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Digital twins for medium span bridges – pilot project bridge Schwindegg – part 2: Asset Administration Shell The term ′digital twin′ is becoming increasingly popular in German‐speaking countries for the digital management and condition monitoring of bridges. Although standardised developments for the use of digital twins have already been initiated in industry and medicine, the first prototypes are currently being implemented in the construction industry. The digital images are typically operated in online environments that are proprietary to the project and have limited reusability. The article investigates the integration of scaling into Building Information Modelling models, which is reaching its limits due to the real‐time capability. It places existing definitions of the digital twin of the industry in the context of the construction industry. The implementation of the Isenbridge in Schwindegg as an Industry 4.0 Asset Administration Shell (AAS) is presented, building on Part 1 of this contribution. We show that an industrial, data‐driven digital twin can also be implemented technically and semantically for engineering structures. The article also presents the future challenges for evaluation and control mechanisms still to be developed for the structure. We also show a possible visualisation. The goal is to develop a syntax for the AAS' communication. [ABSTRACT FROM AUTHOR]

CO2 balancing of bridges with structure lengths up to 40 m As part of a research project, funded by the Gesellschaft für Energie und Klimaschutz Schleswig‐Holstein GmbH (EKSH), CO2 balancing was carried out on a total of 34 real and several hundred generated bridge constructions. The objectives were to develop empirical data, how much CO2 bridge constructions emit and to develop suggestions on how CO2 emissions can be reduced. [ABSTRACT FROM AUTHOR]

Basic and detail design of the Ruhr‐ und Harborcanal bridge in Duisburg The Oberbürgermeister Karl Lehr bridgesection in Duisburg is one of the four Ruhr crossings and has an overarching function for urban traffic and in particular for the industrial location around the port of Duisburg. As a result of the increased load from general traffic and freight traffic from the port, the bridge turned into a bottleneck. In order to cope with the increasing traffic load and increase its capacity, the existing traffic areas of the bridges needed to be expanded. A basic overhaul and extension of the existing, partly very old bridge structures, was ruled out due to their design and structural condition. Therefore, all structures along the bridge section will be replaced by new structures in the same position. This article explains the key aspects of the design and execution planning of the Ruhr and Harborcanal bridges, provides insights into the structural implementation and provides compact information about the overall project. [ABSTRACT FROM AUTHOR]

Experimental investigation on the fatigue behavior of spot‐welded reinforcement – Applications of semi‐precast elements in bridge construction In recent years, various applications for semi‐precast elements in bridge construction have been developed at the Institute for Structural Engineering at TU Wien. As in most cases spot‐welded reinforcement is used within the elements and special attention must be paid to material fatigue in bridge construction, an investigation thereof is of highest importance. After a brief overview of the possible implementations of the elements as well as standards regarding material fatigue, the experimental investigations on the fatigue behavior are presented. The experimental program consists of the testing of 18 axial‐loaded reinforcement bars with spot‐welded transverse elements as well as 12 large‐scale cycling bending tests. The findings confirm the existence of a residual phase in the realistic large‐scale system, resulting in a time period between the first rupture of a reinforcement bar and the total collapse of the system. This behavior is seen as advantageous for the application in practice, as it results in an additional reaction time for possible construction measures. [ABSTRACT FROM AUTHOR]

Digital twins for medium span bridges – pilot project bridge Schwindegg – part 1: sensor equipment In the coming years, bridge maintenance will be an essential task for infrastructure maintenance. Particularly for small and medium span bridges in the municipal road network, there are often no personnel available for structural inspection and maintenance. It will therefore be necessary in the future to develop concepts for semi‐automated bridge inspection. If information is available about the actions and resistances of the structures, the measured values contain important information about the condition of the structure. A concept for this could be digital twins. Intelligent maintenance management can be implemented on the basis of digital twins and the information they contain. Our two‐part article presents the concept of digital twins for medium span bridges. In the first part, the sensor equipment of a single span prestressed concrete frame bridge is presented for monitoring from a digital twin perspective. [ABSTRACT FROM AUTHOR]

BIM pilot projects Hunte bridge and Grawiede bridge – experiences with the BIM tool in design process The design for the replacements of the Hunte bridge and the Grawiede bridge were selected as BIM pilot projects by the Lower Saxony State Authority for Road Construction and Traffic (NLStBV). While the Grawiede bridge crosses a country road with a total span of 9 m over the Grawiede, the Hunte bridge, with a total span of 441 m, crosses the Autobahn 29 over the Hunte east of Oldenburg. These two very contrasting buildings are presented in the following article and the experiences of the drafters with the BIM tool are described. Both bridges were modeled three‐dimensionally, the construction process was linked to the models and finally the quantities and cost calculations were carried out using the models. The modeling depth thus corresponded to 5D BIM simulation. The advantages and challenges that resulted from the planning of the new replacement buildings using the BIM method are shown. [ABSTRACT FROM AUTHOR]

The data related to the failure of bridges that occurred during the period 1977–2017 in India have been collected from various sources, including print and electronic media. The data have been classified under various categories based on their material, cause of failure and others. More than 2130 bridges (excluding culverts and pedestrian bridges) have failed to provide intended service or got collapsed during various phases of construction in recent four decades. Reasons for failure of bridges during their service life as well as during the construction phase have been analysed. The average age of failure of bridges is 34.5 years, which is very low compared to the expected design life. A comparison of the failure cases is made with those from available literature and observed some unique failure patterns of bridges in India. The present study highlights that the collection of data made from open sources can provide information for drawing meaningful conclusions about the service life of bridges. Thus, helps in planning the infrastructural assets management and extending their service life. [ABSTRACT FROM AUTHOR]

Building information modeling (BIM) has been widely accepted in the industry and extensively used in supporting many construction tasks. In the government sector, the USDOT Federal Highway Administration (FHWA) has implemented building information modeling (BIM) for bridge construction. Hence, state DOTs are now faced with heightened pressure in complying with the FHWA's Bridge Information Modeling (BrIM) standardization. Although BIM can provide many benefits to DOTs, current BIM-based platforms for bridges are not fully developed to process traditional two-dimensional (2D) bridge drawings for BIM-based computational tasks involving existing bridges, for example cost estimation. Bridges are a critical infrastructure in any nation's economy, and by law the DOTs are tasked with ensuring that they remain safe for use. To maintain bridges, engineers currently perform periodic inspections, assessing each part of the bridge to identify areas that require maintenance. Maintenance work items are then generated for these areas; these are usually computed traditionally or by systems that still rely heavily on manual inputs. Such processes are time-consuming and cumbersome, and depend on years of bridge technical expertise. To overcome these limitations and improve the accuracy of processes such as generating maintenance work items for bridges, we propose a framework for automatically (1) processing existing 2D bridge drawings for bridges built pre-BIM adoption in the architecture, engineering, and construction (AEC) industry; (2) converting these record drawings into three-dimensional (3D) information models; and (3) converting 3D information models into industry foundation class (IFC) files. The developed 3D models using the proposed framework were compared against developed 3D models using the state-of-the-art method. Experimental results show that the developed framework can be used in developing algorithms that generate 3D models and IFC output files from portable document format (PDF) bridge drawings in a semiautomated fashion. The proposed method uses 3.33% of the time it takes the current state-of-the-art method to generate a 3D model, and the generated models are of comparative quality. [ABSTRACT FROM AUTHOR]

In order to understand the overall picture, the different technologies for the use of thin‐walled prefabricated elements in bridge construction as well as the first‐time application of them in a bridge project in Austria are described in this paper. Thereafter a newly developed construction method for the on‐site fabrication of lightweight box‐shaped segments from thin‐walled concrete elements, strengthened with steel girders, is explained with the focus lying on the construction of a prototype in a 1:1 scaling. The conceptional design, the manufacturing in a prefabrication plant in Austria and the transport to a construction site are illustrated. Finally, an application example of the new technology is shown based on a design using the incremental launching method. The research confirms the feasibility of the on‐site assembly of segments from thin‐walled prefabricated elements and that this construction method, once minor constructive details will be solved in the ongoing research project, has great potential for a broad application in bridge construction. [ABSTRACT FROM AUTHOR]

This work applies life cycle sustainability assessment techniques in the superstructures of small-span bridges for rural and vicinal roads by integrating them into the decision-making process to include sustainability indicators. The study subsequently investigated the potential environmental impacts of three bridge configurations as proposed by Brazilian public agencies, including steel and concrete composite bridges, standard precast concrete bridges, and standard wood bridges. The life cycle assessment and the ReCiPe endpoint methodology were used for three damage categories -ecosystems, human health, and resources' surplus costs- at the midpoint, and one potential impact category (global warming). The study was conducted using 27 bridges, including 11 precast concrete bridges, 13 steel and concrete composite bridges, and 3 wooden bridges. The best indexes were obtained in all categories for bridges composed of steel and concrete. The results reveal indexes that can serve as guides in bridge planning and construction, as this technique can be applied to several types of structures provided they have the same function to determine which is the most environmentally sustainable. [ABSTRACT FROM AUTHOR]

This paper demonstrates the analysis of the relative deterioration trends of the various types of bridge structural design and/or construction to determine and compare their operational structural performances at the serviceability limit states. The study derives operational data from the entire database of the U.S. National Bridge Inventory and analyzes the actual bridge deck areas rather than bridge counts. Deck areas more realistically reflect the actual sizes of bridge types, enabling a more reliable analysis of deterioration trends and providing more objective structural performances. The study analyzes the trends of the proportional accumulation of deterioration by bridge type, considering criteria based on the concept of structural deficiency and the objective of life-cycle expectancy for uninterrupted service life. The multiple-criteria diagnostic approach integrates the rate and pattern performances, based on deterioration trends, with the condition, durability, and longevity performances to determine and compare the overall equivalent structural performances using prioritized weights. As compared to inventory averages, the results reflect the distinct deterioration trends of bridge types and show a decrease in the equivalent structural performances by 10%. As compared to counts, the equivalent structural performances by areas are lower by 3% for all bridge types and 34-40% for some bridges. Also, the annual maximum average accumulation of structural deficiency of all bridge areas is nearly 20% lower than by counts. The average increase in structural deficiency is 0.42% per year, adding to the already existing 9.38% and constituting an average annual increase of structurally deficient (SD) bridge areas by 4.48%. The analysis also identifies premature accelerated accumulation of deterioration for a particular age group within a bridge type, indicating a critical need to investigate the etiology of the deterioration and improve existing and future bridges. The study provides a comprehensive national network-level comparative experience of the operational structural performances of bridge types by area under actual practices and circumstances to help identify critical deterioration, forecast future structural performance, and promote the sustainability of bridge types. [ABSTRACT FROM AUTHOR]

Underwater sound generated by pile driving was recorded during the Hong Kong-Zhuhai-Macau Bridge (China) construction in 2014.The important parameters on the source level, the transmission loss, the time-frequency characteristics, and the method of the noise measurement were introduced in this paper. Signal analysis showed that the waveform of pile driving resembles a series of short pulses, composed of many different frequencies with main frequency energy distribution from 100 Hz to 2 kHz; the maximum value occurs at about 200 Hz. The best-fit shallow water sound propagation model gave a root-mean-square source level of 208.2 dB re $$1~\upmu \hbox {Pa}$$ at 1 m, a transmission spreading coefficient of 17.76, and an absorption coefficient of 0.015 dB/m. The value of transmission loss is in good agreement with the results calculated by the Marsh and Schulkin (M&S) semi-empirical expressions above 1 kHz, but is higher than the M&S results under 1 kHz, which may be due to the muddy seabed and turbid sea water in our study area. Although it is difficult to compare our research results with other studies as there is a lack of details on monitoring conditions (including pile size, hammer energy, environmental background, etc.), this paper provides a new method for underwater noise monitoring and analysis for pile driving in shallow water. [ABSTRACT FROM AUTHOR]

The Delft3D-Flow hydrodynamic model was used to predict the impact of the Hong Kong-Zhuhai-Macau Bridge on the tidal flow in the Pearl River Estuary. In addition, the impacts of the flow currents on nearby bridge piers and artificial islands were assessed. To obtain additional spatial and temporal observations relative to the tidal gauge station observations, the sea surface height, which was derived from satellite altimetry ENVISAT RA-2, was closely correlated with the simulated tidal levels on individual days. These variables were modeled in the presence and absence of the Bridge, and the sea surface height validated numerical model was used to study the impacts of the Bridge on local water levels and circulation patterns. The construction of this Bridge resulted in small changes in tidal levels in that area. The average highest and lowest tidal levels changed by less than 0.01 m, which is about 0.4% of the highest tidal level and 2% of the lowest tidal level. The total tidal range changed by nearly 0.015 m. These results indicated that coastal engineering hardly affects the tidal flow in the Pearl River Estuary. In addition, complex eddy and circulation patterns were discovered near artificial islands. It is important to understand the complex flow patterns to ensure traffic safety during bridge construction and to determine the associated impacts of the bridge on tidal currents in the Estuary. [ABSTRACT FROM AUTHOR]

The automated people mover (APM) bridge project constructed at Princess Nora University (PNU) in Saudi Arabia and inaugurated in May 2012 is a major project with many challenges in design and construction due to its strict time-frame compared with the big scale of the project. Therefore, the design had to be such that it ensured simplicity, time-savings, lowest costs, aesthetics and the high quality required for bridge project elements. For aesthetic reasons, a box section was chosen for all the APM bridge sections for the bridge project, including straight, bifurcation and curved parts. This paper highlights the efficiency of the precast concrete techniques used in the design and construction of big projects such as this elevated APM bridge project at PNU in Saudi Arabia. [ABSTRACT FROM AUTHOR]

This paper demonstrates trends in bridge structural deficiency and evaluates the operational structural performance of various types of bridge structural design and/or construction. The study analyzes the database of the National Bridge Inventory and derives data based on actual bridge deck areas, rather than discrete bridge counts. Based on the concept of structural deficiency and the objective of life-cycle expectancy for uninterrupted service life, the multiple-criteria diagnostic analysis determines condition, durability, longevity, and equivalent performance. For some bridge types, the results reflect limited remaining service life before structural deficiency is reached. Average service life is only 56% of life-cycle expectancy. The relatively higher condition performance contrasts with the significantly poor performance of durability and the relatively lower longevity. The equivalent structural performance of some bridge types is low. Overall, the study provides an indication of the current average potential, which serves as a basis for predicting future performance under similar operational conditions. The systems approach supports more objective design, maintenance, and decision-making practices, leading to more effective operation and management and more sustainable infrastructure solutions. [ABSTRACT FROM AUTHOR]

The lifting of horizontally curved beams (or almost-straight beams with an imperfection in shape) is considered, with application in the construction of bridges. A circularly curved beam that is suspended at two symmetric locations by vertical or inclined cables is analyzed. The cross section of the beam is assumed to be doubly symmetric, the material is assumed to be linearly elastic, the cross-sectional dimensions are assumed to be small relative to the radius of curvature, and the deformations are assumed to be small. Both uniform (St. Venant) torsion and inclusion of nonuniform (warping) torsion are treated. Analytical equations are derived for the overall roll angle of the beam, the internal forces and moments, the weak-axis and strong-axis deflections, and the cross-sectional angle of twist. The behavior depends crucially on the locations of the lift points. [ABSTRACT FROM AUTHOR]

The high expectation of esthetic and functional quality in modern civil infrastructure has resulted in the increased demand for long span bridges. In advanced or developing countries, long span bridges such as cable-stayed and suspension bridges are considered even as landmarks that symbolize the prosperity or culture of the region. These long span bridges require higher level of design and construction technologies than other types of bridges. In particular, the construction of cable-stayed bridges involves precise and sophisticated operation of construction equipment such as derrick cranes. However, it is not easy to plan the operations of a derrick crane before the actual construction process takes place. Unexpected spatial constraints in the construction site may hinder the smooth operation of a derrick crane, which leads to lower than expected productivity and safety. This study applies interactive three-dimensional (3D) computer aided design (CAD) to the derrick crane operation for the purpose of identifying potential problems. Construction managers can have the two way process with the 3D CAD system to interactively test their construction plans and scenarios. The case study shows that the interactive 3D CAD system significantly improves the constructability of the cable-stayed bridge construction. [ABSTRACT FROM AUTHOR]

Construction of bridges is associated with uncertainties that rise due to unavailability of resources, equipment breakdown and/or working environment. Bridge construction techniques can be grouped into six main categories: 1) cast-in-situ on false work, 2) cantilever carriage, 3) stepping formwork, 4) launching girder, 5) pre-cast balanced cantilever, and 6) incremental launching. The latter technique is characterised by minimising the use of falsework. Further, the fabrication and casting of bridge segments are executed at a stationary location, named casting yard (which includes several facilities), deck form, concrete mixing unit, and pumping system. This paper presents a special purpose simulation model to capture the uncertainty associated with bridge construction. The model accounts for the interaction between the different involved resources in construction of bridges using incremental launching technique. The paper describes two methods (single form and multiple forms) of execution used for the segments fabrication. The proposed simulation model utilises STROBOSCOPE as a simulation engine and is coded by Visual Basic 6.0. An actual case study is presented to illustrate the capabilities of the developed model and validate its performance. [ABSTRACT FROM AUTHOR]

The terrorist attack on September 11, 2001 and subsequent potential threats to the United States transportation systems have presented an urgent need to develop emergency response plans in order to quickly react to the possible consequences of an extreme event. Highway bridges, as critical components of the nation’s transportation network, have received increased attention. To respond to the potential threats on highway bridges, a research project was conducted to identify rapid bridge replacement processes, techniques, and needs for improvements. To achieve the research objectives, the research team studied three cases of previous bridge replacements following extreme events. By studying these cases, the research team first sought to identify and expand on lessons learned and then addressed which actions did and did not work effectively under the incident circumstances. Using the lessons learned government agencies and engineering and construction communities could enhance their emergency response plans for future incidents. Next, the research team identified needed improvements so that the research community could investigate new technologies to advance current practices. [ABSTRACT FROM AUTHOR]

The terrorist attack on September 11, 2001, and subsequent potential threats to U.S. transportation systems have presented an urgent need to develop emergency response plans to quickly react to the possible consequences of extreme events. Extreme events include terrorist attack as well as man-made and natural disasters such as explosions, fires, floods, and earthquakes. The objective of this research was to identify strategies and technologies to quickly restore the use of highway bridges, a critical component of the nation’s transportation network, in case they are damaged or destroyed by extreme events. One of the tasks associated with this research was to conduct case studies of previous bridge replacements following extreme events. By studying these cases, the research team sought to identify and expand on lessons learned, address which actions did and did not work well given the circumstances of the incident, and incorporate lessons into the emergency response plan for highway bridges. This paper presents the findings from one of the case studies, the I-40 Webbers Falls Bridge in Oklahoma. [ABSTRACT FROM AUTHOR]

Both the importance and process of estimating highway construction time have increased in significance as roadway user costs themselves have become more significant. In estimating construction time, few parameters are more significant than work item crew production rates and factors significantly affecting those rates. A standardized data collection tool was used to acquire a total of 67 data points from 25 ongoing Texas highway projects between February 2002 and May 2004, for three selected critical work items: beam erection, bridge deck, and bridge rail. With the data, several hypothesized drivers of the crew production rates were analyzed. While the factor of shape of deck (straight versus curved) was identified as a statistically significant driver of bridge deck crew production rate, no statistically significant drivers were found for work items of beam erection and bridge rail. The study also found that both formwork and rebarwork crew sizes have significant relationships with bridge deck production rate. Findings from this study will enable highway agencies to enhance accuracy of contract time estimation for highway bridge construction. The methodology for obtaining field-based production rates will also be beneficial for future researchers. [ABSTRACT FROM AUTHOR]

This paper presents an embodied GHG assessment of a completed highway bridge renewal project in Canada and offers new insights on the strengths and limitations of BIM-based GHG assessments. Bridges play a critical role in transportation infrastructure. As reducing environmental impacts has taken on increasing urgency across the construction sector, bridges have received relatively little study. A quantitative understanding of the embodied greenhouse gas emissions (GHG) in bridges is needed to inform future infrastructure planning, design, and construction. Recent efforts to streamline environmental assessment in construction have led to the creation and adoption of Building Information Model (BIM)-based embodied GHG assessments, taking advantage of the quantity take-off functionality of BIM. However, as BIMs are rarely developed with environmental assessment as the primary goal, their effectiveness for GHG accounting can be limited. GHG assessments of the case study bridge using a BIM prepared before construction and using material and energy quantities records collected on-site during construction, are compared. Using only the quantities from preconstruction BIM, the embodied GHG for the case study bridge is 1.3 × 106 kgCO 2 e. After the adjustments for on-site data collection and factors commonly excluded from BIM, such as on-site fuel use from machinery, it rises to 4.06 × 106 kgCO 2 e, an increase of 212%. Results illustrate the need to change the scope and detail of BIMs if they are to be effective for embodied GHG assessment, and the potential limitations of using BIM in embodied GHG assessment. • Embodied GHG of a bridge is assessed using onsite records and preconstruction BIM. • Assessment based on onsite records resulted in a 212% increase in embodied GHG. • New insights on strengths and limitations of BIM-based GHG assessment are presented. • Results demonstrate BIM-based embodied GHG assessments need to be applied with care. • Scope and detail of BIMs need to be changed for effective embodied GHG assessment. [ABSTRACT FROM AUTHOR]

Accurate data collected from on-going construction projects assists project field engineers with tracking the progress of construction work. The comparison of as-planned schedules against the as-built status of construction enables the involved parties to determine project performance. Periodic monitoring of project performance enables timely identification of discrepancies between the schedule baseline and the project schedule. The rapid identification of discrepancies allows necessary measures to be taken to minimize the impact of a delay on the construction workflow. In transportation projects, the traditional means of acquiring as-built data from a construction site prevents involved parties from receiving the required information from the site in a timely manner. The delay in the communication of information ultimately causes subsequent delays in implementing necessary courses of action targeted toward improving the workflow. Therefore, this project develops a technology-supplemented progress monitoring approach. The approach implements as-built data with a high level of detail is obtained from a jobsite within a reasonable period of time using lidar technology while ensuring the safety of the data collector. The proposed framework utilizes point cloud data obtained using mobile lidar technology and 4D design models to identify deviations of the performed work from the planned work. The framework was tested using as-built data acquired from an on-going bridge construction project, and Percentage of Completion (POC) for the as-built bridge elements are calculated and compared with the as-planned POC. The differences between these two POC values for every element, on a particular scan date, are used for assessing the performance of the proposed framework. The obtained POC difference values ranged from −7% to 6% for most elements, which shows that the developed framework enables tracking the completion of individual bridge elements in an accurate and efficient manner. • 3D design models, construction schedule and mobile lidar data were used to report project progress information. • POC for the as-built bridge elements are calculated and compared with the as-planned POC. • Individual bridge elements can be monitored accurately and efficiently using the proposed framework. • The manual processing time for each epoch is approximately 1 h and 15 min for the case study. [ABSTRACT FROM AUTHOR]

This paper demonstrates the analysis of the deterioration trends of the various types of bridge structural design and/or construction in the entire U.S. National Bridge Inventory, to derive and compare operational structural performances. The approach considers the trends of the proportional accumulation of deterioration by bridge types, based on the concept of structural deficiency and the objective of life-cycle expectancy at the serviceability limit states. The analysis determines the rate and pattern of the deterioration trends. The multiple-criteria diagnostic approach integrates the rate and pattern performances with the condition, durability, and longevity performances to determine the overall equivalent structural performances using prioritized weights. This study produces the most comprehensive national network-level comparative basis of the operational structural performances of bridge types under the actual circumstances. The deterioration trend performances of most bridge types are relatively lower. Also, the overall equivalent structural performances of almost all bridge types are lower. The analysis also helps identify critical accumulation of deterioration for bridge types, suggesting focused improvement efforts necessary for existing and future bridges. The most common stringer/multibeam or girder bridges have relatively higher and faster accumulation of deterioration, generating a below average trend and equivalent structural performances. The results help predict future performances and improve effectiveness of bridge types for sustainable service life. [ABSTRACT FROM AUTHOR]

The construction process is inherently prone to risks. Risk management is an essential and integral part of project management on virtually all construction projects. Risk analysis is one of the core components of risk management that enables professionals to quantify and analyze risks that may pose potential threats to project performance in terms of cost, quality, safety, and time. This research was conducted to identify and analyze risks associated with bridge construction in Pakistan. A questionnaire was conducted to collect data. Risks affecting bridge construction project performance were identified through interviews conducted with engineers and managers involved with various bridge projects. Cost and schedule impacts of project risks were supplemented by conducting a case study using the Monte Carlo simulation. The key findings indicate that financial risks were a major factor that affected cost and schedule objectives. The highest ranked factor identified was unavailability of funds with a relative importance index greater than 85. The results of the Monte Carlo simulation were compared to the actual completion times and costs of activities in the case study. In all cases of this comparison, the actual completion date and costs fell within the predicted distribution of the Monte Carlo simulation, indicating that risk analysis can help project managers to manage cost and schedule risks. Additionally, this study provided risk analysis guidelines, which were unclear. The results of this paper can help engineers, cost control managers, and project managers evaluate particular risks on their projects and avoid delays and cost overruns. [ABSTRACT FROM AUTHOR]