Michael C.H. Yam

Determining Safety Climate Factors in the Repair, Maintenance, Minor Alteration, and Addition Sector of Hong Kong

The accident record of the repair, maintenance, minor alteration, and addition (RMAA) sector has been alarmingly high; however, research in the RMAA sector remains limited. Unsafe behavior is considered one of the key causes of accidents. Thus, the organizational factors that influence individual safety behavior at work continue to be the focus of many studies. The safety climate, which reflects the true priority of safety in an organization, has drawn much attention. Safety climate measurement helps to identify areas for safety improvement. The current study aims to identify safety climate factors in the RMAA sector. A questionnaire survey was conducted in the RMAA sector in Hong Kong. Data were randomly split into the calibration and the validation samples. The RMAA safety climate factors were determined by exploratory factor analysis on the calibration sample. Three safety climate factors of the RMAA works were identified: (1) management commitment to occupational health and safety (OHS) and employee involvement, (2) application of safety rules and work practices, and; (3) responsibility for health and safety. Confirmatory factor analysis (CFA) was then conducted on the validation sample. The CFA model showed satisfactory goodness of fit, reliability, and validity. The suggested RMAA safety climate factors can be utilized by construction industry practitioners in developed economies to measure the safety climate of their RMAA projects, thereby enhancing the safety of RMAA works.

Empirical Study to Investigate the Difficulties of Implementing Safety Practices in the Repair and Maintenance Sector in Hong Kong

Repair, maintenance, minor alteration, and addition work (RMAA) has become more and more important in developed societies, but its safety performance is alarming. For example, RMAA projects accounted for 53.2% of the total construction market and the percentage of RMAA accidents to all construction accidents in the Hong Kong Special Administrative Region (HKSAR) increased considerably in 2007. The RMAA sector has a huge potential for safety improvement. This study aims to explore and evaluate the difficulties of implementing safety practices in RMAA work. The mixed methods approach was adopted, and semistructured interviews and a two-round Delphi survey were conducted for the data collection. Major difficulties were identified, including limited safety resources for small and medium enterprises (SMEs), difficulty in changing the mindset of RMAA workers, and difficulty in performing safety supervision. These obstacles for implementing safety practices in the RMAA sector, if successfully removed, could significantly improve the safety performance of the RMAA sector and the construction industry as a whole.

Feasibility study of shape memory alloy ring spring systems for self-centring seismic resisting devices

Shape memory alloys (SMAs) have recently emerged as promising material candidates for structural seismic resisting purposes. Most of the existing SMA-based strategies, however, are based on the wire or rod form of SMAs, where issues such as gripping complexity and fracture may exist. This paper presents a proof-of-concept study on an innovative type of SMA-based self-centring system, namely, a superelastic SMA ring spring system. The proposed system includes a series of inner high-strength steel (HSS) rings and outer superelastic SMA rings stacked in alternation with mating taper faces, where the resisting load is provided by the wedging action which tends to expand the outer rings and concurrently to squeeze the inner rings. The superelastic effect of the SMA offers energy dissipation and a driving force for recentring, and the frictional effect over the taper face further contributes to the overall resisting load and energy dissipation. The feasibility of the new system is carefully examined via numerical studies considering the parameters of ring thickness, taper angle, and coefficient of friction. The key hysteretic responses, including resisting load, stiffness, stress distributions, source of residual deformation, energy dissipation, and equivalent viscous damping, are discussed in detail. The behaviour of the SMA ring springs is also studied via analytical models, and the analytical predictions are found to agree well with the numerical results. Finally, two practical applications of the new system, namely self-centring HS-SMA ring spring connections, and self-centring SMA ring spring dampers, are discussed via comprehensive numerical studies.

Critical success factors for building maintenance business : a Hong Kong case study

Purpose – Thie purpose of this paper is to present the critical success factors (CSFs) for engaging in the building maintenance business in Hong Kong where maintenance is a major market sector. Design/methodology/approach – In this study, CSFs are identified for the business of building maintenance based on data collected from a questionnaire survey and interviews. Findings – A total of 12 CSFs are identified, such as clients satisfaction, certification of company, reliability of service, quality of service, and company reputation, and most are related to two principal factors, namely maintenance service and organization, and project management. Originality/value – This paper provides a review of building maintenance in Hong Kong and identifies a list of success factors for the business of building maintenance. The identified CSFs and principal factors provide useful reference for maintenance contractors to have a clear understanding of the expectations of the building maintenance market in Hong Kong.

Study of Stress Intensity Factor of a Cracked Steel Plate with a Single-Side CFRP Composite Patching

Composite fiber patching techniques have been considered as alternatives to traditional methods of strengthening and fatigue crack repair in steel structures. It is known that the fatigue strength of a cracked steel element depends on the stress intensity factor (SIF) at the crack tip which is a function of the stress/strain distribution of the plate. This paper presents an experimental study of tension tests of cracked steel plates repaired by single-side carbon fiber-reinforced polymer (CFRP) patching in investigating the strain distribution in the vicinity of the cracked region. The test parameters included patch length, patch width, tapered end, and axial stiffness ratio of adherend. It is shown from the test results that the single-side CFRP patching applied onto the cracked steel plate decreased the crack tip strains significantly in the patched face and increased the strains in the unpatched face. Finite-element analyses of the specimens using both the three layers model proposed by previous resear...

Findings from a research study of construction safety in Hong Kong: Accidents related to fall of person from height

Purpose – Falls continue to be the major cause of fatalities in the Hong Kong construction industry, as well as in other countries. Published statistics of the Labour Department, Hong Kong Special Administrative Region (HKSAR) showed that from 2000 to 2004 approximately half of the fatal construction accidents were a result of fall of person from height. In view of this phenomenon, the purpose of this paper is to present the findings and recommendations of a research paper which investigates the problems associated with fall of person from height in the construction industry.Design/methodology/approach – Accident data obtained from the Architectural Services Department, HKSAR, was analysed according to the 14 available factors collectively to derive explanations for common situations and reasons leading to fall accidents.Findings – The findings of this rigorous analysis are presented to practitioners whose feedback on the findings are recorded by means of a questionnaire survey. The responses from the sur...

Dressing behavior of construction workers in hot and humid weather

BACKGROUND: Construction workers in Hong Kong face high health risks of heat stress, solar ultraviolet radiation, and hazardous substances. A suitable work wear can lower exposure to these hazards, but the actual dressing behavior of construction workers remains unknown. OBJECTIVE: This study examines the current dressing patterns of construction workers and evaluates their limitations. METHODS: The dressing patterns of construction workers were investigated through unconcealed videotaped observation and questionnaire survey to enhance the reliability and validity of this research. RESULTS: Results indicate that construction workers were willing to wear short-sleeved shirts for a cooler feeling, although such dressing patterns may not protect them against solar ultraviolet radiation or hazardous substances. Their preferred darkcolored long pants can decrease the direct exposure to solar ultraviolet radiation and hazardous substances, but they absorb a large amount of radiation heat that increases the hazards of heat stress to the wearers. CONCLUSIONS: Thermal-related attributes were the most significant concerns of construction workers, which serve as key elements for designing appropriate work clothes for construction workers.