I have laid down 7km fiber optical cable (24 core) in a one meter deep trench alongwith 11 kv cable, maintaing a horizontal clearance of 300mm and verticle clearance 150mm with the 11 kv cable. There is one joint at 3.5 KM. My question is about junction box, can we burry the juntion box in the trench, or it should be above ground on proper supports.