In-plane strengthening of masonry buildings with timber panels

Abstract

The in-plane strengthening of masonry walls plays a key role in the improvement of the global seismic behaviour of masonry buildings. Various strengthening techniques are currently available, such as coatings, confinement or injection and the use of cement-based materials or steel- or fibre-reinforced polymers or mortars. In this work, two innovative strengthening techniques for existing masonry buildings were investigated: the use of glued or nailed timber wall panels connected to the outer and/or inner face of the masonry wall. Their effectiveness in reducing the seismic vulnerability of existing masonry walls was assessed in tests and numerical simulations. The test results demonstrated improvements in strength, rocking displacement capacity and energy dissipation capacity. The numerical analyses, conducted with non-linear models calibrated on experimental results available in the literature, confirmed the advantages of these interventions, comparing the effects of using monolithic or coupled glued or nailed wall panels, provided that particular attention is given to their connection to the existing structure.

Seismic Strengthening of Existing Urm Structures Through CLT Elements: Numerical Analysis of the Application of a Novel Intervention Technique

“…The connection system plays a crucial role in the intervention, having to transmit actions from one system to the other and to provide ductility and resistance. However, studies proved that coupling at floors levels, without specific URM-CLT diffused connectors, is enough for shear and displacement capacities improvement of a URM wall [4].…”

“…Those characteristics make the CLT an efficient and versatile element, which use has spread largely in recent years. CLT products are widely used for new buildings, but in recent years are also gaining attention for the retrofit of existing buildings [4][10] [13][14].…”

“…One of the most acknowledged intervention consists in coupling CLT panels to masonry walls, thus providing benefits on structural, energetical and architectural fields [6][15]. In this framework, two main approaches can be adopted, depending on the location of CLT reinforcement panels, at the exterior or interior of walls [4] [14], as shown in Figure 1.…”

“…The intervention described in this paper is addressed to existing URM buildings which need an improvement in terms of structural-seismic capacity, functionality and energetic performances. Based on the effectiveness of URM-CLT coupling walls for shear capacity [4] [5] and energetic performances improvement [6], such as the benefits of stiffened timber diaphragms [7][8], an integrated intervention aimed at the insertion of a CLT endoskeleton within a URM structure was designed.…”

Numerical Study on Seismic Retrofit of Urm Walls Using Timber Panels

“…A detailed description of this retrofit solution and the outcomes of numerical simulations were provided by Giongo et al [1] while the effectiveness of this retrofit technique was experimentally investigated by Giongo et al [2] via onsite testing of masonry shear walls strengthened with timber panels. Further experimental evidence on walls retrofitted with timber panels and timber-to-masonry connections can be found in Borri et al [3], Pozza et al [4], Riccadonna et al [5] and Rizzi et al [6].…”