LC13Specification ReportMain1
LC13Specification ReportMain1
LC13Specification ReportMain1
Estimate Amount:Rs. /-
NAME OF WORK :
SCHEME &AUTHORITY :
This work has been Administrativelysanctioned in the G.O.(D) No.200, Highways and
Minor Ports(HQ2) Dept.Dt.07.02.2011 for Rs.28.72 Croresunder Railway Works Programme for the
year 2011-12.
EXISTING FEATURES:
The Proposed ROB is located in the existing level crossingLC No13 in vepampattu –
Perumalpattu road branching at km 58/4 of NH -205 in between Thirunindravur and Veppampattu
Railway stations.The level crossing is located at about 80m from NH-205.
NECESSITY:
The level crossingLC No13 is located in Veppampattu – Perumalpattu road ,branching at km 58/4
of NH 205. The intensity of Train Vehicle Unit (TVU) at this location is 19500. However as a special case
this work has been taken up under RWP 2011-12.
Hence in order to overcome the above difficulties Road Over Bridge is proposed to allow traffic
to move freely with fewer interruptions with higher overall speeds. In addition, less conflict between traffic
movements reduces the accidents. After completion of the project the agricultural products from the near
by lands can be conveyed to the market without delay and the school children, patients will also reach the
destination without time delay.
The alignment of the ROB crosses th Railway line at an angle of 75 15 26.The Railway proposal
(vide Drawing No CBE/GM1/381/2012) envisages a single span of 37.482m c/c (skew length ) to cover
the crossing.
The road level in Railway span is RL109.250 with a vertical clearance of 6.525m over the existing
track at RL 100.005(top of rail) specified in the Railway GAD. The overall width of superstructure in the
Railway portion is 12.00m,with a carriageway width 0f 7.50m.Footing of 1.5m with crash barrier of 0.5m
has been proposed on neither sides of the carriageway.
BENCHMARK:
The proposed ROB is located in moderate exposure condition and lies in Seismic zone II..
ALIGNMENT:
The alignment of the ROB has been approved by the alignment approval committee on
6.9.2011.The ROB alignment starts at ch 29.717 on Perumalpattu side and crosses the Railway line at an
angle of 75
VERTICAL CURVES:
Suitable vertical curves have been proposed at change of grade locations on both NH-45 side
and Olakkur sides of the ROB. Valley curves have been proposed at the beginning at Ch 15.330m to Ch
45.330m to a length of 30m and at the end towards olakkur side at Ch. 718.438 to Ch.748.438 to a length
of 30m of the ROB.Thesummit curve have been provided at the juncture of sloped and level portion Ch.
404.792 to 434.792 to a length of 30m at NH side and Ch. 486.561 to Ch.516.561 to a length of 30m at
olakkur side.
NH Side
1 Ch 15.330 0 28.104
2 Ch 30.330 0.125 29.229
3 Ch 45.330 0 28.604
NH Side
Olakkur side
Six bores have been taken and the depth of soil strata along with soil classification is detailed
below.
Depth
Chain N
Bore No. From RL Depth Soil classification
age To RL value
m
37.280 33.780 3.50 Silty gravelly sand >100
Fractured Hard
26.730 23.730 3.00
Rock
1.50 29
Silty sand trace
38.410 33.910 3.00 70
gravel
4.50 >100
Completely
3 Ch.647 Weathered Rock
33.910 33.410 0.50
FOUNDATION:
The bore chart reveals that the soil stratum upto 30m consists mainly of sandy silty clay and
clayey silty sand . The N value ranges from 60to 29 uoto the depth of 6m. Below that N value of more
than 35 is observed . based on safe bearing capacity of soil, pile foundation has been provided for
abutments and pier .
If any change in the soil profile is noticed which requires change in foundation level, revised
design of sub structure and foundation shall be made and got approved from the competent authority
before execution.
PROPOSAL IN GENERAL:
The clear carriageway of the ROB in Highways portion will be 7.50m. The overall width of the
roadway will be 8.50m including crash barrier of 0.50m on either side. Service roads on either side or the
ROB have been proposed.
Carriageway 7.50m
C/C of Expansion joint 25.0m c/c for straight spans (19 nos.) and 12m(1nos) and
20.895m for trapezoidal spans (1nos.)
Grade of concrete for RCC items RCC M-35 (Design mix) for structural components & RCC
M30 (Design mix) for other components.
Grade of steel Structural steel other than mesh Fe-415
Mesh reinforcement Fe-240
Superstructure T-beam, cum slab Superstructure
Depth of superstructure 2100mm uniform
Design loading 70R for 1 Lane / Class A for 2 Lanes
Seismic Zone II
Exposure Moderate
Wearing coat 75mm minimum thickness in Vib CC M30 (Designmix) with
reinforcement (Fe240)
Road level at Railway portion RL(+)83.500
Design speed 30kmph
Substructure (i) Abutment – RCC cantilever
(ii) Pier – Single circular column 1800mm dia
(iii) Retaining wall – RCC cantilever
Foundation Pile foundation
Ch.42 to
Retaining wall RL+93.920
Ch.169.797
Ch 169.797 to
Returns
172.817
Abutment A1 Ch 172.817 RL+83.500
Pier P1 Ch.197.817 RL+81.00
Pier P2 Ch.222.817 RL+81.00
Pier P3 Ch.247.817 RL+76.00
Pier P4 Ch.272.817 RL+76.00
Pier P5 Ch.297.817 RL+76.00
Pier P6 Ch.322.817 RL+79.00
Pier P7 Ch.347.817 RL+79.00
Pier P8 Ch.372.817 RL+79.00
Pier P9 Ch.397.817 RL +82.500
Pier P10 Ch.422.817 RL+83.500
RP1 Ch.434.817 -
RP2 Ch.472.299 -
Pier P11 Ch.493.194 RL+80.500
Pier P12 Ch.518.194 RL+80.500
Pier P13 Ch 543.194 RL+80.500
Pier P14 Ch.568.194 RL+84.600
Pier P15 Ch 593.194 RL+84.600
Pier P16 Ch 618.194 RL+84.600
Pier P17 Ch 643.194 RL+78.400
Pier P18 Ch 668.194 RL+78.400
Pier P19 Ch 693.194 RL+78.400
Abutmet A2 Ch.718.194 RL+80.00
Ch 718.194 to
Returns -
Ch 721.214
Ch.721.214 to
Retaining wall RL+95.665
Ch.751.214
Ch.751.214 to
Retaining wall RL+95.520
Ch.844.224
The foundation levels have been fixed by designs wing based on the available bore log
particulars. During execution the soil profile may be ensured by conducting confirmatory bores at each
pier, abutment location and also in the retaining wall portion.
If any change in foundation level is warrented, revised design of substructure and foundation
shall be made and got approved by competent authority before execution.
FOUNDATION:
The foundation shall consist of 6 numbers of bored cast - in- situ piles of 1.2m diameter under
abutment & returns and 4 numbers of 1.2m diameter piles under pier. The pile cap is of size 5.1m x 8.7m
x 1.8m for abutments and 5.1m x 5.1m x 1.8m for piers. The pile caps and shall be in RCC M35 (design
mix ) using 20mm ISS hbg graded metal.
The maximum vertical load on pile (excluding self weight of pile) Under Abutments -1650kN
Under Pier
P10 - 2250kN
P11 - 2250kN
The capacity of pile shall be ensured by conducting initial pile load test and routine load test on
pile as per clause 709.2.1 of IRC : 78-2000 before casting the pile cap.
SUBSTRUCTURE:
Abutments and Returns shall be in Vibrated RCC M30 grade (Design Mix) using 20mm ISS
HBG graded metal. The bed block cum dirt wall over the abutments of 300mm thickness shall be in
vibrated RCC M30 grade (Design Mix) using 20mm ISS HBG graded metal. The Retainingwalls, beyond
the returns shall be in RCC M30 grade (Design mix) using 20mm ISS HBG graded metal.
Single circular column pier of 1800mm dia, in vibrated RCC M30 grded (Design mix) using
20mm ISS HBG graded metal has been proposed for all the spans.
Capping beam over the piers P1 to P9, P11 to P19 has been proposed of size 6.0m x 2.10m x
1.50m (1.50m @ support & 0.8m @ edge) , over pier P10 of size 9.0m x 2.1m x 1.5m in vibrated RCC
M30 (Design mix) using 20mm ISS HBG graded metal.
Filter media of 600mm thickness behind Abutments and Returns is proposed as per IRC 78 -
2000. The filling behind abutment and returns shall be granular having an angle of internal friction value
not less than 35 degree and should be free from cohesion, confirming to Appendix-6 of IRC 78-2000.
PVC seepage pipes 100mm dia. At 1.0m centres(bothways) as per IRC 78-2014(Appendix-6) are
proposed in abutments, returns and retaining walls.
SUPERSTRUCTURE:
T beam cum slab type Superstructures of 25.0m c/c in vibrated RCC M30 grade (Design Mix)
using 20mm ISS HBG grade metal has been proposed for all spans except trapizoital spans . The depth
of superstructure is 2100mm uniform , with three main girder and three cross girder.The overall of
superstructure is 8.50 m . The trapizoital span adjacent to Railway portion on Perumalpattu side has been
as 12.0m c/c with footpath. The depth of superstructure is 1100mm uniform , with four main girder and
three cross girder . The overall width of superstructure is 12.0m .The trapizoital span on Veppampattu
side of railway portion has bee proposed as 20.895m c/c . The superstructure comprises of three main
girder and three cross girder.The depth of superstructure is 1800mm uniform. The overall width of
superstructure is 8050m .The camber and super elevation have been achieved through pedestals.
ELASTOMERIC BEARING:
Elastomeric bearing of size 500mm x 400mm x 80mm proposed under the main girders for all
spans except P10-RP1. The thickness of the elatomers and steel laminates are 12mm and 4mm
respectively with 6 numbers of steel laminates. Elastomeric bearing of size 500mm x 320mm x 64mm
proposed under the main girders for the span P10-RP1. The thickness of the elatomers and steel
laminates are 12mm and 4mm respectively with 4 numbers of steel laminates.The top, bottom and side
covers shall be 6mm. The capacity of bearings shall be ensured by conducting relevant tests (as per
IRC:83) before installation.
MISCELLANEOUS ITEMS:
Wearing Coat: Cement concrete Wearing Coat in vibrated M30 grade (Design mix) using 20mm
ISS HBG graded metal proposed over deck slab and approach slab with Steel reinforcement of 8mm
dia.at 150mm spacing in both directions at the mid depth. For a length of 1m near the expansion joint,
8mm dia. Mild steel bars at 75mm spacing shall be provided as per section:2702.2 of MORT&H
specifications- Rev.5
Strip seal expansion joint of 40mm wide of approved type as per Cl.2607 of MORT&H
specification shall be provided
Crash barrier over the superstructure, returns and retaining walls shall be in vibrated RCC M40
(Design mix) using 20mm ISS HBG graded metal.
Approach slab is proposed for a length of 3.50m from the inner face of dirt wall. The thickness of
approach shall be 300mm at ends and 395mm at centre in vibrated RCC M30 grade (Design mix) using
20mm ISS HBG graded metal. The approach slab shall be laid over a base course of 150mm thick in
vibrated CCM15 (Nominal mix) using 40mm ISS HBG graded metal.
The reinforcement for all RCC items shall be of Fe415 grade confirming to Table 18.1 of IRC:
112-2011. Fe240 grade conforming to Table 18.1 of IRC: 112-2011 have been provided in wearing coat
and meshreinforcement at bearing and jack locations in superstructure, capping beam and bed block.
The development length and lap length of reinforcement shall be in accordance with IRC112-2011.
Welding of reinforcement shall be in accordance with clause 15.205.2 of IRC112-2011.
Clear cover to any reinforcement closest to concrete surface shall be 40mm for superstructure
and 75mm for foundation.
CONCRETE MIX:
All design mix concrete shall conform to Sec.6 & cl.18.5 of IRC: 112-2011 and nominal mix
concrete shall conform to 18.5 of IRC: 112-2011. The minimum cement content shall be 340 kg/m3 and
maximum water cement ratio shall be 0.45 as per Table 14.2 of IRC:112-2011.
SUB ESTIMATES:
Necessary sub estimates have been prepared and approved by the Superintending Engineer /
Divisional Engineer for the following:
In between the retaining walls from Ch:42 to 169.797 on Perumalpattu side and from Ch:721.214
to 844.224 on Veppampattu side, the approach road will be formed for a width of 7.500m.
.
The total amount of sub estimate Rs.80,65,406/-.
The proposed ROB is going to be constructed in the new alignment adjacent to the Olakkur
Railway feeder road On one side of ROB,on Olakkur side Government hospital is located. In between the
proposed alignment and the existing road other residential buildings are also located.
Hence service road has been proposed to serve the inhabitants in this area and other side of ROB.
Service road is provided on one side of the ROB along the ROB for entire length. On the other side of
ROB, the existing road can be used as service road and for the length from the joining point of the
proposed alignment, service road will be provided to a length of 3.75m.
As the proposed Service road runs along the field , protective wall of M15 Concrete is proposed
on one side of the ROB.
The service road is merged with the existing road with a horizontal slope of Min. 1 in 15.
The CBR value of the soil available at site is 2,3 and this cannot be used for formation of
subgrade as per IRC 37:2012. Hence carted earth with CBR value of 8 is provided.The lead for the carted
earth with CBR value 8 is 5 kms.
Pavement composition is designed based on IRC 37-2012 using IIT PAVE.The CVD is taken as
403 i.e. 50% traffic on the existing road.
Pavement composition is designed for 7.87 MSA for bituminous layer based on IRC 37-2012.
Mountable safety kerb is proposed on either side of the retaining wall and trestle portion along service
road to avoid damage to pier, Abutment and super structure from vechiles.
The provision made in the estimate are detailed in the specification report of the Service road
estimate enclosed. The total amount of sub estimate Rs.1,23,83,107/-
Construction of Stair Case
The ROB is proposed to be constructed in the new alignment. For the people residing in the near
by area, to cross the railway track staircase is proposed on eitherside of the railway line.The staircase
are mainly provided for the pedestrian to cross the railway track and to separate the vehicle traffic and
pedestrian movement .Staircase having minimum inner width of 1.5m are provided on all four sides of the
Railway portion of ROB.Each staircase has 6 landing slabs and all are supported on beams and columns
structures. The cost of the staircase works out to Rs.68,77,380/-
Construction of Box Culvert
In order to protect the exposed and plastered surface of the Road Over Bridge from weathering
and to have an aesthetic and pleasing appearance it is proposed to provide colour wash and white wash
over the exposed surface of the Road Over Bridge. The inner side of the crash barrier is proposed to be
painted with alternate strips of black and white colour.. The provisions made in the Estimate are detailed
in the Specifications report of Colourwashing and White washing Estimate. The total Amount of Sub
Estimate is Rs. Rs. 1957576/-.
Provision for Deck Drainage Arrangement
During rainy season surface water flows in the ROB deck and it is necessary to drain off this water
by providing drainage spouts in the deck and connecting through 150mm dia of PVC pipes for 2
consecutive decks are connected then transferred downward through PVC pipes and discharged into the
rainwater harvesting chamber.. The water from the pipes are collected to the rain water collection
chamber constructed to a dia of 2.00 m and 2.50m deep with alternate layer of sand and coarse
aggregate of 500mm layer each. The provisions made in theestimate are detailed in the specification
report of deck drainage arrangement estimate.The total cost of the sub estimate works to Rs. 7,02,000/-
The Crash Barrier provided in the ROB having 0.9M height only. The height of the crash barrier is
not sufficient for protection of fast moving vechicles is proposed to raise it by 0.25m with 100 mm dia GI
pipe with base plate as it will give further protection. The provisions made in the estimate are detailed in
the specifications report of Saftey Hand rail over Crash barrier estimate enclosed here with. The cost of
Sub Estimate is Rs.28,59,800/-.
Apart from the above sub-estimate the following L.S provisions for Sub-works are made in the
Main Estimate.
The traffic intensity in this road is high. The road safety measures for the movement of vehicles
during night hours are important criteria.Hence it is proposed to provide lights at 60m interval on either
side of ROB. For installation of lighting arrangement Rs. 3056339/- provided as L.S provision. The
estimate will be obtained from EB wing and necessary technical approval will be given and tender will be
called after completion of ROB.
The following Lump sum provisions have been made in this estimate:
Provision for variation in depth of foundation: Utmost care is exercised for choosing the type
and depth of foundation. However some times due to unforeseen reasons the depth of foundation may
have to be increased to satisfy the design requirements .An LS amount of Rs. 1250000/- is provided for
this item.
Provision for Land Acquisition and Compensation of structure is made in this estimate since
the alignment falls in the new alignment to avoid curves and bends available in the existing alignment.
Hence land has to be a acquired along the new alignment for which necessary revenue land values are
obtained and the compensations are calculated as per norms. LS amount of
Rs.15000000/- is provided in this
Provision for cost escalation @5% per annum for 2 years. The duration of the work is two
years as per the agreement.GO 60 and GO. 101 stipulates price adjustments at 5%per annum to be
included in the estimate .Price escalation for this work is applicable for all the components namely
cement,steel,bitumen, POL, labour, and other materials. LS amount of Rs. 12892655/- is provided in this
estimate.
Provision for Shifting of Service Utilities is made in the estimate in order to shift the EB poles,
waterlines, transformers etc., which may fall in the alignment isincluded in the estimate . LS amount of
Rs. 10 Lakhs is provided in this estimate.
Provision for Advertisement charges is made because the work may go for one or more
tender calls. LS amount of Rs. 10 Lakhs is provided in this estimate.
Provision for Investigation & DPR Charges : 1% are provided for investigation works, detailed
project report preparation, and any other investigation charges arriving at site as per present practice. LS
amount of Rs. 10 Lakhs is provided in this estimate.
Provision for Labour Welfare fund @ 1% as per GO. LS amount of Rs.
1289266 /- is provided in this estimate.
RATES:
The rates adopted in the Main estimate and Sub estimates are based on the Schedule of Rates
for the year 2015-2016 of PWD and Highways Department.
CONCLUSION:
The entire work shall be executed in accordance with the relevant specification of IRC,
MORT&H 5th Revision & IS codes and circular & instructions issued by the competent authorities from
time to time.