Download presentation
Presentation is loading. Please wait.
Published byMoris Chandler Modified over 6 years ago
1
SAB 3122 CONSTRUCTION TECHNOLOGY AND ESTIMATING Excavation
Dr. Chai Chang Saar
2
EXCAVATION BULKING FACTOR BULKING FACTORS ARE AS FOLLOWS: NO.
TYPES OF SOIL % INCREASE IN VOLUME 1. Sand 10% 2. Clay 20% 3. Ordinary Earth 25% 4. Rocks 50%
3
EXCAVATION Calculation for each activity. If the activities are missing, contractor will experience loss. EXCAVATION ACTIVITIES Excavation from formation level to foundation depth level. Excavated soil taken out. Dispose of excess earth from site. Backfilling and compaction. LABOUR CONSTANT USED IN CALCULATION
4
EXCAVATION 4 stages Site clearance Excavation – m3 hedges – m
bushes, shrubs – m2 cutting down trees – no Excavation – m3 Supporting & strutting By hand Machinery/plant Rental machinery 11/17/2018
5
EXCAVATION WORKS Bulking (disposal) – m3 Backfilling – m3 By hand
Lorry Backfilling – m3 Excavated material Imported material Leveling with hardcore 11/17/2018
6
SITE CLEARANCE Cutting down tress exceeding 600mm and n.e 900mm girth at 1.00m above ground level and grubbing up their roots and filling voids left by removal of roots with material arising from excavation – No General worker RM40/day Sawing machine (Rental) RM35/day 5 tonne lorry (Rental) RM300/day Cutting down trees 5 nos/day 3 general workers to cut down trees 3 general workers to remove Profit 20% 11/17/2018
7
SUPPORT & STRUTTING Figure 1.1 Typical timbering in hard soils
Typical timbering in firm soils
8
SUPPORT & STRUTTING Figure 1.3 Typical timbering in dry loose soils
Typical timbering in loose wet soils
9
SUPPORT & STRUTTING Assumption: 11/17/2018
10
SUPPORT & STRUTTING Assumption: Trench = 20.00m Carpenter = RM 60.00
General = RM 40.00 Timber = RM /tonne (1.40 m³) Nail = RM 4.50/kg Nail = 0.10kg/m² of gross supporting area Timber usage = 15 times 1 Carpenter and 1 General Worker to cut & fix in output 2.25hr/m³ 1 General Worker to remove in output 2.25hr/m³ Allow 10% wastage for timber work Allow 20% profit and overhead 11/17/2018
11
EXCAVATION BY HAND Labour constant for excavation by hand 11/17/2018
12
EXCAVATION BY HAND Adjustment for non-common soil excavation
11/17/2018
13
EXCAVATION BY HANDS Built-up rate must consists of material, machinery and labour costs Material & machinery cost Excavation do not required material cost Excavation by hand, therefore no machinery cost incurred Labour cost Labour constant for trench excavation not exceeding 2.00m = 4 hours/m3 Assumption: Build up rate for 1m3 trench excavation, starting from reduced level, and maximum depth not exceeding 2.00m Allow 20% Profit & overhead 11/17/2018
14
EXCAVATION BY MACHINERY
To get the rate for excavation using machinery, have to find out the excavator output, adjustment and excavator’s running cost Excavator output Loader (m3) Average output(m3/hr) 8 ⅜ 9 12 18 1 25 11/17/2018
15
EXCAVATION BY MACHINERY
Type of soil Multiplier Sand X 1.00 Clay X 1.25 Soft rock X 1.50 Rock X 4.50 11/17/2018
16
EXCAVATION BY MACHINERY
Excavator’s running cost Type (loader) m3) Diesel/hr (litre) Lubricator/week (litre) 4.00 9.00 ⅜ 5.00 12.00 6.00 14.00 7.00 16.00 1 18.00 11/17/2018
17
EXCAVATION BY OWN MACHINERY
Build up rates for excavate oversite to reduce level maximum depth not exceeding 1.00meter by using own excavator ½ m3. Assumption: Average working days = 200days Operator = RM 50.00/day Life-cycle = 5 years Diesel = RM 1.70/litre Lubricator = RM 20.00/litre Loan interest = 10% per year Maintenance = 10% of purchase price for whole lifecycle Transportation to site = 5% of purchase price for whole lifecycle Scrap Value = RM 8,000.00 Excavator purchase price = RM 150,000.00 Allow 20% Profit & overhead 11/17/2018
18
EXCAVATION BY RENTAL EXCAVATOR
Build up rate for 1m3 trench excavation, starting from reduced level max depth not exceeding1.00m by using rented excavator. Assumption Using a ⅜ m³ excavator Rental RM300.00/day (inclusive mobilize to site) Diesel RM 1.70/litre Lubricator RM 20.00/litre Operator = RM 50.00/day Allow 20% Profit & overhead 11/17/2018
19
DISPOSAL % of bulking after the excavation (disposal) 11/17/2018
20
DISPOSAL BY HAND Labour output for loading, hoisting and storing – 1.50hr/m3 Labour output for loading, hoisting, storing, spreading and leveling – 2.00hr/m3 Build up rate for removing 1 m3 excavated material 50.00m distance. Assumption : Excavated material = common soil, 25% bulk Loading, hoisting and storing only Allow 20% Profit & overhead 11/17/2018
21
DISPOSAL BY LORRY Lorry Loader (m3) Diesel/hr (lt) Lubricator/wk (lt)
1 tonne 0.80 3.50 0.50 5 tonne 3.25 6.00 1.00 11/17/2018
22
DISPOSAL BY LORRY Build up rate for removing 1m3 excavated material and deposit in heaps 5km distance. Assumption: Lorry 5 tonne rental= RM /day (inclusive driver) Speed = 30km/hr Loading time: 10 mins Unloading time: 5 mins Common soil, bulking 25% Diesel = RM 1.70/litre Lubricator = RM 20.00/litre Allow 20% Profit & overhead 11/17/2018
23
FILLING WITH EXCAVATED MATERIAL
Build up rate for 1m3 filing to excavation with material arising from excavation. Assumption Labour constant 0.75 hr/m3 25% of compaction and wastage Allow 20% profit & overhead 11/17/2018
24
FILLING WITH IMPORTED MATERIAL
Build up rate for 1m3 filling to excavation with ordinary earth obtained off site. Assumption: Imported earth = RM 15.00/m3 (inclusive delivery to site) 25% of compaction & wastage Labour constant 0.75 hr/m3 Allow 20% Profit & overhead 11/17/2018
25
Exercise Excavation and Dispose Conversion
26
Thank You
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.