① The subgrade filling and excavation sections of the line are unevenly distributed. Seen from the total amount of earth and stone, the excavation amount is greater than the filling amount, and the quantity of spoil is large, which has a great impact on the ecological environment and water and soil conservation along the line. Therefore, adequate engineering measures must be taken. ② The terrain and geological structure along the line are complex, and there are many forms of retaining structures. The filling and settlement period of soft soil and soft soil subgrade section is long, which affects the construction period of paving, erecting and four electricity projects