HSE Risk Assessment of Major Sewage Transport Tunnel Projects at the Construction Stage Based on the StructuralEntropy Weight Method and the Cloud Model

Table 2

The index system for the HSE risk assessment of MSTTPs.

Criteria layer	Indicator layer	Indicator interpretation
Health	Construction noise H1	Shield machines and vehicles in tunnels generate noise, which can give hearing damage to construction workers.
	Humid environment H2	The humidity in the tunnel is exceedingly high, which may lead to skin dipping and erosion of construction workers.
	High ambient temperature H3	Excessive ambient temperature may cause heatstroke in workers.
	Toxic and harmful chemicals H4	Cement, paint, and other items may cause workers to suffer from occupational diseases such as contact dermatitis.
Safety	Excessive deformation S1	Excessive deformation leads to the destruction of the original structure, leading to safety accidents.
	Improper power utilization S2	If the temporary power management is improper, it may easily give rise to an electric shock accident.
	Improper operation of shield segments S3	The improper operation of the construction personnel would end up in segments falling, causing object strike accidents.
	Imprecise installation of launching base S4	The launch base was installed incorrectly and the shield machine could not launch normally, resulting in a safety accident.
Environment	Domestic waste pollution E1	Domestic waste in office and living areas may cause damage to the surrounding environment.
	Exhaust pollution E2	The construction of tunnels uses a lot of machinery, and waste gas will be generated during use. If it is not properly treated, it will pollute the atmosphere.
	Sludges and muds pollution E3	Due to inexperience, it is difficult to achieve zero discharge of construction waste such as engineering sludges and muds.
	Impact on groundwater E4	The earth pressure is not set properly, which may compact the surrounding soil and cause the groundwater level to rise significantly.
	Excessive surface subsidence E5	During the construction of the shield, the surrounding soil is disturbed greatly, and the ground surface has a large settlement.