotechnical and/or geological and engineering conditions leads to damage and construction failures, delays in consider construction, and the increase of the investment budget. That’s why, in order to avoid the above, particular attention should be paid to proper geotechnical and geological-engineering documentation at the design and construction stages. The selected example of the investment analyzed errors in the geological-engineering documentation, which mainly concerned the lack of recognition of locally occurring organic soils, the incorrectly determined location of the groundwater table and the degree of compaction of non-cohesive soils, and numerous errors of calculated values of soil uplift pressure. The detection of the errors presented in the paper made it possible to select the correct technology for the construction of the sanitary sewage system and to increase the thickness of the horizontal shutter made of jet grouting columns in the area of the excavation. In addition, the article discusses the principles of proper calculation of limit states and subsoil testing, which have a significant impact on the implementation of planned investments.

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Structural Design and Construction for Complicated-Shape Tower with Steel Braced Core Frame — A Case Study

Proceedings of the 10th Pacific Structural Steel Conference (PSSC 2013) ◽

10.3850/978-981-07-7137-9_039 ◽

2013 ◽

Author(s):

Du Yong ◽

Sheng Hong-mei

Keyword(s):

Structural Design ◽

Complicated Shape ◽

Design And Construction

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Verification of an Automated Structural Design Procedure Using Ultimate Limit States

Lecture Notes in Civil Engineering - Practical Design of Ships and Other Floating Structures ◽

10.1007/978-981-15-4672-3_8 ◽

2020 ◽

pp. 145-154

Author(s):

Nathaniel Cope ◽

Joshua Knight

Keyword(s):

Structural Design ◽

Design Procedure ◽

Limit States ◽

Ultimate Limit

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Calibrating Partial Factors – Methodology, Input Data and Case Study of Steel Structures

Periodica Polytechnica Civil Engineering ◽

10.3311/ppci.12822 ◽

2019 ◽

Cited By ~ 1

Author(s):

Vitali Nadolski ◽

Árpád Rózsás ◽

Miroslav Sýkora

Keyword(s):

Input Data ◽

Structural Reliability ◽

Construction Materials ◽

Steel Structures ◽

Structural Performance ◽

Limit States ◽

Different Types ◽

Load Effects ◽

Previous Design

Partial factors are commonly based on expert judgements and on calibration to previous design formats. This inevitably results in unbalanced structural reliability for different types of construction materials, loads and limit states. Probabilistic calibration makes it possible to account for plentiful requirements on structural performance, environmental conditions, production and execution quality etc. In the light of ongoing revisions of Eurocodes and the development of National Annexes, the study overviews the methodology of probabilistic calibration, provides input data for models of basic variables and illustrates the application by a case study. It appears that the partial factors recommended in the current standards provide for a lower reliability level than that indicated in EN 1990. Different values should be considered for the partial factors for imposed, wind and snow loads, appreciating the distinct nature of uncertainties in their load effects.

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