2.2 a - msuh structural concept description

P3 Bid for Design, Financing, Construction, Equipment and FM of Response to Bid Doc. Ref.Mowassat Specialized University Hospital Egyptian Ministry of Health – Alexandria University

TABLE OF CONTENTS

1- DESIGN FACT SHEET

2- CODES & STANDARDS

2- STRUCTURAL SYSTEM CONCEPTUAL DESIGN

2-1 Super structure

2-2 Foundation

2-3 Lateral loads analysis

3- CONCRETE WORKS CHARACTERISTICS

3-1 Materials

3-2 Plain Concrete

3-3 Reinforced Concrete

3-4 Ready Mix Concrete

3-5 Curing

3-6 Watertight Construction

3-7 Formwork

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1- DESIGN FACT SHEET

Applicable Codes Egyptian Code of Practice – ECP 2007, 2008 Editions

Hospital Building 3 floors (Basement + Ground + First) covering 100% of BFP + 4 typical floors covering 30% of BFP

Structural System Flat plates (25 cm thick.) (Superstructure)

Structural System Rigid RC raft rested on piles (Foundation) divided in (3) regions (A, B, & C)

Region A: 60 cm thick. Raft rested on piles dia. 50 cm and 23.00m long – 1.80m pile pitch.

Region B: 90 cm thick. Raft rested on piles dia. 60 cm and 20.00m long – 1.80m pile pitch.

Region C: 60 cm thick. Raft rested on piles dia. 50 cm and 28.00m long – 1.80m pile pitch.

Typical Structural Grid Module (6.00x7.50) m

Expansion Joints Every 1500 m2 as shown on drawings

Design Loads Plain Concrete 2.40 ton/m3

Reinforced Concrete 2.50 ton/m3

Lean Concrete 2.20 ton/m3

Back-Filling Soil 1.80 ton/m3

Roofing gravel (for GST) 2.20 ton/m3

HVAC, Ceiling ductwork 0.15 ton/m2

Flooring load 0.15 ton/m2

Partitions brick wall 1.80 ton/m3

Live Loads Patients rooms 250 Kg/m2

Radio (X-ray) rooms 400 Kg/m2

Surgery rooms 400 Kg/m2

Stairs, corridors and balconies 400 Kg/m2

Restaurants, café and praying halls 400 Kg/m2

Theatre and conference halls 500 Kg/m2

Roof floors 100 Kg/m2

Wind load intensity 80 Kg/m2.Earthquake loads according to the ECP 2007.

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2- CODES & STANDARDS

Egyptian code for loads 2008 edition.

Egyptian code for design & construction of reinforced concrete structures 2007 edition.

Egyptian code for design & construction of steel structures 2007 edition.

Egyptian code for structural detailing 2007 edition.

3- STRUCTURAL SYSTEM CONCEPTUAL DESIGN

3-1 Super structure

The Hospitals building will consist of 3 floors (Basement + Ground + First) covering the whole area + 4 typical floors covering about 30% only of the whole area. According to the architectural and MEP requirements of the project, the most suitable structural system could be used is the reinforced concrete flat plates rested on columns, cores and shear walls because of the services facilities as incurred like HVAC ducts, medical gases network, water supply and sanitary networks which conclude to have flat slabs without intermediate beams may obstruct its suggested layout.

The building will be divided by arranged expansion joints into parts having max. average area 1500m2 each respecting the architectural design requirements.

Flat plates are one of the most commonly used structural systems in residential buildings, hotels, commercial buildings, hospitals and office buildings. Flat plates are solid concrete slabs of uniform thickness that transfer the load directly to the columns without the presence of projected beams, drop panels or column capitals as shown in fig.(1). The ease of construction is one of the important aspects that make flat slab systems a very attractive solution. Architects prefer this system because of its flexibility for the columns' arrangement and partitions with no obstruction of light or any services' ducts works.

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Fig. (1)

Flat Slabs may be analyzed and designed by any method that ensures that all the strength and serviceability requirements of the ECP 2007 are satisfied. The steps necessary to perform the designs are briefly summarized as follows:

Choose the appropriate flat slab system according to the intensity of the live load and architectural requirements.

Estimate the slab thickness according to ECP requirements.

Calculate the total static moment to be resisted in the two directions.

Distribute the static moment between column strip and field strip.

Divide the resulting moments by strip width to obtain the moment per meter.

Design the sections to get required reinforcement. Design the slab against punching.

The basic structural design concept could be summarized in points as follows:

Moduled columns grid (6.00x7.50) m spacing will be used.

A flat slab with thickness 25 cm (with or without marginal beams) could be chosen concerning the applied heavy live and ceiling loads.

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The expected reinforcement percentage will be about 130 kg/m3.

Columns, cores and shear walls reinforcement percentage will be about 150 kg/m3.

The mentioned structural design concept is based on a specific design loads criteria could be detailed as follows:

Plain Concrete2.40 ton/m3

Reinforced Concrete2.50 ton/m3

Lean Concrete2.20 ton/m3

Back-Filling Soil1.80 ton/m3

Roofing gravel (for GST)2.20 ton/m3

HVAC, Ceiling ductwork0.15 ton/m2

Flooring load0.15 ton/m2

Partitions brick wall1.80 ton/m3

The assumed Live loads will be taken as follows: Patients rooms

250 Kg/m2

Radio (X-ray) rooms400 Kg/ m2

Surgery rooms400 Kg/m2

Stairs, corridors and balconies400 Kg/m2

Restaurants, café and praying halls400 Kg/m2

Theatre and conference halls500 Kg/m2

Roof floors100 Kg/m2

Wind load intensity80 Kg/m2

Earthquake loads according to the ECP 2007.

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All mentioned loads and consequent load combinations will be applied according to the ECP 2007 recommendations.

3-2 Foundation

According to the recommendations of the supplied soil investigation report a rigid raft rested on piles will be used (Piles). The foundation plan is divided into 3 regions A, B, C.

For region (A) raft foundation with thickness 60 cm rested on piles 50 cm in diameter and allowable working pile load 60 ton, where the pile length not less than 23.00m. The piles will be arranged as a mesh with piles' pitch 1.80m.

For region (B) raft foundation with thickness 90 cm rested on piles 60 cm diameter and allowable working pile load 60 ton, where the pile length not less than 20.00m. The piles will be arranged as a mesh with piles' pitch 1.80m.

For region (C) raft foundation with thickness 60 cm rested on piles 50 cm in diameter and allowable working pile load 60 ton, where the pile length not less than 28.00m. The piles will be arranged as a mesh with piles' pitch 1.80m.

3-3 Lateral loads analysis

For all parts of the building continued only till the second floor level, the effect of lateral loads could be neglected.

For the parts continued till the 7th floor level (represents about 30% of the building area) the effect of lateral loads could be resisted in the two direction by means of a well selected shear walls + cores matching the architectural requirements which will be considered as rigid enough elements able to resist the lateral loads due to wind or earthquake.

Also due homogeneous arrangement of columns, multi story R.C frames assuming the slabs as rafters could be considered as resisting elements against the lateral loads effect.

4- CONCRETE WORKS CHARACTERISTICS

4-1 Materials

- Reinforcement

High tensile steel ST (36/52) with yield stress not less than 3600 Kg/cm2 for bars diam. 10 mm or more.

Mild steel ST (24/37) with yield stress not less than 2400 Kg/cm2 for bars diam. 8 mm or less.

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- Cement

Ordinary Portland cement will be used for all concrete works above the natural ground level.

Cement type must comply with the appropriate Egyptian Code for Design and construction of reinforced concrete structures 2007.

- Aggregates

Fine and coarse aggregates for concrete shall comply with Egyptian Code for Design and construction of reinforced concrete structures 2007.

Notwithstanding such compliance, the nature and particle shape of the aggregate must be such as to ensure that the necessary strength and workability requirements can be met.

The fine aggregate shall consist of clean washed sand, while the coarse aggregate shall consist of crushed or natural gravel or shingle or of crushed limestone rock, to the Engineer's approval.

Aggregates shall not contain any deleterious matter either in any form or sufficient quantity such as to adversely affect the strength and durability of the concrete.

- Water

Mixing water for concrete and water for spraying aggregates and shutters, for curing and like purposes shall be from a source approved by the Engineer. The water shall be clean, fresh, and free from oil, organic matter and other deleterious substances.

Water for concreting shall not contain more than 1000 parts per million sulphates (SO3) nor more than 500 parts per million of chlorides.

- Admixtures

The use of admixtures and additives to promote workability or any other purpose shall only be allowed with the prior approval in writing of the Engineer. Where such approval is given, the additive shall be applied strictly in accordance with the manufacturer's recommendation.

4-2 Plain Concrete

Plain concrete used for foundation works will have Characteristic cube strength Fcu28 not less than 220 Kg/cm2.

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4-3 Reinforcement Concrete

Reinforcement concrete used for different structural elements will have Characteristic cube strength Fcu28 grades as follows:

Piles, Pile Caps, connecting slab at foundation level, retaining wall 300 Kg/cm2.

R.C Slabs and beams and stairs300 Kg/cm2.

Columns, Cores and shear walls350 Kg/cm2.

4-4 Ready Mix Concrete

Ready mix concrete will be used for all R.C works even delivered from approved batch plants or construction wise it will be better to have a project own patch plant.

4-5 Curing

Freshly placed concrete shall be protected from sun, wind, exposure and excessive drying out and cured continuously for a minimum period of 14 days.

Water used for curing shall be fresh well water. Where water is used for curing concrete work buried in the ground, care should be taken to avoid excessive curing water from running below the foundation of the footing.

4-6 Watertight Construction

Where watertight construction is specified on the Drawings :

The Contractor shall be responsible for achieving water tightness of the work so specified.

Joints in concrete shall be located only at positions shown on the Drawings.

Continuous PVC water bars shall be incorporated in all joints, the type & locations of which are to be agreed with the Engineer.

The design of the mix must be such as to produce a dense waterproof and damp proof concrete with the lowest possible shrinkage characteristics.

After completion a thorough check shall be made on all joints to ensure that no imperfection exists.

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4-7 Formwork

Formwork shall include all temporary or permanent moulds for forming the concrete, together with all temporary construction required for their support.

All formwork whether metal or timber shall be securely placed and supported to prevent sagging and bending. All joints are to be closed to prevent leakage of liquid from the concrete, with special care being taken where vibration of concrete will take place. Formwork panels shall have true edges to permit accurate alignments at sides and provide a clean line at construction joints in the concrete. All fair faced concrete edges like steps parapets etc to be provided with a uniform chamfer.

Formwork shall be so designed that no damage to the concrete shall occur when the formwork is removed. It shall be constructed such that the formwork to the sides of members can be removed without disturbing the soffit formwork or its supports. Props and supports shall be designed to allow the formwork to be adjusted accurately to line and level, and due allowance shall be made for any settlement or deflection of the formwork that may arise during construction so that the hardened concrete conforms to the specified line and level. Back propping shall not be permitted.

Formwork shall be treated on those surfaces against which the concrete is to be poured with an approved shutter oil or similar dressing. To facilitate the removal of dirt, debris and the like, wash out holes are to be left where access is difficult. The responsibility for the removal of the formwork shall rest with the Contractor, and in no circumstances shall the formwork be struck until the concrete has attained adequate strength to resist damage, in particular to arises and features. The minimum time that must elapse between casting of the concrete and removal of formwork is given for the Contractor's guidance as follows :

Formwork to vertical surfaces, walls, columns, beams, sides - 24 hours

Soffits of slabs (props left under) - 10 days

Soffits of beams (props left under) - 16 days

Formwork shall be removed without shock or vibration which may damage the concrete.

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2.2 a - msuh structural concept description

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