Shear Wall and Pile Foundation

Engineering Rocks presents

Shear wall and Pile foundation

March 7,2015. Today I felt like an actual “Civil Engineer” at a construction site in Babarmahal, Kathmandu, Nepal. In contrast to the highly needed, but quite perplexing theories, I experienced overflow of tons of concrete knowledge that you and I should know before suiting up for the site.

Do you know how the shear wall looks like? I guess only few of us have seen it in actual.

 

Figure 1: Shear wall.

These are the reinforced concrete walls in buildings to carry vertical as well as lateral loads. The shear term is misnomer as it resists major portion of the lateral shear through flexure deformation and not through shear deformation. The flexure wall is a better term. A structure of shear walls in the center of a large building — often encasing an elevator shaft or stairwell — form a shear core. The shear wall shown in the figure is being constructed for the upper and lower basement of the 9.5 storey , 3 Star hotel. Here, shear wall is constructed for the purpose of resisting the lateral load due to the earth as well as the vertical load. Shear wall constructed is of 9 inch thickness.

I bet that the following picture will help you visualize the pile foundation, if you haven’t seen it.

 

Figure 2: Pile foundation

 

Pile as the geek would say- Pile is a slender structural member made up of steel wood or concrete, which is used to transfer loads to the deeper strata below; when the soil at or near the ground surface is not capable of supporting  the structure to be constructed. In the figure shown we can see a lump of engineer’s nightmare, i.e. Black Cotton soil at the left and bottom side; which has very low bearing capacity, but it is quite gifted soil when it comes to agriculture.  Due to the expansive nature, which swells or shrinks as the water content changes in the soil pile foundation is used in the above case. The pile used here is concrete- friction pile of 10m deep, yes you heard correct it is 10m deep. 

Figure 3: Mat above Pile foundation.

The figure shows the picture of mat of concrete above pile foundation- a typical Pile with Mat foundation. It takes the load of the super structure and transfers below to the pile. Hey do you know why mat foundation is constructed. Guess what, it is to prevent differential settlement of the structure above due to uneven loading.  The Mat foundation shown above is of 4 feet depth, yeah it is thick as hell. Don’t get surprised now there is something more.

  

Figure: Bruj Khalifa

You all know which is the tallest building at present, right? Any ways, I will acknowledge you about that, the tallest building in the world is Burj Khalifa. Its location is 25°11′49.7″N 55°16′26.8″E. Hey don’t start googling, I am just kidding around, it is located in 1 Sheikh Mohammed bin Rashid Blvd - Dubai, United Arab Emirates. Did you know that the Pile foundation of Burj is 43 meter deep , has 1.5 meter diameter and the Mat foundation of it is 3.7 meter thick. Now is the time to get surprised . Anyways it is pretty standard for a kilometer tall building ( actual height 829.8 meter). It is a vertical city in itself.

No wonder you all have known a lot, isn't it?

                                                                                         See ya!!

PS Thank You Dipesh Dhimal Dai