The bending moment diagram is drawn by considering each span AC and CB respectively. If one end of a member is not fixed then the “stiffness” of that member should be multiplied by (3/4). Consider a fixed beam AB as shown below. End B has settled by a distance .

The moment distribution method is a structural analysis method for statically indeterminate beams and frames developed by Hardy Cross. It was published in 1930 in an ASCE journal. The method only accounts for flexural effects and ignores axial and shear effects.

10.3 The Moment Distribution Method for Beams

1. Determine the stiffness for each member.
2. Determine the distribution factors for each member at each node based on relative stiffness of the members using equation (3).
3. Determine the fixed end moments for all members that have external loads applied between the end nodes.
4. For each node in turn:

Explanation: The moment distribution method developed by Hardy Cross in 1930 is useful for analysis of indeterminate beams and frames. The method considers the flexural effect and ignores any effect caused due to shear and axial loadings.

There is a range of beam deflection formulas and equations that can be used to calculate a basic value for deflection in different types of beams. Generally, deflection can be calculated by taking the double integral of the Bending Moment Equation, M(x) divided by EI (Young’s Modulus x Moment of Inertia).

2. (B) → Storey moment = Storey shear x 1 3 of storey height. deflection method), storey shear is +ve or vice versa.”

The base shear formula is: V = 0.2 (W) V represents the shear force that will be generated at the base of a building. 0.2 represents earthquake force. W represents the weight of the building. Single story homes weigh approximately 50 pounds per square foot.

Kani’s method was introduced by Gasper Kani in 1940’s. It involves distributing the unknown fixed end moments of structural members to adjacent joints, in order to satisfy the conditions of continuity of slopes and displacements. Kani’s method is also known as Rotation contribution method.

Base shear, storey shear and base moment are the terms associated with the earthquake. Storey shear factor is the ratio of the story shear force when story collapse occurs to the story shear force when total collapse occurs.

Equivalent storey stiffness of a storey (Ki,eq) is estimated as the lateral force that results in unit lateral translational deformation in that storey (Fig. 4). Thus, this method requires n-additional analyses to estimate storey stiffness of an n-storey building.

STORY DRIFT is the lateral displacement of one level relative to the level above or below. STORY DRIFT RATIO is the story drift divided by the story height.

Story shear is the graph showing how much lateral (read: horizontal) load, be it wind or seismic, is acting per story. The lower you go, the greater the shear becomes (see figure under story shear below). Story drift on the other hand is the plot of the resulting drifts per floor.

SUMMARY: “Soft story” and “weak story” are irregular building configurations that are a significant source of serious earthquake damage. These configurations that are essentially originated due to architectural decisions have long been recognized by earthquake engineering as seismically vulnerable.

The Importance Factor is a multiplier that increases or decreases the base design loads. Therefore, an elevated Importance Factor creates proportionally higher design loads (i.e., a wind Importance Factor of 1.15 is a 15% increase in design wind loads).

Response reduction factor is the factor by which the actual base shear force should be reduced, to obtain the design lateral force during design basic earthquake (DBE) shaking. The response reduction factor (R) is basically depends on Over strength (Rs), Ductility (Rµ), Redundancy (RR).

Here are the steps:

1. Take the response spectrum that is specific to the building site.
2. Calculate approximate period of the building to figure out the spectral accelerations for that building.
3. Reduce the forces by the factor of R.
4. Check the structural demands and basic checks for torsional irregularity.

– Response reduction factor is invariably used by most seismic design codes to include the non-linear response of structure. The non-linear behaviour of the structure is taken into account due to this factor which permits the designer to use a linear elastic force-based design.

In the force-based seismic design procedures, the response modification factor (R) is. the one used to reduce the linear elastic response spectra to the inelastic ones. In other. words, response modification factor is the ratio of strength required to maintain the. structural elasticity.

The depth of slab depends on bending moment and deflection criterion. For obtaining modification factor, the percentage of steel for slab can be assumed from 0.2 to 0.5%. The effective depth d of two way slabs can also be assumed using cl. 24.1,IS 456 provided short span is <3.5m and loading class is <3.5KN/m.

ductile

Zone factors are given on the basis of expected intensity of the earthquake in different zones. In IS Code, it is given based on the Maximum Considered Earthquake (MCE) and service life of the structure in a zone.

Based on the past seismic history, Bureau of Indian Standards grouped the country into four seismic zones namely Zone-II, Zone-III, Zone-IV and Zone-V. Of all these four zones, Zone-V is the most seismic active region whereas Zone-II is the least.

The seismic importance factor (Ie) is used in the Seismic Response Coefficient (CS) equations with the intent to raise the yield level for important structures (e.g., hospitals, fire stations, emergency operation centers, hazardous facilities, etc.).

Among these, Zone V is the most seismically active region and zone II is the least active. According to Modified Mercalli scale, the seismic zone intensity are classified as zone II (low intensity zone), zone III (moderate intensity zone), zone IV (severe intensity zone) and zone V (very severe intensity zone).

What is a Seismic Design Category. If A Seismic Design Category is a classification assigned to a structure based on it’s occupancy category, and the severity of the design earthquake ground motion. Seismic Design Category E – Corresponds to buildings of Occupancy Groups I,II and III in areas NEAR MAJOR ACTIVE FAULTS.

In other words, the earthquake zoning map of India divides India into 4 seismic zones (Zone 2, 3, 4 and 5) unlike its previous version, which consisted of five or six zones for the country.

six zones

Top 10 cleanest railway zones in India 2019

• East Central Railway.
• South Central Railway.
• South Western Railway.
• Northern Railway.
• Northeast Frontier Railway.
• West Central Railway.
• East Coast Railway.
• Western Railway.

Northern Railways

New Delhi