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Segmental tunnel linings have a complex structural behavior that is difficult to predict. Full-scale in situ structural monitoring allows us to gain access to these structures, observe the acting mechanisms, and better understand the actual structural behavior under realistic boundary conditions. In a recent structural monitoring project in Frankfurt, Germany, strains, deformations, and temperatures were measured at the segmental lining of a twin-tube tunnel boring machine (TBM) tunnel. Hereby, internal forces were back-calculated from the strain measurements. The results of the monitoring are presented and discussed in this paper. The measurements began immediately after the assembly of the segments and have been performed continuously over several years. Because of that, it was possible to observe that the internal forces differ significantly between the construction stage and the final state. During the construction stage, the internal forces develop quickly within hours after ring assembly, showing a distribution along the lining's circumference that is hard to predict. Almost all radial deformations occur during this period and remain unchanged afterward. After this first early phase, a period of stress redistribution follows, including significant changes in the internal forces. At its end, the stable, final state is reached. In this state, the internal forces match better with expectations. In the monitored areas, the stresses during the construction stage slightly exceeded those of the final state, which should be avoided for economic reasons. Additional investigations regard the temperature development within the lining, the influence of the second tube construction on the already built tube, and the development of longitudinal ring interaction over time. The latter significantly influences the structural behavior, but its development is often subject to uncertainties. In this case, it was observed that the longitudinal interaction decreases considerably over time. Practical Applications: In the structural design of segmental tunnel linings, structural or geotechnical engineers have various options regarding the available calculation methods and modeling strategies. All of these options are part of the state of the art, and the selection is up to the engineer. However, the results can be quite different depending on the chosen option. Consequently, uncertainties remain regarding the real linings' internal forces and structural reliability. The actual mechanisms can be identified by investigating the real structural behavior of segmental tunnel linings with in situ structural monitoring. Then, with back-analyses, on the one hand, it can be tested to determine how well different calculation methods and modeling strategies correspond to reality. On the other hand, the monitoring data can contribute to improving existing calculation methods, developing new modeling approaches, and establishing more detailed recommendations or optimizations regarding the design and construction of segmental tunnel linings. This paper presents findings derived from a structural monitoring project on a segmental lining. Different mechanisms and aspects, sometimes uncertain or debatable in tunnel design, are discussed regarding their real in situ appearance. The gained data will also be used for further back-analyses and investigations. [ABSTRACT FROM AUTHOR]

Engineering design and construction teams commonly use decision tools, such as rating systems, to manage the complexity of infrastructure projects. However, these systems often focus predominantly on environmental dimensions, potentially overlooking the holistic economic and social aspects of sustainability. This can hinder decision-makers from recognizing the benefits, thereby inadvertently impeding optimal sustainability performance. This research explores a potential solution: reframing the goals of credits on rating systems to explicitly highlight the interconnectedness of environmental, social, and financial dimensions. The aim was to amplify engineers' motivation towards higher levels of sustainability performance. The study examined the effect of the goal-framed credits by comparing the sustainability scores between engineering professionals (n=42) who used the original Envision system and the reframed version when evaluating a case project. The control group participants averaged a score of 95.4 Envision points (37%), while the intervention group averaged 121.8 Envision points (48%). The reframed credits significantly increased engineering professionals' sustainability goal setting. Emphasizing financial and social objectives on credits from the Envision rating system, rather than solely focusing on the existing environmental goals, had a favorable influence on professionals' sustainable design choices. This reframing, by emphasizing the interconnectedness of environmental, social, and financial dimensions of each decision, appears to amplify the awareness, motivation, and selection of higher levels of sustainability achievement, thereby increasing their perceived value and leading to a shift in sustainability-oriented decision-making. The findings suggest that reframing rating systems to better emphasize the interconnectedness of the environmental, social, and financial dimensions of each decision can serve to help engineering teams set higher goals for sustainable performance. Practical Applications: For infrastructure project managers, architects, and designers, this research highlights the significance of considering economic and social aspects alongside environmental concerns. By doing so, it can further empower stakeholders to make more well-rounded and sustainable decisions that benefit both their projects and the communities they serve. Small changes in how decision tools are worded, or framed, can have a significant effect on project goal setting. A better understanding of how framing affects design cognition can also help inform how project managers, architects, and designers present information to their clients. Subtle changes in the decision tools and the way information about projects is expressed cost little compared to the actual cost of infrastructure, offering inexpensive and easy to implement strategies to influence and nudge project teams toward setting higher sustainability goals during the design and construction of infrastructure projects. [ABSTRACT FROM AUTHOR]

As additive construction technologies evolve, the US Army Engineer Research and Development Center has studied the functionality and structural integrity of structures produced using additive construction methodologies. Compared with precast construction, additive construction has multiple advantages including unique geometries, reduction of worker power, no required formwork, and ability to use locally sourced materials. The purpose of this study is to evaluate additively-constructed concrete structures and compare it with conventional construction methods. Static analyses are performed using finite-element modeling on several precast concrete beams and compared with experimental data. A finite-element model was created for additively-constructed beams by incorporating cohesive interaction properties to evaluate the interface strength between three-dimensional (3D) printed layers. To further validate the model, an additively-constructed concrete wall is also experimentally tested and compared with models. Numerical predictions are developed to explore damage caused by interfaces of additively-constructed structures and its effects on the structural performance. Maximum deflections and peak loads were also obtained for the conventional construction method experimentally with finite-element models. [ABSTRACT FROM AUTHOR]

This manuscript first presents the development and then the implementation of simple design aids that allow bridge engineers to quickly estimate idealized moment–curvature relationships for circular concrete columns in compliance with current specifications by using a pocket calculator or a spreadsheet. The design aids were developed in a normalized domain so they are particularly convenient for preliminary stages of design when the engineer may want to know the nonlinear static (pushover) response of circular columns for selected reinforcement ratios (longitudinal and transverse) and axial load levels. The formulation is applicable to column diameters up to 2.44 m (8 ft), longitudinal reinforcement ratios (ρ) from 1% to 3%, spiral reinforcement ratios (ρs) from 0.5% to 2.5%, nominal concrete compressive strengths (fc′) from 28 MPa (4 ksi) to 56 MPa (8 ksi), axial loads from –0.5fyρAg (tension) to 0.5fc′Ag (compression), and grade 420 MPa (60 ksi) reinforcement. Application examples are presented to illustrate the use of the design aids and to validate the obtained results with commercially available software. [ABSTRACT FROM AUTHOR]

In support of the benefit of the nurse + engineer collaborating as community health workers, a recent systematic review [for a description of review types, see Page et al. ([21])] by Berini et al. ([5]) noted that "community health workers can improve access to care in rural settings and may represent a cost-effective investment for the healthcare system." As part of this review, one study was identified where education was delivered by community health workers resulting in improved dental health ([23]). As environmental engineers work to expand our current technological solutions for drinking-water fluoridation, nurses are a natural ally when we foster informed action including behavioral change at the level of individuals, families, communities, and populations. While the public often associates engineers with driving trains or building things ([9]), in fact, according to the Code of Ethics for Engineers, the first fundamental canon of engineering is to "hold paramount the safety, health, and welfare of the I public i " ([11] emphasis added). [Extracted from the article]

The pipe component of a water distribution network (WDN) is sized based on the fixed design demand considering a peak factor and design period. Simulation of the designed network by a hydraulic solver provides nodal pressure head, head loss, velocity, and flow in each pipe as the prime outputs for the design demand, and it can also be used for extended-period simulation for a particular demand pattern over the supply hours. But, in reality, the behavior of the network does not match with such a result in an intermittent water supply (IWS) system due to the fact that all house service connections behave as an uncontrolled orifice. This has made it a challenging task in understanding and in predicting the behavior of the networks by the municipal engineer once the water starts flowing through the house service connections (HSCs). Though the municipal engineer provides the same pipe size for HSCs to all residences, the flow received by each house could vary based on the available pressure head at the ferrule point of the main water supply pipeline. In reality, maintaining constant pressure at each HSC is not feasible due to frictional head loss. Hence, variation in flow at the HSC is inevitable even with a small water supply system. This paper illustrates how to simulate the behavior of an IWS system based on the number of HSCs provided to each pipeline using a hydraulic solver. Hydraulic simulation of the water distribution network that provides IWS to consumers can be implemented easily by adding a fictitious node by assigning an appropriate emitter coefficient to each demand node through a fictitious link having a check valve in it. The method for finding the appropriate value of the emitter coefficient that helps in simulating HSCs is illustrated in the present work. [ABSTRACT FROM AUTHOR]

In the past two decades, Sub-Saharan Africa (SSA) has had massive infrastructure projects development to meet the increasing demand for public services and foster socioeconomic transformation. As a result, there has been an influx of Chinese international contractors (CICs) in SSA in order to close the infrastructure gap. Despite the significant involvement and active participation of CICs in the global construction industry, clearly few studies have investigated the performance of CICs in SSA, and their performance is not very well understood. The goal of this paper is to provide insights into the performance of CICs in SSA using a case study of an engineering-procure-construct (EPC) hydropower project in Uganda, East Africa. A literature review was carried out followed by a case study analysis including interviews with the owner's key senior project participants. Performance is evaluated based on five criteria: schedule; change orders; quality; health, safety, and environment (HSE); and owner satisfaction. The findings indicate poor performance of the CIC with 20% schedule overrun, breach of change order procedures, poor quality of work, high rate of incidents and fatalities, and low level of owner's satisfaction. The findings and lessons learned, though specific to this case study, will be useful for public agencies in developing countries, particularly in SSA, administering similar contracts and projects with CICs. The paper established the poor performance of a Chinese international contractor (CIC) on a hydropower engineering-procure-construct (EPC) project in Uganda, based on five project performance/success criteria: schedule; change orders; quality; health, safety, and environment (HSE); and owner satisfaction. Ultimately, the outcomes of this paper provide practical insights for industry practitioners on performance evaluation of CICs executing projects using EPC project delivery methods. Lessons learned and best practice strategies are also put forward to mitigate the identified performance shortcomings of CICs in future projects and improve the chances of project success. What is truly important, in the end, is owners dedicating sufficient resources for pre-project planning including the selection of competent and credible EPC contractors and the owner's engineer to ensure enhanced project contract administration. [ABSTRACT FROM AUTHOR]

This paper explores the factors that influence male and female engineers' intent to leave. An online questionnaire was completed by 183 female engineers and 229 male engineers. Factor analysis and structural equation modeling were used to develop models of intent to leave for male and female engineers. This study contributes to current knowledge by identifying the specific influence and inclusion factors that increase intent to leave for female engineers, and how these differ from male engineers. The findings show that an increase in access to career opportunities reduces intent to leave for both male and female engineers. This is the only similarity between the two models. Expanding the inclusion measure beyond social inclusion (belonging) to also assess how well individuals are supported to be their authentic selves, identified that for female engineers only, support to bring their authentic selves to work and developing influential relationships decreases intent to leave. For male engineers, pursuing their ideas against the odds reduces intent to leave, while being on the lookout for ways to improve one's life and situation increases intent to leave. Therefore, organizations should ensure men and women have equal access to roles that help them upskill, are able to be their authentic selves, and can develop relationships with people of influence in the organization. [ABSTRACT FROM AUTHOR]

Geopolymers have been long recognized as the next-generation building material due to environmental reasons. However, geopolymers are inherently brittle and usually require high-temperature curing. This paper was intended to develop a ductile engineered geopolymer composite (EGC) under ambient curing conditions. Two types of metakaolin powder with different particle sizes were applied as the solid precursor. The tensile, compressive, and flexural behaviors of EGC with different mix designs were investigated. It was concluded that the combinational application of coarse and fine metakaolin is conducive to the tensile and compressive behaviors of EGC materials. As the alkali concentrations increased from 6 to 14 mol/L , the tensile and compressive strength of EGC increased, whereas the tensile ductility of EGC decreased gradually. Also, the SiO2/Na2O molar ratio had negligible influence on the tensile behavior of EGC, whereas the compressive strength decreased with the increase of SiO2/Na2O molar ratios. A numerical model to predict the flexural behavior of EGC was also proposed, and the accuracy was verified with experimental results. [ABSTRACT FROM AUTHOR]

The ethical implications for the engineering profession of the development and deployment of automated vehicles (AVs) can be explored by analyzing the implications of AVs across three major socio-technical systems--technology, transportation systems, and policy. Mapping the ethical canons of professional engineering societies to these domains provides a lens to investigating existing ethical issues and uncovering issues that still need attention. The codes of ethics for five engineering societies direct engineers to consider, identify, mitigate, and manage how their work affects the public. AV ethics literature in the technology domain has focused mainly on crashes, AV software capabilities, and hardware. This narrow focus signifies that engineers in the technology domain can do more to understand potential impacts beyond AV crash behavior. In the transportation systems domain, among the many ethical issues affected by AVs, how engineers design and deploy surface transportation infrastructure is an example of an ethical system-level problem yet to be addressed. Lastly, the policy domain has begun addressing primary effects like protecting the public from physical harm, but other ethical aspects remain unaddressed. All three domains could benefit from more holistic system-level assessments of the ethical implications of AVs. Engineers can use their professional engineering organization ethical canons to evaluate their contribution to managing ethical issues in these AV domains and improve how automated vehicles serve and safeguard the public. [ABSTRACT FROM AUTHOR]

Practicing engineers use the uncertain bilinear soil spring methodology recommended by engineering guidelines to predict soil loads acting on buried pipelines. Even though more advanced solutions are available in the literature to address these uncertainties, they cannot be practically implemented owing to various industry constraints such as computational and modeling costs. This paper proposes a fitting expression that can enable practicing engineers to produce safer, more reliable outcomes at no additional cost. The proposed expression is based on a calibrated advanced finite-element (FE) model featuring an advanced user-defined Nor-Sand (NS) soil model, and the simplistic Mohr–Coulomb (MC) soil model, which is commonly used in the industry for numerical modeling. The developed FE model was first validated by comparing the upward and peak dimensionless soil forces computed with those predicted by engineering guidelines and other analytical models reported in the literature. A series of FE analyses were then performed using our calibrated FE model incorporating the advanced NS soil model to simulate buried pipe response under downward displacement, which was not realistically captured either with the MC soil model or available engineering guidelines. Results of the analyses were used to derive a fitting expression for predicting the resistance to downward pipeline displacement to address what is lacking in the current industry practice. The developed tool contributes to the design and analysis of buried pipelines by enabling practicing engineers to produce safer, more reliable outcomes. [ABSTRACT FROM AUTHOR]

She holds a B.Eng. in building engineering from Tongji University (2001), a M.S. in civil engineering from the University of Massachusetts (2005), and a Ph.D. in geotechnical engineering from the Georgia Institute of Technology (2010). Dr. Tan's areas of specialization include deep excavation and tunnelling, foundation engineering, forensic geotechnical engineering, and engineering failures associated with climate change. He received his B.Eng. in building engineering from Tongji University (1999), M.Eng. in Geotechnical Engineering from Tongji University (2002), and Ph.D. in civil engineering from the University of Massachusetts (2005). [Extracted from the article]

The numerical simulations were performed with the MARS software prior to January 2020. The following "Acknowledgments" section should be added to the original paper: Acknowledgments This effort was partially sponsored by the US Army Engineer Research and Development Center (ERDC) via Engineering and Software System Solutions, Inc. (ES3). [Extracted from the article]