scholarly journals Rehabilitation of the Roof Timber Trusses of a Multiuse Pavilion

2020 ◽  
Vol 6 (12) ◽  
pp. 2437-2447
Author(s):  
João H. Negrão
Keyword(s):  
Full Text ◽  
Steel Structure ◽  
Timber Structure ◽  
Failure Condition ◽  
Load Bearing ◽  
Load Redistribution ◽  
Roof Structure ◽  
Innovative Solution ◽  
Visual Impact

This paper describes the rehabilitation procedure of the roof timber structure of a multiuse pavilion in Viseu, Portugal. The roof structure consists of a series of parallel double timber trusses, partially concealed above a polyhedral wooden plank-made ceiling. Recently, the support of one of the trusses failed and another one has been assessed as in a pre-failure condition. Some load-redistribution and the prompt shore of the structure prevented the generalized collapse. The subsequent inspection and assessment led to the conclusion that the primary cause of the collapse was the failure perpendicular to the grain of the solid timber elements inserted between the double rafters and tie-beams. The replacement of the existing with a steel structure, and the repair and reinforcement of the existing wooden trusses, were considered as intervention possibilities. The latter revealed much cheaper, less time-consuming and in line with the international recommendations on rehabilitation works, and was therefore adopted. An innovative solution, consisting of the replacement of the central timber elements in all the supports, resulted in minimum visual impact and improved the load bearing capability beyond its original value. Doi: 10.28991/cej-2020-03091628 Full Text: PDF

Experiment of the SCT Joint under Complicated Loading

2011 ◽  
Vol 255-260 ◽  
pp. 607-613
Author(s):  
Bing Liao ◽  
Yong Feng Luo ◽  
Xiao Nong Guo
Keyword(s):  
Bearing Capacity ◽  
Loading Condition ◽  
Steel Structure ◽  
Force Transmission ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Roof Structure ◽  
Axial Forces ◽  
Out Of Plane ◽  
Water Sports

A radial-circle-lined grid shell, its height changed step by step in the radial direction, is adopted in the roof steel structure of the Citizen Water Sports Center in Jiangyin, China. And the Spatial Crossing Tubular (SCT) joint is used for the connection of pipe members. Because the force transmission in the roof structure is different from the traditional truss structure, a lot of SCT joints are in a complicated loading state. The joint forces include axial forces and in/out-of-plane moments. To investigate the mechanical behavior and the load-bearing capacity of a typical SCT joint in such complicated loading condition, a full size model test of the typical SCT joint is conducted. The test process is summarized in the paper, together with the finite element calculation of the typical SCT joint in test conditions. By comparing the numerical results with the test results, several significant parameters of the connection are investigated, including the stiffness change of the joint, the transmission mechanism of forces, the ultimate load-bearing capacity and the failure mode of the joint. After investigation, several useful suggestions are proposed for the SCT joint design. They are also valuable for the design of similar SCT joints under complicated loading condition.

scholarly journals Assessment of Timber Roof Structures before and after Earthquakes

Buildings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 528
Author(s):  
Nikola Perković ◽  
Mislav Stepinac ◽  
Vlatka Rajčić ◽  
Jure Barbalić
Keyword(s):  
Test Methods ◽  
Timber Structures ◽  
Destructive Testing ◽  
Policy Makers ◽  
Load Bearing ◽  
Existing Structures ◽  
Roof Structure ◽  
Before And After ◽  
Timber Roof Structures ◽  
Non Destructive

The global objective of sustainable development has been greatly directed toward the preservation of existing structures. Therefore, condition assessment and reconstruction of existing timber structures have been gaining importance in recent times. This is particularly evident on timber roofs whose elements are exposed to degradation, either because of rheological effects or due to the direct influence of moisture and biological factors. In case of accidental events, such as an earthquake, the question of the structure’s condition is essential for the condition of the entire building. In order to prove the load-bearing capacity and serviceability of existing structures, as well as to check the need for reconstruction, it is necessary to define crucial parameters that are influencing the condition of materials, elements, and systems. Although there are many non destructive testing methods, the frequency and scope of their use, as well as the decision-making approach, have not been defined. In the paper, non-destructive and semi-destructive methods frequently used for timber structures are explained. A systematic review of criteria to be used in the assessment of load-bearing timber structures in a seismic active area was the main objective of this paper as well as the illustration of non-destructive and semi-destructive test methods through a case study involving roof construction of a hundred-year-old building in Zagreb, Croatia. Pre- and post-earthquake inspection was made. The overall condition of the roof structure after two significant earthquakes can be assessed as satisfactory given that the observed system is a large-span and massive roof structure. The presented results and identification of typical damages after the earthquake are presented in order to facilitate policy makers and for the future implementation of development strategies in the renovation of the city.

scholarly journals Real Cyclic Load-Bearing Test of a Ceramic-Reinforced Slab

2020 ◽  
Vol 10 (5) ◽  
pp. 1763
Author(s):  
Albert Albareda-Valls ◽  
Alicia Rivera-Rogel ◽  
Ignacio Costales-Calvo ◽  
David García-Carrera
Keyword(s):  
Cyclic Load ◽  
Structural Response ◽  
Steel Structure ◽  
Steel Beams ◽  
Load Bearing ◽  
Rc Frames ◽  
Industrial Buildings ◽  
Loading And Unloading ◽  
Low Levels ◽  
The City

Ceramic-reinforced slabs were widely used in Spain during the second half of the 20th century, especially for industrial buildings. This solution was popular due to the lack of materials at that time, as it requires almost no concrete and low ratios of reinforcement. In this study, we present and discuss the results of a real load-bearing test of a real ceramic-reinforced slab, which was loaded and reloaded cyclically for a duration of one week in order to describe any damage under a high-demand loading series. Due to the design of these slabs, the structural response is based more on shear than on bending due to the low levels of concrete and the geometry and location of re-bars. The low ratio of concrete makes these slabs ideal for short-span structures, mainly combined with steel or RC frames. The slab which was analyzed in this study covers a span of 4.88 m between two steel I-beams (IPN400), and corresponds to a building from the mid-1960s in the city of Igualada (Barcelona, Spain). A load-bearing test was carried out up to 7.50 kN/m2 by using two-story sacks full of sand. The supporting steel beams were propped up in order to avoid any interference in the results of the test; without the shoring of the steel structure, deflections would come from the combination of the ceramic slab together with the steel profiles. A process of loading and unloading was repeated for a duration of six days in order to describe the cyclic response of the slab under high levels of loading. Finally, vibration analysis of the slab was also done; the higher the load applied, the higher the fundamental frequency of the cross section, which is more comfortable in terms of serviceability.

Experimental Research of Lightweight Composite Wall on Lateral and Vertical Loads

2013 ◽  
Vol 838-841 ◽  
pp. 514-518
Author(s):  
Yi Qing Guo ◽  
Ping Zhou Cao
Keyword(s):  
Steel Structure ◽  
The Self ◽  
Deformation Capacity ◽  
Light Weight ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
New Type ◽  
Composite Wall ◽  
Thin Panel ◽  
Screw Pitch

To overcome the shortcomings of assembly lightweight steel structure residential system in our country. A new type of lightweight energy-saving composite wall is proposed, which is composed by light-gauge shaped steel and thin panel. In order to investigate the load-bearing behaviour and failure mode of the composite wall, 4 wall specimens in full ratio were designed and manufactured. The experiment study is carried out under lateral and vertical loads. The results show that the self-drilling screw integrate the light-gauge shaped steel and thin panel to bear loads. The decrease of self-drilling screw spacing can effectively enhance the load-bearing capacity of the composite wall, and the best choice of the self-drilling screw pitch is 150mm. The composite wall has good bearing and deformation capacity, and it is suitable for applying to light weight steel residential system in our country.

Construction Technology of Large-Span Hybrid Structure of Suspendome with Stacked Arch in Chiping Gymnasium

2011 ◽  
Vol 243-249 ◽  
pp. 6083-6086 ◽  
Author(s):  
Xiao Bei Wang ◽  
Zhen Hua Liu ◽  
Ming Gong ◽  
Lian Fen Weng
Keyword(s):  
High Altitude ◽  
Steel Structure ◽  
Hybrid Structure ◽  
Construction Technology ◽  
Large Span ◽  
Finite Element Software ◽  
Roof Structure ◽  
Temporary Support ◽  
Stress And Deformation ◽  
Lattice Shell

Large-span hybrid structure of suspendome with stacked arch is applied into steel roof of Chiping Gymnasium. The construction of this new type structure system is difficult according to structure characteristics such as its large-span stacked arch, high installation altitude, lattice shell installation, prestressed cable tension, and tight construction period. Temporary support frame, segment lifting and high altitude splicing construction method is adopted to install the stacked arch, and total support, high-altitude spread operation method is used to install lattice dome. A spatial structural analysis is conducted on the supporting system, and the finite element software is adopted to simulate and analyze the installation process of the steel structure roof system. At the same time, stress and deformation of the roof structure are monitored by precise instruments and equipments. As the result, construction safety and quality are guaranteed.

TIMBER FRAME TRUSS CONSTRUCTIONS IN THE LKV SYSTEM

2020 ◽  
Author(s):  
Žikica Tekić ◽  
Ljiljana Kozarić ◽  
Martina Vojnić Purčar
Keyword(s):  
Functional Organization ◽  
Timber Structure ◽  
Basic Principles ◽  
Timber Frame ◽  
Roof Structure ◽  
The One ◽  
Constituent Elements

The paper presents timber frame truss constructions in the LKV system and their application in the one hipped end gable roofs. Special attention is paid to the design of the side sector of the roof, as a function of the static height of the girder and the size of the associated load. The basic principles of functional organization of characteristic roof sectors are given, which is important for defining the geometry of all girders that form a timber structure. Unification of prefabricated elements is important for the production and economy of the timber structure. As part of the timber structure, the position and geometry of the bracings are also given, as constituent elements of the roof structure.

Research on Rigidity of Circular Tubular ZYY-Joint in Single Fold Surface of Multi-Planar Steel Structure of 26th Universaide Shenzhen 2011

2011 ◽  
Vol 255-260 ◽  
pp. 421-427
Author(s):  
Wen Bo Sun ◽  
Tao Hu ◽  
Wei Huang
Keyword(s):  
Numerical Analysis ◽  
Bearing Capacity ◽  
Steel Structure ◽  
Tubular Structure ◽  
Finite Element Software ◽  
Roof Structure ◽  
Stiffness Characteristic ◽  
Single Fold ◽  
Internal Forces ◽  
Tubular Joint

Due to its convenience of construction connection and simple appearance, steel tubular structure with simple joints is widely used in spatial structures. Tubular joint generally belongs to semi-rigid joint. Its different internal detail is closely related to the bearing capacity and stiffness of joints and its stiffness characteristic has some definite effects on the internal forces, deformation and bearing capacity of the steel tubular structure. In this paper, the roof structure of the main stadium of 26th Universaide Shenzhen 2011 was selected as the engineering background. This paper also studied the comparison test on different structural forms of spatial circular tubular ZYY-joints of the peaks of its steel structure by scaling down as the proportion of 1:3, and carried out a numerical analysis on these joints by finite element software ANSYS. It shows that, results of numerical analysis coincide with the experimental results and the joint with ribbed stiffener has better bearing capacity and stiffness, which can well meet the engineering needs.

scholarly journals Fatigue life prediction of mechanical structures under stochastic loading

2018 ◽  
Vol 157 ◽  
pp. 02024 ◽  
Author(s):  
Bohuš Leitner ◽  
Lucia Figuli
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Residual Life ◽  
Steel Structure ◽  
Degradation Process ◽  
Bearing Steel ◽  
Damage Function ◽  
Operating Conditions ◽  
Fatigue Life Prediction ◽  
Load Bearing

Problems of fatigue life prediction of materials and structures are discussed in the paper. Service loading is assumed as a continuous loading process with possible discontinuous events, which are caused by various operating conditions. The damage in a material is due to a cumulative degradation process. The damaging process is then represented either by rain-flow matrices or by a fatigue damage function which is derived using some hypothesis of a fatigue failure criterion. Presented theoretical procedure enables a very effective estimation of a service life and/or reliable evaluation of residual life of any structures under various types of loading and environmental conditions. This approach creates a good basis for powerful expert systems in structural and mechanical engineering. The aim of the paper is to present briefly some results of analysis of load-bearing steel structure loads of special railway crane PKP 25/20i which was utilized in some specific ad relatively hard operating conditions. Virtual models of the structure were being used in an analysis of acting working dynamics loads influence to be able to forecast fatigue life of load-bearing of the crane jib.

Preservation of the Large Timber Roof of the Porta Nuova Railway Station in Torino

2013 ◽  
Vol 778 ◽  
pp. 951-958 ◽  
Author(s):  
Clara Bertolini-Cestari ◽  
Stefano Invernizzi ◽  
Tanja Marzi ◽  
Steni Rolla
Keyword(s):  
Cultural Heritage ◽  
Point Of View ◽  
Timber Structure ◽  
Structural Assessment ◽  
Railway Station ◽  
Roof Structure ◽  
Maintenance Program ◽  
Bearing Structure ◽  
Important Structure ◽  
Design And Construction

Torino, in 1861, was the first capital of the just unified Reign of Italy. In the same year, Eng. A. Mazzucchetti was charged for the design of the railway station of Porta Nuova in Torino, in correspondence of the arrival of the railway connecting Genova. The original conception resembles the bilateral scheme of the King Cross station in London, which is few years older. The design and construction of the station deserved contributions from the most outstanding scientists of that time, including R. Sephenson who provided the details of the lateral roof structures of the station, and the young Eng. A. Castigliano who defended his thesis on the design of the great steel vault above the rails. The two main branches were conceived with masonry bearing structure and a wide span timber roof covered with stone plates. The station, during the years, was object of several interventions, including restorations, dismantling of parts, and changes in the destination of use. Nowadays, the roof structure needs for important maintenance interventions due to the water leaking which caused the deterioration of the beneath timber structure. The present holders are considering the replacement of the entire roof. This solution is not respectful for conservation criteria, nor is affordable from an economical point of view. The present study describes the correct and sustainable approach for the structural assessment, restoration and maintenance program for the preservation of this important structure belonging to cultural heritage.

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