The architect of this project is Amila Ruwan Liyanapathirana and the structural design was done by Isuru S. Amarasena.
The site is located in Negombo area and the common soil nature in that area is a sandy soil with a high water table. The soil is inspected using two test pits. Since this sandy soil was very much good enough for bearing the loads, the only thing proposed was to stabilize the soil using a poker vibrator before placing the screed concrete. As the water table was so high a continuous water pumping method was used before placing the screed and the structural concrete.
The site before the constructions was seen as below.
Below you can see the structural model prepared for the proposed housing unit.
Below you can see the different floor elements with three different colors.
In the below image you can see the Reinforced concrete members in the red color and the steel sections in the green color.
Beams are to be designed for flexure and shear mainly. Below you can see the bending moment diagrams of Beams. Inorder to withstand for the flexure we have to provide adequate reinforcements and member sizes for the beam elements at appropriate places. You can see some larger values in some places. So when you don't have load bearing brick walls under the beams and when you have a moment larger than 22kNm, only you or your masons can't decide the required reinforcement amount and the required size. So you have to go for a real analysis and a real calculation with a help of a structural engineer. Then you can have the most optimized but stable solution for your structural elements. If you don't go for a structural engineer, what mason or the contractor do is, he will provide a large number of reinforcement bars with a huge sized beams. That will end up with wasting your money as well as the structure will be sometimes unsafe. Because if you provide more than the required maximum reinforcement amount, it will lead to a fail of the structure without eve giving you sign of failure. So this is critical and alsways try to go for a structural engineer.
A Pad foundations with 9x9 tie beams and rubble walls was proposed for the substructure. Shown below are some of images taken during the foundation constriction stage.
Below you can see a few of our structural drawings provided for the constructions of the house.
The structural drawings are given with all the required and essential details in a state that very easy to read and understand the contents. Even the client or an ordinary worker can understand the things in it. Because the simplicity should be there as the drawings to be read by simple workers or masons most of the time. When you follow the structural engineers guidelines and the instructions you can finally end up with a solid, stable and also an economical construction. It will be a very relief to you and your mind as you are going to live under that roof for your entire lifetime.
