03-09-2010, 07:32 AM
Hi everybody,
I encountered one time a case where a pool was at the 20th floor of a 21 floors building.
I had to perform a seismic design for it. My approach was to consider the pool full with water, and load the structure with a uniform pressure = [rho*H_water].
But I never was 100% satisfied with this method.
I am asking, what is your opinion if it were to model in ETABS the water in the pool as:
1. a material having density=1000kg/m3, poisson ratio -0.99 and a very low elasticity modulus
2. a dense intersection of horizontal and vertical planes, as to yield overlapped cubes, assigning to this structure the material having "water" properties above
3. asking ETABS to find thousands of eigenmodes, until the concrete structure actually starts to participate... this might be solved by using Ritz vectors.
DId anybody try this and, if so, how can one check the results from the modal analysis? I am convinced that, if this step is correct, the rest should work fine.
I encountered one time a case where a pool was at the 20th floor of a 21 floors building.
I had to perform a seismic design for it. My approach was to consider the pool full with water, and load the structure with a uniform pressure = [rho*H_water].
But I never was 100% satisfied with this method.
I am asking, what is your opinion if it were to model in ETABS the water in the pool as:
1. a material having density=1000kg/m3, poisson ratio -0.99 and a very low elasticity modulus
2. a dense intersection of horizontal and vertical planes, as to yield overlapped cubes, assigning to this structure the material having "water" properties above
3. asking ETABS to find thousands of eigenmodes, until the concrete structure actually starts to participate... this might be solved by using Ritz vectors.
DId anybody try this and, if so, how can one check the results from the modal analysis? I am convinced that, if this step is correct, the rest should work fine.