Practice Periodical on Structural Design and Construction

Due to the large demand to produce clean and renewable energy, offshore wind farms are extensively being used to help with economic development. Offshore Wind Turbine (OWT) structures are usually supported by various types of foundations and its selection depends on several factors such as water depth, economic costs, construction methodologies, seabed bathymetry, soil characteristics, and load characteristics. The present State-of-the-Art review focuses on OWT-monopile foundation systems embedded in multi-layered soil strata subjected to aerodynamic and hydrodynamic loading conditions. The purpose of this study is to carry out a comprehensive review on the performance of OWT-monopile foundation structures to support the design and drafting choices and thereby provide an understanding to reduce the costs. Two specific subject areas are addressed in this paper: (1) Factors affecting the performance of OWT-Monopile Foundation Systems; and (2) Experimental modeling and numerical analyses of OWT-Monopile Foundation Systems. The immediate challenge to the design of OWTs is to analyze the dynamic response of the foundation structure when exposed to both aerodynamic and hydrodynamic loads acting simultaneously. The limitations of the existing guidelines point to the need for improved design methods to obtain an economical design of OWT-monopile foundations. The use of Finite Element (FE) models is effective in studying the functioning of OWT-monopile structures. The present study suggests the development of further numerical models and modifications to the existing ones to properly assess soil-monopile interactions. This study also suggests further investigations on the design and analysis of OWT-monopile foundations considering the effect of (i) aerodynamic and hydrodynamic loading conditions with soil-monopile interactions, and (ii) multi-layered seabed characteristics.

Due to its various advantages, autoclaved aerated concrete (AAC) has been gaining popularity in masonry construction in recent years, and consequently, numerous studies have been conducted in this area since the mid-1980s. Unfortunately, research progress on this subject does not appear encouraging, which is evident from the lack of specific codes and standards on AAC masonry. As a result, various test data presented in the published literature from nonstandard experiments do not agree with each other and pose challenges for uniform design formulation. Beginning with a critical review of earlier work, this paper highlights the discrepancies and shortcomings of the research studies reported to date. The review aims to address the strengths and weaknesses of previous studies and to help streamline future research. A detailed review of research progress on AAC masonry presented in this paper identifies potential challenges ahead.

A significant increase in existing inspection efforts and the creation of more resilient structures using built-in sensors and systems is essential for accurate and reliable assessment and monitoring of structural conditions in order to minimize the risk of catastrophic failure. The acoustic emission (AE) technique could immensely benefit the damage assessment, real-time checking of structural integrity under operating conditions, and identification of the operational risk factors along with the causes of initiation and development of flaws. Therefore, this article presents a comprehensive overview of AE as a potential damage assessment and localization technique to determine the performance and behavior of reinforced concrete (RC) members along with an overview of the latest research in computational AE damage modeling and machine learning tools to optimize the accurate interpretation of voluminous AE data. The primary aim of this review is to identify specific gaps in the literature pertaining to concrete structures that need immediate attention of the researchers working in this domain. The identification of damage mechanisms based on AE events and parameters covered in this review would enable researchers to identify damage sources nondestructively in situ and produce large data sets for detailed statistical analyses of the effects of small-scale local damages in large-scale concrete structures. This review will also be helpful for practicing engineers to choose between different available AE parameters based on the limitations and advantages of these parameters for specific inspection and maintenance requirements of various types of RC structural elements, loading conditions, and failure.

This study investigates the shear behavior of the reinforced recycled aggregate concrete (RAC) strengthened with near-surface mounted-carbon fiber reinforced polymer (NSM-CFRP). Different percentages of the coarse RAC were used. A total of 15 reinforced concrete beams having the same cross section of ($150\times 200\times \mathrm{1,150}{\mathrm{mm}}^3$) were used and strengthened with different spacing, length, and inclination of NSM-CFRP strips. Results indicated that strengthened beams showed comparable behavior with those made with conventional concrete. On the other hand, the behavior of the recycled aggregate concrete beam shows a reduction in the load capacity with 16.5% as the recycled aggregate replacement percentage increased to 75%. The stiffnesses of the strengthened beams were significantly affected by the RAC incorporation ratio because of the weak bond between the epoxy adhesive and the surrounding concrete as the replacement ratio increased more than 25% by volume. Concrete with a higher replacement ratio has lower bond strength and shear strength than concrete made with natural aggregate. As the replacement percentage increased, the cost of the concrete decreased; for instance, a 34% reduction in the cost of aggregate is noted when the replacement ratio increased to 75%.

This paper presents an overview of published literature on prestressed concrete and steel (H- and pipe) pile–to–pile cap (PTPC) connections and the results of the detailed finite-element analyses (FEAs) carried out on the PTPC connections. The embedment capacities of PTPC connections obtained using existing analytical models proposed in the literature have been investigated. The results of the existing analytical models and the FEAs demonstrated that proper embedment depth can provide adequate lateral resistance to the applied loads on the foundations, and therefore it is highly important to understand the behavior of such connections’ details in order to provide a reliable and economical design. This study focuses on a thorough understanding of the connection design capable of developing adequate pile moment capacity (while remaining essentially rigid) without providing for any special reinforcements by just relying on a simple plain pile embedment depth. The observed predictions based on the existing analytical models and the results from the FEAs showed reasonable agreement with the experimental data. It was observed that the FEA is effective in capturing the global and local behavior of the PTPC connections. Even without a special connection detail, the embedment depths alone can contribute to develop adequate moment capacity for the piles with a value equal to the width of the pile. A value in the range of 1.2–1.5 times the width or diameter of the pile is preferable. However, further experimental investigations are necessary to establish the minimum embedment depth to develop the adequate pile moment capacity of steel PTPC connections. The results from the present study demonstrate that FEA can accurately capture the nonlinear behavior for prestressed PTPC connections and point to the need for further experimental and analytical research on concrete cracking behavior at the steel–concrete interface for steel PTPC connections.

Soil-structure interaction contemplates a series of comprehensive studies, such as those related to the use of springs to represent the soil-structure behavior in complex structures. In this context, the present paper aims to apply methodologies available in the technical literature regarding the inclusion of the combined effects of soil, foundation, and structure to represent a timber-concrete composite pedestrian bridge of the Polytechnic School of the University of São Paulo. Numerical models associated with soil-structure interaction methodologies were developed and calibrated using experimental data from monitoring campaigns on the footbridge. Vertical displacement and natural frequency results displayed good adherence with experimental data. Overall, the use of soil-structure interaction provided a satisfactory improvement in the numeric responses. This paper thus demonstrated the importance of adopting adequate representation for the foundation and soil elements to represent the actual behavior of an asset, displaying the influence of the soil-structure interaction. The modeling configuration of this work enables the selection of more reliable numerical models for future analyses.

The objective of this paper is to investigate the behavior of 16 cold-formed steel (CFS) wall panels consisting of 10 panels with a built-up I (BI)-section stud and six panels with a single-lipped C-section stud under compression. Limited studies are available in the literature on the axial performance of sheathed BI-section studded CFS wall panels. The novelty of the study is that for the first time, an investigation is conducted on axial performance of full-scale BI-section studded CFS wall panels with magnesium-oxide board sheathings. A comparison is also presented between the ultimate axial compressive strengths of BI-section studded wall panels and single-lipped C-section studded wall panels. Different sheathing configurations have been adopted in the study by varying the layers of sheathing on either side. Failure modes and ultimate axial compressive strength of all the tested specimens are compared and discussed in detail. Also, for the first time, efficacy of three direct strength methods (DSMs) have been verified against the experimental tests on sheathed BI-section studded CFS wall panels present in the literature database as well as tests conducted by the authors in the present study. Three DSM approaches include current DSM (cDSM) in the North American specifications and two other modified DSM (mDSM) approaches present in the literature. In all the approaches, the sheathing was assumed as continuous elastic supports attached to the C-section. Elastic buckling analysis was performed to evaluate the elastic buckling loads. Further, DSM design formulas were adopted to transform the elastic buckling loads to estimate the nominal axial compressive strength of sheathed CFS wall panel. Differences in the cDSM-predicted and experimental test results imply the inadequacy of current design rules. Due to the clear evidence obtained in the test, local-distortional and distortional-global interactive buckling modes cause substantial ultimate compressive strength erosion in sheathed CFS BI-section columns. Therefore, results obtained using the recommended mDSM approach are within the acceptable variation range with the experimental results because the adopted method takes into account distortional–overall buckling interaction. Structural designers and researchers will have a readily available tool to implement for evaluating the axial compressive strength of such members.

This research set out to create a computational tool for predicting the 28-day compressive strength (CS) of concrete prepared from ordinary Portland cement (OPC) and Portland pozzolana cement (PPC) cement. 1,062 datasets of concrete were collected from laboratory experiments. From 1,062 datasets, 524 samples belonged to OPC and 538 samples belonged to PPC. eXtreme gradient boosting (XGBoost) algorithm optimized with genetic algorithm (GA) was utilized for developing an efficient model. The R value obtained for ${\mathrm{GA}\text{-}\mathrm{XGB}}_{\mathrm{OPC}}$ and ${\mathrm{GA}\text{-}\mathrm{XGB}}_{\mathrm{PPC}}$ models in training (TR) and testing (TS) dataset are almost $\ge 0.90$. Mean absolute error (MAE) and root mean square error (RMSE) values obtained for the ${\mathrm{GA}\text{-}\mathrm{XGB}}_{\mathrm{OPC}}$ model were 2.155 and 2.923, respectively. Similarly, the values for the ${\mathrm{GA}\text{-}\mathrm{XGB}}_{\mathrm{PPC}}$ model were 1.815 and 2.888, respectively. The developed models were found to predict more than 90% of the observations within $\pm 20\%$ variations. The level-1 and level-2 validation results certify the ${\mathrm{GA}\text{-}\mathrm{XGB}}_{\mathrm{OPC}}$ and ${\mathrm{GA}\text{-}\mathrm{XGB}}_{\mathrm{PPC}}$ models’ generalizability. Ultimately, a user-friendly laborless and financially feasible computer software or tool was generated in Python for assistance to the field and design engineers in estimating the CS of concrete.

The Aizhai Bridge is the longest suspension bridge crossing a canyon in the world. A novel pylon–girder detached suspension structure was first adopted in the design of the Aizhai Bridge, which provided a new concept for the design of suspension bridges. Moreover, the application of a high-performance carbon fiber rock anchor system in the bridge provided a new method for applying high-performance carbon fiber materials in engineering structures. In addition, the construction method of the girder-conveying track cable technique proposed for the Aizhai Bridge successfully solved the problem of the erection of the stiffening girders of long-span suspension bridges in mountainous areas. This study mainly introduces the design method, the application of new materials, and the advanced construction technologies of the Aizhai Bridge.

This study presents the application of a novel negative stiffness and inerter damper (NSID) for structural response control of reinforced concrete (RC) elevated liquid storage tanks (LST). The innovative NSID combines the advantages of the two mechanical devices by concurrently combining negative stiffness dampers (NSD) and inerter mechanisms. A multi-degree-of-freedom staging system with a two-mass lumped model (sloshing and rigid masses) for the liquid-filled container is used to model the RC-elevated LST. The stiffness constants associated with these lumped masses are calculated based on the tank wall and liquid mass parameters. The governing equations for the elevated LST model with NSIDs are derived and represented in state-space form. Time history analysis is carried out under near-fault (NF) and far-field (FF) earthquake records to investigate the performance of NSIDs as supplemental dampers. The most effective NSID parameters are found by optimizing them using a parametric analysis. Three different design scenarios based on different placements of NSIDs along the height of an elevated LST are presented. The overturning moment, base shear, rigid mass accelerations, and sloshing displacements are the objective parameters for evaluating the seismic performance and control efficiency of the NSIDs. Numerical studies show that the optimum NSID utilizes a minimum dashpot coefficient and effectively reduces the structural response quantities. In particular, the controlled LST shows a maximum 61.8% reduction in overturning moment compared to uncontrolled LST, which is a considerable decrease.

The perennial deficiencies of the failure models in the materials field have profoundly and significantly impacted all associated technical fields that depend on accurate failure predictions. The heart of this study is the presentation of a methodology that identifies a newly derived one-parameter criterion as the only general failure theory for noncompressible, homogeneous, and isotropic materials subjected to multiaxial states of stress and various boundary conditions, providing the solution to this longstanding problem. This theory is the counterpart and companion piece to the theory of elasticity and is in a formalism that is suitable for broad application. Utilizing advanced finite-element analysis, the maximum internal breaking stress corresponding to the maximum applied external force is identified as a unified and universal material failure criterion for determining the structural capacity of any system, regardless of its geometry or architecture. A comparison between the proposed criterion and methodology against design codes reveals that current provisions may underestimate the structural capacity by 2.17 times or overestimate the capacity by 2.096 times. It also shows that existing standards may underestimate the structural capacity by 1.4 times or overestimate the capacity by 2.49 times. The proposed failure criterion and methodology will pave the way for a new era in designing unconventional structural systems composed of unconventional materials.

Abstract

Failure modes of flexurally strengthened reinforced concrete (RC) beams can be broadly classified into full-bond response and partial-bond response. Among these, peeling (premature failure) and shear-block failure are closely related and cause catastrophic collapse. Provisions in current design standards are largely generalized (too simplified or too complex), and tend to ignore some key parameters. In particular, design standards have not clearly characterized the effect of shear on the peeling. In this work, experiments and numerical studies have been conducted to investigate the shear-peeling failure and differentiate it from other failure modes. The results have been used to extend the existing design recommendations. The proposed design procedure and the finite element (FE) models are validated, and the outcome is compared with the literature. The comparison and the use of the Chi-squared test showed that the proposed design formulations are more appropriate for calculating the moment capacity and predicting the sequence of failure modes of plated RC beams.

Practical Applications

Deterioration of the structure, an increased applied load, or an error in the design are only a few of the causes for the requirement for external strengthening. For example, the beams of many bridges and other constructed facilities urgently need strengthening (external reinforcement). After being retrofitted with fiber-reinforced polymer (FRP) or steel plate at the soffit, RC beams are vulnerable to various failure modes, including conventional failures and undesired early failures (such as plate debonding and peeling). The current design standards either include provisions that could be more generic (too simplistic) or more complicated for practitioners to utilize. Further, the focus is needed on some critical aspects and parameters that determine the failure type. For instance, since shear failure (not a premature failure type) and peeling (a premature failure type) may seem to be comparable in certain circumstances, it is essential that design guidelines accurately specify the influence of shear on the peeling. Although shear failure is also an abrupt failure, it is not uncertain. Therefore, this study provides handy guidelines (in the form of a graphic/diagram/chart) to help professionals evaluate existing structures that have undergone flexural strengthening in the past or to prevent or at least reduce the likelihood of such failures occurring during the design phase.

This paper describes effective design procedures and identify construction challenges encountered in mega revamp projects. Lessons learned through the execution of these projects are discussed. The paper fills existing gaps and pieces together engineering requirements for critical structures that are used in heavy industry. Numerical and simplified analytical models are provided to assist the engineers to model load transfers with reasonable accuracy. An overview of loading mechanisms of various systems is also provided for operational, testing and lifting conditions. Industrial examples are provided for steel modules, pipe racks, and equipment support systems. The procedures presented in the paper are computationally efficient and can be implemented in practice. The theoretical basis and merits of various methods used in the practice are also discussed.

This paper presents two models to design waffle slabs against concentric and eccentric punching shear. The suggested design models modify the current code provisions in two ways by replicating the loss of shear surface area of waffle slabs on the code shear critical section, implementing a modified concrete shear strength equation, and introducing a factor to account for the moment transfer for waffle slabs–column connections subjected to eccentric punching shear. The proposed models were verified with the test results of flat slabs from the literature and then applied to predict the punching shear of waffle slabs. The models agree well with the test results of waffle slabs and the test results of flat slabs.

The study focuses on the structural behavior of concrete-filled steel tubular (CFST) stub columns with conventional cement concrete and nano-silica blended (doses of 4%, 6%, 8%, and 10% nano-silica by weight) concrete core infill of M25 grade under a pure axial compressive load. The strength and deformation capacities, as well as failure modes, of the CFST columns were assessed with reference to steel hollow and reinforced concrete (RC) stub columns. At optimum replacement of cement with nano-silica, the increase in strength from filling the hollow steel columns is about 1.6 and 1.5 times for square and circular sections, respectively. The addition of 6% nano-silica to the cement concrete core of CFST columns showed 2.55 and 1.19 times more strength as compared to RC stub columns with square and circular sections, respectively. As a result, adding nano-silica to the concrete mix increases the core’s axial compressive load carrying capacity and strengthens the nano-silica blended CFST stub column. The addition of the optimum doses of nano-silica increases the higher rate of hydration and rapid formation of hydrated products in the cementitious matrix due to its higher specific surface area. Due to its higher specific surface area, adding the right amount of nano-silica speeds up the formation of hydrated products in the cementitious matrix and makes the rate of hydration faster.

This study aims to review and evaluate the performance of nonparametric and parametric models of magnetorheological (MR) dampers, which are commonly used as structural control devices. To do so, a comprehensive experimental investigation was conducted to examine the behavior of MR dampers to ascertain the performance of the control device while mimicking the alignment when it is used as a structural control device. A total of 156 performance tests were performed, and the results were compared with an optimal numerical Bouc-Wen model. The parameters obtained from performance testing were employed to define the coefficient of determination ($R^2$), which reflects the accuracy of the damper model in predicting the performance of the control device subjected to different external forces. The findings suggest that the parameters of the MR damper obtained from testing the device in a horizontal orientation that simulates its position in practical structural control applications can be reliably predicted by the modified Bouc-Wen model. This study provides useful information on the efficiency and accuracy of MR damper models that can be utilized in the realm of structural vibration control.

Minimizing construction cost while simultaneously meeting structural requirements has been an important topic. This study addresses the application of grey wolf optimization (GWO) to the cost minimization of T-beams subjected to ultimate loading. Both the objective and constraints functions take the self-weight of T-beams into account. Due to their section modulus, T-beams have a high ultimate bending moment capacity, especially over long spans. The objective function has been split into three subobjectives: concrete, steel, and formwork costs. Standard design constraints were followed. The constraint functions include the nonlinear behavior of concrete and steel. Ten T-beams of varied lengths were evaluated, and corresponding low-cost design solutions were provided. The relationship between the length of the T-beam and the efficiency of GWO was demonstrated. Comparisons between optimal solutions attained and standard design solution demonstrated conclusively that the proposed method typically results in large reductions in the quantity of building materials needed. This method can be easily adaptable to various types of RC frame construction and other building codes.

Abstract

Application of the robust optimization (RO) technique to ensure the least possible deviation of structural performance is gaining increasing attention in recent years. However, most RO studies have been conducted in the probabilistic domain, where sufficient uncertainty information is available to construct probability distribution functions of response parameters. But, in many cases, such as for structures under underground blast excitation, hazard parameters like charge weight and charge center distance do not have any definite probability density function. Only their ranges of variations are known to an engineer. Hence, it is more logical to model these parameters as uncertain-but-bounded (UBB) type, which requires only bounds of variations to characterize the uncertainty. The available RO studies in the UBB-domain mainly deal with static loads. Studies on time-variant dynamic loads, such as blast load, are scarce in the existing literature. Also, blast load time-histories show record-to-record variations in their signatures, even with the same setup of hazard parameters. This aspect cannot be considered by the conventional convex programming approaches of RO in the UBB domain. To address all these issues, a new RO procedure is proposed in the present study, which is based on the dual response surface method. The proposed RO procedure can transform the complex simulation-based RO procedure under dynamic blast load to an equivalent deterministic problem with explicit constraints. Thereby, the RO can be easily solved by a gradient-based optimizer. The effectiveness of the proposed approach is elucidated by the complex real-world problems of a multistory building and an underground reinforced concrete bunker. The results are compared with conventional RO approaches. The results show that the proposed approach consistently yields more economic as well as robust solutions in a computationally efficient way.

Practical Applications

This research provides a computationally efficient and easy means to yield economic and robust design solutions of structures subjected to stochastic underground blast excitation. The obtained solutions are robust, as these are least affected due to various sources of parameter uncertainty. The proposed approach is valid even for cases where no statistical distribution of input parameters is available. The efficiency of the proposed approach is tested for a multistory building and a reinforced concrete (RC) bunker, which are practical and complex structures. Material nonlinearity and soil–structure interaction have been considered. The proposed approach uses conventional easy industrial software SAP2000 and Matlab. The method, being generic in nature, can be applied for any form of load application, any type of structure, and any material and analysis type. The charts have been developed for the 20-story building and RC bunker, from which one can work out a budget and risk of explosion for an anticipated explosive charge weight, and charge center distance from the structure.

Geopolymer materials are extensively studied as they are considered more sustainable and eco-friendlier than ordinary Portland cement concrete. This study examined the mechanical characteristics of geopolymer composite. Ground granulated blast furnace slag (GGBFS) was utilized as a binder material. Both polypropylene (PP) and carbon fibers (CF) were added to 0, 0.75%, 1.0%, and 1.25% of the weight of the binder. Hybrid fiber was also used concurrently (CF-1.0 and PP-0.25; CF-0.5 and PP-0.5; and CF-0.25 and PP-1.0). Compressive strength, flexural strength, direct tensile strength, and modulus of elasticity were used to assess the mechanical properties. According to the findings, the best-studied fiber content was 1% for all the types of fiber inclusion (carbon, polypropylene, and hybrid fiber) which considerably improved the mechanical characteristics. However, carbon fiber had a greater impact on the mechanical properties than polypropylene fiber and hybrid fiber. Strain hardening and deflection hardening were achieved and indicated by multiple cracks and ultimate strength.

The beneficial effect of using hybrid frames is realized in terms of the reduction of some desired engineering demand parameters (EDPs). However, this is achieved at the cost of increasing the values of some other EDPs as compared to the rigid frame. A good balance between the two can be achieved by selecting the optimum number of semirigid (SR) connections. In the present study, two schemes of the selection of the optimum number of SR connections are presented to obtain the desired benefit of the hybrid frame. One scheme provides the optimum number of SR connections which provides the desired reductions in the base shear (BS) and total number of plastic hinges formed ($T{H}_{\max }$) with the marginal increase in the maximum inter-story drift ratio (${\mathrm{IDR}}_{\max }$). The other scheme provides the number of SR connections to be used for achieving the limiting drift allowed in the hybrid frame and accordingly, obtains the percentage reductions of the BS and $T{H}_{\max }$. Both schemes are developed using a graphical technique. Three illustrative examples are considered to demonstrate the efficacy of the two schemes using the nonlinear time history analysis under three types of earthquakes (i.e., near and far-field) at three peak ground accelaration (PGA) levels. The results of the study show that in both schemes of providing the optimum number of SR connections, significant reductions in the BS and $T{H}_{\max }$ can be achieved as compared to the fully rigid frame. The corresponding ${\mathrm{IDR}}_{\max }$ in the hybrid frames remains less than equal to the limiting value of the ${\mathrm{IDR}}_{\max }$ prescribed in the literature.

Structural engineers in the early stages of design will consider multiple system configurations, compositions, and materials, including multiple configurations within a single material, in an effort to select the best solution. When tasked to narrow down these options, engineers rely on a variety of skills, heuristics, and techniques, as well as their own expert judgement. Although there is no correct or incorrect technique, different methods could lead to different systems ultimately being selected depending on factors such as designer preference and experience with structural materials, criteria used, outside influences, design performance, and so on. For medical facilities that require higher performing solutions coupled with robust and often conflicting requirements across multiple discipline boundaries, objective decision making becomes more difficult while not overinfluencing biases in the decision process. In talking cues from engineering design, multicriteria decision-making methodologies (MCDMMs) could be a viable route for medical facility system selection. Such applications have been applied to the building industry but have not been heavily studied in the structural domain. This body of work highlights the effectiveness, usage, and applicability of MCDMM strategies for selecting structural systems given conflicting multidisciplinary criteria. MCDMMs have differing strengths and weaknesses (e.g., compensatory, voting, and rank ordering) that affect a rational decision maker’s ultimate choice, which have not been explored in depth. This study compares a set of different designs across well-established multidisciplinary criteria using three powerful methodologies: analytic hierarchy process (AHP), choosing by advantages (CBA), and Pugh matrix (PM). The project was a real built medical facility where this investigation was conducted as part of a research component to a capstone design course. The resulting MCDMM outcomes show that both AHP and PM rankings are identical for the best and second-best alternatives. CBA had slightly different results yet were very comparable. Similar results are present for the lowest ranking systems; they worse systems were identically ranked with AHP and PM.

This paper investigates the economic and operational impacts of two advanced technology initiatives at the Oregon Department of Transportation (ODOT). A three-dimensional (3D) engineered model (3D-EM) and automated machine guidance (AMG) are the results of the agency’s push to take existing 3D design software and create fully detailed 3D computer models for all applicable projects, leading the way for AMG to reach a highly accurate on-the-ground implementation of the project design. Following a case study approach, this paper presents a method to quantify the costs and benefits of this endeavor using return on investment (ROI) and benefit/cost (B/C) ratio, and a method to estimate the odds of PASS (success) for a grade verification point (GVP) using odds and odds ratio. The ROI showed a return of around $23 for every $1 invested in enabling 3D-EMs creation and thus facilitating AMG use on projects for the period from 2014 to 2016. The odds and odds ratio showed that AMG-equipped machines are much more accurate than traditional machines depending on Stakes. The odds of PASS for a GVP in AMG projects are estimated to be 416 times the odds of PASS for a GVP in Stakes projects. The primary contribution of this paper is that it shows how the two investigated technologies, especially when working together, positively impact a state DOT (in this case ODOT) economically and operationally throughout the construction phase of projects.

There is little content on track–structure interaction in current manuals and standards. This paper suggests a method to compute permissible additional tensile and compressive stress in a continuously welded rail of a ballasted transit track due to track–bridge interaction. The method may be followed for other types of track, e.g., direct fixation fastener track. Thus, this paper provides a practical approach for calculation of additional rail stress limits for engineers practicing in the field of railway/bridge designs. The permissible additional tensile and compressive stress is suggested for a ballasted transit track on a bridge. Preventive measures are also discussed in the event of exceedance of permissible stress.