Structural Review of a Commercial Building near Biyagama Free Trade Zone

     This commercial building was proposed to design with 3 reinforced concrete slabs and structural design has not done earlier. The masons and the client together have planned the construction works and first floor slab was casted. The ground floor part and the first slab soffit was finished and they were about to start a food city type shop in the ground floor area. At that time they have noticed several cracks formed under several beams and they have propagated further.
    In that stage client requested to visit the site and he request a remedial measure advice for the issue. Chartered Engineer Isuru S. Amarasena visited the site and took the measurements of the cracks and observed the nature of the cracks. According to the available information amount and types and lengths of the reinforcement  used were noted down. 
    Then he did a structural analysis using a structural design & modelling software and came to know that the adequate reinforcement has provided to the sections (If only their information is correct). Then he believed that should be an issue with the construction material used or the construction method or quality controlling. However according to the available budget frame, further core tests or any quality checking test were avoided by the client. 
    Then he inquired about the further propagation of cracks and after a duration noticed that the propagation has stopped and cracks are still. So he recommended a repairing the cracks using a special non shrinkage grout. 
Below shown is a image of the structural modal used by the structural engineer for the analysis.

Below you can see the deflected beams in the modal

Below you can see the Shear force diagram of the beams of first floor.

Here you can see the bending moment diagram of first floor beams.

This one is an option of constructing an additional column to support the cracked beam

This was a proposal for retrofitting the beams to lower the deflection and  improving the carrying capacity.

This is a 3D deflected modal due to the loads.