FAST TRACK CONSTRUCTION FAST TRACK CONSTRUCTION OF PROJECTSOF PROJECTS

Case Study - Tapovan Vishnugad Hydro Power Project By P&S Department, Dated 24.07.2009

◦Experiences Aspects for timely execution of projects Case Studies of TVHPP

◦Conclusions◦Recommendations

PESENTATIONPESENTATION BRIEF BRIEF

◦Geological Investigations◦Land Acquisition◦Shifting of Structures◦Infrastructure Inputs◦Resistance to blasting◦Use of Latest Technology◦Timely decisions in coherent manner

KEY ASPECTS FOR TIMELY KEY ASPECTS FOR TIMELY EXECUTIONEXECUTION

INVESTIGATION PHASEINVESTIGATION PHASEProper and adequate investigation averts delays during execution stage by:• Choosing best methodology of execution.• Avoiding geological surprises.• Making realistic designs and estimates

thereby avoiding contractual complicacies in later stages.• Proper investigations backed the decision

of deployment of TBM at TVHPP thereby crashing the construction period.

o Knowledgeable & Trained Land Acquisition team.

o Effective R&R Policy Implementation.o Creation of Infrastructureo Use of Latest Technology to reduce

execution time and mitigate environmental concerns

CONSTRUCTION PHASECONSTRUCTION PHASE

LAND ACQUISITIONLAND ACQUISITION◦Liaison with State Departments helps

in speedy approval of land acquisition and other proposals.

◦Liasion office has been established in Dehradun (State capital) to expedite the proposals.

◦Know How of land acquisition procedures to the executives engaged in ground work is crucial.

◦Trained Patwaris were hired to help in ground works.

R&R WORKSR&R WORKS◦ Community development works were

finalized in consultation with local bodies.◦ Medical camps helped in developing

good-will.◦ Community development works helped

villagers in terms of facilities and job.◦ Co-operative societies of the same village

were involved for CD works of a village. ◦ Job preference to PAPs/locals created

conducive environment for project works.

R&R WORKSR&R WORKS

◦Shifting of Structures to ensure unhindered progress of work and to avoid inconvenience to population using the structures.

◦Crucial structures like Temples, Govt. Inter College, Ayurvedic hospitals, suspension bridges and houses were to be shifted from Barrage area.

SHIFTING OF STRUCTURESSHIFTING OF STRUCTURES◦ Public was educated about the need of shifting.◦ All Govt. bodies and local bodies like Panchayat,

Youth club, Mahila Mangal Dals etc were taken into confidence.

◦ Alternative arrangements were made prior to shifting of original structures.

◦ Due respect was paid to local population’s sentiments with the structures especially Temples.

◦ Special care taken to maintain the original architecture of ancient temples to be shifted.

◦ Works of construction of new structures and removal/shifting of old ones was entrusted to PAPs.

◦ It was ensured that the services extended through these structures continued without break.

RELOCATED ANCIENT RELOCATED ANCIENT TEMPLETEMPLE

INFRASTRUCTURE INPUTSINFRASTRUCTURE INPUTS

Approach Roads: ◦Agencies like BRO & PWD are

available at the start of the project to commence approach works.

◦Our experience – They are not good at maintaining

schedules. After the award of main packages, the

approach roads should be included in main packages.

All approach roads should be concrete paved to avoid problems during monsoon season especially for hill roads.

INFRASTRUCTURE INPUTSINFRASTRUCTURE INPUTSConstruction Power:

◦ Construction power is crucial for execution especially when we are using technologies like TBM & Road Header.

◦ Augmentation of Power network was done from Srinagar to Joshimath.

◦ Un-reliability of power was hampering progress.

◦ To tackle the voltage fluctuations in peak hours, OLTC transformer is installed.

◦ Contract should have provision for DG- supply to tackle power interruptions.

INFRASTRUCTUREINFRASTRUCTUREBefore the completion of land

acquisition activities, residences and offices are accommodated in hired buildings.

As an early solution Pre-fabricated offices and porta-cabins are being used as site offices.

Phased construction taken up for Township. Phase -1 of prefab structures for office & Bachelor accommodation has been started.

Use of Latest Technology to reduce execution time

CONSTRUCTION PHASECONSTRUCTION PHASE

◦Location & No. of Adits: Normally 12 km long tunnel needs 2

intermediate adits due to lead distance and ventilation considerations.

Deployment of TBM obviated the need of 2nd adit and this HRT needs only 1 intermediate adit resulting in time & cost savings.

◦Selection of Excavation methodology: Mechanized tunneling such as TBM and Road

header have been used. A conference was held in Delhi and decision

to deploy TBM was taken after elaborate discussions with TBM suppliers.

TBM gives 3-5 times the progress rate of conventional excavation.

TBM & Road Header cause less vibration and pollution and provide much safer working environment.

USE OF LATEST USE OF LATEST TECHNOLOGYTECHNOLOGY

◦Selection of latest Equipment: Drill Jumbos being used for drill & blast

and rock bolting operations provide better progress & efficiency.

High capacity excavators and dumpers for faster excavation and mucking.

Grabs are being used for excavation of cut off wall

Raise climber being used for inclined Pressure Shaft excavation.

Raise Borer deployed for pilot bore and reaming of surge shaft excavation.

USE OF LATEST USE OF LATEST TECHNOLOGYTECHNOLOGY

◦Raise Borer deployed for Surge shaft pilot boring and reaming.

◦Offers higher progress rate, pilot bore completed in 3 days and reaming completed in 12 days.

◦Excavation of Surge Shaft close to populated area by this technology caused practically no disturbance to adjacent population.

USE OF LATEST USE OF LATEST TECHNOLOGYTECHNOLOGY

RESISTANCE TO BLASTINGRESISTANCE TO BLASTINGThe project faced a major obstacle by

people alleging that the blasts for excavation are causing cracks in their houses. This was motivated by experience of nearby Vishnuprayag HPP. To tackle the issue:◦Local administration taken into confidence,◦Frequent interaction & communication with

villagers and representatives,◦ An investigation on impact of blasts on the

structures in project vicinity carried out by independent agency which gave us clean chit.

◦Committees of villagers have now been involved in blast monitoring.

TIMELY DECISION IN TIMELY DECISION IN COHERENT MANNERCOHERENT MANNER

Speed of project depends on the speed of decision making

Decision to change the alignment of Decision to change the alignment of Chormi Adit approach road. New Chormi Adit approach road. New alignment:alignment:

Is 3.5 km long against earlier planned of 8.5 km.

At least 20 ha land acquisition is avoided, resulting in direct saving of approx Rs. 25 Cr. and also saving of land acquisition time.

Also serves as approach road to SFT outfall resulting in time & cost saving.

Provides much shorter approach between 2nd and 3rd adit of HRT thereby improving the accessibility and ease of supervision.

Gives the much required space for muck disposal in the vicinity of Barrage & HRT excavation

APPROACH TO CHORMI APPROACH TO CHORMI ADITADIT

Proposed alignment - 1

Alignment - 2

Chormi (2nd ) Adit Portal

Intake (3rd ) Adit Portal

Barrage Site

The decision to introduce third adit The decision to introduce third adit near Intake end of HRTnear Intake end of HRT◦The decision resulted in:

Early opening of front – Before the opening of front of 2nd adit approx. 1 km excavation of HRT from this new adit is achieved.

Considerable gain in time & cost.

Construction of Part of Third adit Construction of Part of Third adit through separate contract through separate contract ◦Construction of part of third adit was

awarded to M/s Highway & Hydel on 31.08.06.

◦Main HRT package was awarded to M/s L&T AM JV on 28.11.06

◦Thus awarding this small contract helped in early start of work.

◦Before the mobilization of HRT agency: Approach up to the adit was completed. Open excavation was completed. Part of slope protection works were

completed.

Decision to shift the location of TBM Decision to shift the location of TBM adit adit

◦Earlier location involved major support works with huge amount of overburden to be removed.

◦The overburden was likely to disturb the NH 58 which is lifeline of Joshimath Town.

◦A calculated risk was taken by shifting the Portal location closer to ridge line.

◦The decision involved well good co-ordination in Site & Engineering.

◦Decision involved a lot of survey & geological appraisals and need of agencies for these purposes was felt.

Decision to shift the location of TBM Decision to shift the location of TBM adit adit

Earlier Location

Final Location

HRT

TBM assembly in Two PhasesTBM assembly in Two Phases

◦ Against the area requirement of 15X235m for TBM assembly, area available was 10X70m.

◦ An innovative decision to assemble TBM in 2 phases was taken.

◦ First- Adit was excavated up to 130m chainage

◦ After part assembly of TBM up to BU # 11, TBM was pushed up to the face and TBM excavation was started.

◦ At Ch. 294m, TBM was stopped and Assembly up to BU # 21 was completed.

◦ Full fledged excavation was then started.◦ This was ventured for the first time in the

world.

Decision to change the alignment of Decision to change the alignment of approach road to Surge Shaft Top. approach road to Surge Shaft Top. New alignment:New alignment:◦ Involved only 200m length (against 1km)

of fresh construction thereby resulting in cost saving.

◦ This shorter length involved very small blasting and hence found no hindrance to work.

◦ The road is being used by the villagers too thus the strengthening of road is giving goodwill to NTPC among PAPs.

◦ The strengthening works were executed through PAPs resulting in improved relation with the village.

◦ Pilot hole and reaming of Surge Shaft completed well within scheduled time besides cost saving.

APPROACH TO SURFGE APPROACH TO SURFGE SHAFTSHAFT

Proposed Alignment 1

Existing Road to Shelong Village

Alignment - 2

Decision to include approach road to Decision to include approach road to Pressure Shaft Intermediate adit in PH Pressure Shaft Intermediate adit in PH package:package:

◦BRO and PWD were unable to take up the work due to other priorities in the district.

◦Decision to include road in PH package resulted in: Utilization of equipment and mobilization

of agency saving NTPC from idling claims. Saved a lot of time of award &

mobilization. Started Pressure shaft excavation from

intermediate adit before schedule.

SELECTION OF GOOD SELECTION OF GOOD

CONTRACTOR CONTRACTOR

WITH WORKABLE RATESWITH WORKABLE RATES

Experience with SSJV - ZVSExperience with SSJV - ZVS◦ SSJV-ZVS emerged as L1 and got the Barrage

& De - Silting Basin package of TVHPP.◦ Due to unprecedented rise in rates of Steel &

Cement, the rate of concreting items became unworkable.

◦ Situation got aggravated by coinciding financial meltdown of Satyam group.

◦ Barrage package is suffering.◦ A better formula to compensate for such

unusual price hikes of steel & cement should be developed.

◦ Employer bears the market fluctuations where Cement & Steel are provided by the employer.

◦ When it comes to Fast Track Execution of Hydro Projects, speed of decision making is crucial

◦ Investment in geological investigations give high returns.

◦ Geologists are the insurance policy of project.

◦ Hydro Projects are generally constructed in scarcely/less populated areas where even small group of people can affect the progress.

◦ This necessitates good liaison with state & local bodies and better R&R policies

CONCLUSIONSCONCLUSIONS

◦Selection of good contractor with workable rates is a must.

◦Efficient construction methodology and latest technologies reduce construction time.

◦ Innovations should be encouraged.◦Capturing of best practices through

initiatives like this is also important.◦And the most important…A highly motivated and enthusiastic

team of professionals.

CONCLUSIONSCONCLUSIONS

Following can help in fast track project implementation: Effective R&R policy and implementation. Accommodations to be constructed in

early phases of project. Mechanism for compensating unusual

hike in rates of steel & cement. We should be open to revisions in

construction methodology even at the cost of revision in TS.

Designers should pay regular visit to sites.

RECOMMENDATIONSRECOMMENDATIONS

◦ Following can help in fast track project implementation: Agency for survey and geological

investigation should be available during construction phase.

Dispute resolution mechanism is a must for Hydro.

TOC should be accompanied with Engg. Team & designers for effective implementation of their suggestions.

Construction power network should choose alignment involving least land acquisition & Forest patches rather than choosing shortest route.

RECOMMENDATIONSRECOMMENDATIONS