Existence of tasks such as welding, coating or sandblasting

Existence of internal combustion machines in

confined spaces

Class 1 (existence)

Class 1 (existence)

checked against objects scheduled to be around power lines, which can be assessed by 4D modeling platforms and model checkers to produce quantitative outputs, for example, to know where    and

Ventilation Class  1 (existence)

Driver: Means of Egress (MoE)

Description: Confined space injuries led to fatal consequences when no or very limited MoE were in place

Rules to check

Ladders and stairs Class 1 (existence)

Natural light and lighting conditions Class 3 (light path) Anchorage for fall arrest or evacuation systems Class 3 (spotting)

Table 9

Drivers for the risk of ‘‘electric shock”。

Drivers and rules Rule class and  type

of check

Driver: Radial Clearance (RC)

Description: Low RC between power lines and metal equipment regarding their path and hilly terrain drove up the risk of electrocution

Rules to check

when a crane boom might approach the 3 m danger zone around

a power line。 Once being fed with the results of the rule matching process, a reasoning tool can determine each driver and prompt the level of safety risk in a sensible   format。

The safety risk drivers suggested in this research, formulated in more detailed flowcharts, can provide early warnings of potential hazards during the design period。 Having identified it, managers will decide how to treat a risk: some risks will be completely avoided by minor changes in design, while others may be mitigated by managerial measures or even retained in a watch list program。 Indeed, being aware of risks will not eliminate the uncertainty, in return, those risks that are not identified, cannot be  treated (Cooper et al。, 2005; Perminova et al。, 2008)。 This indicates the great significance of discovering the drivers of the safety risks in an object oriented format that can be surveyed automatically and ensure the identification of a greater number of safety risks, regardless of the complexity  or  size of the project。

This research showed that a noticeable number of    accidents

could be predicted if the drivers of the risks were discovered

Whether the location of power lines are specified  in

drawings

Class 1 (existence)

before。 A few studies suggest that an automated checking of  the

Clearance between a crane’s boom and power  lines Class 2 (distance) The terrain around power lines Class 3 (vicinity)

implementation of safety codes can reduce safety risks, but most

presented their results only for some specific safety clauses。 The

Existence of long metal objects in the vicinity of power lines

Class 3 (vicinity)

study on the accident reports in this research revealed that not only violation of safety codes could give clues to the    underlying

Possible states of a crane and its boom Class 3

(pathfinding)

risks, but site situations and design parameters could also   provide

Scheduled loading and unloading tasks near power lines

Structures that require scaffolding in the vicinity of

power lines

Class 3 (vicinity)

Class 3 (spotting)

valuable information of how risks were driven up or down,    and