Maintenance Of Historical Buildings Research Articles

The Stabilization Of The Gothic Roof BearingStructure Of The Frauenkirche In MeiBen WithCFRP-tension

The historic, especially valuable gothic roof bearing structure of the Frauenkirche in MeiBen has been stabilized by the building in of Carbon fibre reinforced plastics loops (CFRP) and therefore further deformation and damage to the whole church construction has been limited. Commencing from an analysis of the existing state, different versions for the stiffening of a historical bearing structure were simulated. Figure 1: Longitudinal section of the gothic church with baroque tower curia [1] Transactions on the Built Environment vol 39 © 1999 WIT Press, www.witpress.com, ISSN 1743-3509 580 Structural Studies, Repairs and Maintenance of Historical Buildings 1 The Frauenkirche of the City of Meifien The Frauenkirche in the market square has been dominating the city centre of the more than 1000 years old town MeiBen. Therefore the reconstruction of this church has become of great importance during the complex town redevelopment. The Frauenkirche in its present form was built as a town church in the early 15th century. It was first mentioned in 1205. The roof truss was added to the churches aisle in about 1447 according to dendrochronological examinations. The church in its form and construction is a typical example of gothic style architecture within Saxony. Figure 2: Cross-section with principal rafter A5 [1] Transactions on the Built Environment vol 39 © 1999 WIT Press, www.witpress.com, ISSN 1743-3509

Greek Temple And Timber Pagoda In Japan -Comparison Of The Aseismic StructuralPerformances

Comparing the aseismic performances of two historical monuments: Greek temples such as the Parthenon in Greece and five-storied timber pagodas in Japan, which survive for centuries, we found some significant similarities in structural performances. The dynamic analyses show that both, as a piled up construction, are based on the common concept of structural design, which we may call Flexible structural designing. Similarities in seismic behaviors between the column composed of marble drums in the Parthenon and the tall assembly of timber elements in five-storied Japanese pagodas are summarized as; 1) comparatively large damping effect at the joints with high non-linearity, 2) conspicuous improvement in shearing resistance produced by the dowels connecting the elements; and 3) generation of a restitutive force produced by the rocking movement of columns. Taking these factors into account, dynamic analyses have been carried out to examine the earthquake resistant capacity against the anticipated ground motions for a return period of 1000 years. Transactions on the Built Environment vol 39 © 1999 WIT Press, www.witpress.com, ISSN 1743-3509 292 Structural Studies, Repairs and Maintenance of Historical Buildings

Cracks In Historic Masonry Walls Due ToSettlement - Experiments And MechanicalModelling

Many walls -of brick or natural stoneof buildings exhibit cracks through the entire thickness of wall. Such cracks are often caused by historic and also by recent differential settlement along the base of wall. Thereby, restraint actions arise in the wall, which are the response to the interaction of the wall with the foundation and ground. In many cases, the causes of cracks must be clarified in order to assess the load carrying capacity of the damaged wall and to decide on eventual structural repair. On the other hand, the possibility of future cracks must be known if additional settlement is to be expected, if repair of foundations and consolidation of ground are to be planned etc. For such tasks, the development of a predictive mechanical model of the interaction is necessary. This report presents first results of this problem. Wall strips of single and triple leaf natural stone masonry were built for experiments (L:H:D = 4.5 nr.l.O m:0.45 m). In a heavy test set-up, a hollow with a bending radius of R ~ 400 m was forced upon the specimen. Forces, deformations and cracks were measured, fracture phenomena were observed. The mechanical model includes the description of the critical settlements and the leading to cracks structural behaviour of masonry walls in bending and shear. Furthermore, strengthening measures and their effects on the behaviour are considered in the model. Transactions on the Built Environment vol 39 © 1999 WIT Press, www.witpress.com, ISSN 1743-3509 750 Structural Studies, Repairs and Maintenance of Historical Buildings

On Lines Of Thrust And Stability Of MasonryArches

The use of lines of thrust to asses the stability of masonry arches, has became very popular on last years. Nevertheless, this form of analysis can be not sure in some cases. The real requirement for the stability of arches is that excentricity of normal forces lies into the depth of the arch. It has been proposed that the same is true for lines of thrust. This paper shows that in many instances the latter is not the necessary condition. 1. The general principles of the stability of masonry As it is well known, a cracked masonry structure can support a bending moment M if an axial force N acts simultaneously. As it can be shown in figure 1. compressions due to normal force form a pair with this force. A' • d. that counteracs bending moment. Transactions on the Built Environment vol 26, © 1997 WIT Press, www.witpress.com, ISSN 1743-3509 170 Structural Studies, Repairs and Maintenance of Historical Buildings h o we can express the equilibrium as: