Measurement for Civil Engineering works

1. Measurement for Civil Engineering works -Retaining Wall-

2. Overview • A retaining wall is generally defined as a vertical wall that holds back earth. However a retaining wall has many uses such as: • A retaining wall for roadside embankments • A retaining wall can separate older roads from highways • A house retaining wall for the garage • A retaining wall helps keep river banks from eroding • A retaining wall to keep earth from stairwells and driveways

3. Common materials used for retaining walls • Wood sheets; • Steel and plastic interlocking sheets; • Reinforced concrete sheets; • Pre cast concrete elements (crib walls and block walls); • Closely spaced in-situ soil-cement piles; • Wire-mesh boxes (gabions); • Anchors into the soil or rock mass (soil nailing).

4. Earth-retaining structures

5. Gravity wall

6. Crib wall

7. Gabion wall

8. Cantilever wall

9. Common types of retaining wall (sides of highway / expressway) block retaining wall Vegetative retaining wall

10. Common types of retaining wall (hill side building development) Segmental block retaining wall system Concrete retaining wall

11. Drainage system in retaining walls

12. Section view- concrete retaining wall Temporary formwork is a MUST to form the shape of retaining wall before in-situ concreting works coming in concreting works and concrete hardening to form the final product of retaining wall structure

13. Section view- Segmental blocks retaining wall

14. Section view- Vegetative retaining wall

15. Section view- concrete retaining wall Retaining wall Ground level Depth of excavation Concrete base footing

16. perspective view- concrete retaining wall length Buttress / piers height width

17. Measurement PrinciplesElement: mass concrete retaining wall ***Refer to drawing given; Main components: • Concrete foundation / bases for retaining wall • Concrete retaining wall • Concrete piers • Weep holes (drainage ) • Pocket of granular fill Total measured length for retaining wall = 30.00 m

18. Taking-off lists (lists of items to be measured) • Excavation works • E.1.5.1 – excavation, foundation, earth -starting from commencing level – m3 • Concreting works • F.1.3.2 – In situ concrete designed mix, Grade 25, in bases – m3 • F.1.4.4 – In situ concrete designed mixed, Grade 30, in retaining wall – m3 • F.1.4.5 – In situ concrete designed mixed , Grade 30, in piers – m3

19. Taking-off lists (lists of items to be measured) • Formwork • F.4.1.1 – Formwork, to sides, of bases – m2 • F.4.1.3 – formwork, to back sides. of retaining wall – m2 • F.4.1.3 – Formwork, to end sides / faces, of retaining wall – m2 • F.4.4.3 – Formwork, to sloping faces of retaining wall – m2 • F.4.1.4 – Formwork, to sides, of piers. – m2

20. Taking-off lists (lists of items to be measured) • Drainage • H.5.1.1 – outlet structures, 100mm diameter weep holes @ 1.8m centre, inside the retaining wall – nos. • Filling • E.3.4.3 – Filling, to structures -between piers, pocket of granular material, continuously. – m3

21. Techniques to take-off into dimension paper

22. Billing paper