Occupational safety & health risk analysis in formwork in high-rise building projects

The implementation of Occupational Health and Safety Management systems remains a significant concern, particularly in the context of multi-storey building construction projects. Within the realm of these complex endeavors, the management of work-related accidents during formwork operations is of paramount importance. This research employs a rigorous methodology involving questionnaire distribution and interviews, complemented by advanced analytical tools such as the Frequency Adjusted Importance Index (FAII) and Bow Tie Analysis. The study focuses on the Indonesian Development University’s high-rise building project, systematically assessing potential hazards associated with formwork activities. Furthermore, this research evaluates the inherent risk levels and proposes comprehensive control measures to mitigate these hazards effectively. By shedding light on the intricate interplay between safety management and high-rise construction, this study contributes to the enhancement of occupational safety and health practices in the construction industry, ultimately promoting safer and more efficient work environments.


Introduction
A work accident is an unwanted incident or event that is detrimental to humans, damages property or losses to processes [1].Instinctively, humans can avoid accidents.It is human nature to stay away from or avoid things that are unwanted or detrimental to him.This desire is not limited to people who have prepared themselves so that no accidents occur, but also applies to anyone.Even people whose behavior is dangerous do not want accidents to happen to them [2].
Formwork, also called formwork, is an auxiliary tool for printing concrete according to the desired size, shape or position and alignment.Formwork consists of several parts that are assembled into a certain construction unit with a practical system.This means that it is naturally only a temporary structure that supports its own weight and the weight of wet concrete, formwork construction must be easy to work with and easy to disassemble and not easily damaged so that it can be used repeatedly.The thing to note is that formwork must be able to withstand existing loads [3].
Thus, it can improve the effectiveness of protection and occupational safety and health in a measurable, planned, and detailed manner.So as to prevent and reduce the risk of work accidents that occur.Therefore, the role of Occupational Health and Safety (OHS) in every job is very important, if in its implementation there is misuse of policies or non-compliance with the rules that have been made, then worker work safety will be disrupted, and work effectiveness will be reduced [4].OHS is an effort to create a safe, comfortable working atmosphere and achieve the highest work productivity.OHS is something that must be implemented not only in the construction sector, but almost all jobs that use human resources (HR) need to implement the OHS [5].If the knowledge of OHS in employees is good and disciplined in its implementation, it will create a comfortable, safe and effective work environment.Because the role of OHS is very important for the effective running of production work in accordance with mutually agreed procedures and will certainly create a high level of work safety in this work environment.The purpose of this is to identify what risks exist in formwork installation work, as well as identifying which risks most often arise in formwork installation work.

Literature Studies
Occupational safety is a specialization of health sciences and its practices which aim to ensure that workers or the working community obtain the highest degree of health both physically, mentally and socially with preventive efforts against diseases/health problems caused by work and environmental factors as well as against common diseases [6].Construction projects require resources, namely man, material, machine, method, money, information, and time.A construction project is a series of activities related to efforts to construct a building, covering the main work in the fields of civil engineering and architecture [7].
Work accidents are a direct result of unsafe actions and unsafe conditions, both of which can be controlled by management.Unsafe actions and unsafe conditions are cited as direct causes of accidents because they are both obvious causes and are directly involved when accidents occur [8].These losses can be in the form of direct or indirect economic losses, for example damage to machinery and equipment, materials, buildings, costs for treatment or care for victims, benefits due to accidents, and decreased project work progress / production quality due to lost time [9].So that the wrong handling process in dealing with a work accident can affect the productivity of construction work and also affect the finances of a project.Therefore risk management in the field of OHS needs to be made, so that the handling of OHS becomes effective, so that the impact of work accidents can be minimized [10].
This research was conducted by analysing data from the formwork installation project, so that a design can be made to overcome safety problems and work accidents on this project in the formwork installation work.This analysis was made and carried out using the bow tie method, a method that has been widely used to design occupational health and accident activities on a project, especially construction projects.
In this research, data processing and analysis were carried out on each data from the survey questionnaire.The variables obtained from the results of this survey questionnaire are processed and analyzed to obtain the dominant work accident indicators in building construction projects can be seen in Table 1.

Bow tie analysis
A method known as bow tie analysis (BTA) produces a diagram shaped like a bow tie that provides a direct picture of risk events.In high-risk scenarios, Bowtie is used to analyze and demonstrate causal relationships.The BTA method is able to describe the relationship between hazards, threats/causes, control/control, and consequences through diagrams [11].This kind of methodology can be used to assess different types of problems, but in terms of safety, this type of analysis is used to assess and support accident analysis, process hazard and implementation of risk management.The bow tie risk analysis method connects hazards and their impacts through a series of event lines which can be graphically depicted in the form of a diagram showing the route to the accident.To prevent the occurrence of work accidents that cause losses to the project, a mitigation action is needed.Appropriate mitigation measures must be guided by events that have happened to previous projects.In the next stage of the risks that have been created and collected, mitigation is made using a bowtie diagram.The purpose of making this diagram is to make it a material consideration for stakeholders to make decisions or appropriate anticipatory steps to reduce the number of accidents and reduce the possibility of work being delayed due to accidents.

HIRARC
The Hazard Identification Risk Assessment and Risk Control (HIRARC) method is a series of hazard identification processes in routine and non-routine activities.HIRARC is an effort to prevent and reduce the potential for work accidents, avoid and minimize risks that occur appropriately by avoiding and minimizing the risk of work accidents and controlling them in the context of carrying out activity processes so that the process becomes safe.Hazard identification, risk assessment and control are part of the risk management system which forms the basis of the OHS Management System.
Companies or organizations are required to set up HIRARC for their companies [12].An industrial activity can never be separated from the potential for work accidents.No matter how small an accident occurs, it will have a big impact on the company and the employees themselves.HIRARC is divided into three stages, namely hazard identification, risk assessment, and risk control.As well as determining control measures based on the data that has been collected to obtain a comprehensive HIRARC model for study strength.This method determines the direction of OHS implementation within the company so that the company is able to solve its own problems, especially OHS management problems.

FAII method
Then an assessment of the risk scale given by an indicator based on frequency and impact parameters obtained from AS/NZS 4360:2004 (Australian standard/New Zealand standard 4360:2004) [13].AS/NZS 4360:2004 according to the Financial and Development Supervisory Agency is a standard that regulates a systematic approach to managing risk that is useful for an organization or institution.This standard is the most frequently used standard and the most widely accepted in general.The Frequency Adjusted Importance Index (FAII) method used is in equation 1 to equation 3.

Probability index and impact index
Then recalculation, this risk assessment uses Risk Management Standard AS/NZ 4360:1999 based on probability and impact levels.The method used to calculate the Probability Index (PI) and Impact Index (II) is in equations 4 to equation 5.

Methodology
The methodology research of the study can be seen in Figure 1.

Analysis and Discussion
In the analysis and discussion of this study, the determination of the highest risk rating using 2 methods, namely FAII and PI, II can be seen in Table 2 and Table 3.

48 High
In Table 2, it can be seen that the most dominant sequence of indicators of work accidents is workers falling from a height, scaffolding that has been dismantled and left around the work environment makes workers disturbed, installation of scaffolding that is not connected properly, and overloaded so that it collapses and falls on workers, workers fall while on the scaffolding due to the excess material load, and the concentration of workers is lost during installation at height.The risk scale of the five indicators is above number 4 and below number 10, the most dominant work accident indicator is occupied by workers falling from a height [14].This is also in accordance with the validation results in Table 3 which places the work accident indicator falling from a height in the first rank with a high risk matrix assessment, so that from the five sequences of the indicators above serious attention is needed from the management.
There are different risk assessment results against the FAII method with PI and II assessments because the risk scale assessment parameters used are different.Until different levels of risk are obtained.If knowledge about occupational safety and health in employees is good and disciplined in carrying it out, then a comfortable, safe and effective work environment will be created.Because the role of OHS is very important for effective production work in accordance with mutually agreed procedures and of course high work safety figures will be created in the work environment.
After identifying the risk scale of the highest factor, Bowtie diagrams are developed and can be seen in Figure 2 to Figure 6.The Bowtie diagrams represent the accident factors and mitigations that must be done to prevent the risk factors from occurring.

Conclusions
Out of the five most dominant indicators of work accidents in high-rise building construction projects, the dominant indicator was obtained in the sub-work of installing and dismantling scaffolding.This subjob produces the highest number of work accident indicators from among other sub-jobs, this requires full attention to this sub-work so that the number of work accidents in the project can be suppressed and minimized.altitude work is an activity carried out by workers on the surface of the land or waters that have different elevations and have the potential to fall which causes the workforce or other people around the location to be injured, died or damaged property.However, there is no specific minimum height standard for a job called working at a height, but most companies use a standard for working above 2 meters which is already included in the category of working at a height.

Figure 1 .
Figure 1.Methodology Study of the Research

Table 1 .
The Variables

Table 3 .
PI and II method's result