Tambaram to Tindivanam – 93.6 kms. ( Km 28 to Km 121.6)
39 kms (Km 28 to Km 67) - Existing 4-lane to be strengthened
54.6 kms (Km 67 to Km 121.6) – Existing 2-lane to be 4 laned
12 Bridges – 1 Major & 11 Minor
1 ROB
3 Underpasses
1 Trumpet Interchange
2 Grade Separators
83 Culverts – 41 pipe & 42 slab

Introduction :
The National Highways NH-45 (Popularly known as GST Road) is one of the important National Highways that connects Chennai with the southern districts of the state including major towns such as Trichy, Madurai etc. This Project work involves strengthening of the existing 4-Lane section from Tambaram to Mamandur (from Km 28/0 – 67/0) and widening to 4 Lane of the existing 2 Lane road from Mamandur to Tindivanam (from Km 67/0 – 121/0). The highway when fully operational will have partially controlled access with service roads being provided for local traffic in urban areas. This Project has been awarded on BOT (on annuity payment terms) to the Concessionaire M/s. GMR Tambaram-Tindivanam Expressways Pvt Ltd. (GTTEPL). For the supervision of this work, the role of an Independent Engineer has been envisaged in the concession agreement and M/s.MSV International Inc. are the Independent Engineer appointed by NHAI. The Concessionaire appointed M/s. UE Development India Pvt. Ltd (UEDI) Bangalore and United Engineer (Malaysia) Berhad, together known as the EPC Contractor for the execution of all the construction works of this project.

The Highways passing through the following:
Perungalathur - An Industrial town
Vandalur - Zoological park – the biggest one in Asia
Guduvanchery - An important town and an industrial area
Singaperumal Koil - Pilgrim town
Chengalpattu - An important town and Taluk headquarters
Madhuranthgam - Pilgrim town
Acharapakkam - Pilgrim town
Melmaruvathur - One of the famous crowd pulling pilgrim towns

2.0 Project Scope

a) Truck lay-bys on both sides at two locations (at Km.70.400 and at Km.113.700)

b) Bus shelters at 49 locations. The main buildings inside the Truck Lay-byes at all the locations and the work of interior furnishing of the buildings have been completed. The works of bus bays are also completed in all respects.

2.3 Toll Plaza
Toll Plazas have been provided at two locations, viz. at Km.52.570 (6+6 Lane) and at Km.103.000 (5+5 Lane). The work of construction of main building, toll office and steel structure for both the Toll Plazas, interior finishing, including electrical cabling, water supply and other installations are completed. The work of PQC, medians and installation of toll booths are also completed in all respects.

2.2 Project Highway
2.5.1 Mainline
I Existing 4-lane divided highway from Km 28.00 to Km 67.00 (Tambaram -Chengalpattu Section) with generally 5.0 m median, 1.5m paved shoulders and 1.0m earthen shoulders shall be upgraded and strengthened to have partially access controlled 4-lane divided dual highway.

ii. The existing 2-lane highway from Km 67.00 to Km 121.00 (Chengelpattu– Tindivanam Section) shall be strengthened and widened to 4-lane divided dual highway with partial access control. The width of each carriageway shall be 7.0 m with 250 mm median edge strip, 5.0 m median, 1.50 m paved Shoulders and 1.0m earthen shoulders, with granular sub base on outer side.

Service Roads
A 5.50m wide pavement with a raised footpath of width 1.5m over lined drain on the outside through the urban areas.

Service roads shall be provided on one or both sides as shown
Section Km 28 to Km 67 – Total Length : 9.825 kms.
Section Km. 67.0 to Km. 121.6 – Total length : 10.328 Kms

Intersections / junctions
At-grade, there are 7 major Junctions and 38 minor Junctions

2.6.2 Grade Separator
Three grades separated intersections/junctions as under:

(i) Existing Natham intersections (km 56.00), replaced by a fly-over.
(ii) Existing Athankarai intersection (km 61.00), replaced by a fly-over.
(iii) Existing Melmaruvathur intersection (km 91.468), replaced by a fly-over.

2.6.3 Interchanges
One new interchange together with associated structures, transfer ramps and speed change lanes as specified in the DPR at the following location: Existing Madhurantagam Bypass Intersection (Km 80.500) replaced by a ‘Trumpet’ interchange.

BRIDGES / STRUCTURES

In the section from km 67.0 to km 121.0, there are 12 existing bridges as mentioned below i.e:

Bridge No. Location (Km) No. of Lanes
69/1 68.3 2 – Lane
69/2 68.4 3 – Lane
73/2 72.7 3 – Lane
77/3 76.7 3 – Lane
80/3 79.225 2 – Lane
84/2 83.25 3 – Lane
103/3 102.766 2 – Lane
105/1 104.54 2 – Lane
105/2 104.788 2 – Lane
111/1 111.00 3 – Lane
112/1 112.067 3 – Lane
120/2 119.9 3 – Lane

Widening of Existing Bridges Only one Bridge No.80/3 (Km 79.225) i.e. Kaliar bridge, which has been widened to 3-lane facility

New Additional 3 – Lane Bridges
12 Nos. New additional 3–Lane bridges are provided by the side of existing bridges as under:
Bridge No. Location (Km)
69/1 68.3
69/2 68.4
73/2 72.7
77/3 76.7
80/3 79.225
84/2 83.25
103/3 102.766
105/1 104.54
105/2 104.788
112/1 111.001
113/1 112.067
120/2 119.9
All bridges are minor except bridge no.80/3, which is a major bridge.

ROBs
In the 4–lane section from km 28 to km 67, there are 2 existing ROBs at the following locations:
ROB No. Location No. of Lanes
---- 52.0 4–Lane
5 / 3 55.4 4–Lane

In the section from km 67 to Km 121 one existing ROB at Km 101.118 with a carriageway width of 9.8m are retained. Additional 3–Lane facility is being added to this ROB by providing a new structure by the existing one on RHS.
Underpasses

In the section from km 67 to km 121, there are 2 existing underpasses i.e. 92/1 and 92/3 at Kms.91.909 and 92.073 respectively having 3–lane facility, which have widened. Three new underpasses at Km.91.471, Km.95.586 and Km.101.100 are provided for 6-lane facility.

Details of these underpasses are given below:
Sl. No. No. / Chainage Remarks
1 Km. 91.471 New
2 Km. 95.586 New
3 Km. 100.975 New
Drainage Culverts
There are 103 culverts (74 HP and 29 slab) in existing 4 lane section Km 28.00 to Km 67.00 which are retained. In 2-lane section km 67.00 to km121.00 there are 86 culverts (44 HP and 42 slab), which are widened to 4-lane except 2 RCC culverts No.96/1 & 96/2, which are reconstructed as 4-lane 2 X 1000mm HP culverts.

Retaining Walls
Reinforced Earth Walls are provided for Flyovers 56/1, 61/1, 92/1 & 96/1.

Drainage
Three types of drains are provided in the Project i.e
1) Concrete covered drains
2) Opened drain with pitching
3) Opened drain without pitching

2.7 Traffic Signs
(i) A complete range of permanent retro-reflective traffic signs is provided for safe and efficient movement of traffic. The signs are of following different categories:
1) Regulatory signs.
2) Warning signs.
3) Cautionary signs.
4) Overhead directional signs.
(ii) Temporary traffic and construction signs are provided during construction and maintenance operations for traffic diversion and pedestrian safety.

2.10 Road Markings
(i) Thermoplastic road markings for lane marking, edge strips, chevron, zebra stripes are provided in accordance with MoST Guidelines/Specifications.
(ii) Kerbs all along the road (including structures) are suitably painted.
Traffic Safety Measures
(i) Pedestrian Guard Rails are provided at the proposed major urban intersection/service roads in order to control and guide pedestrian traffic.
(ii) Metallic Crash Barriers are constructed at the edge of the outside shoulder of the road. These are installed on sections of the road, where the embankment height is more than 6m, at bridge approaches, and where the carriageway passes along large ponds.

Illumination
The entire stretch of the project wherever the built-up areas are there, illuminated beautifully with two armed posts of 10m height and also with 30m high mast poles. These illuminations are so attractive and are illuminating the areas of bus shelters, service roads and junctions. After the illumination, the toll plaza areas become centre of the attractions of the project.

Environmental Importance
At every 1.5m intervals, the plants are planted in the median in two rows for the full length and are being maintained properly to give the greenery look to the project. More tall variety plants are planted all along the boundary of the road on both sides. Small size garden are provided in the areas like toll plaza, truck lay bys and amenities.
About the construction:

This project is a time bound one. To maintain the international standards, advanced imported road equipments are mobilised for speedy completion of the project. Construction of this road consists of three-stage viz., embankment formation, construction of crust and bituminous layer including wearing course. Suitable borrow areas for earth to be used for embankment formation are identified and approved for the quality. Earth from borrows are transported to the road sites using hydraulic excavators i.e. TATA Hitachi, L&T Poclain of 1 cum bucket capacity and dumpers of 15ton capacity. The uniformly dumped earths at site are spreaded in layers of thickness not more than 20cm and levelled or graded by using hydraulic motor graders to required level and line. After checking for the moisture content the calculated quantity of water is added using water tankers for maintaining OMC i.e. optimum moisture content. Then with the help of vibratory compactor the layer compacted to achieve the required dry density.

Over the prepared embankment, the granular sub base material - prepared from crusher plant- is laid in 2 layers of each 150mm thick. Then over these sub- base layer 2 layers of wet mix macadam from central wet mix plant is to be laid. Prior to the bituminous layer of dense bituminous macadam the top surface of the wet mix has to be checked for level tolerance and cleaned for dust free dry surface and this surface has to be primed using cut back emulsion. Then after curing of primed surface, the 2 layers of dense bituminous layer are to be laid using sensor paver for the required line and level and compacted by a set of vibratory tandem rollers and pneumatic tyre rollers. Finally the wearing course of 40mm thick is laid over the DBM surface.

The bituminous mix is prepared from central hot mix plant located at 2 locations i.e. at km 32 & 86 of the project. Both the plants are of batch mix type having a rated capacity of 150 tons per hour and are fully automatic controlled. As per the designed job mix formula the gradation of aggregates, the percentage of bitumen content & temperature of the aggregates, bitumen and the mix are pre set in the computer’s in-built programme to maintain the mix. The output of the batch of mix is checked for all quality control tests as per MOST specifications. Then for transportation of the mix, 20-30 ton capacity dumpers are used. Adequate care is taken at different stages to maintain the temperature of the mix for better workability and workmanship.

The most important aspect for the success of any road project is the success in getting sufficient aggregate quantity. This needs good stone quarry, capacity crusher to crush the raw stones to the required sizes. For this project there are two major quarries one at km 48 and other one at km 86. The crushers at km 48 is of having the crushing capacity of 200 ton per hour and other one at km 86 is with 400 ton per hour. Both are having the speciality of cone crusher and hence a high quality aggregates are produced. Also the crushers are equipped with multi deck vibratory screens for efficient screening of aggregates.
Concrete Guard Posts are provided at intervals of 2 m where the embankment height is over 3m.