Selected Assessment and Retrofitting Application Techniques for Historical Unreinforced Masonry Buildings

2015 ◽  
pp. 525-545 ◽  
Author(s):  
Yavuz Yardım ◽  
Enea Mustafaraj
Keyword(s):  
Laser Scanner ◽  
Fem Analysis ◽  
Structural Behavior ◽  
Masonry Buildings ◽  
Historical Structures ◽  
Structural Problems ◽  
Structural Resistance ◽  
Application Techniques ◽  
Earthquake Vulnerability ◽  
Static And Dynamic Loads

This chapter includes application of recent research on the repair and strengthening of historical structures and provides a structural assessment of five historical mosques in Albania. Apart from visual inspection, terrestrial laser scanner (TLS) data are used to analyze the historical structures. The FEM analysis conducted in SAP2000 aims to investigate the structural behavior of the undamaged model under static and dynamic loads. Stress concentration and mode period results have a considerable difference, which highlights earthquake vulnerability and changes the strategy of possible retrofitting. As a result, possible practical solutions for the structural problems based on previous research and enhancement of the existing structural resistance are suggested.

scholarly journals Effects of soil settlement and deformed geometry on a historical structure

2013 ◽  
Vol 1 (5) ◽  
pp. 5911-5934 ◽  
Author(s):  
Y. Yardım ◽  
E. Mustafaraj
Keyword(s):  
Laser Scanning ◽  
Laser Scanner ◽  
Repair Process ◽  
Stress Concentrations ◽  
Historical Structures ◽  
Damage Repair ◽  
Accurate Definition ◽  
Earthquake Vulnerability ◽  
Soil Settlement ◽  
Definition Of

Abstract. Protecting the historic character of a valued structure during the assessment and damage repair process is a very challenging task for many engineers. Heritage protection is complicated by a lack of design details and restrictions on sample extraction needed to obtain accurate material properties and limited studies on the restoration of certain types of historical structures. This study aims to assess the effects of soil settlement on a structure's stress concentrations and the value of laser scanning techniques on structure analysis in obtaining correct data of settlement vs. deformation. Terrestrial laser scanner (TLS) data are used to analyse the 500 yr-old historical structure of Naziresha's Mosque. The obtained TLS data allow an accurate definition of the imperfect geometry patterns lying on every side of the structure. The soil profile and general crack formation together with TLS measurement proves that the structure deformed toward the south façade, where a railway and motorway are also located. Stress concentration and mode period results have a considerable difference, which highlights earthquake vulnerability and failure mechanisms and changes the strategy of possible retrofitting.

scholarly journals Effects of soil settlement and deformed geometry on a historical structure

2015 ◽  
Vol 15 (5) ◽  
pp. 1051-1059 ◽  
Author(s):  
Y. Yardım ◽  
E. Mustafaraj
Keyword(s):  
Laser Scanning ◽  
Laser Scanner ◽  
Repair Process ◽  
Stress Concentrations ◽  
Historical Structures ◽  
Damage Repair ◽  
Accurate Definition ◽  
Earthquake Vulnerability ◽  
Soil Settlement ◽  
Definition Of

Abstract. Protecting the historical character of a valued structure during the assessment and damage repair process is a very challenging task for many engineers. Heritage protection is complicated by a lack of design details and restrictions on sample extraction needed to obtain accurate material properties and limited studies on the restoration of certain types of historical structures. This study aims to assess the effects of soil settlement on a structure's stress concentrations and the value of laser scanning techniques on structure analysis in obtaining correct data of settlement vs. deformation. Terrestrial laser scanner (TLS) data are used to analyse the 500-year-old historical structure of Naziresha's Mosque. The obtained TLS data allow an accurate definition of the imperfect geometry patterns lying on every side of the structure. The soil profile and general crack formation together with TLS measurement proves that the structure deformed toward the south façade, where a railway and motorway are also located. Stress concentration and mode period results have a considerable difference, which highlights earthquake vulnerability and failure mechanisms and changes the strategy of possible retrofitting.

scholarly journals Use of a Wearable Mobile Laser System in Seamless Indoor 3D Mapping of a Complex Historical Site

2018 ◽  
Vol 10 (12) ◽  
pp. 1897 ◽  
Author(s):  
Andrea di Filippo ◽  
Luis Sánchez-Aparicio ◽  
Salvatore Barba ◽  
José Martín-Jiménez ◽  
Rocío Mora ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Laser System ◽  
Laser Scanner ◽  
Terrestrial Laser Scanning ◽  
3D Models ◽  
3D Mapping ◽  
Interior Space ◽  
Structural Problems ◽  
Heritage Building ◽  
Terrestrial Photogrammetry

This paper presents an efficient solution, based on a wearable mobile laser system (WMLS), for the digitalization and modelling of a complex cultural heritage building. A procedural pipeline is formalized for the data acquisition, processing and generation of cartographic products over a XV century palace located in Segovia, Spain. The complexity, represented by an intricate interior space and by the presence of important structural problems, prevents the use of standard protocols such as those based on terrestrial photogrammetry or terrestrial laser scanning, making the WMLS the most suitable and powerful solution for the design of restoration actions. The results obtained corroborate with the robustness and accuracy of the digitalization strategy, allowing for the generation of 3D models and 2D cartographic products with the required level of quality and time needed to digitalize the area by a terrestrial laser scanner.

scholarly journals Further refinement of the Corbelling Theory for the equilibrium analysis of corbelled domes

2019 ◽  
Vol 6 (1) ◽  
pp. 30-40
Author(s):  
Aguinaldo Fraddosio ◽  
Nicola Lepore ◽  
Mario Daniele Piccioni
Keyword(s):  
Laser Scanner ◽  
Equilibrium Analysis ◽  
Structural Safety ◽  
Structural Behavior ◽  
Thick Shell ◽  
Starting Point ◽  
Further Development ◽  
Load Conditions

Abstract The aim of this paper is to present a further development of the Corbelling Theory [1] for assessing the structural safety of “false domes” constructions like Trulli, and more generally for corbelled domes. In particular, it is well-known that a corbelled dome of a Trullo is a layered thick shell and that only the thin inner layer (candela) has a structural role. The proposed procedure extends the capabilities of the approach proposed in [2] to more general load conditions, including the infill. The effectiveness of the proposed approach is discussed through the analysis of a paradigmatic case study of a Trullo located in Alberobello. Since the geometry of the construction plays a fundamental role in the structural behavior, the starting point of the analysis was an accurate 3D-laser scanner survey of the dome. The obtained results give some interesting insights about the role of the infill load on the equilibrium of such kind of corbelled domes.

Turbine Blade Distortion after Heat Treatment: Preliminary Experimental Investigation and FEM Analysis

2019 ◽  
Vol 827 ◽  
pp. 98-103
Author(s):  
F. de Bona ◽  
Alex Lanzutti ◽  
G. Lucacci ◽  
Luciano Moro ◽  
Jelena Srnec Novak
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Material Properties ◽  
Turbine Blades ◽  
Laser Scanner ◽  
Fem Analysis ◽  
Element Model ◽  
Diffusional Creep ◽  
High Temperature Treatment ◽  
Temperature Phase

During the production process, turbine blades are subjected to a solubilization heat treatment, followed by tempering treatment, in order to obtain better mechanical properties. It is observed that, in some cases, permanent distortion can occur during the high temperature treatment (austenitising temperature). In this work, a high temperature creep resisting steel blade with a simplified geometry is considered. A finite element model is developed considering: the material properties depending on temperature, phase transformation and viscoplasticity (Nabarro-Herring and bilinear kinematic models). A nonlinear transient thermo-mechanical analysis is performed to simulate a standard thermal cycle. Material properties are partially calibrated based on dilatometric tests and partially from data available in literature. Adopting a laser scanner system, the blades geometry is measured before and after the heat treatment to calculate the permanent deflection. Comparing numerical results with experiments, it has been observed that the distortion phenomenon is mainly affected by the low-stress diffusional creep. This effect is due to the fact that, during the heat treatment, the blade is held at high temperature for a relatively long time according to a particular supporting lay-out. To minimize the permanent distortion, the numerical model permits an appropriate supporting system to be set-up, whose validity has been confirmed experimentally.

scholarly journals Robust Design Optimization for Low-Cost Concrete Box-Girder Bridge

Mathematics ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 398 ◽  
Author(s):  
Vicent Penadés-Plà ◽  
Tatiana García-Segura ◽  
Víctor Yepes
Keyword(s):  
Design Optimization ◽  
Robust Design ◽  
Computational Cost ◽  
Robust Design Optimization ◽  
Structural Behavior ◽  
Uncertain Parameters ◽  
Box Girder ◽  
Structural Problems ◽  
Concrete Box Girder ◽  
High Computational Cost

The design of a structure is generally carried out according to a deterministic approach. However, all structural problems have associated initial uncertain parameters that can differ from the design value. This becomes important when the goal is to reach optimized structures, as a small variation of these initial uncertain parameters can have a big influence on the structural behavior. The objective of robust design optimization is to obtain an optimum design with the lowest possible variation of the objective functions. For this purpose, a probabilistic optimization is necessary to obtain the statistical parameters that represent the mean value and variation of the objective function considered. However, one of the disadvantages of the optimal robust design is its high computational cost. In this paper, robust design optimization is applied to design a continuous prestressed concrete box-girder pedestrian bridge that is optimum in terms of its cost and robust in terms of structural stability. Furthermore, Latin hypercube sampling and the kriging metamodel are used to deal with the high computational cost. Results show that the main variables that control the structural behavior are the depth of the cross-section and compressive strength of the concrete and that a compromise solution between the optimal cost and the robustness of the design can be reached.

The Vulnerability Assessment of Historical Masonry Buildings Against Earthquakes by the Modified Equivalent Frame Method

2010 ◽  
Vol 133-134 ◽  
pp. 735-740
Author(s):  
Faramarz Alemi ◽  
Peyman Homami ◽  
Mahmood Golabchi ◽  
Mohsen Akbarian
Keyword(s):  
Vulnerability Assessment ◽  
Failure Modes ◽  
Element Model ◽  
Masonry Structure ◽  
Masonry Buildings ◽  
Shell Elements ◽  
Historical Structures ◽  
Equivalent Frame ◽  
Practical Reality ◽  
Frame Method

Insufficient ductility and lack of integrity have caused extensive damages and undesirable responses in masonry buildings in past earthquakes. These types of structures are distributed all over Iran and the vulnerability assessment of such structure is one of the main concerns between structural engineers. Developing an advance finite element model to simulate the behaviour of a masonry structure is a very complicated procedure which may not be practical and applicable in most cases, so many attempts have been performed to find simple methods for analysing these structures. The Equivalent Frame Method is one of the well-known methods which is rather simple and could be used for vulnerability assessment of some historical structures like Iranian caravanserais. The architectural configurations of Iranian caravanserais were regular and symmetric. When the arrangement of walls and openings are modular it is convenient to model the piers and spandrels as a frame type columns and beams. The simplicity of the conventional Equivalent Frame Method sometime leads to an inaccuracy of the assessment, therefore some modification for the upgrading of this method has been proposed. Using the shell elements beside the frame elements in a modelling procedure may eliminate some disadvantages of the conventional Equivalent Frame Method. In this study a modification has been proposed to improve the upgraded Equivalent Frame Method ability in predicting the failure modes of the masonry walls such as, toe crashing. The proposed modification has been used in the static nonlinear analysing of a masonry structure by the Equivalent Frame Method. The given results have acceptable reconciliation with practical reality and it seems to be useful, especially in a rapid assessments.

Influence of Modal Coupling on the Nonlinear Dynamics of Augusti’s Model

2011 ◽  
Vol 6 (4) ◽  
Author(s):  
Diego Orlando ◽  
Paulo B. Gonçalves ◽  
Giuseppe Rega ◽  
Stefano Lenci
Keyword(s):  
Nonlinear Behavior ◽  
Dynamic Responses ◽  
Phase Portraits ◽  
Modal Interactions ◽  
Structural Problems ◽  
Lumped Parameter ◽  
Modal Coupling ◽  
Post Buckling ◽  
Static And Dynamic Loads

The nonlinear behavior and stability under static and dynamic loads of an inverted spatial pendulum with rotational springs in two perpendicular planes, called Augusti’s model, is analyzed in this paper. This 2DOF lumped-parameter system is an archetypal model of modal interaction in stability theory representing a large class of structural problems. When the system displays coincident buckling loads, several post-buckling paths emerge from the bifurcation point (critical load) along the fundamental path. This leads to a complex potential energy surface. Herein, we aim to investigate the influence of nonlinear modal interactions on the dynamic behavior of Augusti’s model. Coupled/uncoupled dynamic responses, bifurcations, escape from the pre-buckling potential well, stability, and space-time-varying displacements; attractor-manifold-basin phase portraits are numerically evaluated with the aim of enlightening the system complex response. The investigation of basins evolution due to variation of system parameters leads to the determination of erosion profiles and integrity measures which enlighten the loss of safety of the structure due to penetration of eroding fractal tongues into the safe basin.

scholarly journals DEFORMATION MEASUREMENT USING TERRESTRIAL LASER SCANNER FOR CULTURAL HERITAGE

2016 ◽  
Vol XLII-2/W1 ◽  
pp. 89-93 ◽  
Author(s):  
M. O. Selbesoglu ◽  
T. Bakirman ◽  
O. Gokbayrak
Keyword(s):  
Cultural Heritage ◽  
Natural Hazards ◽  
Real World ◽  
Laser Scanner ◽  
Essential Element ◽  
High Accuracy ◽  
Cylindrical Part ◽  
Terrestrial Laser Scanner ◽  
Historical Structures ◽  
Digital Documentation

Historical structures are one of the most essential element of cultural heritage. They reflect history, lifestyle and tradition of a country and society. However, they are damaged through the years due to human activities and natural hazards. Therefore, digital documentation of structures and monuments is critical for preservation, sustainability and protection of cultural heritage. Terrestrial laser scanner is a widespread used tool for obtaining 3D representation of real world. In this study, we aimed to measure deformation of deformed minaret of a historical mosque using terrestrial laser scanner. In order to represent the geometry of the deformed minaret with high accuracy, 31 horizontal sections were created from the transition segment to the spire of the minaret with 30 cm intervals. The changing curvatures of the minaret were analysed in three parts; cylindrical part, balcony part and upper part. The offsets from the vertical axes for the parts of the minaret were found as 10.14 cm, 13.97 cm and 16.51 cm, respectively.

Sign in / Sign up

Export Citation Format

Share Document