approx estimation of rigid pavement and brief and detailed estimation for excavation in hard marroom by blasting

1. Project : Approximate estimation of Rigid pavement
Item : Excavation in Hard Rock (by Blasting)
By
Sandeep Bora AP14003
Anchit Agrawal AP14012
Aditya Avinashe AP14079
Pratik Dalai AP14081
Shivali Kalra AP14088

2. Topics
 Approximate estimation of rigid pavement
 Specifications of excavation in hard rock
 Brief Specification
 Detailed Specification
 Rate Analysis for excavation in hard rock

3. Rigid pavement cost per km
Sr No Project
Distance
(km)
Cost (cr)
Cost/km
(cr)
1 Mudhol Maharashtra border road on SH 18 in Karnataka 107.94 317.60 2.94
Contractor- Ashoka Buildcon and GVR Infra (On going project)
2 Malavalli to Pavagada(karnataka) 193.34 313.65 1.62
Contractor- Sadbhav Engineering Ltd and GKC Projects Ltd
(On going project)
3 Trichy Karur road(4 lane road) 63.00 732.84 2.91
Contractor-Reliance Infra (completed project)
4 Construction of approach road from South Garo Hills to Jetra 17.00 28.76 1.69
(On going project)
5 Construction of road from Pakoti to Kamsha 6.50 9.50 1.46
(On going project)
AVERAGE cost per km 2.13

4. Brief specification
 Excavation for foundation in hard rock by blasting including trimming and levelling
the bed and removing the excavated material and stacking it into measurable heaps
within a distance of 50 meters from site area.
Lift: 0 to 1.5m

5. Detailed specification
 Scope and objectives
 Equipment used
 Material Used
 Workmanship
 Testing and Acceptance Criteria
 Mode of measurement and payment

6. Scope and Objectives
 The purpose of this procedure is to establish the methodology to be followed
for excavation work during the construction phase .
 This procedure is applicable to the execution team. It intends to co-relate and
control the entire task needed to be done in order to achieve satisfactory
construction excavation work.
 Excavation is to be done for Hard rock by the means of blasting.
 We have used a machine intensive approach .
 Scope of work- 10 cubic meter

7. Equipment deployed
 Hydraulic Excavator
 Tipper
 Jack hammer

8. Hydraulic excavator
Excavator(Hyundai 250 R)Purpose:
Digging of trenches ,holes and
foundation.
Material handling,
Pising,
Demolition
Attachment:
Bucket, Breaker,
Auger
Rent
Rs 2200/hr
Capacity:
Bucket size: 0.93 cum

9. Tipper
Tipper (Bharat Benz)Purpose:
 Hauling of material
Charges
 Monthly rent (1.25 lakhs
excluding diesel)
Capacity: 14 cum

10. Jack Hammer
Jack hammerPurpose:
Drilling of holes,
Depth of drilling is 2m in this
case
Action of drilling takes place by
percussion action.
A pilot rod is drilled into the
surface with the help of
jackhammer
Charges: Rs11/ft or Rs 400/hour

11. Material Used
 Explosives
 Special Gelatine (gelatine stick)
 Powergel IDL
 25 mm thick
 Rs 2000/25kg
 Each stick of 125 grams.
 Electric detonator
 SED – Rajasthan Explosives
 1.8 m long wire
 Rs 12 / Piece

12. Workmanship
 Preparation of surface:
o Firstly the ground for blasting should be cleared of all obstacles.
o The ground should be preferably leveled.
o The ground should be cleaned and marked.
 Method of Blasting:
o Holes are to be drilled in triangular pattern for the required length.
o The electronic detonator is inserted into the explosive gel tube which is connected to
the external wire circuit
o Explosives are placed within the hole and are then grouted with dry soil up to the top
o The connection are checked and rechecked by the blaster
o All the explosives are connected in parallel and series connection
o This wire is connected to the detonating fuse.
o warning siren are sounded at an interval of 5 minutes before blasting, all the traffic in
the area should also be halted & red flags to be placed along the way, fragile structure
should be covered by polymer or plastic sheets to avoid damage.
o The blast shed should be located at least 10 m from the blasting area.
o After the detonation has taken place the area is excavated with the help of a excavator &
loaded into the tipper.
o Small pieces of rocks are removed and ground is levelled.

13. Blasting pattern

14. Testing and Acceptance Criteria
 The dimensions of the pits will be checked as per the GFC drawings .
 All over excavations filled back to required lines, levels and grades by placing plain
cement concrete of grade M10 and/or richer and/or by compacted earth, as
directed by the Engineer, at the Contractor’s cost.
 Sand replacement method of testing the field density on site to ensure the desire
densification has been obtained i.e minimum 95% of its maximum dry density.

15. Mode of measurement and payment
 Mode of measurement-
As per IS 1200(Part 1),
o Mode of measurement for Excavation is in cubic meter
o Each dimension shall be measured to the nearest 0.01m
o Areas shall be worked out to the nearest 0.01 sq.m
o Cubical content shall be worked out to the nearest 0.01 cu.m
o Working Authorised working space shall be special in each case. Where authorised
working space is not so specified the following shall apply:
600 mm measured from the face of substructure ( including protective measures, if
any) at lowest level, where extra working space is required.
 Mode of payment-
o Payment shall be done as per the GFC drawings.

16. Rate analysis
 Rate as per calculations: Rs 680.58
 Rate as per DSR 2014: Rs 653
 Rate analysis