The porject is located in Mecca with three towers on same basement , its very traditional construction of towers with expansion joint divides three towers , the towers forms U shape in plan , the challange came up in the project is the connecting bridge between the right and left side 

The brigde is three spans bearing on concrete walls that is elevated from 7th floor to 9th floor with total height of 8.50 meters , the wall is laterally supported by the slabs in 7th , 8th and 9th floor , post tension  ribbed slabs selected to cover the 12 meter spans between the walls , the ribbed slabs is rested on the right and left towers on beams , where the beams is formed with nibs that recieves the slabs on bearing pad designed by BASF to retain the ribbed slabs reactions and allow the movemenet between the brigde and towers that is originally separated in the same locations with expansion joints as described previously 

the project located on the ring road in Mecca in return the bridge as proposed in the tender design drawings to be made of precast concrete is impossible since the cranes cannot be positioned on the road since its not allowed in any form to use the road or to be closed during construction

the challange in the project came up with the formwork since the first bridged slab is 35 meters heigh from the ground floor slab and that makes the deisgn of the formwork itself a challange , the slab is too compilcated for the construction , our project Engineer Mr. Helaly was able to faciltate the coordination process in which all of the main contractor workforce was aware of the slab design and difficulties , the first slab is casted on Jan.06.2016 and project is progressing to cast reminaining slabs

Design Challange 

The walls is connecting two main columns of the tower , the external column is 35 meters high with 1600 mm diameter and the internal column tower is square column of 1600X1600 mm , the wall spanning vertically and horizonttally to support the floor slabs and transfer those loads to columns , the design considered the construction stages and the formwork design that can only retain the load of the 7th and 8th slab weight only , during the design of the walls all this stages has been considered and agreed with the consultant ( zuhair Fayez ) , main contractor ( Al Arif ) and the formwork designers 


Photo courtesy - esolution construction team 


Photo shows stressing ends between the tower and slabs , where the slabs is retained by extended nibs from the tower beams 

photo shows 7th floor slab formowrk designed to retain the load of 7th and 8th floor slab with height of 35 meters 

Mahmoud Helaly

Project Engineer 

esolution construction&Engineering


Article By 

Mohammed Ashour

Associate Member
Tilt Up association 
Big05 Speaker
Member of 
Post-tension concrete institute 
American concrete institute