Analysis of Eduardo Torroja's Tempul Aqueduct an important precursor of modern cable-stayed bridges, extradosed bridges and prestressed concrete

[EN] This paper describes a study of the Tempul Aqueduct, one of the first structures designed and built by Eduardo Torroja. At a time when computers did not exist, Torroja's courage and innovation were outstanding. He was in no way constrained by a lack of theoretical knowledge, inadequate materials and the contemporary doubts about cable-stayed structures. In fact, he was able to build one of the world's first prestressed concrete structures, and a precursor to modern cable-stayed and extradosed bridges. This paper briefly reviews the history of the Tempul Aqueduct, gives the results of the analysis of this structure by several Finite Element Models (FEMs), and compares the FEM results to those obtained by Torroja himself. The FEM results confirm the validity of Torroja's conceptual design. The paper also contains a detailed analysis of the influence of the structural system on the behavior of the bridge and the effect of removing the live loads with the aim of providing a better understanding of the context and behavior of the Tempul aqueduct.Funding for this research has been provided to Mr Lozano-Galant by the Spanish Ministry of Economy, Industry and Competitiveness (Research Project BIA2013-47290-R from FEDER funds). The authors are also grateful to Prof. S. Buonopane of Bucknell University and J.L. Temprado, of COMPOSAN, for their assistance and support. The authors also want to thank the CEHOPU-Archivo Torroja, for all the information and support provided.Lozano-Galant, JA.; Paya-Zaforteza, I. (2017). Analysis of Eduardo Torroja's Tempul Aqueduct an important precursor of modern cable-stayed bridges, extradosed bridges and prestressed concrete. Engineering Structures. 150:955-968. https://doi.org/10.1016/j.engstruct.2017.07.057S95596815

BIM visual programming tools applications in infrastructure projects: a state-of-the-art review

The Building Information Modeling (BIM) methodology improves architectural and infrastructure projects by digitizing their processes throughout their life cycle stages, such as design, construction, management, monitoring, and operation. In recent years, the automation of these processes has been favored by the use of visual programming (VP) tools that have replaced conventional programming languages for visual schemes. The use of these tools in architectural projects is becoming increasing popular. However, this is not the case in infrastructure projects, for which the use of VP algorithms remains scarce. The aim of this work is to encourage both scholars and engineers to implement VP tools in infrastructure projects. For this purpose, this work reviews, for the first time in the literature, the state-of-the-art and future research trends of VP tools in infrastructure projects.This work was funded by the National Agency for Research and Development (ANID) for the Scholarship Program “DOCTORADO BECAS CHILE/2019”–Folio n°72200098 and by the Spanish Ministry of Economy and Competitiveness and the FEDER fund through the projects BIA2017-86811-C2-1-R directed by José Turmo and BIA2017-86811-C2-2-R. Authors are also indebted to the Secretaria d’ Universitats i Recerca of the Generalitat de Catalunya for the funding provided through Agaur (2017 SGR 1481).Peer ReviewedPostprint (published version

Low-cost wireless structural health monitoring of bridges

Nowadays, low-cost accelerometers are getting more attention from civil engineers to make Structural Health Monitoring (SHM) applications affordable and applicable to a broader range of structures. The present accelerometers based on Arduino or Raspberry Pi technologies in the literature share some of the following drawbacks: (1) high Noise Density (ND), (2) low sampling frequency, (3) not having the Internet’s timestamp with microsecond resolution, (4) not being used in experimental eigenfrequency analysis of a flexible and a less-flexible bridge, and (5) synchronization issues. To solve these problems, a new low-cost triaxial accelerometer based on Arduino technology is presented in this work (Low-cost Adaptable Reliable Accelerometer—LARA). Laboratory test results show that LARA has a ND of 51 µg/vHz, and a frequency sampling speed of 333 Hz. In addition, LARA has been applied to the eigenfrequency analysis of a short-span footbridge and its results are compared with those of a high-precision commercial sensor.The authors are indebted to the Spanish Ministry of Economy and Competitiveness for the funding provided through the research project BIA2017-86811-C2-1-R directed by José Turmo and BIA2017-86811-C2-2-R. All these projects are funded with FEDER funds. The authors are also indebted to the Secretaria d’ Universitats i Recerca de la Generalitat de Catalunya, Catalunya, Spain, for the funding provided through Agaur (2017 SGR 1482). It is also to be noted that funding for this research has been provided for the Seyedmilad Komarizadehasl by the Spanish Agencia Estatal de Investigación del Ministerio de Ciencia Innovación y Universidades grant and the Fondo Social Europeo grant (PRE2018-083238).Peer ReviewedPostprint (published version

A review on low-cost sensors compatible with open-source platforms used for life-cycle monitoring of civil structures

Lately, the need for adopting sensors in buildings and infrastructures for monitoring and inspection of the health state of those structures is increasing. This demand is due to the increasing age of the structural stock worldwide. Consequently, more economical ways of Structural Health Monitoring applications are getting huge attention. This paper presents and evaluates several low-cost electronics compatible with open-source digital technologies for static and dynamic Structural System Identification applications. Firstly, an open-source microcontroller (Arduino), the main programable logic controller, and a Raspberry pi, a small single-board computer, are introduced. Secondly, various economic sensors with diverse measurement applications, such as ultrasonic and laser ranging, acceleration, temperature, and humidity, are discussed. Thirdly, multiple experiments in different controlled ambients are applied to assess and compare their tolerances as well as advantages and disadvantages of their use, among their price. Some problems with the Arduino codes and sensor positions emerged during the installation of the sensors and the data collection process. Finally, to attain an effective manner of using these low-cost electronics, this article offers answers to the issues faced.The authors are indebted to the Spanish Ministry of Economy and Competitiveness for the funding provided through the research project BIA2017-86811-C2-1-R directed by José Turmo.This project was funded with FEDER funds. Authors are also indebted to the Secre-taria d’ Universitats i Recerca de la Generalitat de Catalunya for the funding provided through Agaur (2017 SGR 1481). It is also to be noted that funding for this research has been provided for MR. Seyedmilad Komarizadehasl by Agencia Estatal de Investigación del Ministerio de Ciencia Innovación y Universidades grant and the Fondo Social Europeo grant (PRE2018-083238).Postprint (published version

Solving some special cases of monomial ratio equations appearing frequently in physical and engineering problems

We first show that monomial ratio equations are not only very common in Physics and Engineering, but the natural type of equations in many practical problems. More precisely, in the case of models involving scale variables if the used formulas are not of this type they are not physically valid. The consequence is that when estimating the model parameters we are faced with systems of monomial ratio equations that are nonlinear and difficult to solve. In this paper, we provide an original algorithm to obtain the unique solutions of systems of equations made of linear combinations of monomial ratios whose coefficient matrix has a proper null space with low dimension that permits solving the problem in a simple way. Finally, we illustrate the proposed methods by their application to two practical problems from the hydraulic and structural fields.Peer ReviewedPostprint (published version

Analysis of measurement and simulation errors in structural system identification by observability techniques

This is the peer reviewed version of the following article: [Lei, J., Lozano-Galant, J. A., Nogal, M., Xu, D., and Turmo, J. (2017) Analysis of measurement and simulation errors in structural system identification by observability techniques. Struct. Control Health Monit., 24: . doi: 10.1002/stc.1923.], which has been published in final form at http://onlinelibrary.wiley.com/wol1/doi/10.1002/stc.1923/full. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.During the process of structural system identification, errors are unavoidable. This paper analyzes the effects of measurement and simulation errors in structural system identification based on observability techniques. To illustrate the symbolic approach of this method a simply supported beam is analyzed step-by-step. This analysis provides, for the very first time in the literature, the parametric equations of the estimated parameters. The effects of several factors, such as errors in a particular measurement or in the whole measurement set, load location, measurement location or sign of the errors, on the accuracy of the identification results are also investigated. It is found that error in a particular measurement increases the errors of individual estimations, and this effect can be significantly mitigated by introducing random errors in the whole measurement set. The propagation of simulation errors when using observability techniques is illustrated by two structures with different measurement sets and loading cases. A fluctuation of the observed parameters around the real values is proved to be a characteristic of this method. Also, it is suggested that a sufficient combination of different load cases should be utilized to avoid the inaccurate estimation at the location of low curvature zones.Peer ReviewedPostprint (author's final draft

Interoperabilidad de sensores de bajo coste con modelos BIM mediante programación visual paramétrica

The current advances in Smart Cities technology trend towards the creation of complex and interconnected systems, through the application of new software tools and devices based on the Internet of Things, Big Data and so on. However, the cost of certain elements and devices (such as monitoring of environmental and confort parameters) is oftenly very high, leading to exclusive procedures and being used only in relatively singular works or in those in which they have been found, or is foreseeable, to find pathologies. From this point emerges the need for proposing the development of versatile and reliable monitoring protocols from open source digital prototyping platforms and the use of low-cost sensors, in order to lay aside that exclusivity. Thus, it could be possible to contribute to the expansion of the field of application to get greater efficiency and sustainability together. This paper demosnstrates and shows the most effective options of interoperability of low-cost sensors with BIM models to make possible the development of BIM 7D stage, by monitoring thermal data and synchronizing and live updating in a virtual model. This will make possible more accurate simulations, as well as the improving decision-making process over the entire lifecycle of the infrastructure.La coyuntura tecnológica actual de las ciudades Inteligentes se orienta hacia la creación de sistemas complejos e interconectados, con aplicación de nuevas herramientas y dispositivos basados en Internet de las Cosas (IoT), Big Data, etc. Sin embargo, el coste de determinados elementos (como los de monitorización de parámetros de confort ambiental en edificios) suele ser elevado, lo que conlleva a su exclusividad y a utilizarse únicamente en obras relativamente singulares o en aquellas en las que se han encontrado, o es previsible, encontrar patologías. De ello surge la necesidad de plantear el desarrollo de protocolos de monitorización versátiles y económicos a partir de plataformas de prototipado digital de código abierto y la utilización de sensores de bajo coste, a fin de dejar a un lado la antedicha exclusividad y poder, así, contribuir a la ampliación de su campo de aplicación en pos de una lograr una mayor eficiencia y sostenibilidad en conjunto. Este trabajo estudia y muestra las alternativas más viables de interoperabilidad de sensores de bajo coste con modelos BIM para posibilitar el desarrollo de la fase BIM 7D, mediante la monitorización de datos térmicos y sincronización en tiempo real para su visualización en un modelo virtual. Esto permitirá la calibración de simulaciones más precisas, así como la mejora del proceso de toma de decisiones durante el ciclo de vida de la infraestructur

Using RPA for performance monitoring of dynamic SHM applications

Robotic Process Automation (RPA) is a source of growing applications in a number of industries both as an individual technology and as a complement to other technologies (such as Internet of Things (IoT)). RPA allows the automation of human activities on a computer, especially when these activities are repetitive and high in volume. RPA saves man-hours and increases the productive capacity of the processes. The application of RPA in civil engineering is still in its early stages, and there has been little work on the subject in the literature. This paper presents RPA technology, for the first time in the literature, as a long-term management, control, and auto fault correction process for a low-cost accelerometer that can be used in SHM applications. However, this process requires a significant number of man-hours to stay operational, given the architecture of its applications. With the application of an RPA implementation workflow formulated based on the Design Science Research Method (DSRM), the management and control of the data acquisition process of a low-cost accelerometer located on a structural column are automated and put into operation in this study. RPA also made it possible to automatically detect and notify users of errors in the process, restart the process, and bring the process back online every time errors occurred. In this way, an automated process was obtained that operated continually and freed up human labour.The Spanish Ministry of Economy and Competitiveness: BIA2017-86811-C2-1-R; The Spanish Ministry of Economy and Competitiveness: BIA2017-86811-C2-2-R; The Secretaria d’ Universitats i Recerca de la Generalitat de Catalunya, Catalunya, Spain: 2017 SGR 1482; Spanish Agencia Estatal de Investigación del Ministerio de Ciencia Innovación y Universidades grant and the Fondo Social Europeo grant: PRE2018-083238.Peer ReviewedPostprint (published version

Structural system identification by measurement error-minimizing observability method

This is the accepted version of the following article: [Lei, J, Lozano‐Galant, JA, Xu, D, Turmo, J. Structural system identification by measurement error‐minimizing observability method. Struct Control Health Monit. 2019; 26:e2425. https://doi.org/10.1002/stc.2425], which has been published in final form at https://doi.org/10.1002/stc.2425This paper proposes a method for the finite element model updating using static load tests under the framework of observability analysis. Previous works included measurement errors in the coefficient matrix of the observability equations. This impeded the obtainment of accurate estimations. To deal with this issue, the proposed method relocates the errors and incorporates an optimization procedure to minimize the square sum of these errors. This method is able to identify the structural parameters of complex structures where the axial and bending behaviors are coupled, such as inclined beams or frame structures. Its application is illustrated by three structures. First, the method was validated in a beam-like structure by comparing it with other methods in the literature. Then the effects of different factors were investigated in a multistory frame and a rigid frame bridge with inclined piers. These factors include the curvatures, the inclusion of rotation measurements, and the constraints on the range of unidentifiable parameters. The importance of rotation measurements is demonstrated in static structural system identification.Peer ReviewedPostprint (author's final draft

Simplified calculation of shear rotations for first-order shear deformation theory in deep bridge beams

Nodal rotations are produced by bending and shear effects and bending rotations can be easily calculated using Euler–Bernoulli’s stiffness matrix method. Nevertheless, shear rotations are traditionally neglected, as their effects are practically negligible in most structures. This assumption might lead to significant errors in the simulation of the rotations in some structures, as well as the wrong identification of the mechanical properties in inverse analysis. Despite its important role, no other works studying the calculation of shear rotations in deep beams were found in the literature. To fill this gap, after illustrating the errors of commercial software regarding calculating the rotations in deep beams, this study proposed a simple and intuitive method to calculate shear rotations in both isostatic and statically redundant beams. The new method calculates the shear rotation for all segments separately and introduces the result to the total rotation of the structure. This method can be applied to find the shear rotation in a redundant structure as well. A parametric study was carried out to calculate slenderness ratios to determine in what structural systems the shear rotations can be neglected. In addition, the errors in the inverse analysis of deep beams were parametrically studied to determine the role of shear rotation in different structural systems. Finally, to validate the application of the method in actual structures, a construction stage of a composite bridge was analyzed.The authors are indebted to the projects PID2021-126405OB-C31 and PID2021-126405OB-C32 funded by FEDER funds—A Way to Make Europe and Spanish Ministry of Economy and Competitiveness MICIN/AEI/10.13039/501100011033/, BIA2017-86811-C2-1-R and BIA2017-86811-C2-2-R funded by FEDER funds.Peer ReviewedPostprint (published version