Measurement for Civil Measurement for Civil Engineering worksEngineering works

-Retaining Wall--Retaining Wall-

OverviewOverview A retaining wall is generally defined as a vertical A retaining wall is generally defined as a vertical

wall that holds back earth. However a retaining wall that holds back earth. However a retaining wall has many uses such as:wall has many uses such as:

A retaining wall for roadside embankments A retaining wall for roadside embankments A retaining wall can separate older roads from A retaining wall can separate older roads from

highwayshighways A house retaining wall for the garage A house retaining wall for the garage A retaining wall helps keep river banks from A retaining wall helps keep river banks from

eroding eroding A retaining wall to keep earth from stairwells A retaining wall to keep earth from stairwells

and driveways and driveways

Common materials used for Common materials used for retaining wallsretaining 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).

Earth-retaining structuresEarth-retaining structures

Gravity wallGravity wall

Crib wallCrib wall

Gabion wallGabion wall

Cantilever wallCantilever wall

Common types of retaining Common types of retaining wall wall

(sides of highway / expressway)(sides of highway / expressway)

block retaining block retaining wallwall

Vegetative Vegetative retaining wallretaining wall

Common types of retaining Common types of retaining wall wall

((hill side building development)hill side building development)

Segmental block Segmental block retaining wall retaining wall systemsystem

Concrete Concrete retaining wallretaining wall

Drainage system in retaining Drainage system in retaining wallswalls

Section view- concrete retaining Section view- concrete retaining wallwall

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

Section view- Segmental blocks Section view- Segmental blocks retaining wallretaining wall

Section view- Vegetative retaining wallSection view- Vegetative retaining wall

Section view- concrete retaining Section view- concrete retaining wallwall

Concrete base footing

Retaining wall

Ground level

Depth of excavation

perspective view- concrete perspective view- concrete retaining wallretaining wall

length

height

width

Buttress / piers

Measurement PrinciplesMeasurement PrinciplesElement: mass concrete retaining Element: mass concrete retaining

wallwall***Refer to drawing given;***Refer to drawing given;

Main componentsMain components::

1.1. Concrete foundation / bases for retaining wallConcrete foundation / bases for retaining wall

2.2. Concrete retaining wallConcrete retaining wall

3.3. Concrete piers Concrete piers

4.4. Weep holes (drainage )Weep holes (drainage )

5.5. Pocket of granular fillPocket of granular fill

Total measured length for retaining wall = 30.00 Total measured length for retaining wall = 30.00 m m

Taking-off lists Taking-off lists (lists of items to be measured)(lists of items to be measured) Excavation works Excavation works

E.1.5.1 – excavation, foundation, earth -E.1.5.1 – excavation, foundation, earth -starting from commencing level – starting from commencing level – m3m3

Concreting worksConcreting works F.1.3.2 – In situ concrete designed mix, F.1.3.2 – In situ concrete designed mix,

Grade 25, in bases – Grade 25, in bases – m3m3 F.1.4.4 – In situ concrete designed mixed, F.1.4.4 – In situ concrete designed mixed,

Grade 30, in retaining wall – Grade 30, in retaining wall – m3m3 F.1.4.5 – In situ concrete designed mixed , F.1.4.5 – In situ concrete designed mixed ,

Grade 30, in piers – Grade 30, in piers – m3m3

Taking-off lists Taking-off lists (lists of items to be measured)(lists of items to be measured) Formwork Formwork

F.4.1.1 – Formwork, to sides, of bases – F.4.1.1 – Formwork, to sides, of bases – m2m2F.4.1.3 – formwork, to back sides. of F.4.1.3 – formwork, to back sides. of

retaining wall – retaining wall – m2m2F.4.1.3 – Formwork, to end sides / faces, of F.4.1.3 – Formwork, to end sides / faces, of

retaining wall – retaining wall – m2m2F.4.4.3 – Formwork, to sloping faces of F.4.4.3 – Formwork, to sloping faces of

retaining wall – retaining wall – m2m2F.4.1.4 – Formwork, to sides, of piers. – F.4.1.4 – Formwork, to sides, of piers. – m2 m2

Taking-off lists Taking-off lists (lists of items to be measured)(lists of items to be measured) DrainageDrainage

H.5.1.1 – outlet structures, 100mm H.5.1.1 – outlet structures, 100mm diameter weep holes @ 1.8m centre, diameter weep holes @ 1.8m centre, inside the retaining wall – inside the retaining wall – nos.nos.

Filling Filling E.3.4.3 – Filling, to structures -between E.3.4.3 – Filling, to structures -between

piers, pocket of granular material, piers, pocket of granular material, continuously. – continuously. – m3m3

Techniques to take-off into dimensTechniques to take-off into dimension paperion paper

Billing paperBilling paper