ACI - Kuwait Chapter presents the awards of excellence to a project in recognition of outstanding work in concrete construction and practices within Kuwait. The year 2008 Award of Excellence was presented to the SALHIA Real Estate Company for the "Arraya Office Tower" project.

This tower was the tallest building in Kuwait during construction, and remains the tallest completed building when this newsletter is issued near the end of the year 2009. The tower is located in downtown Kuwait City and accommodates 55 rentable office floors. It completes the diverse group of buildings: Arraya Center, Arraya Convention Center and Arraya Car Park.

The following provides details of the design and construction of this Kuwaiti landmark. The Arraya Office tower stands 300 meters above ground level. The record height of the building was achieved in spite of the relatively small site are (1058 m2).

The tower includes a ground floor, two mezzanine floors, 52 office floors (rentable area of 550 m2), three basement floors (service floors) and four mechanical floors. The different levels of the building are serviced via three groups of high-speed elevators, each group was dedicated to serve a different range of floor levels. The 20th and 40th floors act as evacuation floors in case of emergencies.

To enable achieving the record height on a small footprint area, extensive soil tests were carried out. Bore holes were taken to depths of 70 meters below ground level to extract samples.

These samples were used to investigate the properties of the soil under the tower. To minimize the differential settlement, 52 twenty-meters deep piles were constructed under the part of the structure which is most stressed. The tower stood on a three-meter thick reinforced concrete raft.

Self compacting concrete (4 MPa in strength) was used to attain the required speed of casting and adequate passage of concrete through the multi-layers of steel reinforcement in the raft. The shear walls were designed to resist the lateral loads from wind. The level of load during peak wind action was obtained from wind tunnel tests.

The walls and the columns were cast using a special concrete mix designed to achieve strength of 60 MPa. The floor panels were relatively large, exceeding 13x18 meters in the typical floors. Waffle slabs would be the most efficient design for such large slabs. However, construction of such system would delay the construction cycle of each floor to about 11 days.

The Engineer decided to cast a solid 28-cm slab on wide spandrel beams. This reduced the construction cycle to 5 days per floor, and saved about 300 days in the overall construction time of the building. The adequacy of the aggressive use of such a small thickness slab was demonstrated using tests to check for vibration. Some of the long span beams in the floors were pre-cambered 4 cm during construction.

An automatic climbing system was used in casting the vertical walls to allow a more swift construction. A special climbing protection system, and the construction sequence where walls were constructed three floors ahead of the slabs, allowed the construction of the slabs to take place in the safest possible environment.

A GPS system was used to continuously monitor the verticality of the building, the shortening of the columns and the building drift and settlement. A 70-tonnes machine was installed at the roof to support the window cleaning system. This machine was the first of its kind in Kuwait. It was located behind an opening on the inclined roof of the building.

A sliding door on the inclined roof allows the arms of the machine to extend and rotate to provide a flexible reach for window leaning operations. The iconic mast of the tower extended 60 meters above roof level. It is sloped to create a unique and memorable icon against the skyline of Kuwait. For the vision to construct such a special landmark in Kuwait and for breaking the record by building the tallest building in Kuwait, the Salhia Real Estate Company was presented with the 2008 Award of Excellence. Mr. Anwar Al-Usaimi, the Managing director of Salhia received the Award on behalf of the company.

Salhia vision was made possible by numerous parties. Three parties directly involved in the design and construction of the tower were recognized with Certificate of Excellence.

A certificate was awarded to the Architect and Engineer of the tower, the Pan Arab Consulting Engineers. Architect Tarek Shuaib, Partner, received the Certificate on behalf of the Pan Arab office.

A second certificate was presented to the General Contractor, Ahmadiah Contracting and Trading Company. Mr. Mohammad Al-Thuwainy, General Manager of Ahmadiah, received the certificate on behalf of the company.

A third certificate was presented to the concrete supplier, Ahmadiah Contracting and Trading Company. Mr. Mohammad Al-Thuwainy, General Manager of Ahmadiah, received the certificate on behalf of the company.