Concept on positioning of Columns

Question 1:

Comment on the layout of the framing plan concerning earthquake resistance in the two horizontal directions X or Y (dots are columns, lines depict beams). Look into aspects of symmetry, redundancy and bi-directional stiffness and ductility.

Ans:

• symmetry-It is symmetric
• redundancy-It is having uniform distribution of structural elements It is stable for the earthquake vibrations or displacements
• bi-directional stiffness-It has good structural plan able so it increases the resistance and it's exhibit good bidirectional stiffness and resistance
• ductility-In this the columns are placed in a good manner if the column is stron and beam is weak is shows less ductility if the columns are weak then it exhibits more ductility

Question 2:

What are the possible sources of irregularity in the building shown here? Explain how, as an engineer, each of these irregularities should be dealt with.

Ans:If the torsional focre exceeds 1.5times the lateral force Horizontal displacement will be more dur to irregular elevation.

• Height of the floor will be revised
• The elevation of the structure will be revised
• Soft storey structure will be revised

Question 3:

A 4-storey hotel building has an open ground floor for the restaurant. Story 2 to 4 have one row of rooms along each long side in plan, separated by a corridor. The two short sides of the perimeter are fully in-filled in all storeys, except for certain openings at the ends of the corridor at storeys 2 to 4 and along the right-hand side of the ground floor. There is a staircase near the upper left-hand corner, with straight flights between landings at floor levels and in-between floors. Cross-section dimensions are written next to the member no. in meters.

Comment on the features of the structural design and of the layout of infills which are important for earthquake resistance and seismic performance. How do they relate to the almost full collapse of this building (the extreme left-hand bay with the staircase survived, as well as one long-side façade in the rear end, and the frame along the right-hand side in plan).

Ans:

• Irregular structural layout
• Do not have proper infill walls
• Left hand and right hand side retain walls
• IN the front end compared to longer end the length of the beam increases and column size also decrese it will not designed properly to bear the load
• Comparatively the column number must be incresed for the beam length or the retain wall should be proper