Leaning Tower Research Articles

The Leaning Tower of Pisa and the smartphone of the post-tourist

Photograph by J.-F. Staszak. July 2013 We are in front of the Leaning Tower of Pisa, an iconic building if there ever was one. Many tourists are taking pictures: of the structure, of course, but also of themselves in front of it. It isn’t however a matter of the classic photograph, where one poses full-faced, smiling at the camera, with one’s back to the monument, nor of its modality, the ‘selfie’. Rather, it concerns playing with linear perspective—right there where it was invented in the ...

A quantum test of free fall

Physics![Figure][1] The Leaning Tower of Pisa, Italy PHOTO: © STEFANO POLITI MARKOVINA/ALAMY STOCK PHOTO Galileo Galilei is purported to have dropped objects of different mass from the Leaning Tower of Pisa to demonstrate that they fall at the same rate. In formulating his general theory of relativity, Einstein described this as the universality of free fall—that all objects, irrespective of their mass, will behave identically when subject to the same gravitational field. Taking this into the quantum regime, Duan et al. performed Galileo's drop experiment with rubidium atoms of different quantum mechanical spins. With a sensitive atom-interferometer setup, they showed that the atoms fall at the same rate to within one part in 10 million, upholding Einstein's universality proposition for now. While we await a theory that can unify relativity and the principles of quantum mechanics, such precision-based experimental tests should help place bounds on any proposed theories of quantum gravity. Phys. Rev. Lett. 117 , 023001 (2016). [1]: pending:yes

Behavior of the Leaning Tower of Pisa: Analysis of Experimental Data from Structural Dynamic Monitoring

Understanding the structural behavior of heritage buildings is usually a very complicated task because they typically present complex deterioration and damage patterns which cannot be fully evaluated by means of visual inspections. Moreover, the reliability of such constructions largely depends on different materials, structural components and details, the health of which is often unknown or affected by great uncertainties. In this regard, the experimental dynamic testing of heritage buildings and monuments subjected to ambient vibrations has become a valuable tool for their assessment because of the minimum interference with the structure. Traffic-induced vibrations are not always a feasible dynamic load for monumental buildings due to their very low intensity or owing to existing restrictions to road and rail traffic. On the other hand, the analysis of the experimental response under earthquakes can lead to more relevant information about the dynamic behavior of historic constructions, provided that the structure is equipped with a permanent sensor network. Within this framework, the present work illustrates preliminary results carried out from time and frequency domain analyses performed on the experimental dynamic response of the leaning tower of Pisa using seismic records. The main dynamic features of the monument have been identified, and then examined taking into account the seismic input and the soil-foundation-structure interaction.

Behavior of the Leaning Tower of Pisa: Insights on Seismic Input and Soil-Structure Interaction

The most recent studies about the seismic behavior of the leaning Tower of Pisa that consider the soil-foundation-structure interaction date back to twenty years ago. From 1999 to 2001, the foundation of the monument was consolidated by means of under-excavation and the "Catino" at the basement was rigidly connected to the foundation. Meanwhile, significant progresses have been made in the field of earthquake engineering. Therefore, the need exists to assess the dynamic behavior of the Tower in light of the novelties occurred in the past decades. In the present study, the mechanical characteristics of the foundation have been calibrated comparing the outcomes of the experimental dynamic monitoring with the results of the finite element analysis performed on a simple but effective model. The scenario earthquakes for return periods equal to 130 years and 500 years are also presented.

Observation-guided constitutive modelling for creeping landslides

Creeping landslides are common in mountainous areas, causing significant damage to buildings and infrastructure. The major difficulty in modelling of these landslides is the inability of laboratory tests to reproduce adequately the macro behaviour in the creeping soil masses. The proposed approach of observation-guided constitutive modelling addresses this issue by considering a creeping landslide as a series of macro elements, where monitoring of displacements and pore water pressures allows the derivation of suitable constitutive models and their parameters. The paper proposes three generalised models describing the behaviour of pore water pressures, sliding layer and slip surface, which can be adapted to fit the observational data. The three models are integrated into the boundary value problem, the solution of which helps to explain the evolution of the landslide and to predict its future behaviour using probabilistic approaches. When applied to the St Moritz-Brattas landslide in Switzerland, the calibrated landslide models proved to be successful in describing the complex behaviour of all three distinctive regions of the landslide. The paper also explores possible ways for predicting the landslide reaction to extreme rains and forecasting the long-term displacement evolution in the vicinity of the Leaning Tower of St Moritz, which will be critical for planning its future stabilisation.

Risperidone Induced Pisa Syndrome in a Male Adolescent.

Pisa syndrome, a rare dystonic reaction resulting from prolonged exposure to antipsychotic medications, is characterized by persistent dystonia of trunk muscles and abnormal posture. It is called Pisa syndrome, because the abnormal posture resembles the Leaning Tower of Pisa. Different from other types of dystonic reactions, Pisa syndrome is more prevalent in females and in older patients with organic brain changes. A 15-year-old male patient with mental retardation was admitted to pediatric neurology clinic for the complaint of abnormal posturing. He had been taking only risperidone for the last four years. Over the last month, the patient gradually developed tonic flexion of trunk and head toward left and was diagnosed with Pisa syndrome. In this paper, we aimed to discuss the association between risperidone use and Pisa syndrome in light of the available literature.

The Star Wars Scroll Illusion.

The Star Wars Scroll Illusion is a dynamic version of the Leaning Tower Illusion. When two copies of a Star-Wars-like scrolling text are placed side by side (with separate vanishing points), the two scrolls appear to head in different directions even though they are physically parallel in the picture plane. Variations of the illusion are shown with one vanishing point, as well as from an inverted perspective where the scrolls appear to originate in the distance. The demos highlight the conflict between the physical lines in the picture plane and perspective interpretation: With two perspective points, the scrolling texts are parallel to each other in the picture plane but not in perspective interpretation; with one perspective point, the texts are not parallel to each other in the picture plane but are parallel to each other in perspective interpretation. The size of the effect is linearly related to the angle of rotation of the scrolls into the third dimension; the Scroll Illusion is stronger than the Leaning Tower Illusion for rotation angles between 35° and 90°. There is no effect of motion per se on the strength of the illusion.

Monitoring leaning towers by geodetic approaches: effects of subsidence and earthquake to the Ghirlandina Tower

Summary The research focuses on structural monitoring and movements identification applied to cultural heritage protection. The final purpose is the integration among different and independent technologies for analyzing and investigating the geometry changing over time of ancient leaning towers. The paper deals with a novel strategy implemented to compute differential vertical displacements starting from results obtained by repeated high-precision leveling network adjustments. These results usually aim at monitoring the subsidence phenomenon, while their use in engineering applications is more or less absent in literature. Moreover, the multidisciplinary approach is also able to analyze subsidence gradients in order to extrapolate the trend of the vertical axis and compute structure's rotations. The approach is applied to the Ghirlandina Tower, Modena (Italy), in order to identify the leaning and the subsidence trend. About 30 years of leveling campaigns provide a useful dataset to test the methodology, which is finally validated by the independent observations collected by a pendulum. The approach allows to compute the mean total displacement since 1984 of about 4.7 cm with 30% occurring over the last 6 years. In the same period, the total overhang of the tower (1.30 m in 2007) increased by about 19.1 and 10.4 mm towards southwest. The approach is also able to identify anomalous behavior of the tower such as the reversal tilting trend due to the scaffolding in the years of restoration and the permanent deformation suffered after the 2012 Emilia Romagna earthquake (failure of 4 mm in 6 months). Copyright © 2015 John Wiley & Sons, Ltd.

Representations of Truth

Katherine Anne Porter submitted a group of stories called “Legend and Memory” to The Atlantic Monthly in 1934, but instead of the reception she hoped for, The Atlantic Monthly responded with a request for significant revisions. These recommendations, as Porter adamantly explained, would change the collective meaning of the stories. And yet, Porter ultimately chose to concede, publishing the stories separately in other magazines before finally collecting them together again in The Leaning Tower and Other Stories (1944). Over the next twenty years, Porter would publish the stories (later called The Old Order stories) in two more collections— The Leaning Tower and Other Stories, The Old Order: Stories of the South from The Leaning Tower, Pale Horse, Pale Rider, and Flowering Judas and The Collected Stories of Katherine Anne Porter. Each time she chose not to edit individual stories but rearranged the order of the stories. Individually, each story is like a sketch, or one component of the protagonist Miranda’s construct of identity from the perspective of an adult looking backward and remembering as a child. And yet collectively, these stories reveal memory’s process of reconstruction and how the perspective of time transforms event through addition, elimination, and arrangement. Using text, correspondence, manuscripts, and cognitive research to examine the progression of Porter’s work on The Old Order stories in three collections over more than thirty years, “Representations of Truth: The Significance of Order in Katherine Anne Porter’s The Old Order Stories” traces the progressive ordering of these stories from their original submission to their final collection in The Collected Stories of Katherine Anne Porter (1965). This essay argues that Porter’s rearrangements reflect a reconstructive process of memory. Over time, the reorganization of The Old Order stories demonstrate a shift in Miranda’s memories from a chronological positioning to a representational ordering, allowing Miranda to reexamine her perspective on past experiences.

Comparison of natural and artificial forcing to study the dynamic behaviour of bell towers in low wind context by means of ground-based radar interferometry: the case of the Leaning Tower in Pisa

The study of Cultural Heritage assets needs the application of non-destructive and non-invasive monitoring techniques. In particular, monuments and historical buildings which are open to the visitors and/or subject to important stress must be studied for their dynamic response. In the last 10 years the new ground-based radar interferometry technology has been developed allowing to monitor displacements from a point of sight far from the studied targets. It virtually provides a continuous mapping of displacements of the observed structures up to 10 µm with a range resolution of 0.75 m. In this paper, the application of ground-based interferometry on one very important historical building, the Leaning Tower of Pisa in Italy, is reported. The analysis of these kind of structures is important to catch their dynamic response to natural actions in general, and also to assess the effects due to pedestrian and users, and consequently to define functional capabilities and levels of acceptable dynamic stress. The studied structure was subject to artificial loading by synchronous movement of about 20 people. Artificial forcing led the structure to a resonance condition with the same frequency of the one due to the natural noise excitation, which was separately measured, and with an oscillation amplitude more than thirty times greater than the natural one (in conditions of weak wind). During the passive stages of the survey the recorded structural vibrations were very closed to the instrumental sensitivity, making difficult to distinguish vibration amplitudes amplifications of various segments at various heights. Through the spectral analysis of the acquired data it was possible to estimate the vibration frequencies of the first modal shapes of the structure along two orthogonal directions. The power spectra of the passive survey data have the same maximum frequency of the active but contain more noise at low frequency.

‘Two hundred ninety‐four’: Remediation and multimodal performance in tourist placemaking

We offer here a multimodal discourse analysis of a range of verbal (writing and speech), nonverbal (movement and gesture) and technological (photography and video) resources used by tourists at the Leaning Tower of Pisa. In doing so, we pin‐point the recycling and layering of mediatized representations (e.g. guidebooks and official brochures), mediated actions (e.g. climbing the Tower or posing in front of it), and remediated practices (e.g. posting a YouTube video of oneself climbing the 294 steps to the top of the Tower). Through this kind of empirically‐based examination of tourists’ discursive and embodied performances – their ways of talking about and behaving in spaces – we witness how people never simply visit places but are always actively shaping and making these places. The Leaning Tower of Pisa is, therefore, as much an emergent production of the tourist imagination as it is a pre‐existing, lop‐sided construction of stone.

Role of Monitoring in Historical Building Restoration: The Case of Leaning Tower of Pisa

A short summary is presented of the studies and the actions of Committees appointed in past 50 years for the Tower of Pisa. The discussion first addresses the attempts carried out during the whole history of the Tower to measure its movements and the efforts made to understand the origin and causes of its inclination. A history of foundation rotation has been also deduced by means of a precise architectural survey, which has led to a diagnosis for the inclination and its increase in time. As a consequence, several hypotheses for its stabilization have been proposed. All the measures for leaning tower stabilization need the application of observational method for their implementation. The observational method is strictly based on a comprehensive monitoring system, both described in the second part of the paper. The aims are to stress the importance of a well-conceived monitoring system and to propose the extension of concept of monitoring to construction history details. The data and actions described are from the work carried out by committees appointed by Italian Government during the second half of 20th century, in particular by the committee chaired by Professor Jamiolkowski, appointed in 1991. The authors have collaborated with this committee since 1993, and they are still in charge of the monitoring and maintenance of the Tower of Pisa.

Galilei was Wrong: Angular Nonradial Effects of Radial Gravity Depend on Density of Matter

Although in mathematical sense the actual meaning of Galilei's experiments conducted at leaning tower of Pisa is that he failed to detect any measurable impact of composition of matter on gravitating bodies, the obvious failure is mistakenly interpreted as experimental confirmation of lack of the impact instead. Galilei did not really perform internal validity checks of his experiments, because he did not ensure that he actually measured what he was supposed to measure. However, a modern experiment devised to test the impact of large mass on gravitational phenomena has revealed presence of (formerly unanticipated) extraneous frequency decrease in rays coming from Taurus A, when they passed close to our Sun (i.e. near occultation). The experiment has effectively confirmed that density of matter of the mass source of locally dominant gravitational field (which was our Sun‟s field) affects gravitational interactions happening on equipotential surfaces surrounding gravity center of the field. Also very similar experiment involving radio waves, which too exhibited (formerly unexpected) frequency decrease when they traveled along practically equipotential surface of Earth, has reaffirmed that conclusion. Hence contrary to Galilei, effects of nonradial (i.e. tangential and/or binormal) components of radial gravitational force fields depend (inversely) on (equipotential exposure to) the, assumed as practically constant and uniformly distributed, density of matter of the mass source of the local field.

Laboratory test of the Galilean universality of the free fall experiment

There is a popular myth that Galileo dropped two objects of the same shape but different mass, noted their equal fall time, and concluded that gravitational motion is independent of the mass of the object. This paper demonstrates that this experiment—if actually performed—most likely would have yielded a different result and thus with modern eyes led to a different conclusion. The paper consists of two parts: (1) a theoretical description with a numerical and an analytical solution of the problem, and (2) an experiment of the Galilean type that provides experimental evidence within 1% accuracy that the theory applies. Previous papers on this subject have been almost exclusively theoretical and/or calculational, and we emphasize the suitability of the performed experiment as an affordable instructional exercise, e.g. for undergraduates. We find a difference in impact time of 0.109 s for otherwise nearly identical objects of masses differing by about a factor of 3, mlight = 57.52 g and mheavy = 173.62 g, dropped from a height of 23.192 m, about half of the height of the Leaning Tower of Pisa. Very convincing agreement between experiment and theory, including an account of the fluid dynamics in air, is achieved. By use of the theory thus corroborated, the calculated difference in height at first impact corresponding to the Galilean case is about 5.8 m (assuming a lead ball and an ebony ball, each the size of a tennis ball), easily detectable both visually and, with a difference in impact time of about 0.22 s, aurally. The time difference is also sufficiently large to be unlikely to be caused by inaccuracy in release time. This gives an indication that if Galileo did actually perform the experiment, he may have chosen to neglect small differences (≃10%) in impact times observed using large differences (factor ≃ 10) in mass.

Galilei was Wrong: Angular Nonradial Effects of Radial Gravity Depend on Density of Matter

Although in mathematical sense the actual meaning of Galilei's experiments conducted at leaning tower of Pisa is that he failed to detect any measurable impact of composition of matter on gravitating bodies, the obvious failure is mistakenly interpreted as experimental confirmation of lack of the impact instead. Galilei did not really perform internal validity checks of his experiments, because he did not ensure that he actually measured what he was supposed to measure. However, a modern experiment devised to test the impact of large mass on gravitational phenomena has revealed presence of (formerly unanticipated) extraneous frequency decrease in rays coming from Taurus A, when they passed close to our Sun (i.e. near occultation). The experiment has effectively confirmed that density of matter of the mass source of locally dominant gravitational field (which was our Sun‟s field) affects gravitational interactions happening on equipotential surfaces surrounding gravity center of the field. Also very similar experiment involving radio waves, which too exhibited (formerly unexpected) frequency decrease when they traveled along practically equipotential surface of Earth, has reaffirmed that conclusion. Hence contrary to Galilei, effects of nonradial (i.e. tangential and/or binormal) components of radial gravitational force fields depend (inversely) on (equipotential exposure to) the, assumed as practically constant and uniformly distributed, density of matter of the mass source of the local field.

Stability and seismic analyses of leaning towers: the case of the minaret in Jam

SUMMARYThe leaning Minaret of Jam, one of the tallest in the world, was declared as the Afghanistan's first World Heritage Site by UNESCO in 2002. The global stability analysis of the tower against soil collapse is first evaluated in the present configuration, in the hypothesis of increasing bending moment at the base section, assuming elastic‐perfect plastic behavior for the soil. Then, a finite element model is set up, which is used for the modal analysis and then for the seismic push‐over analysis, based on both single and multi‐modal approaches. Copyright © 2014 John Wiley & Sons, Ltd.

Analysis Methods of Reasonable Finished State of Space-Twisting Cable Leaning Tower Cable-Stayed Bridge

Aimed to solve the problem that the reasonable finished state (RFS) of space-twisting cable leaning tower cable-stayed bridge (SLCSB) is inconsistence with actual finished state. The numerical analysis and field test methods are used. Firstly, based on comprehensive studying of the interaction between influencing factors of the finished state and construction state, analysis methods of coupling RFS and rational construction state (RCS) are proposed with the thought of construction process control implanting into design stage. Secondly, a main span of 220m SLCSB is used as example, the coupling analysis method proposed in the paper was proved. Finally, with some data measured from actual project, it shows that: this method can ensure the cable tension, the main beam and the main tower bending moments forming RFS at the same time, while the problems of the inconsistency between RFS and one-step bridge status is solved.

Earthquakes and ancient leaning towers: Geodetic monitoring of the bell tower of San Benedetto Church in Ferrara (Italy)

Abstract In May–June 2012, several seismic events took place in the Po River Plane in northern Italy, with a maximum magnitude of M W 5.86 (M L 5.9)] and the epicentre located about 32 km from the centre of Ferrara. Many historical buildings were seriously damaged and others showed marked deformations or differential settlements. Therefore, it was necessary to place many of them under monitoring, using fast and safe measurement techniques to quickly obtain accurate information on ongoing structural deformation. This paper presents the case study of the bell tower of San Benedetto Church in Ferrara (17th century), which was already under monitoring at the time of the earthquake because of its remarkable leaning angle. Immediately after the seismic events, monitoring of the bell tower was repeated. Digital levelling indicated a marked differential settlement of the foundations with regard to the trend of secular movement, while terrestrial laser scanning (TLS) revealed a significant increase of the inclination of the tower's axis, confirming the results from levelling and showing good integration of both monitoring techniques.

The atrium as structural strategy in new skyscrapers which decline the verticality: case studies

In the last decade, a new type of high rise building has been emerging. They are leaning or undulating skyscrapers which become real architectural icons by defying the building logic that the preservation of the vertical line implies. The acceptance of this last aspect is making emerge several works of this kind signed by some of the most influential architectural firms in the world. But, do these new involve works new structural concepts or strategies that answer to their singular characters? Here, the structural solution of two examples is analyzed to identify those contributions with a structural/architectural nature that could became a base for the development of this type. The use of the atrium is recognized as one of them. An assessment based on models of its influence on the structural behavior of leaning towers is carried out.

3D map of Pisa’s Leaning Tower heralds a new era in scanning

3D map of Pisa’s Leaning Tower heralds a new era in scanning