Zhuojin Pipe Fitting Co., LtdApplication of Fuzzy Grey Relational Comprehensive Assessment in Risk Analysis of Fastener Steel Tube Formwork Support Systems
Literature Overview
This paper by Jin Weiliang and colleagues from Zhejiang University and Zhejiang Construction Investment Group, published in the Journal of Southeast University (Natural Science Edition) in 2006 (Volume 36, Issue 4), addresses the risk assessment of fastener steel tube formwork support systems (also known as scaffolding support systems) using a fuzzy grey relational comprehensive assessment method. The research was funded by the Ministry of Construction Research Project (05-R1-13) and Zhejiang Provincial Construction Department Science and Technology Project (Jiankefa [2003] No. 226).
Fastener steel tube formwork support systems are widely used in construction for supporting formwork during concrete pouring operations. These systems are subject to various risks including structural instability, connection failures, material defects, and improper assembly, which can lead to catastrophic collapses with serious consequences for worker safety and project schedules. The development of a systematic risk assessment methodology is therefore of critical importance for construction safety management.
Methodology and Assessment System Design
The study introduces fuzzy numbers into the grey relational comprehensive assessment framework, proposing a multi-indicator, multi-level grey relational comprehensive assessment method based on fuzzy number plane distance. This methodological innovation addresses the challenge of dealing with uncertain and imprecise evaluation data, which is common in construction risk assessment where expert judgments and field observations are inherently subjective.
The assessment system design follows a structured approach:
- Indicator system construction: A multi-indicator, multi-level evaluation system was developed specifically for fastener steel tube formwork support system construction risk assessment. The indicators cover structural design, material quality, assembly quality, construction management, and environmental factors.
- Weight determination: The weights of each evaluation indicator were determined through questionnaire surveys of 10 construction projects. This empirical approach ensures that the weights reflect actual industry practice and expert consensus rather than purely theoretical assumptions.
- Scoring system: The scoring values for each indicator were also determined through the questionnaire surveys, establishing a standardized basis for risk evaluation.
| Assessment Level | Example Indicators | Weight Determination Method |
|---|---|---|
| First level | Structural safety, construction quality, management | Expert questionnaire |
| Second level | Connection reliability, member stability, load capacity | Expert questionnaire |
| Third level | Specific measurable parameters | Expert questionnaire + field data |
The multi-level structure allows for systematic evaluation from broad categories down to specific measurable parameters, providing both a comprehensive overview and detailed diagnostic information.
Fuzzy Grey Relational Analysis Framework
The fuzzy grey relational analysis framework combines two powerful tools: fuzzy number theory for handling uncertainty and grey relational analysis for multi-criteria decision making. The key innovation is the use of fuzzy number plane distance as the measure of similarity between evaluation objects and reference standards.
The methodology involves the following steps:
- Fuzzification of evaluation data: The standard values and scoring values are represented as fuzzy numbers, acknowledging the inherent uncertainty in expert judgments and field measurements.
- Plane distance calculation: The distance between fuzzy numbers is calculated using the plane distance method, which considers both the position and spread of the fuzzy numbers.
- Grey relational grade calculation: The grey relational grades are computed based on the plane distances, providing a quantitative measure of the similarity between each evaluation object and the reference standard.
- Comprehensive assessment: The grey relational grades are aggregated using the determined weights to produce a comprehensive risk assessment score for each support system.
The use of fuzzy numbers is particularly appropriate for construction risk assessment because:
- Expert judgments about risk levels are inherently imprecise and can be represented as fuzzy numbers rather than crisp values.
- Field measurements often have measurement uncertainty that can be captured by fuzzy number representations.
- The fuzzy approach allows for a more nuanced assessment that reflects the true nature of construction risk, which is rarely black and white.
Engineering Practice Implications
The assessment method and system developed in this study have several practical applications in construction engineering:
- Pre-construction risk screening: The assessment system can be applied during the design and planning phase to identify high-risk support systems that require additional review or enhanced safety measures.
- Construction monitoring: The multi-level indicator system provides a structured framework for construction monitoring, ensuring that all critical risk factors are systematically evaluated during the construction process.
- Post-incident analysis: The methodology can be applied retrospectively to analyze the causes of support system failures, helping to identify which indicators were most predictive of failure and improving future risk assessment accuracy.
- Standardization and codification: The assessment system provides a basis for developing industry standards or guidelines for fastener steel tube formwork support system risk management, promoting consistent safety practices across the industry.
The questionnaire-based weight determination approach, while practical, has limitations that should be acknowledged. The sample size of 10 projects may not be sufficient to capture the full range of construction conditions and risk profiles. Future work should expand the sample size and consider using more sophisticated weight determination methods such as the Analytic Hierarchy Process (AHP) or entropy weight method to complement the expert judgment approach.
Summary
This study presents a systematic and innovative approach to risk assessment of fastener steel tube formwork support systems, combining fuzzy number theory with grey relational analysis to handle the uncertainty inherent in construction risk evaluation. The multi-indicator, multi-level assessment system provides a comprehensive framework for evaluating construction risks, and the questionnaire-based weight determination approach ensures practical relevance to industry practice. The application to 10 construction projects validates the methodology and demonstrates its effectiveness. Engineers and safety managers in the construction industry should consider adopting this assessment framework as a tool for systematic risk management of support systems, with appropriate adaptations to local conditions and project-specific requirements. The integration of fuzzy logic with grey relational analysis represents a methodological advancement that addresses the inherent uncertainty in construction risk assessment more effectively than traditional crisp-value approaches.