Safety Risk Identification and Assessment for Beijing Olympic Venues Construction

New technologies, new materials, and innovative designs have been extensively adopted in Beijing Olympic venues construction. The extreme requirements for time deadline and competition function expose the venues construction to high risks. These risks would potentially bring negative impacts on the site safety performance. Meanwhile, there is a lack of systematic management for safety risks in China’s construction industry, especially for large projects such as the Beijing Olympic venues construction. This paper identifies and assesses safety risk factors inherent in Beijing Olympic venues construction with the involvement of 27 experienced and highly respected experts from government agencies, the construction industry, and academe through brainstorming, workshop discussions, and questionnaire surveys. The finding reveals that more than half of the critical safety risk factors are from contractors and subcontractors such as: lack of emergency response plan and measures; workers’ unsafe operation, and contractors ignoring safety under schedule pressure. Based on these critical safety risks, a risk register is composed and a model is developed in application of the analytic hierarchy process to assess the status of risks on site safety. The model has been attempted in two Olympic venue projects under construction and the validity has been approved. The risk checklist, register, and assessment model developed in the paper were integrated into the risk management system that has been used for Beijing Olympic venues construction.     

New Method for Measuring the Safety Risk of Construction Activities: Task Demand Assessment

The task demand assessment (TDA) is a new technique for measuring the safety risk of construction activities and analyzing how changes in operation parameters can affect the potential for accidents. TDA is similar to observational ergonomic methods—it does not produce estimates of probabilities of incidents, but it quantifies the “task demand” of actual operations based on characteristics of the activity and independent of the workers’ capabilities. The task demand reflects the difficulty to perform the activity safely. It is based on (1) the exposure to a hazard and (2) the presence and level of observable task demand factors—that is, risk factors that can increase the potential for an accident. The paper presents the findings from the initial implementation of TDA and demonstrates its feasibility and applicability on two different operations: a roofing activity and a concrete paving operation. Furthermore, the paving case illustrates how the TDA method can compare different production scenarios and measure the effect of production variables on the accident potential. The findings indicate that the method can be applied on activities of varying complexity and can account for several risks and task demand factors as required by the user. The selection of task demand factors is a key issue for the validity of the method and requires input from the crew and safety management. The limitations of the methodology and the need for further research are discussed. Overall, TDA provides a tool that can assist researchers and practitioners in the analysis and design of construction operations.     

Construction Safety Risk Mitigation

Construction safety and health management has improved significantly following the Occupational Safety and Health Act of 1970. In response to this legislation, contractors began implementing safety programs to reduce occupational safety and health hazards on construction sites. Researchers recently found that the current process of selecting specific elements for a safety program is informal. This paper describes the results of a recent study designed to determine the relative effectiveness of safety program elements by quantifying their individual ability to mitigate construction safety and health risks. In order to determine the effectiveness of individual safety program elements, the following research activities were performed: (1) an appropriate safety risk classification system was created using an aggregation of relevant literature; (2) highly effective safety program elements were identified in literature; and (3) the ability of each safety program element to mitigate a portion of each of the safety risk classes was quantified using the Delphi method. The results of the research indicate that the most effective safety program elements are upper management support and commitment and strategic subcontractor selection and management and the least effective elements are recordkeeping and accident analyses and emergency response planning. It is expected that the data presented in this paper can be used to strategically select elements for a safety program, target specific safety and health risks, and influence resource allocation when funds are limited.     

Model for Environmental Risk Assessment of Tourism Project Construction on the Egyptian Red Sea Coast

An environmental risk assessment model was developed to evaluate the environmental risk associated with the construction of tourism projects along the Red Sea coast of Egypt. The model estimates the risk of causing environmental harm to existing ecological receptors, while considering the cumulative effect of different stressors and impacts. It combines risk assessment and environmental impact assessment (EIA) into a unified analysis process. It assists planners, cooperating with the EIA team, in the analysis of different planning alternatives, construction methods, and mitigation measures. It also assists decision makers in evaluating the submitted EIAs before issuing construction permits. The model is based on a specially designed network diagram that describes the intermediate links between construction activities and existing ecological receptors. Based on the model results, activities responsible for high risk levels could be tracked backward for better management, where the effect of different mitigation measures could be investigated.     

Quantitative Risk Assessment of Cut-Slope Projects under Construction

In some cut-slope projects landslide is a common problem during construction due to unfavorable geomorphological and geomechanical conditions. It is necessary to do a quantitative assessment of the risk posed by landslide before determining the budget or tender price. This paper outlines a general procedure for doing this, followed by an example to demonstrate the approach in comparison to a known failure. Finite-element analyses identify the most dangerous landslide scenario among all construction steps. The slope failure probability is then estimated using reliability theory based on the most dangerous construction step. After identifying the potential failure surface and estimating the volume of the sliding mass, the runnout behavior of sliding mass is simulated to delimit the extent of likely impacted area. Then, the exposed elements at risk and their vulnerabilities are identified and analyzed. The landslide risk is assessed quantitatively for three types of consequences: casualties, economic loss, and time overrun. Compared with actual consequences, the estimation results were in acceptable agreement with the case study. The paper demonstrates that it is feasible to analyze the risk associated with landslides during construction of cut-slopes.     

Understanding and Improving Your Risk Management Capability: Assessment Model for Construction Organizations

Implementing risk management in construction projects and organizations may bring a number of benefits and therefore it is necessary to have risk management as an integral part of a construction organization’s management practice. The aim of this paper is to develop a risk management maturity assessment model for construction organizations. The paper describes the development process of a Web-based RM3 (risk management maturity model), including its contents, its validation and testing, as well as its applications. The RM3 developed has five attributes namely, management, risk culture, ability to identify risk, ability to analyze risk, and application of standardized risk management process/system. These attributes are measured against four levels: initial, repeated, managed, and optimized. It is found that the proposed RM3 was suitable and useful. Using the RM3, it is found that the Australian construction industry’s overall risk management maturity level was relatively low (where 32% rated at Level 2 and 52% rated at Level 3). Furthermore, it is found that the weakest attribute was “analyzing risks” followed by “application of standardized risk management process.” It is therefore necessary to provide more training on qualitative and quantitative risk analysis to construction personnel and to develop and apply standardized enterprise risk management. It is concluded that the proposed RM3 is suitable for construction organizations to assess their risk management maturity levels and find ways for improvement.     

Evaluating Risk in Construction–Schedule Model (ERIC–S): Construction Schedule Risk Model

Research was undertaken to develop a method to assist in the determination of the lower and upper activity duration values for schedule risk analysis by program evaluation and review technique analysis or Monte Carlo simulation. A belief network was the modeling environment used for this purpose, and the resulting model was named Evaluating Risk in Construction–Schedule Model. The development of the belief network model consisted of four steps. First, construction schedule risks were identified through a literature review, an expert review, and a group review by a team of experts. Second, cause effect relationships among these risks were identified through an expert survey. This led to the development of the structure of belief network model. Third, probabilities for various combinations of parents for each risk variable were obtained through an expert interview survey and incorporated into the model. Finally, sensitivity analysis was performed. The model was tested using 17 case studies with very good results.     

Fast and Accurate Risk Evaluation for Scheduling Large-Scale Construction Projects

This paper presents the development of a novel probabilistic scheduling model that enables fast and accurate risk evaluation for large-scale construction projects. The model is designed to overcome the limitations of existing probabilistic scheduling methods, including the inaccuracy of the program evaluation and review technique (PERT) and the long computational time of the Monte Carlo simulation method. The model consists of three main modules: PERT model; fast and accurate multivariate normal integral method; and a newly developed approximation method. The new approximation method is designed to focus the risk analysis on the most significant paths in the project network by identifying and removing insignificant paths that are either highly correlated or have high probability of completion time. The performance of the new model is analyzed using an application example. The results of this analysis illustrate that the new model was able to reduce the computational time for a large-scale construction project by more than 94% while keeping the error of its probability estimates to less than 3%, compared with Monte Carlo Simulation methods.     

Construction Project Network Evaluation with Correlated Schedule Risk Analysis Model

Schedules are the means of determining project duration accurately, controlling project progress, and allocating resources efficiently in managing construction projects. It is not sufficient in today’s conditions to evaluate the construction schedules that are affected widely by risks, uncertainties, unexpected situations, deviations, and surprises with well-known deterministic or probabilistic methods such as the critical path method, bar chart (Gantt chart), line of balance, or program evaluation and review technique. In this regard, this paper presents a new simulation-based model—the correlated schedule risk analysis model (CSRAM)—to evaluate construction activity networks under uncertainty when activity durations and risk factors are correlated. An example of a CSRAM application to a single-story house project is presented in the paper. The findings of this application show that CSRAM operates well and produces realistic results in capturing correlation indirectly between activity durations and risk factors regarding the extent of uncertainty inherent in the schedule.     

Risk Assessment Model of Tendering for Chinese Building Projects

This paper presents a risk assessment model for tendering of Chinese building projects on the basis of identification and evaluation of the major risk events in the Chinese construction market, investigations and interviews from which the factors inducing the risk events were determined, questionnaires on building projects within China’s borders, and the logistic regression method. The findings show that, to a certain extent, the risk of tendering for projects and the risk of a contracted project can be assessed through analysis of factors such as owner type, source of project financing, existence or lack of past cooperation between contractors and owners, the intensity of competition for tendering, the reasonableness of the bid price, and the degree of support from the contracting company to its projects. The model can serve as a supplementary tool for Chinese contractors in making decisions for project tendering within Chinese borders. At the same time, it is of reference significance for international contractors, enabling them to further understand the risks in the contract market for Chinese building projects.     

Scheduling-Based Risk Estimation and Safety Planning for Construction Projects

This paper considers the issue of safety risks on construction sites. It introduces the concept of combined effect of different risk factors to the accident. For proper safety planning, safety managers need to be well aware of the direct causes of the accident as well as indirect factors that adversely effect on site safety. If it is observed that if a hazardous environment exists at the site, then either that hazardous environment must be eliminated or occupations and processes related to that hazard must be properly protected. One of the measures for evading such hazardous situations is to predict such situations and to reschedule the start time of high-risk situation so that risks are not concentrated during certain periods and at certain locations. In order to predict when and where the risk will reach its highest level, analysis should be performed based upon various information including statistical sources such as accident histories and this should be done in coordination with the activity scheduling. This paper analyzes the result of accident history and provides information about vulnerable situations. In addition, it presents a theory of safety planning method which estimates the risk distribution of a project and helps the safety manager to both estimate situations of concentrated risk and then to reschedule it when it is necessary.     

Risk-Based Safety Impact Assessment Methodology for Underground Construction Projects in Korea

Safety of construction projects may be affected by various factors such as types and scale of projects, construction methods, safety management procedure, climate, site conditions, etc. Among them is the quality of design in relation to safety. Presently, however, designers typically are not involved in construction safety. They are often uncertain of their responsibilities in relation to construction safety and fail to be responsible for avoiding or reducing safety-related risks. In this study, the concept of safety impact assessment to achieve “design-for-safety” in the design phase is introduced. For this purpose, a safety impact assessment model was devised, and a methodology using the risk-based safety impact assessment approach for open-cut type underground construction projects in Korea is suggested. The suggested methodology includes a safety information survey, classification of safety impact factors caused by design and construction, and quantitative estimation of magnitude and frequency of safety impact factors. A checklist which can be easily used for assessing the safety performance of design products is also proposed. A real-world case study on the safety impact assessment of a subway construction project in Korea is also provided in the paper.     

Assessment of Safety Performance Measures at Construction Sites

Various methods for the measurement and classification of safety performance at construction sites, e.g., timing relative to the moment of accident, data collection method, safety effectiveness criterion, performance measure, and frequency and severity of the measured event, are analyzed. The effectiveness of the various methods and the extent of their use at construction sites are examined. Attributes that are investigated include efficiency, reliability, and validity and diagnostic capacity of the measure in order to identify the cause for success or failure, respectively, of the safety program at a site. The data for the study were collected through questionnaires which were addressed to the largest construction companies in the United States. The most effective and the most widely employed measurement methods were lost‐day cases, doctor's cases, and cost of accidents. The least effective and most limited in use were the no‐injury cases.     

Construction Project Risk Assessment Using Existing Database and Project-Specific Information

This paper develops a risk assessment methodology for construction projects by combining existing large quantities of data and project-specific information through updating approaches. Earlier studies have indicated that risk assessment is still difficult for practicing engineers to use due to the requirement of data on too many input variables. However, the availability of existing large quantities of data and project-specific information makes it possible to simplify the risk assessment procedure. Two main ideas are pursued in this paper to facilitate practical implementation: identify and evaluate the critical risk events, and develop a systematic updating methodology. Both epistemic and aleatory types of uncertainties in the data are considered, and corresponding updating procedures are developed. The proposed methodology is illustrated for the construction risk assessment of a cable-stayed bridge.     

Risk Assessment Methodology for Underground Construction Projects

This paper presents a risk assessment methodology for underground construction projects. A formalized procedure and associated tools were developed to assess and manage the risks involved in underground construction. The suggested risk assessment procedure is composed of four steps of identifying, analyzing, evaluating, and managing the risks inherent in construction projects. The main tool of the proposed risk assessment methodology is the risk analysis software. The risk analysis software is built upon an uncertainty model based on fuzzy concept. The fuzzy-based uncertainty model is designed to consider the uncertainty range that represents the degree of uncertainties involved in both (1) probabilistic parameter estimates and (2) subjective judgments. Other tools developed in this study include the survey sheets for collecting risk-related information and the detail check sheets for risk identification and analysis. The paper finally discusses a detailed case study of the developed risk assessment methodology performed for a subway construction project in Korea.     

Generic Process Mapping and Simulation Methodology for Integrating Site Layout and Operations Planning in Construction

The present research is intended to address dynamic construction-process simulation methods, with a focus on how to effectively model resource transit among various activity locations in the site system. Following a review of basic simulation paradigms and recent research developments, we propose a new process mapping and simulation methodology for modeling construction operations. The simulation algorithm is presented and the process mapping procedure is illustrated step by step using an earth-moving example featuring technology and resource constraints. It is straightforward to convert the resultant process mapping model describing workflows and resource flows over site locations into a simulation model. A STROBOSCOPE model is formed for the same problem definition to contrast and cross-validate our methodology with the established activity cycle diagram-based modeling approach. One additional case of modeling the concreting site operations by the hoist and barrow method is also given to demonstrate the application of the proposed methodology in practical settings.     

Fuzzy Analytical Hierarchy Process Risk Assessment Approach for Joint Venture Construction Projects in China

Research and practice show that construction joint venture (JV) activities in China are opportunities that can bring potential benefits but at the same time may generate many risks. While research has studied these risks and presented useful advice for managing individual risks, the methodologies used to analyze the risks were mainly qualitatively based, and there is a gap in using the quantitative method that can integrate a risk expert’s knowledge to assess the risks associated with JV projects. This paper sets up a hierarchy structure of the risks and then develops a fuzzy analytical hierarchy process (AHP) model for the appraisal of the risk environment pertaining to the JVs to support the rational decision making of project stakeholders. An empirical case study is used to demonstrate the application of the proposed fuzzy AHP model. It is concluded that the fuzzy AHP model is effective in tackling the risks involved in JV projects. The information presented in this paper should be shown to all parties considering JV business opportunities in China, and the proposed approach should be applicable to the research and analysis of risks associated with any type of construction projects.     

Integrating Construction Operation and Context in Large-Scale Construction Using Hybrid Computer Simulation

This research proposes a hybrid simulation approach based upon the principles of system dynamics (SD) and discrete event simulation (DES), which facilitates a better understanding of complex interactions among various processes in large-scale construction. The significance of the construction context that interacts with construction operations is highlighted, and a hybrid SD-DES approach is proposed as a means to capture the feedback between the two. In particular, this paper focuses on how to seamlessly integrate SD and DES within the framework of a modeling perspective. For the purpose of substantiating the discussion, a pipeline installation process is modeled using the proposed hybrid approach, with specific consideration given to how the approach can serve to address complex interactions between operation and context.     

Measurement and Risk Scales of Crane-Related Safety Factors on Construction Sites

This paper addresses quantitative measurement and risk scales of safety hazards on construction sites due to the work of tower cranes. Hazard measurement and risk scales are essential components of an integrated model aimed at quantitatively determining the safety level of individual construction sites, on a comparative basis. The paper focuses on two factors identified in earlier studies as considerably affecting safety on sites with tower cranes, “overlapping cranes” and “operator proficiency.” These two factors are inherently different from each other in their characteristics and therefore also in the methods used to measure both the factors and the risk resulting from them. A probability-based method was prescribed for the measurement of overlapping cranes, while the analytical hierarchy process method and knowledge elicitation from experts were applied to develop metrics for operator proficiency. In both cases, an intimate understanding of the crane work environment is necessary. The uniform format and specific methodologies presented here can be used in the development of measurement techniques and risk scales for other safety factors concerning crane operation on construction sites.