STRUCTURE DESIGN REQUIREMENTS

The design of piles and foundations shall be based on the soil investigation carried out by the Contractor and on the preliminary loading tests performed at site as specified in the Technical Specification.

Unless otherwise required by manufacturer’s equipment specifications, the total settlement of structures shall not exceed 3 cm.

The supporting structural steel for all buildings and structures furnished by the Contractor shall be adequate strength, stiffness and rigid and shall be adequately braced for the loads to which the steel will be subjected, and shall be completely suitable for the service.

All steel structures shall be designed by the working stress method, and all reinforced concrete structures shall be designed by the ultimate strength method, based on the latest edition of the AISC and ACI-318 Codes respectively.

The design shall conform to applicable requirements of the codes and standards referenced in clause above.

All Contractor’s designs, detailing and shop drawings shall be approved by the Owner before fabrication and construction.

DESIGN LOADINGS

The design of the civil works shall take account of all loads applied including Dead, Imposed, Wind, Thermal, Dynamic, Settlement, Movement, Seismic and other loading, condition where appropriate. Temporary load during testing, maintenance and erection shall also be considered.

The standards used and loading assumptions made shall be stated in the design basis and calculations.

LOADING CRITERIA

All structural components shall be designed for the following minimum loads:

Dead Loads

The dead loads consist of structure and equipment of a permanent and semi permanent nature.

The load includes the weight of framing, roofs, floors, walls, partitions, platforms, and all permanent equipment and materials.

The vertical and lateral pressures of liquids shall also be treated as dead loads.

Live Loads

Live loads consist of assumed unit loadings deemed sufficient to provide for movable or transitory loads such as people, portable equipment, fixture and parts lay down.

Live loads used for design shall not be less than those listed below. Other design loads are described separately in another section.

Live Loads

The following minimum live load shall be used into the design:

General:

Roofs 150 kg/m²

Offices 400 kg/m²

Assembly and locker rooms 500 kg/m²

Laboratories 500kg/m²

Stairs and walkways 500 kg/m²

Platform & gratings 500 kg/m²

Ground floors 1250 kg/m²

Surcharge adjacent to plant structures 1250 kg/m²

Load at top of any handrail on any direction 100 kg

Power Building:

Turbine Bay operating floor 1250 kg/m²

Auxiliary Bay operating floor 1000 kg/m²

Turbine Lay-down area 2500 kg/m²

Mezzanine 750kg/m²

Control room 1000 kg/m²

Switchgear floor 1000 kg/m²

Cable room 750 kg/m²

Battery room 1250 kg/m²

Coal conveyor Gallery, Tripper area or

Surcharge adjacent to plant structures -

Transfer House 1250 kg/m²

Steel grating 750 kg/m²

Notes:

a.1 Equipment loads shall be considered when designing floors. Live loads given shall not be superimposed over the areas occupied by the equipment unless there is space for possible storage or traffic under the equipment.

a.2 The floors shall be designed for the removal of equipment as required per the equipment removal arrangement.

a.3 Interior partition wall loads shall be considered when designing floors.

Pipe Hanger Loads

Piping loads for main steam, boiler feed, condensate, and extraction lines shall be specifically determined and located.

Piping expansion loads and dynamic load shall be considered on an individual design basis. Loads imposed on perimeter beams around pipe chase areas will also be specifically determined.

Pipe dead loads for other areas shall be determined as uniform loads per square meter of floor area and shall be carried to columns and foundations as pipe dead loads.

Impact Loads

The following minimum impact factors shall be used in addition to other loads for components supporting reciprocating or rotating machines, hoist, cranes, or other equipment creating dynamic forces; unless the Contractor uses larger values:

· For supports of elevators 100 %

· For cab-operated traveling crane support girders and their

connections 25 %

· For pendant-operated traveling crane support girders and

their connections 10 %

· For supports of light machinery, shaft or motor driven 20 %

· For supports of reciprocating machinery or power driven units 50 %

· For hangers supporting floors and balconies 33 %

Construction Loads

All structural components shall be designed for anticipated loadings imposed by construction.

Appropriate areas of the ground floor slabs of the power plant buildings and adjacent underground utilities shall be designed to support the operating loads of large construction cranes. The steel framing system shall be designed for stability at all stages of erection.

Wind Load

Minimum loads shall be based on wind velocity of 2 knots or wind stagnation pressure of 60 kg/m², adjusted for height above ground, shape factor and other requirements in accordance with American National Standards Institute (ANSI) A 58.1.

The stack shall be designed by taking into account to oscillation due to wind pressure.

Seismic Load

The seismic load shall be zone 1 accordance the latest Indonesian earthquake standard published by Ministry of Pemukiman & Prasarana Wilayah.

Crane Load

Crane lateral forces shall be determined in accordance with the requirement of AISC.

Lane Load

The minimum truck and lane loading shall be the AASHTO HS-20-44 loading.

Abnormal Load

This load shall include loads by postulated accident condition such as emergency torque of generator, and other loads as given by equipment manufactures.

Loading Combination

The load combination for reinforced concrete structure with ultimate strength design as shown on the Table 4.4.3 – 1.

The load combination for steel structure with elastic design is shown on the Table 4.4.3 – 2.

TABLE Part 4.4.3 - 1

LOAD COMBINATION FOR REINFORCED CONCRETE
STRUCTURE WITH ULTIMATE STRENGTH DESIGN


		LOAD

LOADING CONDITION	NO.	NORMAL									SEVERE				DESIGN
											ENVIRONMENTAL				STRENGTH

		D	D_d	L	L_n	T₀	R₀	C	P₀	M₀	E	W	H	Wv

Construction	1	1.1		1.3	1.1		1.1	1.3		1.3		1.3			ACI 318
	2		0.9		1.1			1.3		1.3		1.3			ACI 318

Test	3	1.1		1.3	1.1	1.3	1.4	1.3	1.3	1.3					ACI 318

Normal	4	1.4		1.7	1.4	1.7	1.4	1.7	1.7	1.7					ACI 318
	5	0.9			1.4		0.9								ACI 318

Severe	6	1.1		1.3	1.1	1.3	1.1	1.3	1.3	1.3	1.4			0.5	ACI 318
	7	0.9			1.1	1.3	1.1	1.3	1.3	1.3	1.4			0.5	ACI 318
	8	1.1		1.3	1.1	1.3	1.1	1.3	1.3	1.3		1.3		0.9	ACI 318
	9	0.9			1.1	1.3	1.1	1.3	1.3	1.3		1.3		0.9	ACI 318
	10	1.1		1.3	1.1	1.3	1.1	1.3	1.3	1.3			1.3	1.3	ACI 318
	11	0.9			1.1	1.3	1.1	1.3	1.3	1.3			1.3	1.3	ACI 318

TABLE Part 4.4.3 - 2

LOAD COMBINATION FOR STEEL STRUCTURE
WITH ELASTIC DESIGN


		LOAD

LOADING CONDITION	NO.	NORMAL									SEVERE				DESIGN
											ENVIRONMENTAL				STRENGTH

		D	D_d	L	L_n	T₀	R₀	C	P₀	M₀	E	W	H	Wv

Construction	1	1.0		1.0		1.0	1.0	1.0		1.0					1.33 AISC
	2	1.0		1.0			1.0	1.0		1.0		1.0			1.33 AISC
	3		0.75					1.0		1.0		1.0			1.33 AISC

Test	4	1.0		1.0	1.0	1.0	1.0	1.0	1.0	1.0					1.33 AISC


Normal	5	1.0		1.0		1.0	1.0	1.0	1.0	1.0					1.00 AISC
	6	1.0		1.0	1.0	1.0	1.0	1.0	1.0	1.0					1.33 AISC

Severe	7	1		1.0	1.0		1.0	1.0	1.0	1.0	1.0			0.33	1.33 AISC
	8	0.75			1.0		1.0	1.0		1.0	1.0			0.33	1.33 AISC
	9	1		1.0	1.0		1.0	1.0	1.0	1.0		1.0		0.75	1.33 AISC
	10	0.75			1.0		1.0	1.0		1.0		1.0		0.75	1.33 AISC
	11	1		1.0	1.0		1.0	1.0	1.0	1.0			1.0	1.0	1.33 AISC

Note: Load Definitions

A. Normal Loads

D - Dead Load - This includes self-weight of structure, waterproofing,

insulation, fireproofing, siding, partitions, equipment, mechanical and electrical components, etc.

D_d is minimum Dead Load

C - Crane Load – Crane and trolley loads including lift load, weight of trolley

and bridge and their impact.

L - Live Load - This includes loads that vary in magnitude such as occupancy load, moving vehicle load, etc.

L_n is minimum occupancy Live Load during test, seismic and severe

environmental event.

Po - Pressure Load - Internal pressures at normal operating condition.

Ro - Reaction - Normal-operating reactions of piping, duct and cable trays at

support or anchor points.

To - Temperature loads - Most critical transient or steady state thermal loads

condition on the structure at normal operating or shutdown condition.

This also includes other thermal effects such as frictional loads due to

expansion.

Mo - Other miscellaneous loads such as the high voltage line pull - off loads,

belt pull loads, and vehicle loads etc.

B. Severe Environmental Loads

E - Seismic Load

W - Wind Load

H - Hydrostatic Load

WV - Wave Load

DETAIL DESIGN REQUIREMENT

Foundation Design

The pile length shall be based on the soil investigation result and loaded tests of piles.

A minimum safety factor shall be provided as shown below:

- Overturning 1.50

- Slidding 1.10

- Bouyancy 1.25

In general the foundation design should ensure that:

The machine can be operated efficiently and reliably without undue or excessive wear. Foundation dynamic analysis shall be submitted for approval.

The foundation itself suffers no damage or settlement sufficient to cause the machine to function in efficiency or to require realignment.

The waves propagated through the soil by vibration of the foundation should not be harmful to persons or to adjacent structures, sensitive machinery or processed.

The foundation adapted is the most economical which will meet all the necessary requirements.

The seasonal variations in the ground water table level and the effect of such variations shall be taken into account on the foundation characteristic.

Concrete Design

Individual foundations of a building shall be interconnected in two directions generally at right angles by members designed for an axial tension and compression equal to 10 % of the maximum vertical load on either-foundation under seismic conditions.

If the axial load in one of the interconnected columns is less than 20 % of that in the other column, the design axial load shall be taken as 10 % of the average vertical load on the two foundations under seismic conditions.

Steel Structure Design

All structure shall be designed to support the above imported loads.

Design, detail, construction and erection of structural steel shall conform to the requirements of AISC or other International code but should be similar or better than AISC code.

The depth of fully stressed beams and girders shall not be less than Fy/56000 (Fy in kg/cm²) times span unless allowable stresses are reduced. The corresponding maximum L/D ratio for A36 shall be 22 for simply supported members. The L/D ratio not exceeds 30 under any circumstances.

For cantilevered beams, the maximum L/D ratio shall not exceed 5.

For strut members, i.e. members subjected to axial load and bending due to self-weight only, the L/D ratio shall not exceed 22.

For flexural members supporting reciprocating or rotating machinery, the maximum L/D ratio shall be 12.

The deflection of beams, girders under normal load shall not exceed 40 mm or L/300 whichever is less.

The deflection of plate girders or vertical trusses supporting columns or heavily loaded posts shall be limited to L/1000 but not to exceed 20 mm.

All connections shall be shop welded and field bolted and shall conform as a minimum to AISC Manual Table II (bolt) and Table III (weld) unless noted otherwise. Special connections shall be designed by Contractor for connections having large shears, axial forces, moments and copes.

The maximum slenderness ratio (KL/r) of the steel columns shall be limited to 200.

The steel lateral load-resisting system shall be analyzed and designed to function independently from shear-resisting concrete or concrete masonry exterior and interior walls, and concrete floor slabs acting as shear-resisting diaphragms.

The lateral deflection or drift of a story relative to its adjacent stories due to seismic event shall not exceed 0.005 Hsx as defined in the UBC. Hsx is the story height of the vertical bracing panel.

The maximum drift due to wind load shall be limited to 0.002H, where H is the building height below the level under consideration.

The bracing system should be laid out with regard to permanent and temporary access requirements for equipment removal purposes.

The horizontal deflection of girt due to wind load shall be limited to 1/180 of the span. For girt supporting windows, the allowable horizontal and vertical deflections shall be consistent with the manufacturers’ requirement (typically 6 mm for glass windows). The vertical deflection of the carrier beam shall be limited to the lesser of 25 mm or 1/300 of the span.

The minimum access gallery width shall be 75 cm unless noted otherwise. A minimum headroom clearance of 2.1 m shall be maintained over all galleries. All gratings shall be galvanized and suitable for the outdoor environment.

Grating, checkered plate or metal deck shall not be considered as lateral support for the floor beam.

The column base plates and shear bars shall be designed so that the bearing stresses on concrete foundations do not exceed the allowable value for 225 kg/cm² concrete in 28 days.

All column base plates shall be founded on concrete foundations at grade level unless otherwise noted.

ARCHITECTURAL DESIGN REQUIREMENT

Floor

An additional topping slab over the structural concrete slab shall be used where switchgear is to be installed or where specifically required for setting of Contractor’s equipment.

Ceramic tile floor finish shall be used in the building areas such as, the offices, the meeting rooms, the kitchens, the hall ways, the stairs, and other areas indicated on the Bid drawings.

Raised floor/elevated floor shall be used in the computer and control rooms for encase equipment drains and conduits.

Glazed tiles shall be used for the toilets, locker and shower rooms.

The battery room floor and wall shall be coated with epoxy coating. The epoxy shall have chemical resistance to alkalis acids solvents, and beverages with the material density and bonding strength of not less than 1.3 kg/cm³ and 25 kg/cm² respectively.

Metal Siding & Metal Deck Roofing

The metal siding and metal roof decks for the building shall be in accordance with technical specification.

Insulated metal siding and insulated metal roof shall be provided at least for the steam turbine buildings, control building, and others building as required, and shall be designed to obtain thermal and noise reduction in accordance with the above referenced specification.

The color of metal siding and roof deck shall be as specified in the Bid drawings or as selected by the Owner after award of this contract with no additional cost to the Owner.

All gutters shall be galvanized steel, similarly coated and colored to match the siding.

All metal siding and roof shall be designed weather, water and dust tight.

The metal deck roof pitches shall be minimum of 5⁰ with respect to horizontal plane. All roof water shall be collected at edge gutters and down spouts and discharged on the concrete splash blocks at grade.

Exterior and Interior Masonry Walls

Exterior Walls

Walls for the building, shall be made of Hollow concrete block masonry wall. The wall shall be plastered and coated finished on both side surfaces.

All complete exterior walls shall weather, and dust tight.

Interior Walls

Hollow concrete block masonry which is plaster and coated finished on both side surface shall be provided for the interior walls.

Doors

Wooden doors with aluminum frame shall be used for the office, the toilet rooms and the light duty interior door applications.

Steel doors and aluminum frame shall be used in other buildings based on Owner’s approval.

Single doors shall be minimum 0.80 m wide and 2.10 m high. Where double doors are required they shall be sized with consideration for equipment removal.

Doors more than 2 m wide shall be electric operated steel rolling doors.

Vision panels of the doors shall be clear polished wire glass.

The doors located in the control shall be sound proof and shall have a minimum sound transmission class rating of 40 decibels.

All normally opening door leaves shall be fitted with heavy duty type door closers.

The Contractor shall submit shop drawings to the Owner for approval before fabrication.

Windows

Windows shall be anodized aluminum with clear polished glass except in the turbine building where wire reinforced glass shall be used.

Windows provided in the control room shall be insulated glass or double glass in order to obtain noise and thermal insulation.

Louvers

Louvers shall be used in the equipment rooms and other areas for ventilation purposes.

Louvers shall be anodized aluminum louvers and at exterior locations shall be provided with the insect screen.

Ceilings

The layout of suspended ceilings shall be made with close coordination with the ventilation, the air conditioning and the lighting requirements.

Suspended acoustic tile ceiling shall be provided in the office areas, the computer room, the laboratory, etc.

Suspended moisture resistant acoustic tile ceiling shall be provided in the toilets, the locker and the shower rooms and kitchen.

Stairs

Steel stairs shall be used in general plant area where it is use for service of equipment or to travel from one gallery level to another.

Ladders

Ladders shall be provided in all pits, manholes, to all roof over 6 m above the ground where there is no access by a stair on to the floor and the equipment galleries where no stair system is provided.

Hand Rails

Hand rails shall be provided for the following area :

· Around every stairway floor opening

· Around every floor opening into which a person can walk

· Every open-sided floor, walkways and platforms

· Adjacent to dangerous equipment

OTHER CIVIL DESIGN REQUIREMENT

Roads

CBR test on the finished level of sub grade shall be held to a maximum value of 8 with 6 is preferable.

Minimum radius of curvature shall be 15 m.

Unless otherwise noted on the Bid drawing the main road width shall be 8 m with 1.5 m shoulder, other roads shall be 6.00 m with 1.0 m shoulder.

Loading over culverts and pipes shall be in accordance will AAHSTO HS20-44 except for areas subject to loading by the special heavy haul vehicles.

The Contractor shall provide additional traffic signs along the new road in the Power Plant as directed by the Owner.

Storm Drainage

The Contractor shall design and provide the drainage system but not limited to as specified in the Technical Specification and as shown on the Bid drawing.

For the storm drainage system, the ditches and the culvert shall be adequate to discharge surface run off due to a 10 years recurrence interval storm.

The minimum size of culverts shall be 300 mm wide and the culverts shall be made of reinforced concrete. The culvert shall be designed for a maximum velocity of 2.5 m/sec.

The storm sewer shall be provided with adequate number of manholes with heavy-duty frame and covers.

Minimum diameter of manholes shall be 1000 mm and manholes shall be installed at the changes in grade, size or alignment, at all intersections and interval, not greater than 100 m.

The ditches shall be of reinforced concrete and minimum slope as directed by the Owner.

Transformer Area Drainage & Oil Separator

To contain accidental oil spills, all drainage from the transformer area and Diesel fuel-unloading facility shall be routed through an oil separator.

The design of transformer pit and piping from the transformer pit to oil separator shall be based on the largest flow expected from the following condition unless Contractor requires larger.

Surface run-off shall consider 10 years recurrence interval from the transformer area.

Deluge system flow for the largest transformer fire protection system-estimated flow rate 30 liters/s.

Accidental oil spills from the largest transformer-estimated spilled oil volume of 3000 liters unless the Contractor requires larger.

The size of the main line connecting to the oil separator shall be sized to handle additional flow from other area as required.

Sanitary Waste Water

The Contractor shall design and provide the septic tank and shall be reinforced concrete with manholes and baffle.

The septic tank with drainage system shall have a sufficient capacity for accommodation of the minimum 50 person for the facilities of the control building, the water treatment plant, and the substation building.

Drainage from the mess room and toilet area of building above shall be routed to the septic tank before discharged to the wastewater storage pond.

The elevated piping from the building to the ground level and piping to the waste water storage pond shall be cast iron and under ground piping to septic tank shall be PVC pipe with the minimum size of 150 mm diameter.

Clean out shall be provided at every 30 m and each change in direction of the sewer system.

Prior to the design of the tile drainage absorption field, Contractor shall perform percolation tests to determine the absorption rate. Based on the field percolation test results the size of the absorption field shall be determined.

Plant Water

Drainage system from the plant water shall be discharge to the wastewater storage pond.

Piping material can be cast iron, PVC or GRP according to the requirement.

Shelter

The shelter shall be provided for, but not limited to the following equipment/plant:

a. Demin Pump

b. Service Water Pump

c. Other structures as directed by the owner

The shelter shall be designed with steel structure and provided with metal roofing. Floor shall be designed with reinforced concrete slab.

Oil Pipe and Cable Bridge

Oil pipe and Cable Bridge shall be steel structure pipe sleepers and bridge abutments shall be reinforced concrete founded on prestressed concrete pile.

Chemical Resistant Lining

All water and the wastewater concrete tanks and ponds shall be lined with epoxy coating with fiberglass fabric reinforcements suitable for the chemistry of the effluent.

DESIGN PHILOSOPHY AND BASE REQUIREMENTS

All Contractor’s designs, detailing and shop drawings shall be approved by the Owner before fabrication and construction.

DESIGN LOADINGS

STRUCTURE WITH ULTIMATE STRENGTH DESIGN

TABLE Part 4.4.3 - 2

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