CIVIL AND STRUCTURES KEY ISSUES AND ACTIONS

FOR SUCCESSFUL PROJECT EXECUTION

OF LARGE THERMAL POWER PLANTS

POWER LINE MEET 22ND AND 23RD MAY 2012

S K KODANDARAMAIAHDirector(BD) & CEOSunil Hi Tech Engrs Ltd

INDUSTRY PERSPECTIVE AND EXPECTATIONS

• Capacity to add 15000mw/ year • Managing costs with Civil and structures being about 20% of EPC cost &45-50% of BOP Costs

• Cycle time Pressures- 250/300mw 24-26 months- 500/600mw 32-34 months- 660mw 44 months

• Needs about 50% of Labour needs of a Power plant• Better Lay Out management with reduced Land availability• Project delays related to Labour non availability• Civil and Structures key input for Electro Mech packages • Cut down of delays of BTG/Mech packages of 6 to 12 months

due to Civil works• Concreting requirement 4M M3 and Structural reqt of 5 lac MT/year• Focus on improving Engg inputs and Optimization of BOQ• Increased mechanization to reduce manpower• Better interface management & Engg Co ord to reduce delays• Sound planning and sequencing of work

CONTRACT STRUCTURE AND RESPONSIBILITIES

Owner/EPC Contractor

OwnersEngr

Structural

Civil & Str BTG & BOP

Detailer

Fabrication

Erection

Raw MatsFrom

Steel Plants• Res for Civil & Str• Infrastructure• Raw Mat Supply• Providing Civil fronts

• Plant Engg• Engg Drgs

• Fab. Drawings• Cranes• Welding eqpt• Skilled/Unskilled• Painting• Bought out items

OR

Civil

Excavation

Architectural& Buildings

concreting

• Batching plant• Other equipment • Sand & Metal• BOIs,Cement & Steel• Bar bending• Labour

Un certainty in the Soil conditions and below ground work Infrastructure of Land development, Temporary roads, drains Availability of Metal and Sand Key engg inputs from BTG Vendor & BOP Elect/Mech packages Key layout issues and land availability constraints Storage yard and Fabrication yard space availability Inadequate investment in Infrastructure Roads, drains, power & water Engg co ordination issues between Civil and other areas Interfacing issues between Civil and Structures Interfacing issues between Civil and Electro- Mech Non availability of labour carpenters, barbenders, welders, fitters Seasonal labour strength depletion and turn around Delivery of Critical steel sections in Rolled and Plate sections Volatility of steel prices Major Delays in Civil & Structural works

- Between Boiler & ESP- Bunkers on the LHS – General delay of 4 to 6 months

CIVIL & STRUCTURAL WORKS KEY ISSUES

Concreting in Different Areas

% age of concreting

0

10

20

30

40

50

60

NDCT /Chimney

Buildings Flooring work

FoundationSuper Str.

• TG & Bunker Floors Critical• Str completion key• Buildings Delay due to- Engg- BOI items- Const material- Labour

• Major augmentation at the time of LU and Coal firing

• Serious manpower shortages

VARIOUS INTERFACING ISSUES TO BE TACKLED

Completing the Furnace bottom AH works beneath O meter along with Boiler Foundations

Simultaneous commencement of work in - Boiler area- ESP Area- TG Area( A, B & C rows)- Commencement of Fabrication of TG Structures Engg drgs of TG Building str from grid 0 to 7 at the time of commencement CEP pit and CWP drgs release early to Facilitate A and B row foundation

continuity Mill side foundations on the RHS along with Boiler work up to O level Aux col interfacing with CW Pit and its eng drg release Completion of Aux col foundations prior to TG Deck casting CEP sump along with the liners to be finished prior to TG Deck work Also prioritize the foundations for ducting between ESP to Chimney planning Foundations work of Transfer Points & Boiler to ESP AB Bay floor at the operating level on A row and B row side

Areas Needing AttentionFrom Project Events Points of View

Sl No Description( Boiler)

Event Remarks

1 Ducting work not complete

LU & CF • Boiler inside duct• BOF to ESP• Duct Foundation inputs issues• Manpower & Welders problems• Shortfall of 30 to 40%

2 Coal Piping & Mills completion Problems

Syn & CF • Foundations• Mat feeding issues• Prob of erecting coal pipes• CHP & AHP Civil work problems

3 Left side Milling system

Full Load • Affects 3000 to 5000mt of Boiler work• Late foundation readiness• Integration of TPs, Gallaries, Feeder Floor,Bunkers,Mills & Coal piping

4 LU & CF shortfalls from the beginning

LU & CF • At HT/LU about 20% shortfall• At CF 10 to 15% shortfall• Water & Elect systems civil delays

Major Shift in Attitude: Do Initial LU with Coal Firing

Sl No

Description Others)

Event Remarks

5 Mismatch betweenTG Deck and TG building Readiness

TG Erection Start

• CEP/CW Piping interface delays• Aux Col Readiness &Deck support removal

6 Left side Bunker Structure

Full Load

• Late start/Foundations availability• Inadequate Cranes & manpower• Mat feeding problems

7 BOF to ESP Foundations & Str• For Ducts• For FD/PA Fans• Fan Handling str• TPs of CHP• PAPH Str

LU/CF/Full Load

• Prioritizing FD & PA fan foundations• How to accommodate Duct &TP foundations• working on TPs, Ducting & Fans simultaneously

8 Pipe rack • Foundations• Structures

LU/CF • Early start can help events• Interfacing and approach issues to be worked out

Critical out look on Thermal Power Cycle times(500-600mw units)

Boiler Island:• Civil Engg and Initial Civil works very critical• BLU and Coal firing to be most critical • Other events can only be inputs for the above• Typically @ HT, the physical shortfall of LU work is 15-20%• For full load operation the physical shortfall can continue to be 10-

15%• Major input delays from Civil Side

Problem Areas:• Not identifying the Commissioning sequence at the time of Civil

works forMilling system(RHS OR LHS), Ducting system between Boiler and ESP

• Too many civil works at a time between Boiler & ESP- Duct foundations & Duct work- Fan Foundations & Fans erection- CHP Transfer point foundations & Transfer Point Erection

TG Island Side• Interfacing of CEP Pit, CW Piping along the A and B row of TG

Building

• Aux column foundation work and structural work around the TG Deck & Operating Floor completion with TG Building work

Key Cycle times with Proper interface management

• Foundation start to LU :25-27 months• LU to CF: 3 - 5 months• TG Side Foundation start to EOT Crane+TG Deck-12-14M• TG Start to Barring Gear 12 months

TG Deck and Structure up to 660 MW

Sl. no

Project Unit TG Deck casting

comp. in

TG Bldg with TG

floor readiness

EOT Crane readiness

TG Bldg. Structure with floors readiness

(In months) (In months) MT (In months) MT

1 DB Power(600 MW)

# 1 13 months 15 Months 11 Months 2900 MT 18 months 6500 MT

# 2 18 months (Anticipated)

21 Months (Anticipated)

17 months (Anticipated)

2900 MT 23 months (Anticipated)

6000 MT

2 Koradi(660 MW)

# 8 14 months 18 months 12 Months 3000 MT 21 months (Anticipate

d)

5200 MT

# 9 21 months (Anticipate

d)

23 months (Anticipated)

18 Months 2500 MT 27 months (Anticipate

d)

5200 MT

# 10 26 monthsAnticipated

28 monthsAnticipated

24monthsAnticipated

2500 mt 32monthsAnticipated

5200mt

3 Vallur(500MW)

# 1 14 Months 750 MT 27 Months 6500 MT

# 2 19 Months 2000 MT 40 Months 6500 MT

NEED TO MATCH THE DECK AND FLOOR SCHDULES

KEY PROBLEM AREAS OF BTG CIVIL WORKS

TEMPORARY FRAMING ARRANGMENT FOR INSERTS WORK OF TG DECKFOR 660MW L&T MHI DESIGN

SUPPORT FROM DEVLOPERSSUPPORT FROM DEVLOPERS

• Liberal investment in Infrastructure

• Infrastructure of Roads, Drains, Sewerage system,Lighting- to with stand Indian Monsoon(2 seasons)- Fit for movement of heavy cranes(200-400mt) & HeavyDumpers

• Establishing reliable Construction & Water supply

• Drinking water facility

• Adequate Lighting arrangements

CIVIL WORKS-Improving Schedules

o Simultaneous excavation on Boiler, RHS of Mill, ESP & Duct Supportso Explore possibility of Civil works between Boiler & ESP before

commencement of Boiler Erectiono Start the TG area foundation along with Boilero For AB,BC bay along with Aux columns for Floor worko Prioritise Floor castings & use Deck sheeting'so Use cranes for Erection of Cribs erection for TG Deck/or cuplockso Provide Hard crusted surface for Fabrication Areao Provide clear approach roads & Drainso Commence Fabrication of Structures along with Excavationo Complete the TP foundations before Boiler Hydraulic test o Erection of Bunkers with Cranes or Jacking Systemo Prioritise the completion of main control and ESP control roomo Kick start of Water system side of Civil workso Focus on the Cable and Pipe racks as a parallel activity

GOOD START IN CIVIL WORKS ENABLES MEETING SCHEDULES

QUANTUM OF STEEL STRUCTUES FOR LARGE POWER PLANTS

Sl No Area 250mw 500/600mw 660mw Remarks

1 Power House Str 5000 6500 7500

2 Bunker Str 3500 5000 6000

3 Pipe Racks 600 1500 2500 Common

4 Service Building 750 1800 2000 Common

5 ESP Cont Room 250 400 500

6 Comp House 100 150 200 Common

7 Air washer Room 150 200 250 Common

8 Work shop Building 200 350 400 Common

9 CWP House 500 1000 1200 Common

11050 16900 20350

FOR MULTIPLE UNITS 2 2 5Capacity in MW 500 1000/1200 3300

Total Structures 19900 28500 76350

Coal Handling Str 5000 9000 15000

24900 37500 91350Per MW Steel use in MT 50 31 28

APPLICATION IN MEGA AND ULTRA MEGA PROJECTS1000/1200mw and >3200mw

Total Quantum of work 37500mt / 1,00,000mt

Completion schedule 36 / 45 months per unit

Packaging can be part of main Civil works or in BTG civil work for BTG Area

TG Building has two or three bays( Typ for 2 x 600 MW :- 42mx240m)

Bunker on the left and Right side of Boiler or between TG building & Boiler

70% Plates and 30% Rolled Sections

Material Handling is a major input

Fabrication Area Reqt is about 30000m2 to 50000m2

Can be 7 to 10% of Project Costs

Transfer points betn Boiler & ESP can be part of main Str Package

TYPICAL BUNKER SHELL SECTIONAL VIEW FOR ONE UNIT

Bunker Shell RCC SS Hopper

ABCDE

FEEDER FLOOR

TRIPPER FLOOR

BUNKER SHELL

BUNKER HOPPER

22.4m

56.6m

Deck Sheet

Cladding for Bunker Sealing

NM

A

• COLUMN HT. OF BUNKER SUPPORT STRUCTURE IS :- 68.0 m

• SAME HAS BEEN FABRICATED & ERECTRED IN 3 PARTS

• 1st PART is OF 27.0 m IN LENGTH WEIGHING 60.0 MT

• 2nd Part is OF 17.0 m IN LENGTH WEIGHINH 22.00 MT.

• 3rd Part is OF 22.0 m IN LENGTH WEIGHINH 14.00 MT. 22.0 mtr

feeder floor

Bunker supporting str

Tripper floor

Roof floor METHODOLOGY OF BUNKER STRUCTURE AND BUNKER SHELL ERECTION

150 MT Capacity crane

A

•BUNKER SHELL ARE SUPPORTED ON TWO ROWS OF COLUMNS MRK M & N.

• BUNKER SHELL HT. IS 12.5 m

• SAME IS BEEN FABRICATED & ERECTED IN 3 PARTS

•1st PART IS 5.0 MITER HEIGHT AND WEIGHT IS AROUND 15.00 MT

•2nd PART ALSO 5.0 MITER HEIGHT WEIGHT AROUND 15.00 MT

•3rd PART IS 2.50 MITER WEIGH AROUND 7.50 MT . 22.0 mtr

feeder floor

Bunker supporting str

Tripper floor

Roof floor METHODOLOGY OF BUNKER STRUCTURE AND BUNKER SHELL ERECTION

150 MT Capacity crane

N

M

A

•THE BUNKER SHELL 1ST PART WITH 4 NOS STUB COLUMN RESTED ON DIRECT BUNKER SUPPORTING STRUCTURE TOWARDS M-ROW WERE ERECTED.

• AFTER PROPER ARRESTING THE SAME 2ND PART AND 3RD PART WERE ERECTED.

• AFTER THAT TRIPPER FLOOR BEAM AND ROOF BEAM WERE ERECTED.

• SS HOPPER ALONG WITH THE RING BEAM HAD BEEN ERECTED.

•FINALLY N- ROW BRACINGS & BEAMS HAD BEEN ERECTED.

22.0 mtr feeder floor

Bunker supporting str

Tripper floor

Roof floor METHODOLOGY OF BUNKER STRUCTURE AND BUNKER SHELL ERECTION

150 MT Capacity crane

N

BOLTED STRUCTURES ADVANTAGES & DISADVANTAGESStructures present status

• General practice of Fab & Ern @ site• Make shift arrangement for fabrication• Design by Customer & Detailing by Contractor• Material supply by mostly customer• Site erection of welded joints• Erection tolerances can be flexible• Welding by MIG/MAW welding• Schedules 30-40 months for 500/600mw units

Bolted Design Requirements• All the structures including cols, main &sec beamsof bolted design

• Needs factory manufacture with NC/3 axis m/cs• Very close tolerances for manufacturing & Ern• Transportation logistics to be worked out• Local MM logistics for storage @ site• Design and Detailed Engg to be with Owner• Raw material supply with the Vendor• Manufacturing to gear up to handle 60 to 80mt wts• Large infra and area to be created for offsite work

Advantages• Factory made work, better quality• Erection can be faster• No need for large infrastructure at site• No burden of raw material procurement• Welding work can be eliminated• Saving in cycle time if properly managed• work can be done with less work force• CENVAT benefits can be taken

Disadvantages• Fab + Ern cost go up by 20 to 25%• ED on factory dispatch's on site work• Transportation cost extra on large components• No flexibility on managing matching items • Non sequential supplies can delay the site work• can nullify the advantages if shipments are non sequential• Addl cost for site storage and MM• High levels of accuracy for manufacturing & tolerances• High levels of erection accuracy reqd• Detailing to be done by Customer• Total cost per MT can go up by 10-12%

MAJOR PROBLEMS AND CHALLENGES FOR STRUCTURAL WORKS IN POWER PLANTS

Structural and Civil works are to be integrated for better execution Very poor infrastructure at site for Fabrication yard and Movement of material Major mat. availability problems with Plates of 32mm,36mm,40mm &

Rolled sections ISMB 300,400,500 & 600 General Delay of 3 to 5 months in Critical Steel Sections Volatility in Steel Prices Manufacturing capacity of higher sections limited and mismatch between

Site reqt and Steel Plant Rolling plans Engg input issues between Mechanical inputs for Civil Const Drgs Transportation bottlenecks for Heavy items at site- Poor Roads Availability of skilled welders and fitters & Material Handling Equipment Mismatch with the events of Mechanical fronts with Civil and Str fronts

like- EOT Crane Readiness in TG hall- TG Building readiness for Mechanical Erection- Bunker Structure for Coal Firing system of Boiler- Bunker readiness for Coal firing- CHP Transfer point Erection Problems( Very tall structures)

CAPABILITIES & LEARNINGS Critical steel sections in manufacturing to be augmented for timely supply

Better to discuss with the steel supplier at the beginning with tentative sections

Need for Deployment of Higher Capacity cranes of 150mt to 250mt

Present capacity to be increased by about 30-50% for 12th Plan Objectives

There is a general shortage of experienced good Civil and Structural Engrs.

Shop manufacturing as a substitute to site fabrication can be an alternative

Bolted structure can be an alternative to Welded structure for site joints

Investment in site infrastructure for proper Fab Yards, Roads and Approaches

Development of skilled welders and Fitters for site work

Development of more agencies for Fabrication detailing drawings

Safety standards for tall structures erection to improve

Suitable Price Escalation for Steel Price volatility cover up

FOCUS AREAS KEY ACTIONS

Boiler Foundations • To excavate the Mill side foundations on RHS• To do Bottom ash hopper foundations to GL

A, B Structure column erection • CEP and CWP engg clearance for RCC work• Engg drgs for Cols, bracings, Floors ,trusses• Heavy lift crane

Floors in AB and BC Bay • Readiness of Aux cols• Deck sheeting arrangement

TG Deck work/TG operating floor readiness

• Cup lock/staging arrangement• Inserts incorporation with proper material handling• Bar bending and placement arrangement for reinforcement• UPV testing arrangement & Deck support dismantling

Foundations between Boiler & ESP & TPs

• Priority for Duct and Fan Foundations for LU• Priority for TP foundations for CF• Sequencing of foundations, duct work and CHP work & clearances• Erection of TPs the most difficult structure

BOP Buildings( DM plant, CWP House, FOPH,Aerator,Service building, APH, Silos

• Labour arrangement• Shuttering & staging material• Drgs• Clearances

SAFETY RECORD SAFETY RECORD ––Civil & structure packageCivil & structure package

LOOKING AHEAD…… Engg inputs to be ahead for 3 to 5 months progress of site work Adequate and timely investment in Roads, Drains, Const Power & Infra Improve mechanization and reduce dependence on labour

- More Use of Boom placers, concrete pumps- Use of Deck sheeting for floor work- Use of RMC wherever it is feasible- Use of higher capacity cranes and more in nos- Use of Tower cranes for Building works Pre pone CHP Civil works between Boiler and ESP by 6 months Better integration of Civil and Structural works of TG Building Invest in Monsoon preparation on temporary works Switch over to Bolted structure for major structural work HR initiatives for Strengthening Civil and Structural Supervision Improving Construction safety records Provide differential rates for concreting of Buildings & Floor works Proper escalation clauses for Cement and Steel price volatility Prioritize Bunker work on RHS and LHS Plan for LU with Coal firing instead of Coal firing for Full load operation