Construction Safety in Design Process Roozbeh Ghaderi¹ , Mohammad Kasirossafar² ¹ Member ASCE, Department of Civil and Enviromental Engineering, Amirkabir rd University (Tehran Polytechnic). Postal code 71436-84548, # 10.1, Sarv alley, 3 st , Eram st, Shiraz, Iran; PH (+98) 917-712-4569; FAX (+98) 711 225-1440; email:
[email protected] ² Department of Civil and Enviromental Engineering, Amirkabir University (Tehran Polytechnic). P.O. Box 91865-588, Mashhad, Iran; PH (+98) 915-110-9887; FAX (+98) 511 765-6622; email:
[email protected] 1- ABSTRACT
Concerning the risk and incidents happening unexpectedly at working sites all around the world, construction industry has one of the first ranks between others according to relevant international and official statistics and formal evidences. Considering loss of life and property which such an incident can impose to the human being and society, it is obviously concluded that preventing from such accidents will preserve parts of human and financial sources which are both economic production factors. When it comes to construction, the main factor of accidents happening may briefly be entitled to the shortage of safety and security. This article is structured to believe that the main concept of safety is related to the quality of design rather than construction process and is trying to prove the fact that designers are the most capable to decrease the incidence rate of accidents.Some research results are included in this article to support of above mentioned issue and it is Indicated that 33% of incidents are linked to design process in Iran. Therefore undeniable role of designers and consultants is consequently highlighted enough due to access to the safe construction. In other words, the more applying the safety in architecture and structure design can lead us to the fewer incidents while construction and operation process. Keywords: Design for safety; Construction hazards; Architecture and Structure Design; Safety in Construction Contracts
2- INTRODUCTION
In the past, safety programs were usually based on “reform after incident” which dealt with incidents examination and control. With this meaning, that safety engineering come into action after occurring an event and it was attempted to identify the causes of event by doing the required investigations, and was utilized the results as a base for restraining of similar incidents occurring. Safety activities of this kind have two major deficiencies. First, it must occurs an event then safety
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engineering would do an action which leads to imposing high expenses and its other deficit was disability in complete recognition of preventable happenings. With evolution and development of restraining systems, this idea emerged that for the safety of systems refinement it should not be let the incidents occur anymore. So it was made an effort to develop methods for analyzing the events in order to determine happening of the potential of such risk before system operation. Nowadays, the results of these efforts have been caused that safety is based on the well-designed, organized program and as a “pre-occurrence” approach which is posed on the basis of “analysis-control” method. At the present time it is believed that in new safety systems, emphasis should be on acceptable level of safety in design phase and before production or operation and evaluation of system risks before imposing loss. According to statistics, which is presented by labor administration of different countries, and international organizations every year, most occurrence of occupational risks and workplace incidents are happening in construction industry. Also construction incidents are leading to delay in the process of project progress, increase in expenses and incurring a loss to contactors reputation and reliability (Wang et al, 2006). In spite of public believes, which say most of incidents are happening due to workers carelessness, it is more possible that decisions of high rank authorities can play an important role in occurring of incidents in constructing industry. Today’s advancements in identification of hazards and evaluation of risks in construction projects are not only far way from ideal, but also safety management system are still challenging with informational hindrances (not registering and sharing the incidents report and lack of informational sources in smaller projects for risk analysis). Preventing of identifiable risks occurrence and removing them is always more secure and more economical than finding a cure after incident occurrence. If we find the roots of construction incidents, we find not only contractors but also designers (architects and structural engineers) would affect the health and safety of construction workers (Gambatese and Hinze, 1999; Behm, 2005; Frijters and Swuste, 2008; Gambatese, Behm and Rajendran, 2008; Toole and Gambatese, 2008). Perhaps in the past no one was thought of designers’ role as an effective factor in projects safety. Unfortunately designers are not aware of their impact on construction safety but they do not have the required knowledge and experience for playing an effective role in the safety. 3- RESEARCH LITERATURE 3-1- Safe Design Concept
In 1985, international labor organization obliged the designers to consider the identification of safety condition. Investigation about relationship between design
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and safety of construction in England proved that there is a close relationship between design and idea of safe construction ( Jeffrey and Douglas, 1994). Szymbereski (1997) declared the major priority for implementing of safe construction is considering the safety in design phase. There are a lot of obstacles in the performance of safety design idea, here we mention two cases of them. 3-1-1- Legal Issues and Concerns of Responsibility
In several studies, designers’ solicitudes have been examined in regard to legal prosecution and extension of their responsibilities for incidents. Due to legal complications, many designers avoid too much focusing on safety issue (Hinze & Wiegand, 1992). According to Coble study (1997) regulations are just making a small portion of designers to interfere in the idea of safe design. A clear development in England has resulted in ratification of body of laws CDM Construction (Design and Management) Regulations. This regulation was applied in 1995 which force designers to consider safety in course of design in order to be assured that there are some preventing ways of potential risks in project construction phase. The aim of CDM regulations is providing a revolution in construction culture with use of all potentials and progress in consideration and solving workplaces safety and health matters (Owain Jones, Tony Baxendale, 1999). In 2002, France and some European courtiers also ratified a set of instructions (Gibb, 2004). These regulations make the designers responsible to workers for providing safety and health (Behm, 2005). 3-1-2- Construction Contracts
One of the implementation obstacles of safe design idea is the nature and form of construction projects. Discontinuity of design and construction phase is one of the main issues in realization of safe design idea. The language and type of contract between employer and designer on the one hand and between employer and contractor on the other hand, put safety of workplace, equipment, methods, techniques, structure and operation on the contractor responsibility (Hinze, 2001). 3-2- Construction Hazards Prevention Through Design (CHPtD)
Haslam research (2003) on the 100 construction incidents in England indicated architecture designers and structural engineers cause the reduction of risk in more than half of incidents (Behm, 2005). Behm in his study in 2005 has dealt with this subject that designing to what extent and intensity is related to accidents in construct. 230 cases of reported ones in “NIOSH” (the National Institute for Occupational Safety ad Health) and “FACE” (Fatality Assessment Control and Evaluation) organization were selected randomly to examine the relationship of this
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incidents with design which were evaluated accurately by using the expended model of Gambatese. It determined 42% of losses are related to designing. One of the other studies has already been done in this case by GRIC (2010) (Group of Construction Research and Innovation) in Technical University of Catalonia, Department of Construction Engineering, Spain, suggests a quantitative methodology that helps designers by evaluating the related performance of safety in design of residential constructions through the utilization of risk analysis-based approach. This methodology is comparing the safety risk degree in various construction designs and classifying each of them corresponding to safety risks importance. In this process, 90 considerable risks of safety are classified in 22 different groups of constructing activities, which led to defining 45 performance indicators. This methodology for inexperienced designers has induced ease in correct choices among different designing options. The promising point of this methodology is that designers would be able to compare construction techniques and systems in design phase and determine its corresponding level of safety risk without any restraint in designer’s aptitude and innovation (Marta Gangolells, Miquel Casals, Nuria Forcada, Xavier Roca, Alba Fuerres, 2010).
3-3- Design Suggestions
In Spanish group research, which is mentioned above, risk analysis was provided for different designing choices, materials variation, and implementation techniques ( For instance; choosing type of structure from the viewpoint of being concrete, the ways of its performance like in-site concrete or use of prefabricate elements and also sort of materials and the way of performing construction front). Finally ranking each of them in regards to risk degree would result in some design suggestions that considerably reduce the total design risk. In the other investigation done by Gambatese and Hinze (1998) through direct and phone call interview with whom involved in construction and making use of their knowledge and experience and also by investigating workers safety guides, check lists and safe design guides were led to collect of several design suggestions in order to combine them with design tools. The design for construction safety toolbox is a source, which is available for designer to consider and perform standards like CDM (Gambatese and Hinze, 1998). 4- RESULTS FROM THE RESEARCH
The aim of this research is to imply the issue that in regard to workplace condition in Iran, design to what extent and intensity is related to incidents and losses of construction works. For perceiving of relationship between design and construction risks, a conventional statistical society of happened incidents and their happening reasons are required.
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For realizing this point, some of the happened incidents reports in construction workplaces were examined. These reports are supplied by Iran social security organization. 681 cases have been registered by this organization as of March 2005 until March 2006. In this study, 100 incidents of these collections in accordance to Iran’s construction incidents distribution and happened incidents percentage randomly selected corresponding to the sort of incident in Iran. Incidents evaluating expert team which are including a representative from a consultant and design company with 22 years of background, a representative from a contractor company with 18 years background and a safety specialist of a insurance firm evaluated accidents. For this purpose, any incident was investigated in case of incident features (the effective element on incident), absence or presence of documented design suggestions, which could decrease the risk exposure and determine new design suggestions that would lower the accident exposure. For answering to the matters that whether the incidents are related to design, 3 questions that each has Yes/No response are provided for each party to reply. Question 1- Dose the incident cause damage to structure and dose this damage
related to design? Question 2- In case of execution whether the existing design suggestion in design phase could decrease risk exposure? Question 3- Is it possible to establish new design suggestion for minimizing risk exposure? If at least one answer is "Yes", the incident will be related to design and if all of them are No, the incident will not be related to design. This model was extended by Gambatese. Behm studies (2005) also used this same model. The potential human error would be negligible, since those who reply are consist of 3 different groups including designers who may intend to ignore the relationship between design and accident, contractors that due to separation of construction phase from design, may wish to relate accident occurrence to design and safety specialist who treat incident as an unpleasant and expected event. After incidents evaluation and examination of presented answers for each incident, it is indicated 33 cases are linked to design. With regards to the corresponding of examined statistical society with features of happened incidents and incidents distribution of construction industry in Iran, it can be concluded that with expansion of the design for construction safety concept, 33% of incidents are preventable.
5- CONCLUSIONS
Construction industry incidents sometimes cause despite and lead to legal complain, but usually the group which deals with this matter less, are designer. For various reasons they do not consider themselves in charge of providing and
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preserving safety. Maybe the construction culture, lack of safe design training system and acquiring needed skill have resulted in suspicion that just contractors are responsible for preserving workplaces safety. Since last 3 decades after proving that decision-making in project primary phases could affect safety, the design for construction safety concept has been improved. Accomplished studies are indicating the key role of designers in construction safety which is variable, depending on workplace conditions and safety considerations during performance. According to accomplished studies by authors, in Iran 33% of construction accidents are related to design. As the most common contracting system in Iran is Design Bid Build (DBB), There has been a gap between design and safety consideration. It is clear that most of the benefit from safe design is given to contractors, but applying safety in designers view is not the contractors’ ability owing to the separation of design and construction phase. Due to joint association of designers and constructors in Design and Build (DB) contracts, constructors’ experience and concerns and their connection with design are comprehensible for designers. Moreover, owing to their mutual benefit in such contracts, designers’ safety responsibility has increased and consequently we would see safer designs. A way of designers training for realizing safe design idea is information expansion and transferring experiences between designers and constructors, providing new design suggestion and combing with design tools. After finding out the reason and condition of incident occurrence and informing about risks, designers can control and reduce the risks by preventing accident reasons.
6- RECOMMENDATIONS
According to established results, safe design idea is faced a lot of obstacles and problems. After verification, the authors of this article suggest several solutions for these obstacles, which probably would provide subjects for future research. 1For realization of the design for construction safety idea, it is required some sort of cultural affairs among designers. Unfortunately most designers do not get involved themselves in safety and in their viewpoint safety and design are considered as two distinguish matters. The suggestion that we offer for present condition, is training of safety to Design engineers. However, we know that it is difficult and time-consuming to impose the safety belief to those Design engineers who have just got used to an old style and method of design. For improving this situation in future, adding some new units in university courses in order to progress impression from safety is necessary. 2One way of safety condition improvement is increasing the individuals’ responsibility in safety. Today contractors’ major concern is safety, since according
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to current regulations they are more responsible than others. Providing standards and regulation like CDM, which necessitate the designers to identify risks and utilize new ways of construction in order to reduce e risks, can gradually involve designers in the safety. However separation of design from construction process has caused deficiency in designers safety skill in recognition of details and identification of critical points linked to designing in workplace operation. Contracts such as design build not only can eliminate these weaknesses but also helps to record and documentation design necessities for workers safety. It can help to improve the conditions by change in contractual and organizational structure of projects with authority confirmation of employer to construction management for selecting of designers with better safety background and controlling of design process by safety experts of construction management team and also monitoring hazardous actions of contractor by this team. Legal obligations can be considered safety experts of construction management team as responsible for providing and controlling safety beside designers. 3Following above mentioned safety regulations, it is delightful to mention that law can be used to stop unsafe construction, in design phase, through formation of a commission in organization of issuing construction license with the aim of investigating each design from safety consideration aspects in addition to technical consideration. So if the mentioned design got a minimum score of a safe design, it would be approved otherwise it would be referred back to designers for reformation and applying safety consideration. 4One of the obstacles for investigation about safe design is the lack of documented and reliable sources about related incidents statistics and reports related to designers. As the last suggestion, we emphasize on necessity of establishment of an organization for collecting, registering and analyzing exist design suggestions linked to safety and exchanging of information among researchers and providing an independent source for classifying and publishing information in order to provide a set of new design suggestions related to the safety. 7- REFERENCES
Baxendale, T., and Jones, O. (2000). "Construction design and management safety regulations in Practice - progress on implementation." International Journal of Project Management 18, 33- 40. Behm, M. (2005). "Linking construction fatalities to the design for construction safety concept." Safety Science 43, 589–611. Gambatese, J., and Hinze, J. (1999). "Addressing construction worker safety in the design phase Designing for construction worker safety." Automation in Construction 8, 643–649.
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Gambatese , J. A., and Behm, M., and Rajendran, R . (2008). "Design’s role in construction accident causality and prevention : Perspectives from an expert panel." Safety Science 46 (2008) 675–691. Gangolells, M., and Casals, M., and Forcada, N., and Roca, X., and Fuertes , A. (2010). "Helping professionals better perform Construction Hazards Prevention through Design." Journal of Safety Research . Gibb, A., Haslam, R., Hide, S., Gyi, D., 2004. "The role of design in accident causality". In: Hecker, S., Gambatese, J., Weinstein, M. (Eds.), Designing for Safety and Health in Construction. University of Oregon Press, Eugene, Oregon, pp. 11–21. NIOSH, 2005. DRAFT strategic and intermediate goals and performance measures. National Institute of Occupational Safety and Health, Construction Program, November 21, 2005. Szymberski, R., 1997. "Construction Project Safety Planning." TAPPI Journal 80 (11), 69–74. Toole, T. M., and Gambatese, J. A. (2008). "The trajectories of prevention through design in construction." Journal of Safety Research, 39(2), 225í230.
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