Real Construction Project Research Articles

A multi-server information-sharing environment for cross-party collaboration on a private cloud

Abstract Interoperability remains the key problem in multi-discipline collaboration based on building information modeling (BIM). Although various methods have been proposed to solve the technical issues of interoperability, such as data sharing and data consistency; organizational issues, including data ownership and data privacy, remain unresolved to date. These organizational issues prevent different stakeholders from sharing their data due to concerns regarding losing control of the data. This study proposes a multi-server information-sharing approach on a private cloud after analyzing the requirements for cross-party collaboration to address the aforementioned issues and prepare for massive data handling in the near future. This approach adopts a global controller to track the location, ownership and privacy of the data, which are stored in different servers that are controlled by different parties. Furthermore, data consistency conventions, parallel sub-model extraction, and sub-model integration with model verification are investigated in depth to support information sharing in a distributed environment and to maintain data consistency. Thus, with this approach, the ownership and privacy of the data can be controlled by its owner while still enabling certain required data to be shared with other parties. Application of the multi-server approach for information interoperability and cross-party collaboration is illustrated using a real construction project of an airport terminal. Validation shows that the proposed approach is feasible for maintaining the ownership and privacy of the data while supporting cross-party data sharing and collaboration at the same time, thus avoiding possible legal problems regarding data copyrights or other legal issues.

A hybrid simulation framework for modelling construction projects using agent-based modelling and system dynamics: an application to model construction workers' safety behavior

ABSTRACTThe integration of system dynamics (SD) with ideas from agent-based modelling (ABM) offers potential to combine the strengths of the two methodologies. By investigation of the previous research works, it is revealed that there is a lack of a simple and applicable framework to develop a hybrid SD–ABM simulation approach. This research proposes a hybrid SD–ABM simulation framework for modelling construction projects. The dynamics of project environment arising from the complex interrelated structure of various influencing continuous factors are taken into account using SD. The complexity of the system emerges from the interactions between different agents is also accounted by ABM. The SD and ABM simulation paradigms are finally combined. To evaluate the performance of the proposed hybrid simulation framework, it is implemented in a real construction project. The safety behaviour of different working groups involved in the project is modelled using the proposed hybrid simulation framework. The influence of safety behaviour of different working groups on the project performance is finally assessed. The achieved simulation results show how the value of unsafe behaviour of different agents is varied throughout the project duration due to the interactions with other agents as well as the safety-related regulations that exist in the site.

Improved Adaptive Harmony Search algorithm for the Resource Leveling Problem with minimal lags

Abstract The Resource Leveling Problem (RLP) aims to provide the most efficient resource consumption as well as minimize the resource fluctuations without increasing the prescribed makespan of the construction project. Resource fluctuations are impractical, inefficient and costly when they happen on construction sites. Therefore, previous research has tried to find an efficient way to solve this problem. Metaheuristics using Harmony Search seem to be faster and more efficient than others, but present the same problem of premature convergence closing around local optimums. In order to diminish this issue, this study introduces an innovative Improved and Adaptive Harmony Search (IAHS) algorithm to improve the solution of the RLP with multiple resources. This IAHS algorithm has been tested with the standard Project Scheduling Problem Library for four metrics that provide different leveled profiles from rectangular to bell shapes. The results have been compared with the benchmarks available in the literature presenting a complete discussion of results. Additionally, a case study of 71 construction activities contemplating the widest possible set of conditions including continuity and discontinuity of flow relationships has been solved as example of application for real life construction projects. Finally, a visualizer tool has been developed to compare the effects of applying different metrics with an app for Excel. The IAHS algorithm is faster with better overall results than other metaheuristics. Results also show that the IAHS algorithm is especially fitted for the Sum of Squares Optimization metric. The proposed IAHS algorithm for the RLP is a starting point in order to develop user-friendly and practical computer applications to provide realistic, fast and good solutions for construction project managers.

WBS-based dynamic multi-dimensional BIM database for total construction as-built documentation

Abstract As-built documentation is valuable to assist decision-making in project control, and building operation and maintenance applications. Given the importance of as-built documentation, the quickly maturing technology of building information modeling (BIM), an object-oriented information-integration platform, has led to the emergence of concurrent as-built documentation during the construction phase. However, in the current practice, integrating construction records into BIM remains a challenge due to their heterogeneous and unstructured data formats. This paper presents a work breakdown structure (WBS)-based database design to enable the creation of a dynamic multi-dimensional BIM database to incorporate construction records in a timely manner. In this study, the construction records were defined as additional dimension, and a WBS code-based automated linking mechanism between construction project tasks and BIM objects was created to generate the multi-dimensional BIM database. The automatic linking mechanism and the WBS-based dynamic multi-dimensional BIM database were tested and verified through the implementation of a real construction project schedule and a BIM model. The test results illustrate that the newly created method is successful in incorporating construction records collected during the construction phase to generate a dynamic BIM database for generating complete as-built documentation.

Study on the Expansion of a Cement-Based System Containing Sap Polymer and Supplementary Cementing Materials

In this paper, the addition of admixed superabsorbent polymer (SAP) improved the microstructure and durability-related properties in a cement-based system with supplementary materials. This is an important issue in real construction projects when good durability properties are required. This study investigates the effect of SAP on the systems using cement replacement by fly ash and silica fume considering the strength properties and durability properties of paste under sulfate attack of cement-based system. The replacement considered in the study was of 10% silica fume and 20% fly ash in each case, the dosage of SAP was 0.25% of the total amount of cementitious material. The results showed that the addition of SAP in the cement-based system improved the compressive strength and reduced expansion to sulfate attack. Scanning electron micrographs showed that utilization of fly ash with silica fume and silica fume with SAP resulted in a much denser microstructure, thereby, leading to an increase in compressive strength and lower expansion under sulfate attack.

Stability analysis of slope in strain-softening soils using local arc-length solution scheme

Soils with strain-softening behavior — manifesting as a reduction of strength with increasing plastic strain — are commonly found in the natural environment. For slopes in these soils, a progressive failure mechanism can occur due to a reduction of strength with increasing strain. Finite element method based numerical approaches have been widely performed for simulating such failure mechanism, owning to their ability for tracing the formation and development of the localized shear strain. However, the reliability of the currently used approaches are often affected by poor convergence or significant mesh-dependency, and their applicability is limited by the use of complicated soil models. This paper aims to overcome these limitations by developing a finite element approach using a local arc-length controlled iterative algorithm as the solution strategy. In the proposed finite element approach, the soils are simulated with an elastoplastic constitutive model in conjunction with the Mohr-Coulomb yield function. The strain-softening behavior is represented by a piece-wise linear relationship between the Mohr-Coulomb strength parameters and the deviatoric plastic strain. To assess the reliability of the proposed finite element approach, comparisons of the numerical solutions obtained by different finite element methods and meshes with various qualities are presented. Moreover, a landslide triggered by excavation in a real expressway construction project is analyzed by the presented finite element approach to demonstrate its applicability for practical engineering problems.

An effective approach with feasible space decomposition to solve resource-constrained project scheduling problems

Abstract Resource-constrained project scheduling problem is a classic problem in construction project. Aimed at solving this problem, an effective approach with decomposition on time windows is proposed in this paper. This approach is to select one activity to do decomposition and to partition the feasible space of the original problem into some feasible subspaces, in which solutions are generated by using an extended serial scheduling scheme. Double justification is also performed in the process of searching in subspace. Four strategies for selecting activity to do decomposition, three strategies for decomposition and a strategy on sampling size in various subspaces are designed. The results of experiments on two real construction projects show that the strategy based on degree for selecting activity and the strategy based on initial schedule for decomposition can obtain the best results. When compared with some other exiting algorithms, it is proven that the decomposition-based approach is effective and competitive.

A multi-attribute model for construction site layout using intuitionistic fuzzy logic

Abstract Most researchers have concentrated on studying optimization models to produce optimal construction site layout plans using different algorithms, while the overall method for evaluating and selecting the best site layout generated from optimization models has received less attention. In an optimization model, construction cost is generally considered in the objective function. However, several objectives, such as security and tie-in with external transportation, are difficult to quantify in the objective function and were not considered in previous studies. This paper focuses on evaluating and selecting the construction site layout considering qualitative objectives. An intuitionistic fuzzy multi-attribute decision-making model is developed that combines intuitionistic fuzzy set theory and the technique for order preference by similarity to the ideal solution (TOPSIS). This model overcomes the shortcomings of a traditional fuzzy set when describing ambiguous and unclear circumstances by using membership functions. The application of this model for site layout selection is shown to be reasonable and effective based on data from a real construction project.

Network Theory-Based Analysis of Construction Project Risks

<p>Because of their specific and complex characteristics, construction projects are exposed to numerous risks of various natures, which make their management more difficult. In this setting, Project Risk Management is an indispensable activity for their successful delivery. It consists in the risk identification, assessment, prioritization, treatment, monitoring and control. This paper presents a novel approach for the identification of construction project risks and a network theory-based methodology for their modelling and analysis. These models serve as a powerful tools comparing to classical methods and provide a support for decision-making regarding Project Risk Management. A case study of a real construction project is used to illustrate these findings.</p>

Optimizing the Utilization of Shareable Equipment in Multiple Shifts for Construction Projects

Construction equipment is often shared among many construction projects. In a real construction project, supply of this critical equipment is often limited, which often generates negative impacts on project performance. Multiple shifts are very effective and efficient for achieving schedule acceleration while resolving resource conflicts among project activities for shareable equipment. This paper presents a novel multiple-equipment shift-scheduling model that is capable of optimizing the utilization of critical and shareable construction equipment in multiple shifts for construction projects. The model is designed to help construction planners identify and generate optimal shift work plans and schedules that can simultaneously minimize the project duration and total shareable equipment utilization cost while complying with all of the availability constraints. An example is analyzed to illustrate the use of the present model and demonstrate its new and unique capabilities in optimizing equipment utilization in multiple shifts for construction projects.

Optimization of the construction scheme of the cable-strut tensile structure based on error sensitivity analysis

Optimization of the construction scheme of the cable-strut tensile structure based on error sensitivity analysis is studied in this paper. First, the element length was extracted as a fundamental variable, and the relationship between element length change and element internal force was established. By setting all pre-stresses in active cables to zero, the equation between the pre-stress deviation in the passive cables and the element length error was obtained to analyze and evaluate the error effects under different construction schemes. Afterwards, based on the probability statistics theory, the mathematical model of element length error is set up. The statistical features of the pre-stress deviation were achieved. Finally, a cable-strut tensile structure model with a diameter of 5.0 m was fabricated. The element length errors are simulated by adjusting the element length, and each member in one symmetrical unit was elongated by 3 mm to explore the error sensitivity of each type of element. The numerical analysis of error sensitivity was also carried out by the FEA model in ANSYS software, where the element length change was simulated by implementing appropriate temperature changes. The theoretical analysis and experimental results both indicated that different elements had different error sensitivities. Likewise, different construction schemes had different construction precisions, and the optimal construction scheme should be chosen for the real construction projects to achieve lower error effects, lower cost and greater convenience.

An improved robust buffer allocation method for the project scheduling problem

ABSTRACTUnpredictable uncertainties cause delays and additional costs for projects. Often, when using traditional approaches, the optimizing procedure of the baseline project plan fails and leads to delays. In this study, a two-stage multi-objective buffer allocation approach is applied for robust project scheduling. In the first stage, some decisions are made on buffer sizes and allocation to the project activities. A set of Pareto-optimal robust schedules is designed using the meta-heuristic non-dominated sorting genetic algorithm (NSGA-II) based on the decisions made in the buffer allocation step. In the second stage, the Pareto solutions are evaluated in terms of the deviation from the initial start time and due dates. The proposed approach was implemented on a real dam construction project. The outcomes indicated that the obtained buffered schedule reduces the cost of disruptions by 17.7% compared with the baseline plan, with an increase of about 0.3% in the project completion time.

Adoption of Cloud Based Decision Support System for Building Information Modeling Software Selection

An increasing numbers of BIM software available in market has led to selection problem among the construction companies. Furthermore, an adoption of BIM is not only involved numerous of attributes, but also required high investment. Thus, selection of appropriate BIM software that fit project need has becoming more apparent. Therefore, this study aims to provide an analytical tool to evaluate and select the most suitable BIM software in fuzzy environment through adoption of contemporary Information Technology (IT) which is Web 2.0. The proposed Web DSS namely topsis4BIM has based on a real construction project in Malaysia.An analytical methodology in topsis4BIM was based on Multi Attributes Decision Making method using fuzzy TOPSIS.The software were evaluated and selected by BIM expert based on seven attributes and five alternatives software. In addition, this study has introduced a new architecture of DSS development through the current Web technology such as Web 2.0 and cloud computing.

Development of a computerized risk management system for international NPP EPC projects

Over the past decade, Nuclear Power Plant (NPP) projects have been increasingly forced to cope with potential risks, which seriously impacted achieving the target completion time and cost. NPP projects have frequently exceeded the planned time and cost despite reliable estimates at the start of the project. This was attributed to unpredictable causes at the beginning and to shortage of proper tools to quantitatively analyze the inevitable uncertainties. To overcome these difficulties, computerized systems have been widely proposed in the construction industry as effective aids to proactively control the potential risks and to monitor continuously their status and variation. However, there are few risk management systems focused on NPP projects. In this study, we developed a computer-based risk management system for NPP projects, called Nuclear Risk Management System (NuRMS), which is helpful for furnishing project managers with warning signals as a project is progressing and for tracking the changes in risk variation at a desired confidence level. In developing the NuRMS, the Risk Breakdown Structure (RBS), the weights for risk categorization, computation of the Total Risk Score (TRS), and integration of risk analysis tools with relation-based and cost-loaded activity schedule were core tasks. To demonstrate the efficiency of the developed NuRMS, the system was operated using risk information derived from constructing the auxiliary buildings of Shin-Kori units 3 and 4 located in Korea, as an illustrative case. The results showed the system's capacities and suggested that it may be applied to a real NPP engineering, procurement, and construction project. The developed NuRMS is expected to assist a project manager in monitoring, tracking, and controlling potential impacts of risk events during the overall implementation of NPP projects.

Analyzing project cash flow by a new interval type-2 fuzzy model with an application to construction industry

Reliable knowledge of project cash flow is essential for effective project management. Since the nature of project is uncertain and easily effected by different criteria, considering uncertainty has become a vital part of any effective project management approach. Cash, as one of the most important project resources, requires reliable management techniques. In this paper, a new interval type-2 fuzzy project cash flow analysis model based on interval type-2 fuzzy project scheduling is proposed to predict project cash flow in different periods of project life cycle. Despite using type-2 fuzzy sets in various practical problems, they are new to project management; thus, they are used in this paper to address the uncertainty and lack of sufficient knowledge in project activity durations and costs. In the first part, interval type-2 fuzzy project scheduling model is introduced, and then the forward and the backward passes are defined. In order to improve this part, a new flexible and controllable method of interval type-2 fuzzy ranking is introduced. In the second part, a model of cash flow assessment is proposed under an interval type-2 fuzzy environment. This model is able to calculate the minimum and the maximum cash distribution, cash flow of project in different periods and total direct cost of projects in addition to cash flow uncertainty. The presented model provides the manager with a comprehensive insight into the cash required in different stages of project and helps the managers to locate the periods with highest uncertainty. The model also uses the concept of alpha-levels to analyze different levels of risk of uncertainty. For the purpose of illustration, the proposed interval type-2 fuzzy model is used to generate cash flow of main activities of a real construction project in a developing country, and the results are presented. The results present high flexibility of model in expressing and considering uncertainty and vagueness, in addition to its high capability in the risk evaluation. Finally, the results of the case study are used to present the managerial implications.

Risk and Uncertainty Assessment Model in Construction Projects Using Fuzzy Logic

In the global construction market, most construction companies are willing to undertake international projects in order to maximize their profitability by taking advantage of attractive emerging markets and minimize dependence on local market. Due to the nature of construction works, there are lots of risks and uncertainties associated with the company and project conditions. Therefore, how the profitability of the project changes with occurrence of various risk events, in other words, the sensitivity of project costs to risk events, should be estimated realistically. This paper offers a comprehensive risk assessment methodology that provides a decision support tool, which can be utilized through the bidding decisions for international construction projects introducing a risk model that facilitate this assessment procedure, prioritize these projects and evaluate risk contingency value. The risk models is developed using the analytic hierarchy process (AHP) to evaluate risk factors weights (likelihood) and FUZZY LOGIC approach to evaluate risk factors impact (Risk consequences) using software aids such as EXCEL and MATLAB software. The reliability of the developed software has been tested by applications on a real construction projects. The proposed methodology and decision support tool have been proved to be reliable for the estimation of cost overrun due to risk while giving bidding decisions in international markets. Therefore, the developed model can be used to sort projects based upon risk, which facilitate company’s decision of which project can be pursued. The developed risk model is validated, which prove its robustness in risk assessment (97%) in company level and (105%) in project level. It can also be used to sort construction projects based upon risk. The developed contingency risk model demonstrate the ability to evaluate risk contingency value by aggregating rules combining company risk index and project risk index using fuzzy logic approach and MATLAB software.

房地产类建设项目水土保持防治措施体系探讨

房地产类建设项目一般位于市区或城镇，其水土流失防治措施体系直接关系到城市生态环境的建设。笔者结合工作实际，分析了该类建设项目水土流失特点和水土流失危害，并提出了该类项目水土保持措施防治体系，以期为房地产建设项目的水土保持方案编制及水土保持措施体系的制定提供参考。 Real estate construction projects are generally located in urban areas or towns, of which soil erosion control measures system is directly related to the construction of urban ecological environment. To provide reference for establishment of soil and water conservation scheme of real estate construction project, as well as soil and water conservation measures, the characteristics of soil erosion and the hazard soil erosion in this kind of construction projects were analyzed. Furthermore, the control system of water and soil conservation measures for this kind of project was put forward.

Knowledge-based Minimization of Railway Infrastructures Environmental Impact

Life Cycle Assessment (LCA) and intelligent data analysis can help in reducing carbon and water footprints of rail infrastructure construction projects. The goal is to improve the railway construction processes with regard to their environmental impact, mainly in those aspects related to climate change such as carbon and water footprints.Based on a set of 27 indicators of every task in the construction process, a comprehensive compilation of basic information was performed, where the main project units and their sub-tasks were reviewed and analyzed.Afterwards, focus was on analyzing the transformation from environmental impact to carbon and water footprints, by means of the development of a consolidated evaluation methodology. A tool is being developed based on data mining and computational intelligence approaches. It will allow knowledge-based alternative project units scheduling, conditioned to previously selected specific footprint values and environmental indicators. This decision support system (DSS), based on multi-criteria and multi-objective intelligent optimization algorithms, will help to reduce carbon and water footprints of rail infrastructure construction projects by around 10% and 5%, respectively.Tests are going to be performed on two real high speed railway construction projects. That way, a global search procedure provides an analysis of the best alternatives in the scheduling and execution of the project units and their environmental impact offering a front of solutions displaying different trade-off amongst several ‘footprints’.Results will allow the development of a series of environmental impact indicators, which will support rail infrastructure construction companies becoming more sustainable and efficient by minimizing their environmental impact.

Construction Materials-based Methodology for Time-Cost-quality Trade-off Problems

Time, cost, and quality (TCQ) as a triple constraint of construction projects have dependent and conflicting objectives. Considering the limited resources, estimation of the approximate TCQ is a complex and dynamic problem. In addition, the uncertain nature of construction projects and highly variable alternatives make the decision making process a complicated issue. In order to overcome these difficulties, many researchers in the related academic literature introduced different mathematical models on the TCQ trade-off problem so far. In these models, two different approaches were used to estimate TCQ-related data. In the continues approach, it was assumed that the relationship among these three components could be expressed by continuous functions. In the discrete approach, it was accepted that (i) the construction method, (ii) the crew formation, and (iii) the crew overtime policy have some impacts on the project TCQ and that the relationships among these three components become discrete. However, in previous studies, construction materials that have a significant impact on TCQ of construction activities and projects were not taken into account completely during the data formation process. As an exception, El Rayes and Kandil [1] considered different strengths of concrete as material alternatives in a highway construction project. In fact, all the studies focused on proving the applicability of different optimization techniques instead of optimizing TCQ of a real construction project. In this context, some simple projects including a limited number of activities were used to evaluate the applicability of the developed models. Therefore, in the present study, it is aimed to outline a new two-step methodology, including the alternative construction material utilization, for TCQ trade-off problems, especially for building projects which enable the utilization of the high variety of construction materials. For this purpose, the impact of construction materials on TCQ of a project was explained in a detailed manner.

Estimation Of Task Completion Times With The Use Of The PERT Method On The Example Of A Real Construction Project

AbstractThe article presents briefly several methods of working time estimation. However, three methods of task duration assessment have been selected to investigate working time in a real construction project using the data collected from observing workers laying terrazzo flooring in staircases. The first estimation has been done by calculating a normal and a triangular function. The next method, which is the focus of greatest attention here, is PERT. The article presents a way to standardize the results and the procedure algorithm allowing determination of the characteristic values for the method. Times to perform every singular component sub-task as well as the whole task have been defined for the collected data with the reliability level of 85%. The completion time of the same works has also been calculated with the use of the KNR. The obtained result is much higher than the actual time needed for execution of the task calculated with the use of the previous method. The authors argue that PERT is the best method of all three, because it takes into account the randomness of the entire task duration and it can be based on the actual execution time known from research.