Highway sign support analysis utilizing field testing and finite element modeling

Development of a baseline for structural health monitoring for a curved post-tensioned concrete box–girder bridge

This paper presents the Electromechanical Impedance Spectroscopy (EMIS) method employing a novel piezoelectric wafer active sensor (PWAS) with sub-resonators, which can generate additional resonant peaks to enhance the impedance signature. In order to develop an in-depth understanding of the mechanism behind the sub-resonator effects, an analytical investigation is conducted first. The theoretical solution for the impedance of the new sub-resonator PWAS transducer is derived. Furthermore, numerical simulations are carried out to demonstrate the effectiveness of the new transducer to create additional resonant peaks. Harmonic analysis of coupled field finite element (FEM) models is conducted. Material degradations are modeled by altering the material properties like density and elastic modulus. Comparative investigations are carried out with both conventional PWAS transducers and sub-resonator PWAS transducers. EMI damage indices based on the spectral amplitude and frequency variation features are used to quantify the material degradation and simultaneously prove the superiority of the sub-resonator PWAS over the conventional PWAS. Additionally, a high-damping dog-bone specimen is employed to conduct the creep experiment lasting for twenty-four hours with a recording interval of two hours. The impedance spectra are obtained by the Bode-100 impedance analyzer. The experimental results further demonstrate the improved sensitivity of the sub-resonator transducer, which is in good agreement with the theoretical and numerical findings. The paper finishes with summary, concluding remarks, and suggestions for future work.

Integration of TLS-derived Bridge Information Modeling (BrIM) with a Decision Support System (DSS) for digital twinning and asset management of bridge infrastructures

<p>Bridge Management Systems (BMSs) are sophisticated software tools, widely used for managing bridges. Comprising a centralized database of all relevant information for the entire bridge stock and analytics to forecast bridges’ condition and maintenance cost, BMSs are irreplaceable tools, used by all the National Road Authorities (NRAs) around the world. These powerful tools, although different from one another, all lack adequate visualization of bridges. Recently, numerous researcher proposed using the Building Information Models (BIMs) to address this issue.</p><p>This paper presents the geometric approach of introducing BIM to BMS. Rather than trying to thoroughly connect these two robust systems on the object definition level, this approach focuses on geometry. The paper firstly shows how all the inventory information from BMS can be associated with corresponding BIM objects. Afterward, the ways to include the condition assessment data into BIM are proposed. Once the basics of the geometric approach are explained, the example of connecting BIM with BMS is presented. The example is based on KUBA, the Swiss BMS.</p><p>Finally, the feasibility, as well as the challenges of the presented approach are analyzed. The analysis focused on two important questions. Firstly, it considered if BIM is capable of making workflow changes in the Infrastructure Asset Management (IAM) the same way it did it in the construction industry. Secondly, it evaluated the BIM capability to describe all the condition assessment information relevant to IAM.</p>

In the higher frequency range, an inductor can be considered an equivalent circuit model, which is formed of a series branch of a resistance and an inductance paralleling a parasitic capacitance (PC). The capacitance gives a large contribution to the high performance of the inductor. This paper presents a 2D parallel plane field and 3D electrostatic finite element model for the toroidal ferrite core inductor and the stray capacitances (SC) between every two turns are calculated. The equivalent capacitances network can be built and the equivalent lumped capacitance, i.e., PS can be calculated. Moreover, the PS can be obtained using the measured resonant frequency and the calculating inductance and resistance at this frequency. Contrasting calculated results with the measured one, it was demonstrated that the fringe effect of an inductor is crucial to build its electrostatic model. If only considering the SC between the three neighboring turns, the value of equivalent PC will reach above 95% of the total value of which all turns of the coil are considered. The PC has a linear relationship with permittivity of the ferrite magnetic core and the insulating coats of conductor, which is more obviously influenced by the insulating coats.

The use of bridge management systems (BMS) by infrastructure stakeholders has led to the collection and retention of large quantities of data concerning the condition states of bridges throughout national and regional networks. The database for the BMS is often populated by the results of routine visual inspections, based on a prescribed scale for defining the condition state of the bridge’s individual elements, and of the bridge structure as a whole. The populating of the database also leads to the storage of large quantities of so-called metadata; which can describe the physical parameters of the bridge. The availability of this data allows the assessment of the BMS using multivariate techniques to enhance the life-cycle assessment of bridge networks, through advanced descriptive and predictive techniques applied to deteriorating network assets. Multivariate techniques such as principal component analysis have been demonstrated by the authors to be effectively applied as a descriptive tool to an existing BMS, and the results of a case study of a large dataset of bridges indicate its viability to be integrated into data-based approaches to infrastructural asset management.

Offshore wind energy is one of the most potent among renewables and thus the worldwide number of offshore wind turbines increases rapidly. The foundations of the wind turbines are typically fastened to the seabed by impact pile driving, which comes along with a significant amount of waterborne noise. To protect the marine biosphere, the use of noise mitigation systems, like bubble curtains or cofferdams, may become necessary. In this context, the model-based prediction of underwater sound pressure levels as well as the design and optimization of effective sound mitigation measures by using numerical models is one of today’s challenges. The current work presents a modeling approach that consists of a near field finite element model and a far field propagation model. Furthermore, it has been found necessary to generate a benchmark to allow for a qualitative and quantitative comparison between the manifold modeling approaches that are currently developed at various institutes and companies.

The need to optimize investments in bridge maintenance has created a demand for improved bridge management systems (BMS). Outdated practices in bridge inspection and constant advances in information technology have also contributed to this demand. The use of Digital Twins (DT), although well established in other industries, is still incipient for asset management and structural analysis of bridges. There is a great deal of research on Building Information Modelling (BIM) for bridge inspection, but its post-construction potential is still under-explored. This study presents a state-of-the-art review of the literature on asset management for bridges using digital models such as BIM and digital twins. The review was conducting using a systematic approach. Despite the rapid increase in research on DT and the amount of existing research on BIM, several gaps remain to be addressed, such as the lack of consensus about the definition of digital twins, which has led to wrongful categorisation of digital models as DT. The complex data flow and software compatibility required to develop a functional DT have hindered the exploitation of their full potential so far. The integration of BIM post-construction to BMS and existing automation technologies can also significantly improve current practices of bridge management.

Extensive laboratory tests were conducted in the test box at the University of Kansas (KU) to measure the response of Steel-Reinforced High-Density Polyethylene (SRHDPE) pipes. The laboratory tests conducted have some limitations, for examples, on installation conditions. To provide information that can improve the understanding of the short-term and long-term behavior of the pipe, field tests were conducted. Strain gages to measure steel and plastic strains, displacement transducers to measure the changes in diameter of the pipe, pressure cells around the pipe to measure the distribution of the pressure were installed and data were collected both during the installation and loading of the pipe. In this paper, the deflection of the pipe under a test truck loading is presented. Based on the field testing on the SRHDPE pipes, it can be concluded that (1) the deflections measured under the test truck for the SRHDPE pipe were much smaller than the permissible deflection of 7.5 % according to the Kansas Department of Transportation (KDOT) pipe and culvert specification (2007) during installation, (2) modified Iowa formula over predicted the deflection of the pipe under the applied load, and (3) the relation proposed by Masada (2000) can be used to determine ratio of the horizontal to vertical deflection of a buried SRHDPE pipe.

Low frequency sound may contribute to human annoyance by inducing building vibration involving both rattling and whole body vibrations. The basic mechanism, verified by a series of field measurements, is that transmitted low frequency noise excites floor vibrations. Hence, improved sound insulation at the lowest frequencies will also mitigate floor vibrations. While techniques for sound insulation at higher frequencies are well known, there is a lack of knowledge on how to design countermeasures providing good low frequency sound insulation, especially for lightweight structures. To close this knowledge gap, a broad research program on low frequency sound transmission and sound induced vibrations has been performed. The aim of the study has primarily been to develop cost-effective countermeasures against low frequency noise for lightweight building structures, which also has a good effect in the frequency range that determines the A-weighted sound level. A countermeasure with stiffening of the walls and roof using steel sheet profiles screwed to the existing studs in combination with plywood panels was proposed. The study involved laboratory measurements, Finite Element simulations, proposal and design of countermeasures, as well as full-scale field testing of the proposed countermeasures in a typical Norwegian wooden building. In this paper we present an overview of the results from the laboratory measurements and the full scale field testing. The study showed that the proposed countermeasure combined with improvements of windows and balanced ventilation gives about 10 dB reduction of the A-weighted indoor sound level from F-16 aircrafts and 30-70% reduction of the floor vibrations.

Recently, a large number of studies were conducted on bridge asset management systems. An objective of bridge management is to compute an optimal repair policy with some indexes including the life cycle costing. However, bridge administrators often can not secure a sufficient annual budget to carry out an optimal repair strategy, so they usually have to prioritize the repairs under a budget constraint. The bridge components which can not be repaired at the optimal timing are repaired in the following time period (year). In Japan a large number of bridges are constructed during a high-growth period, and as a result it is expected that these bridges will be replaced simultaneously in the near future. This results in increasing the demand for bridge repair rapidly. On the other hand, the reduction of the fiscal expenditure resulting from the increase of the social security costs and the decrease of the tax revenues because of the declining birthrate and the “aging society” problem makes it necessary to reduce the maintenance budget of bridges. Under these conditions, in order to respond to the needs resulting from the new provision of social capital, regarding building and maintaining bridges, it is necessary to develop a bridge management system which can estimate the repair demands accurately and aid in planning the budget control efficiently. This study proposes a comprehensive bridge management system (BMS) which performs rational bridge maintenance. Furthermore, the study developed BMS computer application software to be utilized in real works of bridge maintenance. The BMS application is divided into three systems, 1) inventory system to manage the database, 2) asset management system to plan the repair strategy, and 3) accounting system to record the repair results and control the budget. The asset management system is divided into three sub-systems, a) strategy level, composed of five modules for long term budget planning, b) tactics level which decides the middle-term repair priority according to the outputs of the strategy level, and c) annual level which records the repair results for each fiscal year. The second section of this paper, presents the research fundamentals of the BMS. In the third section some methodologies of the BMS are described. The fourth section describes the usage of the BMS application. Finally, the fifth section presents a case study as it was applied to the bridge systems managed by the Himeji Office of Ministry of Land, Infrastructure and Transport.

A live-load test and a three-dimensional (3D) finite-element (FE) model of a three-span continuous prestressed–concrete girder bridge are described in this paper. The precast prestressed-concrete simple-span girders are made continuous by pouring a continuity diaphragm between the girders ends. Special reinforcement is extended from the girders’ bottom flanges into the diaphragm to ensure continuity under positive moments that result from time-dependent effects such as creep, shrinkage, and temperature gradient. This detail was adopted in a recently constructed bridge. The bridge has been instrumented with embedded and surface-mounted sensors and was monitored for over 2 years to evaluate the performance of the new continuity detail. A live-load test was carried out to evaluate the response of the new detail under truck loads. Field test data were used to validate a 3D FE model that was developed for the entire monitored segment. Once the FE model was validated, it was used to investigate the effi...

Recent advances in instrumentation have made it feasible to measure the transient strain tensor caused by small changes in fluid volume or pressure in the subsurface and this has opened the door to new opportunities for characterization and monitoring during CCUS. We have demonstrated this method by deploying strainmeters at shallow depths (30 to 40m) and then conducting injection well tests in an underlying reservoir at 530m depth. The resulting data indicated that the horizontal strain at shallow strainmeters was tensile and the vertical strain was compressive. The radial strain was less than the horizontal strain, and the strain rates decreased from 100 nanostrain/day to roughly 10 ne/d over a few days (1 nanostrain = 1 part per billion strain). We then used the strain data to estimate reservoir properties, geometry and pressure through inversion of poroelastic forward models using both numerical and novel analytical methods. The average horizontal strain in the caprock resembles the transient pressure in the underlying reservoir and classic type-curve methods from transient well testing can be used for preliminary interpretations of strain data. We have developed fast, closed-form analytical solutions to a pressurized poroelastic inclusion and inhomogeneity in a half-space. Numerical models developed using finite element methods allow more details of the subsurface to be included in the inversion, but they require much longer run times and this makes inversion cumbersome using standard methods. We have developed an inversion approach that uses a proxy model created using machine learning to do most of the forward calculations. This approach markedly reduces the computational requirements and makes it feasible to use Bayesian inversion with large numerical models. Bayesian inversion is important because it provides predictions with uncertainties, which makes the results useful for decision making. We have shown with field tests and simulations that the strain tensor in the caprock is sensitive to pressure in the reservoir, reservoir properties and boundaries, and pressure in the caprock caused by leaks. These results indicate that measuring and interpreting the shallow strain tensor could be a valuable tool for both initial reservoir characterization efforts and long-term monitoring during CCUS. Recent advances in instrumentation have made it feasible to measure the transient strain tensor caused by small changes in fluid volume or pressure in the subsurface and our objective was to evaluate opportunities for strain monitoring during characterization and monitoring for CCUS. Our approach was to deploy strainmeters at shallow depths (30 to 40m) and then conduct injection well tests in an underlying reservoir at 530m depth. The results indicate that the horizontal strain at shallow strainmeters was tensile and the vertical strain was compressive. The radial strain was less than the horizontal strain, and the strain rates decreased from 100 nanostrain/day to roughly 10 ne/d over a few days (1 nanostrain = 1 part per billion strain). We then used the strain data to estimate reservoir properties, geometry and pressure through inversion of poroelastic forward models using both numerical and novel analytical methods. The average horizontal strain in the caprock resembles the transient pressure in the underlying reservoir and classic type-curve methods from transient well testing can be used for preliminary interpretations of strain data. We have developed fast, closed-form analytical solutions to a pressurized poroelastic inclusion and inhomogeneity in a half-space. Numerical models developed using finite element methods allow more details of the subsurface to be included in the inversion, but they require much longer run times and this makes inversion cumbersome using standard methods. We have developed an inversion approach that uses a proxy model created using machine learning to do most of the forward calculations. This approach markedly reduces the computational requirements and makes it feasible to use Bayesian inversion with large numerical models. Bayesian inversion is important because it provides predictions with uncertainties, which makes the results useful for decision making. In conclusion, we have shown with field tests and simulations that the strain tensor in the caprock is sensitive to pressure in the reservoir, reservoir properties and boundaries, and pressure in the caprock caused by leaks. These results indicate that measuring and interpreting the shallow strain tensor could be a valuable tool for both initial reservoir characterization efforts and long-term monitoring during CCUS.

The safety issue during bridge construction and operation has become a major concern for the society. This research focuses on how to conduct integral health-status assessment for bridges in operation on the basis of test and monitoring data. The result of the assessment will be the foundation of bridge maintenance, damage repair and reinforcement decision-making. Bridge state assessment origins in America, where bridge management systems were developed to give comprehensive assessment and help make daily management and maintenance decision for medium and small bridges. Afterward, different bridge health-status evaluation methods have been developed. For small and medium bridges, bridge assessment is usually conducted by applying assessment code. For complicated bridge, such code could not reflect the complexity of the structure. Another assessment method is reliability method. Reliability method is based on theory of probability and fully considers the uncertainty of structures. Analytic Hierarchy Process (AHP) is proposed in the 1970s to conduct multi-criteria decision-making combining qualitative and quantitative factors. (Saaty 2008) Bridge state assessment is a typical multicriteria decision-making problem. In the assessment model, multiple assessment indexes should be taken into consideration, including quantitative indexes and qualitative indexes. When the AHP assessment model is built and the weight of each index is derived, the evaluation value of the base indexes of the model should be derived and then be integrated by a certain relationship to get an integrated evaluation value representing the general state of the bridge. This research focuses on the evaluation value of base level indexes and the integrated evaluation method. The base level indexes of the bridge health-status assessment model are all from field test and monitoring directly. They need to be transformed to unified non-dimensional evaluation value. Considering the fuzziness and uncertainty of the evaluation process and transformation process, fuzzy grading is used to give a quantitative description of the base index’s evaluation. Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) is a multiple attribute decision making method, which was developed for ranking and evaluation of limited number of alternatives (Yoon & Hwang 1995). Under AHP assessment framework, an improved fuzzy TOPSIS method has been proposed to conduct overall assessment of bridges. An integrated evaluation method is proposed by improving TOPSIS method and adapting it to bridge health-status assessment. The improvements include: ① absolutization of positive and negative ideal solution value; ② establishment of the virtual ideal solutions; ③ calculation of variable weight of base-level indexes considering the impact of the variation of the base-level indexes ④ fuzzy assessment based on level sets; ⑤ defuzzificaiton and standardization treatment of the assessment result. A case study applying the proposed fuzzy TOPSIS methodis introduced. This implementation verifies the feasibility and utility of the proposed method.

Fatigue analysis of sign-support structures during transportation under road-induced excitations