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GUJARAT TECHNOLOGICAL UNIVERSITY

BRANCH NAME: Civil Engineering

SUBJECT NAME: Earthquake Engineering

SUBJECT CODE: 2170612

B.E. 7th SEMESTER

Type of course: Applied Mechanics

Prerequisite: Mechanics of Solids, Structural Analysis I & II, Design of Reinforced Concrete

Structure.

Rationale: This subject is conceptual applications of principles of dynamics and earthquake

resistant design & detailing of RC structures. Some special topics like Earthquake resistant

masonry structures, liquefaction, structural controls and seismic strengthening are included aiming

students know that these are challenges in this subject. This subject is useful to understand the

behavior of the structure subjected to earthquake forces and earthquake resistant design of the

structure.

Teaching and Examination Scheme:

Teaching Scheme Credits Examination Marks Total

Marks L T P C Theory Marks Practical Marks

ESE

(E)

PA (M) ESE (V) PA

(I) PA ALA ESE OEP

3 1 0 4 70 20 10 30 0 20 150

Content:

Sr. No. Content Total

Hrs

% Weightage

1 Earthquake Basics:

Interior of Earth, plate tectonics, faults, consequences of

earthquake, Basic parameters of earthquake, magnitude &

intensity, scales, Seismic zones of India, damages caused during

past earthquakes (worldwide).

3 10

2 Fundamentals of Earthquake Vibrations of buildings Static load v/s Dynamic load (force control and displacement

control), simplified single degree of freedom system, mathematical

modelling of buildings, natural frequency, resonance v/s increased

response, responses of buildings to different types of vibrations

like free and forced, damped and un-damped vibration, response of

building to earthquake ground motion, Response to multi degree

(maximum three) of freedom systems up to mode shapes.

11 25

3 Design Philosophy:

Philosophy of earthquake resistant design, earthquake proof v/s

earthquake resistant design, four virtues of earthquake resistant

11 25

Suggested Specification table with Marks (Theory):

Distribution of Theory Marks

R Level U Level A Level N Level E Level C Level

20 30 20 20 5 5

Legends: R: Remembrance; U: Understanding; A: Application, N: Analyze and E: Evaluate C: Create and

above Levels (Revised Bloom’s Taxonomy)

Note: This specification table shall be treated as a general guideline for students and teachers. The

actual distribution of marks in the question paper may vary slightly from above table.

Reference Books:

1. Manish Shrikhande & Pankaj Agrawal; Earthquake resistant design of structures, PHI

Publication, New Delhi

2. S.K.Duggal; Earthquake resistance design of structures; Oxford University Press, New

Delhi.

3. A.K.Chopra; Dynamics of structures , Pearson, New Delhi

4. Clough & Penzin; Dynamics of structures

5. Park & Pauly; Behaviour of RC structure

6. John M.Biggs; Introduction to Structural Dynamics

7. C V R Murthy - Earthquake Tips, NICEE

8. IITK-GSDMA EQ26 – V -3.0 Design Example of a Six Storey Building

9. S S Rao; Mechanical Vibration; Pearson, New Delhi.

structures (strength, stiffness, ductility and configuration), seismic

structural configuration, Introduction to IS: 1893 (Part I), IS: 875

(Part V). Seismic load: Seismic Coefficient Method – base shear

and its distribution along height. Introduction to Response

spectrum, IS code provisions.

4 Lateral Loads on Buildings:

Lateral Load Distribution (SDOF): Rigid diaphragm effect,

centers of mass and stiffness, torsionally coupled and uncoupled

system.

Lateral Load Analysis: Analysis of frames using approximate

methods like portal & cantilever methods

6 15

5 Ductile Detailing:

Concepts of Detailing of various structural components as per IS:

13920 provisions.

5 10

6 Special topics:

Introduction to Earthquake Resistant Features of un-reinforced &

reinforced masonry Structure, Confined Masonry, Soil

liquefaction, Structural controls, Seismic strengthening.

6 15

10. IS Codes: Criteria for earthquake resistant design General provision & Building - IS: 1893 (Part

I)- 2002

Code of Practice for Ductile Detailing of RC Structures - IS: 13920 (1993).

Code of Practice for earthquake resistant design & Construction of buildings – IS 4326

(1993).

Improving Earthquake Resistance of Earthen Buildings - IS 13827(1993)

Guide lines for Improving Earthquake Resistance low strength masonry buildings - IS

13828 (1993)

Course Outcome:

After learning the course the students should be able to:

1. Determine the response of SDOF & MDOF structural system subjected to vibration

including earthquake.

2. Apply the concept of Earthquake Resistant Design & concept of lateral load distribution on

buildings.

3. Determine the lateral forces generated in the structure due to earthquake.

4. Apply the concept of ductile detailing in RC structures.

Term Work:

Term work shall consist of laboratory works and following:

1. At least 25 problems based on the syllabus of Earthquake Engineering which are uniformly

distributed & graded from each of the topic

2. Seminar/project assigned by the faculty member.

Design based Problems (DP)/Open Ended Problem: (This may be considered as a part of

term work)

1. Site visit of real life structures to understand the irregularities. (Take Photographs)

2. Site visit of construction site to understand ductile detailing. (Take Photographs)

3. Model preparation to understand the behavior of structures under earthquake forces.

List of Experiments:

Following experiments should be carried out in laboratory.

1. Spring Mass model

2. Mode shapes of three storey building

3. Response of structure with & without Shear wall and bracing system

4. Response of building with re-entrant corner

5. Behaviour of structure under pounding

6. (a) Liquefaction potential of clayey & sandy soil (b) Response of structure with isolated,

raft & pile foundation under liquefaction

Major Equipment:

1. Shake table to simulate earthquake

2. Models required to perform above experiments

List of Open Source Software/learning website:

1. www.nicee.org

2. www.eeri.org

3. www.gsdma.org

4. www.ndma.gov.in

5. www.nptel.iitm.ac.in/courses/

6. www.nisee.berkeley.edu/elibrary/getpkg?id=NONLIN

ACTIVE LEARNING ASSIGNMENTS:

Preparation of power-point slides, which include videos, animations, pictures, graphics for better

understanding theory and practical work – The faculty will allocate chapters/ parts of chapters to groups of

students so that the entire syllabus to be covered. The power-point slides should be put up on the web-site

of the College/ Institute, along with the names of the students of the group, the name of the faculty,

Department and College on the first slide. The best three works should submit to GTU.

1. Presentation on study of past Indian & International Earthquakes one each

2. Presentation of any one earthquake tip & every student will participate in Quiz based on

Earthquake Tips.

1

Seat No.: ________ Enrolment No.___________

GUJARAT TECHNOLOGICAL UNIVERSITY BE - SEMESTER–VII (NEW) - EXAMINATION – SUMMER 2017

Subject Code: 2170612 Date: 29/04/2017 Subject Name: Earthquake Engineering(Departmental Elective - II) Time: 02.30 PM to 05.00 PM Total Marks: 70 Instructions:

1. Attempt all questions. 2. Make suitable assumptions wherever necessary. 3. Figures to the right indicate full marks.

4.IS 1893 & IS 13920 are permitted

Q.1 (a) Explain four virtues of earthquake resistant design. 07

(b) Explain damped free vibration system in detail. Also derive the

expression for displacement. 07

Q.2 (a) Explain mathematical modelling using appropriate examples. Also

list dynamic parameters of model. 07

(b) A cantilever rod having span 1.2m is subjected to a point load of

98.1 N at its free end. The cross section of beam is square having

12mm side. The system initially at rest was displaced through

40mm and released to vibrate. Determine following

1. Undamped and damped natural frequencies

2. Amplitude after 2 cycles

3. Number of cycles when amplitude reaches to 2mm

Take damping coefficient as 15 N.S/m and modulus of elasticity as

210 GPa.

07

OR

(b) Explain earthquake resistant features of masonry structures. 07

Q.3 Using static coefficient method, calculate lateral forces at each floor

level for an SMRF hospital building frame having following data.

( a ) No. of storey: 10

( b ) Thickness of slab: 160 nun

( c ) Size of Beam & column: 600mm x 600mm

( d) Bays @ x and y direction : 4

( e ) Bays width: 4 m

( f ) Storey height: 3 m

( g ) Finished wall thickness is 250mm for exterior wall

( h ) Live load : 4 kN/m2

Take floor finish as 1 kN/m2. Water proofing of load 1.5 kN/m2 has

been provided at terrace. Assume any additional data if required for

the building frame and neglect the weight of interior infill wall

panels. Building is situated in Ahmedabad.

14

OR

Q.3 (a) Differentiate the following terms

1. Storey drift and storey shear

2. Soft storey and weak storey

3. Importance factor and response reduction factor

06

(b) For the rigid floor shown in the Figure – I, find design lateral forces 08

2

for the columns as per IS 1893 provisions if design lateral force

acting on floor is 200 kN along X direction. All columns are of

same height and size 300x900mm. Mass is uniformly distributed on

the floor.

Q.4 (a) Explain the effect of building configuration on seismic response in

brief. 07

(b) Define liquefaction and explain the causes and remedial measures

of liquefaction. 07

OR

Q.4 (a) Describe concept of ductile detailing & explain factors affecting the

ductility of structures in detail. Also explain ductile detailing of

beam – column joint as per IS 13920 – 1993.

07

Q.4 (b) Briefly explain base isolation. 07

Q.5 (a) A three story building frame with uniform floor height of 4m is

having lumped masses of 4.5 tonns, 3.5 tonns and 2.5 tonns at first,

second and third floor respectively with uniform storey stiffness of

650 kN/m at each floor. Calculate natural frequency and

corresponding mode shapes for the fundamental mode only. Also

draw mode shapes.

14

OR

Q.5 (a) Analyze the building frame shown in Figure - II by cantilever

method and draw shear force, bending moment and axial force

diagrams.

10

(b) Define terms: i) Diaphragm action ii) Rigid diaphragm iii) Flexible

diaphragm iv) Centre of mass v) Centre of rigidity 04

*************

Figure - I Figure - II

Page 1 of 3


GUJARAT TECHNOLOGICAL UNIVERSITY BE - SEMESTER–VII(NEW) • EXAMINATION – WINTER 2016

Subject Code:2170612 Date:18/11/2016

Subject Name:Earthquake Engineering(Departmental Elective - II)

Time: 10.30 AM to 1.00 PM Total Marks: 70 Instructions:

1. Attempt all questions.

2. Make suitable assumptions wherever necessary.

3. Figures to the right indicate full marks.

4. Use of IS: 456, IS: 1893, IS: 4326, IS: 13920 and SP: 16 is permitted in exam hall,

provided that they do not contain anything other than the printed matter inside.

Q.1 (a) Figure 1 shows the layout of a typical floor of a 10 storied building.

Consider the following data:

Typical floor height = 3.6 m (slab top to slab top)

Slab thickness = 120 mm

Floor finish = 1 kN/m2

Live load = 4 kN/m2

All beams of 230 mm x 420 mm (including slab)

Columns, CA = 400 mm diameter, CB = 600 mm x 300 mm

Shear walls, SW1 = 150 mm x 1300 mm, SW2 = 150 mm thick

230 mm thick full height brick masonry wall, only on outer periphery of

building.

Modulus of elasticity = 25000 N/mm2.

Calculate the size of shear wall SW2, so that centre of stiffness lies on grid – B

(i.e. xcs = 5 m).

07

(b) Calculate the seismic weight at any typical floor considering the data given in

Q.1 (a).

07

Q.2 (a) Figure 2 shows the plan of single storey building with four shear walls. Consider

the stiffness of shear wall about stronger axis as ‘9k’ and stiffness of about

weaker axis as ‘k’. Calculate the joint forces on each frame considering the storey

shear of 100 kN along earthquake in x-direction.

07

3 m

4 m

3 m

CB CA

1

2

3

4

A B C D

SW2

SW1

CA CA

CA CA

CB CA

CA

CA

3 m 4 m 5 m y

x

Figure 1

Page 2 of 3

(b) Calculate the centre of mass at any typical floor considering the data given in Q.1

(a). (Neglect the self weight and space occupied by columns and shear walls)

07

OR

(b) Figure 3 shows the plan & vertical c/s of building. Determine whether the

building has vertical stiffness irregularity or not considering the lateral force

along ‘x’ direction. Consider circular columns are of size 300 mm diameter and

rectangular of size 300 mm x 460 mm as per orientation. All beams of size = 230

mm x 460 mm, slab thickness = 100 mm, LL at all levels = 3 kN/m2 and FF = 1

kN/m2, modulus of elasticity = 25000 N/mm2.

07

Q.3 (a) Define: Magnitude, Intensity, Hypocenter, Isoseismals, Seismogram, Rayleigh

waves, Tectonic plate. 07

(b) Explain and sketch the provisions of ductile detailing of reinforcement at various

locations in beams. 07

OR

Q.3 (a) Explain the capacity design concept of ductile detailing using chain analogy and

state its application in beam design. 07

(b) Explain: Seismic design philosophy and four important virtues (parameters) of

earthquake resistant design of structures. 07

Q.4 (a) A forced undamped vibration system consists of simply supported beam of 6 m

span which supports a machine of weight 980 kN placed at the centre of the span.

The machine exerts the harmonic force of 15 kN with the forcing frequency of

10 rad/sec. Calculate the maximum dynamic amplitude of vibration for the

system by considering width of beam as 0.5 m and depth as 0.1 m. Consider E =

2 x 105 MPa. Neglect the self-weight of beam.

07

(b) A two storied building has lumped floor weights from bottom to top as 95000 N

& 78500 N with 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.

07

OR

A B

4 m

4 m

y

x 1

2

Figure 2

3.5 m

3.5 m

5 m

5 m

3 m

6 m 4 m

x

Figure 3

Page 3 of 3

Q.4 (a) Develop the equation of motion for free damped single degree-of-freedom

system and derive the general solution of displacement response. 07

(b) A Three Storied building has lumped floor weights from bottom to top as 30 kN,

40 kN & 20 kN with storey stiffness of 50,000 N/m, 35,000 N/m & 20,000 N/m

respectively.

From the free vibration analysis the natural frequencies and corresponding mode

shape coefficients are obtained as follows:

ω1 = 1.674 rad/sec, ω2 = 3.913 rad/sec and ω3 = 5.827 rad/sec

{ф1}= {ф11, ф21, ф31}= {0.33, 0.72, 1.0}

{ф2}= {ф12, ф22, ф32}= {-0.47, -0.53, 1.0}

{ф3}= {ф13, ф23, ф33}= {4.97, -2.4, 1.0}

Consider the building as ordinary residential building with ordinary RC moment-

resisting frame (OMRF) proposed on medium soil at Zone III.

Calculate the design lateral forces at each floor in each mode. Also calculate

storey shear force considering participation of all modes using SRSS method.

07

Q.5 (a) An idealized SDOF system consists of a RCC water tank shaft of 4 m outer

diameter & 120 mm wall thickness, which supports a container with lumped

weight of 2800 kN at its top. The effective height of column shaft is 15 m. The

damper offers the resistance of 25 kN at the velocity of 3 m/sec. Calculate the

damping ratio and state whether the system is under damped, over damped or

critically damped. Also calculate the damped frequency. Consider E = 25000

N/mm2.

07

(b) Explain: (i) Types of structural controls.

(ii) Soil liquefaction. 07

OR

Q.5

Figure 4 shows the plan of two storied brick masonry important building

proposed at Zone III. Consider the thickness of wall A & B as 460 mm and of

wall C & D as 340 mm. Decide the maximum size of windows for wall C

considering width of door as 900 mm using IS: 4326 provisions. Also, enlist in

detail with sketches, the necessary strengthening arrangements recommended for

this building as per IS : 4326 provisions.

14

*************

D

8.0 m c/c

3.0 m c/c

Wall A Wall B

Wall C

Wall D

W W

Figure 4 W

1


GUJARAT TECHNOLOGICAL UNIVERSITY BE - SEMESTER–VI (OLD) - EXAMINATION – SUMMER 2017

Subject Code: 160605 Date: 01/05/2017 Subject Name: Earthquake Engineering Time: 10:30 AM to 01:00 PM Total Marks: 70 Instructions:


4. Use of IS: 1893-2002(Part-1), IS: 13920-1993 and IS: 4326-1993 is permitted.

Q.1 (a) Define following terms:

1. Fault

2. Free Vibration

3. Storey Drift

4. Damping Ratio

5. Retrofitting

6. Dynamic Magnification Factor

7. Design Basis Earthquake

8. Intensity

08

(b) Differentiate between the following:

1. Vibration and Oscillation

2. Centre of Mass and Centre of Stiffness

3. Flexural Failure and Shear Failure

06

Q.2 (a) Derive the expression of Amplitude for single degree free undamped vibration

system with usual notations

07

(b) A water tank is idealized as a single degree of freedom system having

equivalent weight of 15000 kN, damping ratio as 5% and stiffness factor as

25000 kN/m. Calculate (1) the natural time period (2) the damped time period

(3) damping constant and (4) the maximum horizontal displacement at the top

of the water tank if it is excited by a seismic force equivalent to 25,000 sin (5t)

N.

07

OR

(b) A spring mass model consists of 10 kg mass and spring stiffness 8 N/mm and it

was tested for viscous damped vibration. Test recorded two successive

amplitudes 2.0 and 1.75. Determine (1) the natural frequency of undamped

system (2) the logarithmic decrement (3) damping ratio (4) damping coefficient

(5) damped natural period

07

Q.3 (a) Write short note on different types of Seismic Waves generated during

earthquakes.

07

(b) Calculate natural frequencies and time period for the system shown in figure 1. 07

OR

Q.3 (a) Enlist the common modes of failure of Masonry Buildings and explain any two

mechanisms in detail.

07

(b) Explain the importance of ductility of structure during its seismic performance

and enlist different types of ductility.

07

Q.4 (a) Explain the Short Column Effects in detail. 07

(b) Explain the theory of Soil Liquefaction in detail. 07 OR

2

Q.4 (a) If a column of size 450 x 450 mm is having the longitudinal reinforcement of

2% of the gross cross sectional area, detail the longitudinal reinforcement of the

column satisfying all criteria of IS 13920-1993 and workout the special

confining hoop reinforcement as per the code along with neat sketch of

longitudinal section. Take the clear height of the column = 4 m, Grade of

Concrete M20, Grade of Steel Fe 415 and clear cover to longitudinal

reinforcement is 40 mm.

07

(b) Explain degrees of freedom in detail with some examples. 07

Q.5 (a) Explain Response Spectrum Method in detail. 07

(b) Explain Base Isolation Techniques in detail. 07

OR

Q.5 (a) Explain in detail the Strong Column – Weak Beam Design approach used in

earthquake resistance design of structure.

07

(b) Explain with neat sketches the techniques of Column Jacketing and Beam

Jacketing.

07

Figure 1

*************

1


GUJARAT TECHNOLOGICAL UNIVERSITY BE – SEMESTER – VI (OLD).EXAMINATION – WINTER 2016

Subject Code: 160605 Date: 24/10/2016

Subject Name: Earthquake Engineering

Time: 10:30 AM to 01:00 PM Total Marks: 70

Instructions:




4. IS 1893 and IS 13920 are permitted.

Q.1 (a) For a RCC framed school building, find the design seismic base shear and lateral

force at every floor level on the structure using static co-efficient method.

Consider following data.

(1) Location : Bhuj (2) Soil condition : Medium soil

(3) Plan dimension : 2 bays of 4 m each along X direction and 2 bays of 4 m

each along Y direction

(4) Elevation: 3 storey including Ground storey, each 3.5 m floor height

(5) Loading: Dead load is 15 kN/m2 and live load is 3 kN/m2 for floors.

10

(b) Explain importance of vibration analysis in detail. 04

Q.2 (a) Derive an equation of motion for single degree free damped vibration system 07

(b) Explain in detail classification of earthquake. 07

OR

(b) Explain plate tectonic theory and its mechanism. 07

Q.3 (a) Explain the earthquake resistance feature of masonry structures. 07

(b) A vibrating system consisting of a mass of 50 kg and a spring of stiffness 4 ×

104 N/m is viscously damped. The ratio of two consecutive amplitudes is 20:16.

Determine the natural frequency of undamped system. Also find damping ratio

and damped natural frequency.

07

OR

Q.3 (a) Give difference between (1) magnitude and intensity (2) strength and stiffness 07

(b) A SDOF viscously damped system makes five complete oscillation per second.

The amplitude of vibration reduces to 15% in 60 cycles. Find damping ratio.

07

Q.4 (a) Analyze the two bay two storeys RC frame by Portal method. Lateral force of

100 kN & 60 kN is acting at first & second floor respectively. Height of each

storey 4 m. Bay width of each bay is 4 m. Draw shear force and bending

moment diagram.

07

(b) Explain in detail (1) Rigid diaphragm (2) Centre of Mass and Centre of stiffness 07

OR

Q.4 (a) Explain in detail concept of mathematical modeling 07

(b) Explain soft storey and storey drift in details. 07

Q.5 (a) Explain base isolation techniques in details. 07

(b) Explain how “ductility of building” can be effectively design for earthquake

resistance structure. 07

OR

Q.5 (a) Explain Liquefaction and give remedial measures for it. 07

(b) Discuss the capacity design concept in ductile detailing. 07

*************


GUJARAT TECHNOLOGICAL UNIVERSITY BE - SEMESTER–VI- EXAMINATION – SUMMER 2016

Subject Code:160605 Date:11/05/2016 Subject Name:Earthquake Engineering Time: 10:30 AM to 01:00 PM Total Marks: 70 Instructions:

1. Attempt all questions. 2. Make suitable assumptions wherever necessary. 3. Figures to the right indicate full marks. 4. Use of IS 1893 and IS 13920 is permitted.

Q-1 (a) Define following terms:

(1) Epicentre (2) Base Shear (3) Soft storey (4) Damping Ratio (5) Frequency Ratio (6) Dynamic Magnification Factor

6

(b) Differentiate between the following: (1) Magnitude & Intensity (2) Seismograph & Seismogram (3) Iso-seismal & Meizo-seismal (4) Inter-plate & Intra-plate earthquakes

8

Q-2 (a) Derive the expression of displacement for free vibration of damped SDOF system

with usual notations.

7

(b) A spring mass model consists of 10 kg mass and spring of stiffness 15 N/mm was tested for viscous damped vibration. The test recorded two consecutive amplitude is 1.8 cm and 1.3 cm respectively. Determine (i) Natural frequency of un-damped system (ii) Logarithmic decrement (iii) Damping ratio (iv) Damping coefficient (v) Damped natural frequency of system.

7

OR (b) A SDOF system consists of 6 m high column of 500 mm diameter which supports

the heavy mass of 10,500 kg at its top. The system is subjected to a harmonic force of 2000sin80t N. Consider 10% damping and E = 2 × 105 MPa. Calculate the steady state amplitude and also state whether the system will have resonance or not?

7

Q-3 (a) Draw Mathematical Model and Free body diagrams for following: (i) Un-damped Free Vibration of SDOF system (ii) Un-damped (harmonic) excitation of SDOF system (iii) Damped (harmonic) excitation of SDOF system

7

(b) A two storey building is idealized as two springs and masses having the values of the same as k1 = 2 kN/m, k2 = 4 kN/m, m1 = 200 kg and m2 = 100 kg respectively from the foundation. Calculate all the natural frequencies and all the normalized mode shapes.

7

OR Q-3 (a) Locate the center of mass and center of stiffness for the Figure – 1. All column sizes

are 300 mm x 600 mm. 7

(b) Explain various bands and vertical reinforcements for earthquake resistant masonry structures.

7

Q-4 (a) Explain four virtues of earthquake resistant design. 6 (b) Attempt ANY TWO:

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

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

(3) Elastic rebound theory

8

OR Q-4 For a RCC framed office building, find the design lateral forces and its

distribution along the height, using static coefficient method. Consider following data:

a) No. of storeys = 4 b) No. of bays in X & Y direction = 5 c) Storey height = 4 m d) Width of each bay = 6 m e) Size of beam = 300 mm × 500 mm f) Size of column = 400 mm × 400 mm g) Thickness of slab = 150 mm h) External wall thickness = 230 mm i) Internal wall thickness = 150 mm j) Parapet wall = 150 mm with 1 meter height k) Live load = 4 kN /m2 l) Location = Ahmedabad m) Type of soil = medium soil

14

Q-5 (a) Analyze the structure as shown in the Figure.2 by Portal method and draw the

bending moment diagram. 7

(b) (i) Define: Liquefaction and state its effects. (ii) Write a note on Structural Control

3 4

OR Q-5 (a) Analyze the structure as shown in the Figure.2 by Cantilever method and draw

the bending moment diagram. 7

(b) Discuss in detail the concepts of the ductile detailing in Column and Footing. 7


GUJARAT TECHNOLOGICAL UNIVERSITY BE – SEMESTER – VI EXAMINATION – WINTER 2015

Subject Code:160605 Date:10/12/ 2015 Subject Name: Earthquake Engineering Time: 2:30pm to 5:00pm Total Marks: 70 Instructions:

1. Attempt all questions. 2. Make suitable assumptions wherever necessary. 3. Figures to the right indicate full marks. 4. IS 13920, IS 1893, IS 4326 IS 13835and IS 13828 are permitted.

Q.1 (a) Derive expression for the response of SDOF free damped structural system. 07 (b) Write short note on Logarithmic Decrement. 07 Q.2 (a) Explain the term mathematical modeling with taking different examples of

structures. Enlist the dynamic parameters of model also. 07

(b) Determine the natural frequency of a cantilever beam of span L, subjected to mass m on the free end of beam performing the δ displacement.

07

OR (b) Determine the natural frequency of a cantilever beam with spring support at free

end, subjected to mass m on the tip of beam performing the δ displacement. The length of beam is L.

07

Q.3 (a) Explain Rigid diaphragm effect with neat sketch. 07 (b) Define the term: focus, epicenter, epicentral distance, magnitude of earthquake,

intensity of earthquake, PGA and base shear. 07

OR Q.3 (a) Explain earthquake design philosophy for building. 07

(b) Elaborate on the seismic waves developed during earthquake and its effects on structure.

07

Q.4 (a) Explain the salient feature of masonry structure constructed in earthquake prone zone.

07

(b) What is soft storey problem? Explain how soft storey problems can be eliminated in the existing buildings

07

OR Q.4 (a) Explain how ductile design is helpful for better earthquake resistance. 07

(b) What are the assumptions made in portal and cantilever method? State their limitations also.

07

Q.5 (a) Explain the step wise procedure to find the base shear of multistory building with seismic coefficient method with codal provisions.

07

(b) Write short note on Liquefaction and remedial measures. 07 OR

Q.5 (a) Explain the response spectrum method and differentiate this method with other methods also.

07

(b) Explain base isolation techniques in details. 07

*************

1

1


GUJARAT TECHNOLOGICAL UNIVERSITY BE - SEMESTER–VI EXAMINATION – Summer 2015

Subject Code:160605 Date:12/05/2015


Time: 10.30AM-01.00PM Total Marks: 70 Instructions:




4. Use of IS: 1893-2002(Part-1), IS: 13920-1993 and IS: 4326-1993 is permitted.

Q.1 (a) For a two storey Steel framed railway station building with concentric bracing and

without infill wall, find the seismic base shear, using equivalent lateral load

method. Consider following data. (i) Location : Ahmedabad (ii) Soil condition :

Medium soil (iii) Plan dimensions : 3 bays of 4 m each along X direction and 4

bays of 3 m each along Y direction. The intensity of dead load including column,

beam and slab is 12 kN/m2. Consider Live load on floor 3 kN/m2. Consider 20 %

damping. Height of floor is 3m.Also plot lateral load distribution diagram.

09

(b) Answer following questions. 05

1. Define Resonance.

2. Evaluate with reason: For very stiff system PGA is equal to ZPA.

3. In which type of wave propagation volume of the medium changes but shape

does not change? Explain.

4. Give difference between accelerogram and accelerogroph.

5. What are the basic elements of any mathematical model in Earthquake

engineering? Give the equation of forced damped vibration for SDOF system.

Q.2 (a) For a square column of size 400 mm X 400 mm work out the diameter of the

special confining hoop reinforcement as per IS:13920-1993. Take the concrete

grade M 25 and steel grade Fe 415. Clear cover to longitudinal reinforcement is

40 mm.

07

(b) Derive the equation of damped free vibration of single degree of freedom system. 07

OR

(b) Define Logarithmic decrement, how it is measured and derive the equation of

Logarithmic decrement.

07

Q.3 (a) A two storey single bay RC frame is supported by four corner columns. Building

is located in Surat has lumped floor weights of 200 kN & having storey stiffness

80 kN/m at every floor level. Perform free vibration analysis and determine all

natural frequencies & sketch all mode shape.

09

(b) An acceleration response spectrum for SDOF system having 5% damping is

shown in figure 1. Calculate maximum base shear and moment if the time period

of the system is 0.5 sec. Take mass 8000 kg and height 4 m. What is the peak

ground acceleration for this ground motion?

05

OR

Q.3 (a) A spring mass model consists of 10 kg mass and spring with stiffness 7 N/mm,

was tested for viscous damped vibration. Test recorded two successive amplitudes

2and 1.5 Determine the natural frequency of undamped system, the logarithmic

decrement, damping ratio, damping coefficient, damped natural period.

07

2

(b) Set up the equation of motion for the following damped SDOF system without

external force and solve for the response under given condition.

K=320 N/m, m= 5 kg, c= 4 N-s/m, x(0)=1 and xͦ(0)=7.6.

07

Q.4 (a) Explain earthquake resistant features of masonry structures. 07

(b) Give difference between (i) magnitude and intensity (ii) Soft storey and weak

storey.

07

OR

Q.4 (a) Write short note on (i) Types of waves (ii) Earth interior. 07

(b) Explain elastic rebound theory in detail. 07

Q.5 (a) Analyze the three bay two storeys RC frame by Portal method. Lateral force of

200 kN & 120 kN is acting at first & second floor respectively. Height of first and

second storey is 4 m and 3 m respectively. Bay width of each bay is.4 m. Draw

axial force, shear force and bending moment diagram.

07

(b) Write short note on liquefaction. Explain factors affecting liquefaction. 07

OR

Q.5 (a) Explain in detail (i) Rigid floor Diaphragm effect (ii) Torsionally coupled and

uncoupled system

07

(b) Enlist the different methods of structural control and explain any one in detail. 07

Figure-1

*************

1


GUJARAT TECHNOLOGICAL UNIVERSITY BE - SEMESTER–VI • EXAMINATION – WINTER • 2014

Subject Code: 160605 Date: 03-12-2014

Subject Name: Earthquke Engineering

Time: 02:30 pm - 05:00 pm Total Marks: 70 Instructions:




4. Use of IS 1893 and IS 13920 is permitted

Q.1 Using seismic coefficient method estimate the storey lateral forces at each floor level

for a RCC framed office building and draws the distribution of storey lateral forces and

shear.

Use following data

(i) No. of storey and height: 5 storey with 3.5 m storey height

(ii) No. of bays : 4 bays along X and Y direction

(iii) Bay width: 5 m along, both X and Y direction

(iv) Slab Thickness : 125 mm

(v) Size of beam : 0.3 m (width) x 0.45 m (depth below soffit)

(vi) Size of column : 0.40 m x 0.40 m

(vii) Wall : 150 mm thick brick masonry All

(viii) Parapet: 1 m high 230 mm thick brick masonry

(ix) Live Load : 4 kN/m2

(x) Location : Gandhidham (Kutchh)

14

Q.2 (a) Choose most appropriate answer from the given alternatives.

(i) Zone factor generally represents..

(A) Seismicity of a region

(B) Importance of the structure

(C) Size of Structure

(D) None of these

(ii) Generally damping for steel structure is taken as..

(A) 5% of critical damping

(B) 2% of critical damping

(C) 10% of critical damping

(D) 20% of critical damping

(iii) Fastest seismic waves are…

(A) Love waves

(B) Raleigh waves

(C) P waves

(D) None of these

(iv) Generally Intensity of earthquake….

(A) Increases away from the epicenter

(B) Remains constant

(C) Decreases away from the epicenter

(D) None of these

(v) The Himalaya has immerged from which inter plate interaction?

(A) Divergent Plate Boundary

(B) Convergent Plate Boundary

(C) Transformed Plate Boundary

(D) None of these

07

2

(vi) Earthquake is classified as shallow focus if focal depth is ….

(A) Less than 70 km

(B) Less than 7 km

(C) Less than 14 km

(D) Less than 700 km

(vii) Maximum intensity scale based on MSK scale is….

(A) X

(B) V

(C) XI

(D) XII

(b) Derive the motion equation for the forced undamped vibration. 07

OR

(b) Derive the motion equation for the free damped vibration 07

Q.3 (a) List the four virtues of good earthquake resistance design and describe any one in detail. 07

(b) List and sketch the earthquake resistance feature of ordinary brick masonry structure. 07

OR

Q.3 (a) Explain soft storey? Explain how soft storey problems can be eliminated in the existing

buildings.

07

(b) Explain how ductile design is helpful for better earthquake resistance. 07

Q.4 (a) For a floor slab shown in the fig.1, Locate centre of mass and stiffness. Find design

eccentricity and torsional moment if 200 kN force acts long Y direction. All columns

are of 300 X 600 mm c/s with same height. Mass is uniformly distributed.

07

(b) Write short note on Liquefaction and remedial measures 07

OR

Q.4 (a) Write short note on structural control 07

Q.4 (b) Describe various strengthening methods for RCC columns and beams through

illustrative sketches.

07

Q.5 (a) Analyse the plane frame shown in the fig. 2 using an appropriate approximate method

and sketch SF and BM diagram.

07

(b) The building frame shown in the Fig.3 is given a 120 mm lateral displacement and

released from the rest to vibrate freely. Find the logrithmatic decrement and

displacement of the system after 10 cycles and comments on the result. Consider 5%

damping. Take EIcolumn = 1.2 x 1012 Nmm, EIbeam = ∞.

07

OR

Q.5 (a) What is mathematical modeling? Enlist the dynamic parameters of model. Prepare

mathematical model of the system shown in the fig.4 and find natural frequency of the

system.

07

(b) A SDOF vibrating system is having following parameters.

m= 10 kg , k=80 N/m ,C=10 N s /m.

Determine (i) Damping Factor (ii) Natural Frequency ( iii) Damped frequency (iv)

Logarithmic decrement (iv) No. of cycles after which the original amplitude reduces to

25 % .

07

3

********

Fig.1-Q-4(a)

8 m

8 m

4 m

1000 kg

Fig.3 Q-5(b)

6 m 6 m

Fig.2-Q-5(a)

4 m

120 kN

60 kN

4 m

K=15 N/mm

50 mm dia.1 m long

MS Rod

m=15 kg

Fig.4 Q-5 (a) OR


GUJARAT TECHNOLOGICAL UNIVERSITY BE - SEMESTER–VI • EXAMINATION – SUMMER 2014

Subject Code: 160605 Date: 26-05-2014 Subject Name: Earthquake Engineering Time:10.30 am to 01.00 pm Total Marks: 70 Instructions:


Q.1 (a) Calculate lateral forces in the critical direction at each floor level for a building of

government office having building frame with following data by collector office seismic coefficient method. also draw lateral load distribution diagram & shear diagram. (a) No. of storeys =5 (b) No. of bay of X & Y direction=7 (c) Storey height=3.5 m (d) width of each bay in X & Y direction=6 m (e) Size of beam=0.3 m ˟ 0.45 m (f) Size of column=0.45 m ˟ 0.45 m (g) Wall thickness =0.230 meter (h) L.L.=4 KN/m2

(i) Location:- Gandhinagar

14

Q.2 (a) (i)What points should be kept in mind while designing earthquake resistant brick masonry structure? (ii)Describe seismic waves in detail.

07

(b) Derive an equation for single degree undamped vibration system. 07 OR (b) Rigid frame shown in Fig.1, having infinitely rigid girder which is disturbed

horizontally by initial condition of X0=0, X0=4 m/s, t=0. (a)Find natural period and frequency (b)The displacement and velocity at any time t.

07

Q.3 (a) Explain base isolation techniques in details. 07 (b) Explain how “ductility of building” can be effectively designed 07 OR Q.3 (a) (i) Discuss Seismography and its applications

(ii)Define: Focus, Epicenter and Foreshocks 07

(b) Explain how rigid diaphragm effect can be considered while analyzing buildings for seismic forces.

07

Q.4 (a)

(b)

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1


GUJARAT TECHNOLOGICAL UNIVERSITY BE - SEMESTER–VI • EXAMINATION – WINTER 2013

Subject Code: 160605 Date: 04-12-2013


Time: 02.30 pm - 05.00 pm Total Marks: 70 Instructions:




4. Draw neat and clean sketches whenever required.

5. IS 13920, IS 1893, IS 4326 IS 13835and IS 13828 are permitted.

Q.1 (a) A four storied square RC framed building shown in Fig. 1 with live load 4

kN/m2 is to be constructed in Surat. Work out seismic forces on the structure by

seismic coefficient method using IS 1893. All beams and columns size 300mm

x 400 mm. Thickness of roof and floor slab 120 mm thick. Wall is of 150 mm

thick all around. Height of each floor 3m. Density of concrete 25 kN/m3.

10

(b) Explain in short “Rigid Diaphragm Effect”. 04

Q.2 (a) Locate the center of mass and center of stiffness for the Fig. 2. All column sizes

are 300 mm x 600 mm. 07

(b) Discuss the behavior of the following masonry walls in seismic regions.

(i) Unreinforced masonry wall

(ii) Reinforced Masonry wall

(iii) Infill masonry wall.

07

OR

(b) Draw the detailed sketch of (i) Different ways of beam jacketing as IS code and

(ii) Placing of vertical bars and closed ties in columns as per IS code. 07

Q.3 (a) Explain the terms (i) Story drift and story shear (ii) soft story and weak story 08

(b) With detail sketch explain the essential requirements to ensure box action in a

masonry building. 06

OR

Q.3 (a) Explain earthquake design philosophy for buildings. 07

(b) Explain seismic surface waves with schematic diagrams. 07

Q.4 (a) Derive the equation of motion and its solution for forced damped vibration

system. 08

(b) Write short note on mathematical modeling. 06 OR

Q.4 (a) Derive the equation of motion and its solution for forced undamped vibration

system. 08

(b) Write short note on “Logarithmic Decrement”. 06

Q.5 (a) A spring mass dashpot system having a spring of stiffness of 343 N/m. the mass

of 3.43 kg displaced 32 cm beyond the equilibrium position and release to

vibrate. Derive the equation of motion for the given system. Assume damping

coefficient = 13.72 N.s/m.

07

(b) Explain the term in detail “Peak Ground Acceleration”. 07

OR

Q.5 (a) Determine the natural frequency of the system shown in Fig.3. EI = 3 x 1013

N.mm2.

07

(b) Write in short note on “Soil Liquefaction” and its effect. 07

2

*************

1


GUJARAT TECHNOLOGICAL UNIVERSITY BE - SEMESTER–VI • EXAMINATION – SUMMER 2013

Subject Code: 160605 Date: 30-05-2013 Subject Name: Earthquake Engineering Time: 10.30 am - 01.00 pm Total Marks: 70 Instructions:

1. Attempt all questions. 2. Make suitable assumptions wherever necessary. 3. Figures to the right indicate full marks. 4. IS 1893 Part 1 2002 & IS 13920 – 1993 are allowed in the examinations

Q.1 (a) Derive expression for the response of free damped SDOF structural system. 07

(b) Force-Displacement relationships are shown in fig (1) for three different materials. Arrange these materials in descending order with proper calculation for following criteria

1. Strength 2. Stiffness 3. Ductility 4. Energy absorption capacity

Also give your opinion about material which is the best among all with respect to above criteria.

Q.2 (a) State whether following statements are true or false. Give logical reason for your answer :

1. Numbers of intra-plate earthquakes in world are more than numbers of inter-plate earthquakes.

2. Kochi is having maximum earthquake risk. 3. Peak ground acceleration (PGA) & Zero period acceleration (ZPA) are

same. 4. Performance of shear walls which are located near geometric centre of

building is better than the identical shear wall located on periphery. 5. A building is located on the boundary of zone IV & V. It will be

designed as if it is in zone IV. 6. Code specifies higher value of R for building having better performance. 7. Two identical building to be constructed in zone IV & V. Building in

zone V should be designed for lower lateral load than building in zone IV.

07

(b)

(b)

A two bay single storey RCC plane frame in which lumped mass of 20 tonne is supported on three columns (AB, CD & EF) having fixed support. LAB = 0.5 LCD = 0.25 LEF = 2 m Calculate (i) (i) Natural frequency of damped vibration (ii) BM & SF at support for the RCC frame after five cycles of vibration if floor is displaced horizontally by 300mm & suddenly released. Assume rigid diaphragm action. Take fck = 25 MPa & size of column 600 mm x 600 mm. Assume 8% damping.

OR Explain the phenomenon of resonance. A SDOF system consists of 5 m high column of 300 mm diameter which supports the heavy mass of 20 tonne at its top. The system is subjected to a harmonic force of 200 Sin 50t kN. Consider 20% damping & E = 2.1 x 105

N/mm2. Calculate the maximum dynamic amplitude. Also state whether system will have resonance or not?

07 07

Q.3 (a) Calculate base shear for hotel of Gujarat Tourism (100 rooms) in Mount Abu with following data by static coefficient method.

07

2

(a) No. of storey = 15 (b) No. of bay in x direction = 2 I No. of bay in y direction = 5 (d) storey height = 4.0 m (e) Width of each bay = 5 m (f) Size of beam = 300 x 450 mm (g) size of column = 600 x 300 m (h) LL = 3 kN/m2 (i) Thickness of slab = 150 mm (j) Damping = 9% of critical damping (k) Type of soil = Soft soil Assume suitable data if required. Write all your assumptions & clauses of IS 1893 (2002).

(b) Ref Q 3 (a) Calculate lateral forces at each floor level. Also draw distribution of lateral force at each floor level.

07

OR Q.3 (a) Explain any two

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

2. Differentiate Static DOF & Dynamic DOF. Explain assumptions to reduce dynamic DOF of multi-storey building.

3. Differentiate (i) Magnitude & Intensity (ii) Seismograph Vs Seismogram (iii) S wave & Love wave (iv) center of mass & center of stiffness

07

(b) Attempt any two 1. Explain mathematical modeling in detail. Draw mathematical model for

any two structural system. 2. Enlist various codes of practice along with correct name related to

earthquake engineering. 3. Elastic rebound theory

07

Q.4 (a) Attempt any two

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

2. Enlist two major/great Indian intra-plate & two interpolate earthquake with usual details.

3. Two pendulums are hanging on an ideal spring. The frequency of first pendulum is twice the frequency of second pendulum & the mass of first pendulum is four times the mass of second pendulum. What is the stiffness of the second pendulum with respect to first?

07

(b) Analyze the 4 bay two storey RC frame by any appropriate approximate method of analysis if 400 kN & 200 kN forces are acting at first & ground storey. Draw axial force, shear force & bending moment diagram. Height of floor = 5 m & bay width is 4 m.

07

OR Q.4 (a) Attempt any two

1. Explain soft storey & discuss its performance of soft storey building in past earthquakes. How will you avoid soft storey?

2. Explain the concept of base isolation. Discuss its suitability. 3. A spring mass (k1, m1) system has a natural frequency f1. Calculate the value

of stiffness of other spring which when connected to k1 in series decreases the frequency by 50%.

07

Q.4 (b) A 10 m high single storey industrial RC building (SDOF) having plan dimension 20 m x 15 m is located in Delhi. Floor slab of the building is supported on four corner columns. Calculate the eccentricity & carry out lateral load distribution as per IS 1893 Part I 2002 if 2700 kN force is acting at floor level. Size of columns are 300 mm x 300 mm

07

Q.5 (a) Explain ductile detailing of column as per IS 13920 – 1993. Also give limitation

of this code. 07

3

(b) a. A SDOF system having the amplitude of vibration in successive cycle are 0.90, 0.45, 0.23, 0.11 units respectively. Determine damping ratio of the system.

b. Earthquake force acting in horizontal direction at the top of a single storey building frame is 2000 kN. & slab is supported on three columns. What is the shear force distribution in the column if column having different moment of inertia? Take (I)1 = 0.5(I)2 = 0.25(I)3

07

OR Q.5 (a) For the two storey building frame having lumped masses 20 tonne at floor

levels having first storey stiffness 60 kN/m & second storey stiffness is 90 kN/m. Perform free vibration analysis & draw all mode shapes. Also calculate the length of 300 mm thick shear wall at ground storey to avoid soft storey effect.

07

(b) Explain following 1. Earthquake resistant feature of masonry structure. 2. Liquefaction and give remedial measures for it.

07

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