How to set maps and game types?

i use this scripting for server setting and what not,

-game garrysmod -console +ip 205.234.153.125 -port 27015 +maxplayers 6 +exec server_cfg.txt +map gm_construct

i have changed the map this way,

-game garrysmod -console +ip 205.234.153.125 -port 27015 +maxplayers 6 +map gm_ps_hugeflatconstruct +exec server_cfg.txt

but how do i change the game type, to say zombie survival, and i have downloaded the zombie survival 4.1.3 addon to my dedicated server.

+sv_gamemode <gamodehere> +sv_defaultgamemode <samegamemodehere>

where do i add that?