Authoritative Engineering Tutorial Voiceover

Following the three-step method of "enhanced drainage, water blocking, and foundation stabilization," treat the subgrade defects in the section. "Enhanced drainage": First, add drainage ditches between tracks to divert accumulated water between tracks into culverts on both sides; Second, transform the wall on one side of the road shoulder into permeable concrete to facilitate timely drainage of accumulated water from the ballast bed; Third, excavate the softened layer of the subgrade, shape the roadbed arch surface into a triangle, and create a 4% slope toward both sides of the track for drainage. Dig slots in the upper part, and add water nails at two-meter intervals. The water nails connect horizontally from inside the ballast bed to the inside of the side ditch retaining wall, constructing underground water drainage channels. "Foundation stabilization". After the water nails are installed, use graded crushed stone to replace and fill the roadbed surface to enhance the bearing capacity of the roadbed surface. "Water blocking", lay a double-layer fiber drainage board above the roadbed arch surface to block surface water from flowing to the subgrade surface through the gaps of clean backfilled ballast. Direct the water through the drainage board to the side ditches on both sides, and add ballast cages to replace ballast retaining strips for easier drainage.