Masonry

Answer 1

Masonry strength is based on the strengths of the unit. Mortar and pattern -of units the strongest bond / pattern is strecher

Question 2

Mortar classes

Answer 2

Class I ( 10 M Pa ): in highly stressed walls or multistory
Class 2 (5 M.P. A ): normal applications.
Class 3 ( 1.5 m.p.a ) light loaded and limited exposure to dampness

Question 3

Characteristics of earthquakes

Answer 3

1. Stress occurs in fault lines due to movement, causing plates to snap/slip causing earthquakes
2. The (compession)p wave is 2 x faster and hits first but the S wave is more destructive
3. When it hits the earth it makes surface waves and travel radially at a speed of 8 km/s

Question 4

P wave and S wave movements

Answer 4

1. Expand and contract ( lateral movement
2. Expand and contract and shearing / rolling ( elliptical ) - love waves are horizontal - Rayleigh are vertical -

Question 5

Most destructive wave

Answer 5

S (Rayleigh)

Question 6

Wave propagation is effected by

Answer 6

Elastic moduli and soil density

Question 7

Best materials to build on for eq

Answer 7

1. Solid bedrock - waves travel faster with low amplitudes
2. Consolidated sediment - waves slow down with higher amplitudes leading to worse destructions
3. Water saturated is sand / mud -Consolidated sediment ditto but worse due to liquefaction _

Question 8

Basic parameters of building destruction-

Answer 8

1. Foundation materials
2. Eq frequency normally about 20Hz in relation to the building
3. Eq resistance of the building

Question 9

Why do eq occur in SA

Answer 9

Due to increased mining activity

Question 10

How much do plates move

Answer 10

50 mm / year

Question 11

Conceptual design for E Q (rule 1 and 3 )

Answer 11

Rule l: simplicity in design allowing to predict the flow of forces

Rule 3: torsional resistance structure and member resistance should be able to resist torsion this can be done by including shear walls or bracing in two arthogal directions

Question 12

Cd rule 5 and 4

Answer 12

4. Diaphragm behavior of slabs - should be able to transfer seismic forces tovertical resisting members
5. Foundations - it should be able to distribute seesnier forces evenly to the ss

Question 13

Cd 7 and 8

Answer 13

7.. free standing walls and chimney should be avoided, parapets should be braced

8. The entire structure should be tied together, structural frames should be monolithic

Question 14

Cd 10 and q