mv cable joints.

i have a route of 1.8 km from the power plant to the housing colony transformer.

i need to lay underground cable(mv cable 13.8 power supply) at one meter depth. and no trench, its just open excavation and bury .

now my problem is that i have no single length cable for this route.

with available cable as per site situations if i joint there are 4 joints coming throughout the length other than end connections.

but there are 2 joints coming at a short span length of 80 meter. although cable jointing kit will be used for the same.

so my question is there , for this length how many maximum joints can be allowed.

2nd is, what will be the bad effects of short span of 2 joints within 80 meter other than joint heatings.

is it advisable to put 2 joints in 80 meters of length for this voltage, when its possible to avoid by putting new lengthy cable.

please share yr expert comments.