Assignment 1 - Load Combinations - Questions

CE3166 Structural Steel Design and System Semester 1, AY2016/2017

Assignment Set 1 – LOAD COMBINATIONS

Level of difficulty: EASY

Assessment 1.1 (3 marks) Determine the ultimate or factored load for the roof of an industrial building which is subject to the following characteristic loads: Dead load Roof imposed load Rain load Wind load

= = = =

4.8 kN/m2 2.0 kN/m2 3.5 kN/m2 2.5 kN/m2 upwards

Which load combination controls the design of the roof?

Assessment 1.2 (3 marks) A column in a building is subject to the following characteristic axial loads: 45 kN compression from dead load 95 kN compression from roof imposed load 20 kN compression from rain accumulated on the roof 30 kN compression from wind Calculate the factored load to be used in the design of the column. Which load combination controls the design of the column?

Assessment 1.3 (3 marks) A 8 m long fixed-ended beam is subject to various characteristic loads as shown in Figure A1.3. Calculate the factored load to be used in the design of the beam. Which load combination controls the design of the beam? Dead load = 45 kN/m Imposed load = 100 kN/m Wind load = 20 kN/m

Wind load = 40 kN/m

8m Figure A1.3

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CE3166 Structural Steel Design and System Semester 1, AY2016/2017

Level of difficulty: INTERMEDIATE

Practice 1.4 Figure A1.4 shows a 12 m long beam with an internal hinge at B which is pin-supported at points A, C and E. The beam is subject to various characteristic dead and imposed loads as shown in Figure A1.4. DL = 70 kN IL = 90 kN

DL = 10 kN/m IL = 15 kN/m

A

E B

C

D

Hinge 4m

2m

3m

3m

Figure A1.4

Based on the appropriate load combinations, calculate the design values for the following quantities: (a)

Maximum reaction at support A.

(b)

Maximum reaction at support E.

(c)

Maximum hogging (i.e. negative) moment in the beam at support C.

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CE3166 Structural Steel Design and System Semester 1, AY2016/2017

Practice 1.5 A pin-jointed truss is subject to several unfactored loads as shown in Figure A1.5. Based on the appropriate load combinations, calculate the design values for the following quantities: (a)

Maximum compression in member AB.

(b)

Maximum compression in member GH.

(c)

Maximum tension in member AG.

Assume that the effect of initial sway imperfections is negligible. DL = 50 kN IL = 30 kN

DL = 50 kN

WL = 20 kN D

E

C

F

B

G

A

H

3.6 m

WL = 20 kN

IL = 40 kN

3.6 m

WL = 20 kN

3.6 m

4.8 m Figure A1.5

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CE3166 Structural Steel Design and System Semester 1, AY2016/2017

Level of difficulty: DIFFICULT

Practice 1.6 Figure A1.6(a) shows a simply-supported observation deck that is built on top of a hotel. The self-weight of the deck and its imposed load are 15 kN/m and 30 kN/m, respectively. The deck also supports an elevated walkway on one end and hanging gardens on the other end. The self-weight of the elevated walkway is 80 kN with an imposed load of 100 kN, while the dead load from the hanging gardens is 150 kN.

Elevated walkway B

Observation deck

C

A

D

Hanging gardens

3m

7m

4m

Figure A1.6(a)

(a)

Calculate the design load on the column at point B.

(b)

Determine whether the column at point C needs to be designed for tension.

(c)

What is the maximum bending moment that the deck structure must be designed for?

(d)

What is the maximum vertical displacement under imposed loads that the observation deck must be designed for?

The bending rigidity of the deck structure EI is 450000 kN·m2. You may make use of Figures A1.6(b) to A1.6(e) in your calculations.

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CE3166 Structural Steel Design and System Semester 1, AY2016/2017

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CE3166 Structural Steel Design and System Semester 1, AY2016/2017

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