Joint Layout Design: Finding the Strongest Connections within Segmental Masonry Arched Forms

Segmental arched forms composed of discrete units are among the most common construction systems, ranging from historic masonry vaults to contemporary precast concrete shells. Simple fabrication, transport, and assembly have particularly made these structural systems convenient choices to construct infrastructures such as bridges in challenging environmental conditions. The most important drawback of segmental vaults is basically the poor mechanical behaviour at the joints connecting their constituent segments. The influence of the joint shape and location on structural performances has been widely explored in the literature, including studies on different stereotomy, bond patterns, and interlocking joint shapes. To date, however, a few methods have been developed to design optimal joint layouts, but they are limited to extremely limited geometric parameters and material properties. To remedy this, this paper presents a novel method to design the strongest joint layout in 2D arched structures while allowing joints to take on a range of diverse shapes. To do so, a masonry arched form is represented as a layout of potential joints, and the optimization problems developed based on the two plastic methods of classic limit analysis and discontinuity layout optimization find the joint layout that corresponds to the maximum load-bearing capacity.

Overlapping Perspectives

<p>All urban sites around the world have their own unique, evolving historical identity. However, this identity can often become obscured, or even lost, over time due to the progressive changes that occur to the transforming urban context. An urban site's evolution may include newly reclaimed land, conflicting grid alignments as new roads are added, new buildings being constructed that fail to reaffirm site identity in relation to existing conditions and historic buildings that become re-purposed with a subsequent loss of their original architectural identity. The site selected for this design research investigation is Queens Wharf in Wellington. Located in the heart of New Zealand's capital city, where land meets sea at the center line of the city's skyline, Queens Wharf occupies one of the most important sites in the capital. However, the principal problem of this site is its lack of coherent place identity. This problem has arisen in relation to five main factors: 1) very large, anonymous new metal shed buildings have been added in poor relationships with historic masonry and timber ones; 2)heritage buildings have been re-purposed, and their interior programmes are no longer represented by their architectural facades; 3) enormous, contemporary, and very unattractive buildings such as the TSB Arena house programmes that change throughout the year, preventing the exterior architecture from providing identity to what is happening within; 4) a confluence of conflicting grids has developed over time at this site; and 5) Queens Wharf's important location at the edge of city and sea near the center line of the city's skyline provides a significant opportunity for this site to act as a visual gateway to the capital city, but this opportunity remains unfulfilled. The thesis proposes that architecture can play an essential role in establishing place identity for Queens Wharf by: 1) implicating historic architectural features into new architectural interventions – so that the historic buildings are fundamentally important to understanding the new and vice versa – by integrating the new and the old in ways that present all the stages of the site’s evolution as important chapters in its overall tale; 2) exposing interior programmes to the outside to establish architectural identity through programmatic visibility; 3) establishing new architectural interventions as 'pivots' to help make sense of conflicting grid alignments; 4) arranging architectural interventions as a framing device and an important liminal threshold between the opposing conditions of land and sea.</p>

Overlapping Perspectives

<p>All urban sites around the world have their own unique, evolving historical identity. However, this identity can often become obscured, or even lost, over time due to the progressive changes that occur to the transforming urban context. An urban site's evolution may include newly reclaimed land, conflicting grid alignments as new roads are added, new buildings being constructed that fail to reaffirm site identity in relation to existing conditions and historic buildings that become re-purposed with a subsequent loss of their original architectural identity. The site selected for this design research investigation is Queens Wharf in Wellington. Located in the heart of New Zealand's capital city, where land meets sea at the center line of the city's skyline, Queens Wharf occupies one of the most important sites in the capital. However, the principal problem of this site is its lack of coherent place identity. This problem has arisen in relation to five main factors: 1) very large, anonymous new metal shed buildings have been added in poor relationships with historic masonry and timber ones; 2)heritage buildings have been re-purposed, and their interior programmes are no longer represented by their architectural facades; 3) enormous, contemporary, and very unattractive buildings such as the TSB Arena house programmes that change throughout the year, preventing the exterior architecture from providing identity to what is happening within; 4) a confluence of conflicting grids has developed over time at this site; and 5) Queens Wharf's important location at the edge of city and sea near the center line of the city's skyline provides a significant opportunity for this site to act as a visual gateway to the capital city, but this opportunity remains unfulfilled. The thesis proposes that architecture can play an essential role in establishing place identity for Queens Wharf by: 1) implicating historic architectural features into new architectural interventions – so that the historic buildings are fundamentally important to understanding the new and vice versa – by integrating the new and the old in ways that present all the stages of the site’s evolution as important chapters in its overall tale; 2) exposing interior programmes to the outside to establish architectural identity through programmatic visibility; 3) establishing new architectural interventions as 'pivots' to help make sense of conflicting grid alignments; 4) arranging architectural interventions as a framing device and an important liminal threshold between the opposing conditions of land and sea.</p>

Analysis of Tram Traffic-Induced Vibration Influence on Earthquake Damaged Buildings

The Zagreb 2020 earthquake severely damaged the historic centre of the city. Most of the damage occurred on historic masonry residential buildings, many of which are situated very close to the tram track. Although traffic-induced vibrations generally do not affect surrounding buildings, they can be harmful to buildings damaged by a previous earthquake. Vibrations could contribute to the further propagation of existing cracks. The effect of vibrations depends on many factors, one of the most important being the distance between the track and the building. The vibrations are highest at the source, and the energy loss occurs due to transfer through the soil to the recipients. The impact of tram-induced vibrations on earthquake-damaged buildings in the city of Zagreb is investigated in this paper. The analysis is conducted on a tramway network scale to identify critical locations by performing continuous monitoring on the tramway network and risk analysis based on the distance of buildings from the track, vibration amplitude at source, and building damage. Further investigation is based on the level of buildings to evaluate the influence of vibrations on actual buildings damaged in the Zagreb earthquake. Based on detailed signal analysis, the vibration characterization is performed, and the influence on damaged masonry buildings is evaluated.

Sustainability considerations in remediation, retrofit, and seismic upgrading of historic masonry structures

This paper addresses the problem of sustainability in remediation, retrofit, and seismic upgrading of historic masonry structures. Different rehabilitation techniques and some successful applications throughout the Balkans and Italy are described, with particular emphasis to the shear reinforcement of wall panels. The selected techniques aim at improving the seismic performance, preserving the structures for future generations, having the least impact in altering the architectural and heritage values, as well as being sustainable, in terms of reduced carbon dioxide emissions, reversibility, and low energy consumption. The use of cross-laminated timber (CLT), natural fibers, and fiber-reinforced Polymers (FRP) jacketing with natural lime coatings are discussed. The paper concludes by summarizing key successes of the proposed rehabilitation solutions in conservation engineering and suggests areas in which these could be used with great advantage.

Estimation of Mechanical Properties and Mass Density of Al-Malwiya Masonry

This paper presents the first estimation for the mechanical properties and the mass density of the masonry of Al-Malwiya heritage minaret. Many approaches are investigated in order to estimate the modulus of elasticity, shear modulus, Poisson’s ratio, and the mass density for this historic masonry. The mechanical properties are estimated by using empirical formulas and analytical equations, while the mass density is estimated after carrying out experimental tests for the extracted samples of the historic mortar. The estimated properties showed relatively low values compared with the newly constructed masonries, but they were interpreted as reasonable for such a historic construction.