Project 5

Project 5 Project Name & Job Title: Structural study of adding two floors above the main building of the Ministry of Social Solidarity in the Agouza district in Cairo, Egypt. Based on the request of the Ministry of Social Solidarity in Egypt to me to study the possibility of adding two upper floors above the ministry building to increase the capacity of the building. This building is considered governmental and administrative. Hundreds of employees working in the ministry, and citizens as well, come to it daily. This project is considered a real challenge, and it was necessary to study its structural safety first to find out whether it is able to bear the current loads or not. It was found from the study that it is constructively safe, but the problem is if the reinforced concrete floors are added , it may affect its bearing capacity. So I took a decision to add steel stories instead of concrete ones, because its weight are lighter. Details What I Personally Performed in This Project: o Firstly, I conducted the following tasks:  Visual inspection to find any defects and cracks in concrete skelton  Core test for some selected structural elements(from existing building) to determine the actual concrete compressive strength  Overall structural evaluation for existing building to show its structural safety under gravity & lateral loads based on ACI 562-16, ECP 201-2012 & ECP 203-2018 Codes. From the calculation, the structure is seemed structurally SAFE. o Secondly, I prepared finite element model by Csi ETABS software for the existing ministry building and I added two reinforced concrete stories above the existing stories in the model. ETABS showed the straining actions , I have checked the status of all RC columns . Most of the columns were unsafe; this proposed solution is costly due to retrofitting and strengthening works for unsafe concrete columns. o Thirdly, I prepared another finite element model by Csi ETABS software for the existing ministry building and I added two steel stories (consists of steel columns, main steel beams, secondary composite beams & composite slab)above the existing stories in the model. In the model, I have extended all concrete shear walls in the building till the final story, to can resist the lateral loads from seismic and wind and to reduce the bending moments on the steel columns in the added two stories. Consequently, reduce the cross-sections, leading to construction cost reduction. ETABS showed the straining actions , I have checked the status of all RC columns. All columns were safe, hence, no retrofitting works and no additional cost, this due to the lighter weight of steel stories compared to concrete ones. Used Design Codes: 1. ACI 562-16 code (Code Requirements for Assessment, Repair, and Rehabilitation of Existing Concrete Structures and Commentary) for assessment of existing concrete building. 2. Egyptian Code of Practice for Design and Construction of Concrete Structures: Code No. ECP 203-2018 for checking the structural safety of concrete Skelton (RC columns, beams, slabs shear walls & raft foundation) of original building before adding steel stories. 3. Egyptian Code for Calculating Loads and Forces in Structural Work and Masonry (ECP 201-2012). 4. Codes used for design the added steel stories is Egyptian Code of Practice for Steel Construction and Bridges (allowable stress design - ASD) ,Code No. (205) ,Ministerial Decree No. 279 – 2001. , it is very close and identical in many clauses with the (AISC ASD 89): AISC USA Manual of Steel Construction: Allowable Stress Design 9th Edition, (1989). Used Tools for Analysis & Design 1. Csi ETABS 2015 Software 2. Autodesk AutoCAD Software 3. In-house spread sheets Based on the above studies, I took a decision to add steel floors (consists of steel columns, main steel beams, secondary composite beams & composite slab) instead of concrete ones, this decision save hundred thousands of Egyptian pounds in case of adding concrete floors due to retrofitting works for unsafe columns in the below stories as mentioned above.