Muscat, Oman, International Airport Project September 2007

Forecourt Complex Concept Design Report

Introduction

The Forecourt Complex is two (2) complexes that house the two (2) Multi-Storey Car Parks including their Administrative Office Buildings. The two (2) Car Parks are almost identically mirrored at North-South direction and are symmetrical about the centre line of the Passenger Terminal Building. The Forecourt Complex has relative levels corresponding to the ground floor level of the PTB which defined as Level 0.000 (R) = 7.800.

Each Multi-Storey Car park building will be structured mainly with a reinforced concrete moment resisting frames consists of cast-in-situ columns, beams and slabs and will be supported by tied-strip footings. The Ramps roofing systems shall be structural steel frames with prefabricated roofing panels and insulations. Car Park Shades structures shall be tapered built-up steel T-Beams supported on pipe struts with purlins and prefabricated roofing panels. Any walls attached within the structures will be disregarded in the analyses owing to their very minimal restraining effects on the Forecourt complex.

Adjacent to the Multi-Storey Car Park buildings are the Administrative Office Buildings. Each Office building, though aesthetically connected to each Car Park building, will be structurally isolated to contain the effects of seismic movements and thermal expansion of structural frames. Accordingly, two (2) movement joints, one along each lateral direction but with a covered floor area of application not exceeding 3600 m², shall be applied also on each of the Car park buildings owing to the design assumptions requirement that induced seismic lateral displacements would have to be contained enough in any applied lateral directions, in addition to the presumed thermal expansion stresses brought upon by difference in temperatures and the estimated ground settlements. Similarly, each Ramp shall have a minimum two (2) transverse isolation joints, with isolated longitudinal length not exceeding 60 m, to restrain any lateral longitudinal movements.

The facades of the Car Park Buildings are open facades with no concrete up-stands or perimeter walls along the slab edges. The structural slabs will have a trowelled finish of high quality able to receive suitable abrasion resistant moisture proof concrete protective coating and indication stripes directly.

Outline Specification

The Forecourt Complex structural frames will be supported by rectangular and square reinforced concrete strip foundations embedded 2.50 m. (min) from undisturbed or compacted ground surface. The lateral size of the pad foundations will vary from 2.50 m. - 5.0 m, with depth range of 0.85 m. (min) to 1.70 m (max). Ground Beams will connect all the structural frames on each building in the Forecourt Complex. Each structural column will be tied together

with a ground beam, the size of which is approximately 0.60 x 0.75 m.Columns that form the structural framing system on the Forecourt Complex will be reinforced concrete square columns with sizes of 0.70 m x 0.70 m (min) to 0.90 m x 0.90 m (max).Ground slabs at the Car park lowest level will be 0.20 m thick reinforced concrete slabs panels with isolation and thermal joints applied at both directions to contain the effects of slabs expansion stresses.Beams that frame the Forecourt Complex structural system will be reinforced concrete beams with width range of 0.40 - 0.70 m., and a depth range of 0.75 - 1.00 m.The structural floors will be framed by reinforced concrete slabs with thickness range of 0.30 m - 0.50 m (max). Each floor slab system will be restrained at edges to stiffen the whole structural system.

A reinforced concrete parapet shall be applied along exterior edges of the Car Parks and Ramps that serves as safety barrier to contain any accidental impact loadings.

To restrain the forces brought upon by seismic, thermal, uneven base settlements and applied moving loads, the Ramps shall be considered as isolated structures restraining independently such applied stresses; with sufficient flexibility against any lateral and vertical movements with respect to the overall behavior of the interfaces of structural systems on the Forecourt Complex.

Block Walls in the Administrative Office Buildings shall be insulated walls.

Structural Concepts

The Forecourt Complex Structural Systems are conceptualized based from the structural systems behavioral aspects of responses on the applications of applied loadings on the structures. It is assumed that the application of Framed Reinforced Concrete Structural System on the Forecourt Complex shall sustain enough the needed flexible resistances of the structures against the applied loadings coupled with side sways and plumb displacements. Owing to the lesser degree of behavioral applications of the presumed lateral loadings that are ascertained to act on the Structural Systems - since the ratio of the total exposed building height and applied lateral displacements is considered minimal, the assumptive need for a structural shear walls to lessen the amount of applications of the estimated displacements is therefore eliminated.

Accordingly, since the required bearing pressure constraints for equilibrium to contain the applied combined stresses on the Structural Systems supports points have been assumed not going beyond the nominal parameters of the allowable independent bases of resistance then an application of mat foundation as base of supports is disregarded; instead spread pad footings will constitute the bases of supports for the Structural Systems. Similarly, due to the symmetries of the floor modules continuities a large imbalance stresses are not foreseen - a lesser degree of rotations and tensile developments at supports base points are therefore sustainable enough with strip foundations.

To render the Forecourt Complex Structural Systems points of restrains adequately feasible enough to contain the magnitudes of the applied displacements in any course of actions brought upon by the imparted joints and assumptive points stresses resulted from the applications of the applied seismic, thermal and uneven ground settlements stresses, each Car Park building will be isolated quadrupled with movement joints; with distributed covered floor area of isolation application not exceeding 3600 m² and with an isolated length not exceeding 60 meters and with due considerations on the effects of induced seismic torsional moments that shall perceive to act on each isolated unit of the building if the unity ratio of mass and rigidity coincidence could not achieve owing to movement joints asymmetrical locations. Movement joints load transfer and interface points shall be capable enough to restrain any lateral and vertical displacements stresses in any direction in addition to the induced reactions due to combined ultimate stresses. Accordingly, each Ramps Structural Systems shall also be isolated from the Car Park Structural Systems, with at least two (2) transverse movement joints and with an isolated longitudinal lengths not exceeding 60 meter in length. Similarly, the Administrative Office building structure adjacent to the Car Park shall also be isolated from the Car Park Structural Systems with the provision of movement joints capable enough to sustain any induced lateral and vertical displacements stresses.

Owing to aesthetic requirements the movement joints shall be applied with due consideration on the elimination on the needs of additional column and foundation supports along the joints of isolation lines. It is therefore concluded that without the application of such movement joints the Forecourt Complex Structural Systems would need to have much greater amount of resistances against induced lateral and vertical displacements stresses, which would require the system to have bigger member sizes with added reinforcements to restrain such displacement stresses, in addition to the application of much bigger bases of supports such as raft foundation to contain the wide-coverage uneven ground strata settlements.

To restrain the side sways and plumbs strain effects of seismic movements and uneven ground settlements stresses including any instability and imbalance stresses, in addition to the isolation joints, all the Structural Systems Reinforced Concrete Columns shall be tied together with a grade beams adequately enough to resist any compression, tension and torsion stresses brought upon by such induced stresses. If the Structural Columns are opted not to be tied with ground beams then bigger sizes of Structural Columns are foreseen in addition to the application of Mat Foundation in lieu of Strip Footings as support bases and instability and imbalance controller at the most critical structural systems joints.

Accordingly, Structural Steel Columns are chosen not quite feasible to be used on the Forecourt Complex Structural Systems due to the following technical engineering aspects: firstly - ductility demand - the elastoplastic response of the structural system on seismic forces; is the ratio of the inelastic movement of the structure to the elastic movement which requires the structural system,

in addition to the seismic additional detailing requirements on its complex connections, to be rigid or braced enough to attain such demand for ductility, of which bigger sizes of steel columns are foreseen for rigid frames and lateral braces for braced frames which would affect the aesthetic requirements on the Forecourt Complex, and secondly - deflection considerations - owing to effects of moving loads including impact stress though minimal in applications, will brought upon on the structural systems nominal cyclic long term deflections which would require the system to have bigger member sizes with added complex seismic detailing connections and adequate braces to lessen the magnitude on buckling and slenderness requirements, in addition to the corrosion and fireproofing protection systems that also would affect the aesthetical aspects of the Forecourt Complex.

Similarly, Precast or Prestressed Concrete Structural System is disregarded due to its design requirements on complex establishment of overall seismic in-plane force paths, complex applications on its connections including large amount of needed movement tolerances to restrain the induced seismic stresses and displacements, provision of overall vertical tension ties which would require the establishment and application of seismic effective ground and base interface connections.

Reinforced Concrete Beams and Slabs shall frame the Forecourt Complex Structural Flooring Systems. Owing to the induced lateral and vertical displacements stresses in addition to the combined applied ultimate stresses, it is assumed that the applied Flooring Systems shall have conceivable rigidity - enough to contribute to the overall restraining stiffness of the whole Structural Frame Systems in terms of joints, interfaces and correlational assumptive robustness behavioral aspects.

Accordingly, composite slab systems is not considered owing to elastoplastic response requirement on the structural system, applied deflection considerations, additional seismic detailing requirements on complex connections, and corrosion and fireproofing requirements. Similarly, flat slab structural systems is not considered as the best feasible floor framing option due to, in addition to its economic disadvantage comparison implications, the establishment of complex concentrated edge points connections requirement along the lines of movement joints - concentrated stress transfer at isolation lines support points.

Though there are some walls on the sets of buildings on the Forecourt Complex such as external perimeter walls and safety barrier walls on the Car Parks external edges, such walls are considered incapable to contribute on the overall strain stiffness of the Forecourt Complex Structural Systems and hence structurally disregarded relevant to the overall assumptive behavioral functions and capacities of the structural system against induced stresses brought upon by applied service and ultimate loadings on the buildings and ramps.

Roofing System and Car Shades structural systems shall be of steel structures and built-up tapered roof beams with prefabricated insulated aluminum roofing

panels - lightweight enough to lessen the needed restraining stresses on its bases which shall be absorbed by the supporting slabs on the Car Park decks. Accordingly, owing to wind and seismic induced forces including thermal stresses, the Car Park Roofing Systems shall have supports joints flexible enough to contain any transverse and longitudinal lateral displacements brought upon by such applied movements on the roof framing systems.

However, even though the Car Shades Roofing systems, with built-up beams and rolled steel purlins roofed with prefabricated roofing panels but without insulation, are similarly lightweight enough will have their bases fix to the slabs due to the large assumptive concentrated induced surface point loads and flexural stresses acting on their single struts base supports points brought upon by the cantilevered actions of the whole framing systems. Accordingly, the Car Shades roofing systems shall have transverse movement joints at every 60 meter maximum longitudinal distance capable to restrain any lateral transverse and longitudinal side sways displacements brought upon by transient seismic and wind loadings coupled with combined ultimate permanent applied stresses on the car shades structures. The effects of material corrosions due to environment and utilization factors on members strains sustainable competence on the Car Park roofing system and car shades structural steel frames shall be taken into account in the whole assumptive behavioral restraining capacities applications, of which the minimum thickness of any aspects of rolled sections will be 8 mm and 10 mm for built-up sections.

To guard against the decaying effects of material strain corrosions and hence to prevent the impairment and dissipation of energy restrains on affected members reinforcements, all foundations and grade beams of the sets of buildings in the Forecourt Complex will be waterproofed and dampproofed in accordance with their applied levels of embedment corrosion exposures to soil water and chemical seepages proportionate to the estimated mean sea level. Waterproofed membrane materials shall be technically sophisticated enough to contain any water and chemical exfiltration and infiltration seepages in addition to its shredding adequacy - tensile and compressible capacity to restrain any surface applied stresses on the members. Accordingly, all building decks directly expose to environmental climate factors shall be waterproofed with due consideration on the amount of periodic accumulated rainfall and any water pondings on the affected building decks.

Interfaces

Interfaces between adjacent buildings in the Forecourt Complex shall be by movement and slip joints with adequate flexibility to restrain any induced lateral and vertical displacements brought upon by applied seismic and thermal stresses including any calculated deformations due to uneven ground settlements. Such movement and slip joints shall be capable enough to provide the needed aesthetical floor continuities between isolated floor edges with sophisticated expansion/contraction material properly installed on the joints. Effects of building configurations on affected adjacent buildings will be taken into consideration on the magnitude of application on such movement and slip joints to restrain any induced tearing, crushing and battering stresses due to

seismic oscillation rotational forces.

Architectural interfaces with the structural frame systems shall take into considerations all aesthetical finishes material installations and applications with respect to the effects of frames deflections, sways and expansions due to applied loads. Architectural finishing materials including roof waterproofing shall be in accordance with manufacturer's instructions and installed with enough flexibility to retain its designed levels, forms and line of axes with the use of sophisticated hinges and fixers against any movements on the frame systems. Aesthetical floor tiling systems including its mortar shall withstand, in addition to the designed applied floor loadings, any imbalance loadings brought upon by the structural frame systems movements.

Mechanical interfaces with the structural frame systems shall be by hangers, inserts and other applicable methods of interfaces but such interfaces shall not impair the design strength capacities of affected members of the frame systems. With due considerations on the members tension and compression sides and the effective concrete compression strength, inserts near the supports and for pipes passing through slabs shall be installed above the beams neutral axis and within the zone of half of the maximum shear distance from the face of supports. Accordingly, inserts near to mid-portions of beams shall be installed below the beams neutral axis and within half of the beam middle length.Electrical interfaces shall

Information Technology interfaces will be

Civil interfaces with the structural systems shall be …