Soft soil replacement

To control subgrade settlement, the treatment of subgrades on soft soil sections often involves complex processes and requires a longer duration. If lightweight fill material is used for the subgrade, it can reduce the amount of treatment needed for the soft soil subgrade.

If the original soil is excavated and replaced with lightweight materials, theoretically, the roadbed load will not increase, and settlement will not occur. Filling the roadbed with lightweight soil reduces the roadbed's own weight, effectively controlling settlement. Saving the roadbed treatment process shortens the construction period, and it is commonly used in road projects on soft soil sections. In road engineering, the soil below the pavement surface is typically used from 0-80cm with a wet bulk density of 6.5 KN/m³; below 80cm from the pavement surface, bubble-mixed lightweight soil with a wet bulk density of 6 KN/m³ is used for filling; this reduces the roadbed's weight and effectively controls settlement.