Earthquake Engineering — Summer 2022

Define Following terms: (1) Epicenter (2) Magnitude of Earthquake (3) Resonance.

Differentiate between the following: (1) Magnitude & Intensity (2) Iso – seismal & Meizo – seismal.

Derive the expression of displacement for free vibration of damped SDOF system with usual notations.

Define Following terms: (1) Soft storey (2) Damping ratio (3) Ductility.

Write short note on Short Column Effect.

Aspring mass model consists of 18 kg mass and spring of stiffness 25 N/mm was tested for viscous damped vibration. The test recorded two consecutive amplitude is 2.0 cm and 1.5 cm respectively. Determine (i) Natural frequency of un-damped system (ii) Logarithmic decrement (iii) Damping ratio (iv) Damping coefficient (v) Damped natural period.

Afree vibration test is performed on the single degree-of-freedom system. The mass of the system is 300 kg which is displaced by 3 cm and suddenly released. The time required to complete 15 cycles of oscillations is 5 s. Calculate the stiffness of the system. Write the equation of motion for the system and calculate the displacement after 10 sec. Consider initial velocity as 1 m/sec.

Explain the importance of ductility.

Explain base isolation techniques in details.

Write short note on liquefaction. Explain factors affecting liquefaction.

Enlist the different methods of structural control.

Explain how soft storey problems can be eliminated in the existing buildings.

Explain with sketches: Seismic waves and its types.

Explain in detail (1) Rigid diaphragm.

Explain importance of vibration analysis in detail.

Philosophy of earthquake resistant design. Give four virtue of good earthquake resistant design.

What is centre of mass and centre of stiffness?

Differentiate between the following: (1) Seismograph & Seismogram1 (2) Inter-plate & Intra-plate earthquakes.

Explain ductile detailing of beam as per Indian standard 13920.

Enlist various codes of practice along with correct name related to earthquake engineering.

Discuss the capacity design concept in ductile detailing.

Atwo storied building has lumped floor weights from bottom to top as 95000 N & 78500 Nwith storey stiffness of 5 x 105 N/m and 4 x 105 N/m respectively. Perform the free vibration analysis & determine natural frequencies and corresponding mode shape coefficients. Also sketch the mode shapes.

Explain various irregularities found in the civil engineering structures from earthquake point of view.

Write short note on Logarithmic Decrement.

Explain the criteria for earthquake resistant design & detailing of masonry structures.