In order to study the key design parameters of pressurization air supply system of longitudinal evacuation route in underwater highway tunnel

combining the characteristics of longitudinal evacuation route

the calculation method of pressurization air supply volume in longitudinal evacuation route is proposed by drawing on the design demand of pressurization air supply system in general construction.Then the pressurization air supply system of longitudinal evacuation route is studied by numerical simulation method.It is indicated that the pressurization air supply volume calculated by air velocity method is about 20 times larger than that calculated by pressure difference method

and the width of escape exit slot has a major influence on the computation of pressurization air supply volume when using the pressure difference method

whose project serviceability is bad.It is known that the security request of evacuation is basically met when the blowing-in speed in evacuation route reaches 1.5 m/s through numerical simulation

which is consistent with the results calculated by air velocity method.The results would provide a reference for the design of pressurization air supply system in evacuation route of the tunnels using the longitudinal evacuation pattern.