civil and structures key issues and actions for successful project ...

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 KODANDARAMAIAH Director(BD) & CEO Sunil 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

• Plant Engg • Engg Drgs

Owners Engr

Owner/EPC Contractor

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

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

Structural

Raw Mats From Steel Plants

OR Civil & Str BTG & BOP

Civil

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

Detailer

Excavation

Fabrication

concreting

Erection

Architectural & Buildings

CIVIL & STRUCTURAL WORKS KEY ISSUES  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

Concreting in Different Areas % age of concreting 60

• 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

50 40 30 20 10 0 NDCT / Chimney

Buildings

Flooring Foundation work Super Str.

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 Attention From 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 between TG 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/F ull 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 1015% Major input delays from Civil Side

Problem Areas: •

•

Not identifying the Commissioning sequence at the time of Civil works for Milling 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

1

2

3

Project

DB Power (600 MW)

Koradi (660 MW)

Vallur (500MW)

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

13 months

15 Months

11 Months

2900 MT

18 months

6500 MT

#2

18 months (Anticipate d)

21 Months (Anticipated)

17 months (Anticipate d)

2900 MT

23 months (Anticipate d)

6000 MT

#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 months Anticipated

28 months Anticipated

24months Anticipated

2500 mt

32months Anticipated

5200mt

#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 DECK FOR 660MW L&T MHI DESIGN

SUPPORT 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) & Heavy Dumpers • 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 Supports o Explore possibility of Civil works between Boiler & ESP before commencement of Boiler Erection o Start the TG area foundation along with Boiler o For AB,BC bay along with Aux columns for Floor work o Prioritise Floor castings & use Deck sheeting's o Use cranes for Erection of Cribs erection for TG Deck/or cuplocks o Provide Hard crusted surface for Fabrication Area o Provide clear approach roads & Drains o Commence Fabrication of Structures along with Excavation o Complete the TP foundations before Boiler Hydraulic test o Erection of Bunkers with Cranes or Jacking System o Prioritise the completion of main control and ESP control room o Kick start of Water system side of Civil works o 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

5

Capacity in MW

500

Total Structures

19900

28500

76350

5000

9000

15000

24900

37500

91350

50

31

28

Coal Handling Str

Per MW Steel use in MT

1000/1200

3300

APPLICATION IN MEGA AND ULTRA MEGA PROJECTS 1000/1200mw 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 TRIPPER FLOOR 56.6m

BUNKER SHELL BUNKER HOPPER FEEDER FLOOR 22.4m

E

D

C

B

A

M N Bunker Shell SS Hopper

Deck Sheet Cladding for Bunker Sealing

RCC

METHODOLOGY OF BUNKER STRUCTURE AND BUNKER SHELL ERECTION Roof floor • COLUMN HT. OF BUNKER SUPPORT STRUCTURE IS :- 68.0 m

Tripper floor

• 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.

Bunker supporting str

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

150 MT Capacity crane

22.0 mtr feeder floor

A

METHODOLOGY OF BUNKER STRUCTURE AND BUNKER SHELL ERECTION Roof floor •BUNKER SHELL ARE SUPPORTED ON TWO ROWS OF COLUMNS MRK M & N.

Tripper floor

• 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

Bunker supporting str

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

22.0 mtr feeder floor

M N

150 MT Capacity crane

A

METHODOLOGY OF BUNKER STRUCTURE AND BUNKER SHELL ERECTION Roof floor •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.

Tripper floor

Bunker supporting str

• SS HOPPER ALONG WITH THE RING BEAM HAD BEEN ERECTED. •FINALLY N- ROW BRACINGS & BEAMS HAD BEEN ERECTED.

22.0 mtr feeder floor N

150 MT Capacity crane

A

BOLTED STRUCTURES ADVANTAGES & DISADVANTAGES Structures 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

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

Bolted Design Requirements • All the structures including cols, main &sec beams of 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

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 – Civil & 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