1 General Provisions 1 2 Terms and Symbols 2 2. 1 Terms 2 2. 2 Symbols 5 3 General Substructure 6 3. 1 General requirements 6 3. 2 Roadbed 7 3. 3 Fill embankment 11 3. 4 Cutting substructure 15 3. 5 Boundary region treatment between the excavation and fill substructure 18 3. 6 High embankment and steep slope embankment 18 3. 7 High slope in cutting 23 3. 8 Rock embankment 27 3. 9 Light weight material embankment 30 3. 10 Embankment with industrial waste material 36 3. 11 Borrow pits and spoil sites substructure 38 4 Substructure Drainage 40 4. 1 General requirements 40 4. 2 Surface drainage 41 4. 3 Underground drainage 46 5 Substructure Protection and Retaining Structures 50 5. 1 General requirements 50 5. 2 Slope protection 51 5. 3 Substructure protection along riverside 53 5. 4 Retaining wall 56 5. 5 Slope anchorage 65