> I'm sure there are some significant practical limitations I am ignorant of.
Yes, the steel framing or reinforced concrete panels that would be needed to hold up the precast concrete sidewalk would be very expensive. You don’t need the entire conductor accessible anyways, that’s what tuggers and mule tape are for, pulling wire.
Also, all of the pipes would need to be supported from the underground concrete/steel structure and you would also need a lot of (expensive) expansion joints. Laying pipes in the ground and burying them lets the earth support them instead of pipe hangers.
There are some colleges/institutions to do use tunnels to run steam pipes through a campus, and they tend to build purpose-built tunnels for those. I’m not a pipefitter, so I’m unsure why steam pipes get their own tunnels, perhaps a MechE or pipefitter can weigh in!
Underground electrical feeder conduits (on customer premises, I only deal in the electrical world beyond the utility transformer secondary) are typically run in concrete encased ‘duct bank’, with manholes every so often. Electrical vaults/manholes are available as precast pieces that you simply lower into place.
Yes, the steel framing or reinforced concrete panels that would be needed to hold up the precast concrete sidewalk would be very expensive. You don’t need the entire conductor accessible anyways, that’s what tuggers and mule tape are for, pulling wire.
Also, all of the pipes would need to be supported from the underground concrete/steel structure and you would also need a lot of (expensive) expansion joints. Laying pipes in the ground and burying them lets the earth support them instead of pipe hangers.
There are some colleges/institutions to do use tunnels to run steam pipes through a campus, and they tend to build purpose-built tunnels for those. I’m not a pipefitter, so I’m unsure why steam pipes get their own tunnels, perhaps a MechE or pipefitter can weigh in!
Underground electrical feeder conduits (on customer premises, I only deal in the electrical world beyond the utility transformer secondary) are typically run in concrete encased ‘duct bank’, with manholes every so often. Electrical vaults/manholes are available as precast pieces that you simply lower into place.
Precast electrical vaults: https://www.ecbabbert.com/utility/electric-structures/electr...