Concept on positioning of Columns

1) Aim & Introduction : 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.

Procedure :

Investigation of Framing Plan with Respect to symmetry in X & Y - axis

X Axis

If we split the plan vertically half,it will look mirrored,So we can Conclude the given plan is Symmetric in X-axis.

Y Axis

If we Split the plan Horizontaly Half,it will look mirrored,So we can conclude the given plan is symmetric in Y-axis.

Investigation of Framing Plan with Respect to Redudancy in X & Y - axis

X- Axis

The Columns in X-direction are Comparitively more and evenly Spaced.So the structure is more redundant in x-direction

Y-Axis

The Columns in X-direction are Comparitively lesser and evenly Spaced.So the structure is redundant Lesser than that of x-direction.

Investigation of Framing Plan with Respect to Bidirectional stiffness in X & Y - axis

the Columns in Horizonatal direction are connected in Straight Beams.This Means any Lateral Load passing from left end of building will have its path straight till it reaches right end of the building.So no or Less possibility of force diversion takes place.

The Columns in vertical direction are Not Connected in Straight Beams.So the lateral load passing from the south side of the building may pass on t to east and west side to reach the next bay.there will be a major force diversion taken in y direction due to seismic force.the Framing is weak while comapred to Bi directional Stiffness in X-axis.

Investigation of Framing Plan with Respect to Ductility in X & Y - axis

More Columns in X-direction when compared to Y-Direction.it will result i n higher Stiffness of the building in x-direction which would reduce the ductility in X-axis

More Over the x-force will pass from one bay to its next due to beam alignment,whereas the y-force will struggle to pass through.The North and south beams are arranged zigzag connection which leads to discontinous bracing

we can Conclude that from the given frame line y direction is more ductile than x-direction.

Result : From the above question we came to know in detail about these terminolgies.

2) Aim & Introduction : 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.

Procedure : the following are the irregularities that are detailed below.

Vertical irregularity : The Building Plan Area is Large in Bottom Storeys,The FLOOR Plan Areas are getting reduced with increase in heights.

soft Storey Mechanism : the Building has uncovered opening Space in 6th floor.As there is no occupancy or a partition wall thisnwill lead to plastic hinge formation

Slopy BAse : The Building is Constructed on a slopy ground in one side.this will lead to significant Variation in the Stiffness.Few levels may be subjected to soft storey mechanism

Result: from the Above picture we are able to identify the irregularities in the building through noticing it.

3)Aim & Introduction :To 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.

Procedure :

• Open ground Floor - this denotes the soft storey mechanism acts on the building
• Rooms along 2 bay Seperated by an open corridor- the bays filled with rooms will have higher mass comapred to the middle bay left open for corridor.this induces irregularity along height uniformity
• two Sides Covered with Infill walls-this Means the Building's left and right sides pheriphery is more stiffer during seismic forces
• Staircase Portion at left top corner-Usually staircase and lift portion are stiffer than other parts because of concentrated concrete elementd.so the staircaseportion conatins more stiffness in provided building plan
• No Framing Connection along Y-axis-we Could see no Structural beams Provided along the vertical direction between the columns.this makes the building more vulnerable during north south seismic forces
• beams Connected along column minor axes-the columns are having longer dimensionin y-direction.this means they are more stiffer along y-direction.but the beams are running along the x-direction which would attractr much lesser lateral forces and hardly transfers it
• variation in Column Axes- the internal columns are having higher sizes compared to exterior columns.But this will lead to significant difference in lateral drift of columns.so the concrete floor might have suffered heavy out of plane shear which would led to collapse.

Result : TheFolloing conditions which has been termed has been defined.