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Effects of earthquakes associated surface ruptures on engineering structures
Published in Ömer Aydan, Earthquake Science and Engineering, 2023
As seen in the epicentral area of the 2009 L’Aquila earthquake and other earthquakes, older nonengineered dwellings made with load-bearing masonry walls supporting tiled roof or reinforced concrete slab roof. The different types of masonry are random rubble stone with mud/lime/cement mortar, small block cut stone in mud/lime/cement mortar, large block cut stone in mud/lime/cement and brick masonry in mud/lime/cement mortar. Most dwellings made of mud mortar generally either totally collapse or are heavily damaged during major earthquakes. Figure 7.2 shows several examples of the heavy damage to masonry structures with mud mortar. On the other hand, if masonry buildings are constructed using lime or cement mortar, they perform much better and the total collapses are much less as seen in the same figure. Most of the standing masonry buildings in the pictures are such structures. Especially, the use of cement mortar together with well-spaced concrete slabs improves the structural integrity of buildings. There are also hybrid-type buildings combining wooden beams and frames and masonry-type infill walls as seen in Figure 7.3.
Monitoring systems for masonry tunnels
Published in Hiroshi Yokota, Dan M. Frangopol, Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations, 2021
Alfred Strauss, Hans Neuner, Corinna Harmening, Christian Seywald, Michael Österreicher, Elisabetta Pistone
In Austria, the ÖBB-Infra AG, as infrastructure company for rail transportation, operates about 150 tunnel structures that are more than 100 years old and the majority consists of masonry tunnels. The masonry can be very different in nature and can include various types, ranging from sandstone or brick masonry to natural stone and quarry stone brickwork. Aging effects as well as effects by the operation life or the environment can trigger damages, especially in the area of the vault and of the abutments. These typically can manifest in the form of cracks (longitudinal, transverse, oblique or reticular), spalling, shuttering as well as holes and wet spots. In order to repair these damages, renovation measures of various types have to be carried out (for example, conventional vault renewal, tunnel-in-tunnels, vault renewal by full-construction or partial renewal). Depending on the depth and the profile width, potential reduction in the load-bearing capacity of the structure can occur due to masonry removing, thus making monitoring during construction indispensable.
Structural materials
Published in Angus J. Macdonald, Structure and Architecture, 2018
Masonry is a composite material in which individual stones, bricks or blocks are bedded in mortar to form columns, walls, arches or vaults (Figure 3.1). The range of different types of masonry is large due to the variety of types of constituent. Bricks may be of fired clay, baked earth, concrete, or a range of similar materials, and blocks, which are simply very large bricks, can be similarly composed. Stone too is not one but a very wide range of materials from the relatively soft sedimentary rocks such as limestone to the very hard granites and other igneous rocks. These ‘solid’ units can be used in conjunction with a variety of different mortars to produce a range of masonry types. All have certain properties in common and therefore produce similar types of structural element. Other materials such as dried mud, pisé or even unrein-forced concrete have similar properties and can be used to make similar types of structural element.
Predicting compressive strength of cement-stabilized earth blocks using machine learning models incorporating cement content, ultrasonic pulse velocity, and electrical resistivity
Published in Nondestructive Testing and Evaluation, 2023
Navaratnarajah Sathiparan, Pratheeba Jeyananthan
As masonry, and especially earth masonry, loses strength over time, appropriate care is required to maintain it in good condition. To achieve this, important factors need to be taken into account when selecting a method and materials for repairing the structure. Prior to repair, a number of tests need to be carried out to provide up to date information on the condition of the structure, the compressive strength of the CSEBs and other factors, without compromising serviceability. Non-destructive testing has been shown to be an effective way of obtaining vital details about the quality and uniformity of masonry work without causing damage. Masonry structures can be inspected and assessed using these non-destructive testing techniques without causing any damage to them. This allows masonry structures to be properly maintained and repaired, maintaining their structural integrity and safety. As a result, this work provides a methodical evaluation of the compressive strength prediction of CSEBs using non-destructive testing methods and machine learning techniques. This evaluation can help to expand the knowledge and practical applications of this subject.
Seismic Behavior of Brick Masonry Walls Strengthened with Different Types of Fiber Nets
Published in Structural Engineering International, 2022
Zongcai Deng, Minghua Chen, Minggao Gong
“Masonry structure” refers to the structure making up the main load-bearing components, like walls and columns, being bricks and mortar. Masonry structure has been the main structure of rural housing construction in many countries because it is economical and practical. Different from the infill masonry walls in reinforced concrete structures, masonry structure has high brittleness, low intensity and poor integrity, internationally recognized as a kind of building structure with relatively poor seismic performance.1 Curved elements, like arches and vaults, are common in masonry structures, and easily collapse in earthquakes. Worldwide, masonry structures still form a large proportion of rural residential and school buildings. For these buildings and some ancient masonry architectures2 with historical value, strengthening and restoring is more economical and feasible than pulling down and reconstructing. Therefore, it is of great significance to study the seismic strengthening of masonry structures.
Experimental analysis of rubble stone masonry walls strengthened by transverse confinement under compression and compression-shear loadings
Published in International Journal of Architectural Heritage, 2018
Fernando F. S. Pinho, Válter J. G. Lúcio, Manuel F. C. Baião
Rubble stone masonry is a heterogeneous material used in the construction of walls and foundations of ancient buildings. It is based on the two main materials: natural stone and hydrated air-lime mortar. The use of locally sourced stone, rubble, or stones from quarries, together with the different qualities of each type of stone, help to explain the variety of stone masonry constructions. The use of different kinds of stones, brick pieces or roof tiles, bed joints, courses, and wall cross section types result in a huge variety of masonry types, with a significant difference in the mechanical properties of the walls (Feo et al. 2016; Penna 2015). Furthermore, specific sorts of masonry walls can be found, depending on the size and shape of the stone elements (rubble, cut stone, cobblestone, etc.), their arrangement (coarse, erratic), the type of stone (sandstone, limestone, tuff, etc.), and mortar characteristics. One leaf or multiple leaf stone walls—with or (mostly) without effective connections between the leaves—may be found (Almeida et al. 2012; Gattesco and Dudine 2010), including a high percentage of voids into the inner-core (Giaretton et al. 2017). These building materials have a reasonable performance under compression (Almeida et al. 2012), but a lack of resistance to tensile stress (Appleton 2003; Milosevic et al. 2013; Psilla and Tassios 2009).