Comparison of load reduction and replacement schemes of foam concrete at the intersection of subway and road

The replacement system using foam concrete or EPS board functions similarly to decrease tunnel base pressure and top load. The building procedure consists of these sequential steps:

The completed tunnel structure receives backfilled soil which receives compaction along its sides and on top with a specific amount of filled soil as part of the construction process.

The soil filling operation should proceed with compacting the substance while reserving areas for material unloading and storage.

Backfill with lightweight materials.

An upper layer of reinforced concrete slab must cover EPS slab surfaces because foam concrete remains weak in strength thus needing supplemental load distribution.