Underground utilities AFAIK do not suffer unduly from moisture in the conduits. WIthint their conduits, cables are typically separately insulated with tough outer covers. And the problem of weight is removed. The cheaper cost of overheads brings costs uncounted in human misery through power outages, for example. The cause of these collapses is the extremes of movement from wind and weight from ice buildup.

The problem of frost is essentially a depth and materials problem. The range of motion caused by frost heaves of terrain is relatively low; they do tend to break up concrete ducts which have very little flex in them. Rethinking the parameters of the conduits might lead to a more flexible AND more durable solution.


A