https://transport.vgtu.lt/index.php/EST <p>Engineering Structures and Technologies &nbsp;publishes original research on the implementation of scientific and technical equipment in sustainable building.&nbsp;<a href="https://journals.vilniustech.lt/index.php/EST/about">More information ...</a></p> Vilnius Gediminas Technical University en-US Engineering Structures and Technologies 2029-882X <p>Authors who publish with this journal agree to the following terms</p> <ul> <li class="show">that this article contains no violation of any existing copyright or other third party right or any material of a libelous, confidential, or otherwise unlawful nature, and that I will indemnify and keep indemnified the Editor and THE PUBLISHER against all claims and expenses (including legal costs and expenses) arising from any breach of this warranty and the other warranties on my behalf in this agreement;</li> <li class="show">that I have obtained permission for and acknowledged the source of any illustrations, diagrams or other material included in the article of which I am not the copyright owner.</li> <li class="show">on behalf of any co-authors, I agree to this work being published in Engineering Structures and Technologies as Open Access, and licenced under a Creative Commons Licence, 4.0 <a href="https://creativecommons.org/licenses/by/4.0/legalcode">https://creativecommons.org/licenses/by/4.0/legalcode</a>. This licence allows for the fullest distribution and re-use of the work for the benefit of scholarly information.</li> </ul> <p>For authors that are not copyright owners in the work (for example government employees), please <a href="mailto:%20journals@vilniustech.lt">contact VILNIUS TECH</a>to make alternative agreements.</p> https://transport.vgtu.lt/index.php/EST/article/view/18403 <p>The article consists of 3 parts. String analyzes with symmetrical loading, combined parametric analyzes of string structure with symmetrical loading and combined string structure analyzes with asymmetrical loading. Through various parameters, the influence of different parameters of the string on its behavior is revealed. The influence of prestressing in the combined string structure is also released. To assess the correctness of the results, an experimental study was carried out in the laboratory, after the structure was designed from steel elements.</p> <p><strong>First published online</strong> 20 January 2023</p> Edmundas Beivydas Copyright (c) 2022 The Author(s). Published by Vilnius Gediminas Technical University. http://creativecommons.org/licenses/by/4.0 2022-12-30 2022-12-30 14 1 1–6 1–6 10.3846/est.2022.18403 https://transport.vgtu.lt/index.php/EST/article/view/23007 <p>The evaluation of the load-bearing capacity of existing structures is a central and important part in the work of structural engineers. Currently, engineers are confronted with the challenge of applying design rules developed for new structures in the evaluation of existing ones as no specific recommendations exist on a European level. As a contribution to this, a first step of this study is the evaluation of the reliability level of timber elements subjected to common limit states. Based on these analyses, modifications of the target reliability and of partial safety factors (PSF) for existing structures on the resistance side are studied. Considering a modification of the target reliability, the PSF for the material strength could be proposed with <img src="/public/site/images/irena/Screenshot_2025-02-10_152148.png" width="78" height="18">&nbsp;for compressive and flexural strength in limit states, where variable actions are present. Additionally, options for incorporating updated material parameters from a survey on site supported by technical devices are discussed and further need for research is identified. Subsequently, this paper provides a stepwise evaluation procedure including modified PSF considering both, an update of the target reliability and update of the material parameters obtained by a survey on site and is thus adaptive for different individual cases and level of information.&nbsp;</p> <p><strong>First published online</strong> 10 February 2025</p> Maria Loebjinski Zheng Li Wolgang Rug Hartmut Pasternak Copyright (c) 2022 The Author(s). Published by Vilnius Gediminas Technical University. http://creativecommons.org/licenses/by/4.0 2022-12-30 2022-12-30 14 1 7–23 7–23 10.3846/est.2022.23007