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Lapped scarf joints for reconstruction of historical structures
Kunecký, Jiří ; Fajman, P. ; Hasníková, Hana ; Kuklík, P. ; Kloiber, Michal ; Sebera, V. ; Tippner, J.
This paper presents a description of the repair of timber structures using a prosthesis scarf\njoint designed for the replacement of damaged parts of beams. This new scarf joint makes use\nof the strutting effect of inclined contact faces where the forces are transmitted through\nwooden coupling elements - wooden dowels or keys. The scarf can be modified in four\nvariants according to the relevant stress and is suitable for historically valuable timber\nstructures. It meets both functional and aesthetic requirements. The designer - structural\nengineer will learn in the methods the load bearing capacity or stiffness of the beam with the\ndesigned joint, its recommended dimensions and detailed geometry. The contractor will\nappreciate the description of the execution and maintenance of the joint.
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The use of carpentry joints for the repair of historical structures
Kloiber, Michal ; Kunecký, Jiří ; Hasníková, Hana ; Sebera, V. ; Tippner, J. ; Fajman, P. ; Růžička, P. ; Stejskal, D.
The conservation process describes the way of using prosthesis lap scarf carpentry joints for reconstruction of historical timber structures. This new scarf joint makes use of the strutting effect of inclined contact faces where the forces are transmitted through wooden coupling elements - wooden dowels or keys. The process consists of several chapters describing the diagnostics of original wood and the repaired structure, the design of the joint and execution of the joint. It also includes examples of succesful reconstruction made with according to this conservation process.
Fulltext: content.csg -  PDF
Plný tet: 0459383_2015_Kloiber_et_al_Vyuziti_celodrevenych_tesarskych_spoju_pri_opravach_historickych_konstrukci_PP_NAKI-004_AVV - PDF
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Lapped scarf joints for repairs of historical structures
Kunecký, Jiří ; Fajman, P. ; Hasníková, Hana ; Kuklík, P. ; Kloiber, Michal ; Sebera, V. ; Tippner, J.
This guideline presents a description of the repair of timber structures using a prosthesis scarf joint designed for the replacement of damaged parts of beams. This new scarf joint makes use of the strutting effect of inclined contact faces where the forces are transmitted through wooden coupling elements - wooden dowels or keys. The scarf can be modified in four variants according to the relevant stress and is suitable for historically valuable timber structures. It meets both functional and aesthetic requirements. The designer - structural engineer will learn in the methods the load bearing capacity or stiffness of the beam with the designed joint, its recommended dimensions and detailed geometry. The contractor will appreciate the description of the execution and maintenance of the joint.
Fulltext: content.csg - PDF
Plný tet: 0459382_2016_Kunecky_et_al_Celodrevene_platove_spoje_pro_opravy_historickych_konstrukci - PDF
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Measuring strength and modulus of deformability of wood in compression parallel to the grain in a bored hole by a small jack\n
Kloiber, Michal
The publication is dedicated to the methodical description of the technical solution and the measurement of strength and modulus of deformability of wood in compression parallel to the grain in a bored hole by pushing apart grips of a small jack and loading the walls of the hole. The methodology presents the principles of the device usage and measurement result evaluation for the purposes of surveys of historical monuments and projects for their rescue or appreciation. Currently, there is no other method allowing determination of mechanical properties of wood, such as strength and modulus of elasticity in compression parallel to the grain, directly in the field without sampling. Therefore, the research was oriented to the development of a simple method, practically applicable for the purpose of structural-technical surveys of timber structures, in particular historical monuments. The resulting methodology meets the protection of the cultural heritage standards, in particular the requirement to minimize interference with the original material, while retaining high reliability of the determined wood mechanical properties of wood.
Fulltext: content.csg - PDF
Plný tet: 0453514_2015_Kloiber_Mereni_pevnosti_a_modulu_pretvarnosti_dreva_CM_NAKI-001 - PDF
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Diagnostic of timber structures
Kloiber, Michal
Diagnostic of timber structures is a special field of engineering, that is focused on timber assessment, evaluation of defects and assessing the safety and reliability of existing wood structures. Special task is the diagnostic of timber structures in historical objects. In such cases, usually, we can not use the standard methods for determining the mechanical properties of wood, it is necessary to meet the requirement of minimum intervention into the object structure. The aim of the presentation is to inform the professional audience about the possibilities of application of diagnostic methods, which provide the required information with a high consideration for preservation of the original material and the object design concept. Quality diagnostic uses very sophisticated methods and can be costly, however, often provide accurate data even in low invasiveness, which is valued at the historical object diagnostic. Overall cost of the technical and diagnostical survey of structure can be reduced by cost savings on demolition and repair works.
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The numerical assessment of a full-scale truss reconstructed employing a traditional all-wooden joints
Milch, J. ; Tippner, J. ; Sebera, V. ; Kunecký, Jiří ; Kloiber, Michal ; Navrátil, M.
The assessment of mechanical behaviour of all-wooden joints used in historical timber structures such as churches, castles etc. is currently paid a big attention in the Czech Republic, and Central Europe as a whole. The reasons are (a) a high number of such structures; (b) their significance to the national cultural heritage and maintenance for preserving their cultural value; and (c) missing information about global mechanical behaviour of joints and whole truss structures when loaded. Generally, valuable historical monuments need to be evaluated as regards the structure and safety of all timber elements in the structure for their future preservation [1]. The present paper shows a novel methodology for virtual assessment of mechanical behaviour used in a historically valuable gothic truss structure of St. James's Church in Brno, which is very valuable from both structural and architectural points of view. The church was constructed between1220 and 1724, the used styles including the Romanesque, the Gothic and the Neogothic. Also carpentry master Anton Ebenberger participated [2]. The aim of this paper was to describe the real loading of a joint that corresponds to the real function of a joint in the truss structure during the loading owing to new positions of replacement joints in the truss. Currently, the truss of St. James’s church shows large defects including decayed members; therefore, renovation is needed. The restoration of the truss should be carefully implemented in the structure and analyzed beforehand. Therefore, the numerical approaches based on FEM were used to evaluate the mechanical behaviour of the beam truss with a detailed 3D solid joint.
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Research Report on Condition Assessment of Wood-destroying Damage to Log Walls of a Landless Person's Cottage of Leskovec (orig. No. 70) and a Cottage of Lužná (orig. No. 28) now in the Museum in Rožnov pod Radhoštěm
Kloiber, Michal ; Hrivnák, Jaroslav ; Bláha, Jiří
The subject of the research report was to assess the condition of and identify the wood-destroying damage to the walls of a landless person's cottage of Leskovec and a cottage of Lužná, two log structures that are part of the exhibition at the Wallachian Museum in Rožnov pod Radhoštěm. The report focused on locating points, classifying the degree of damage, determining the extent of concealed attack by the means of non-destructive devices, specifying whether wood is subject to a fungal attack (mycological damage) or insect attack (entomological damage) and drawing the results obtained in the plan documentation. The report was based on direct and mediated visual observation using an endoscope and mainly on measurements taken using a resistance microdrilling device and also on ascertainment of mechanical properties of wood using expanding jaws in the borehole. Based on the results, specific procedures for rehabilitation measures were designed and elements designed for structural rehabilitation were marked in the drawing documentation.
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Research Report on Condition Assessment of the Holy Ghost Tower's Roof Frame in Telč
Bláha, Jiří ; Kloiber, Michal ; Frankl, Jiří ; Buzek, Jaroslav
The subject of the research report was to assess the condition of and identify the range of wood-destroying damage to the roof frame of the Holy Ghost tower in Telč focused on locating critical points, classifying the degree of damage, determining the extent of concealed attack by the means of non-destructive devices, specifying whether wood is subject to a fungal attack (mycology) or insect attack (entomology), including the drawing of the results obtained in the drawing documentation of the existing condition of the roof frame. Based on the results, specific procedures for rehabilitation measures were designed and elements designed for structural rehabilitation were included in the drawing documentation. The report is based primarily on direct and mediated (endoscopic) visual observations supplemented by measurements using a resistance microdrilling device.
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