Worksheet @1 - Loads Design PDF

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MONASH UNIVERSITY

ENG1001 LIGHTER, FASTER, STRONGER

WORKSHEET 1 – LOADS & DESIGN

Name: Student ID: Team No.:

You need to watch the videos for Week 1 for completing the following tasks. To gain FULL marks for Worksheets ALL workings MUST be shown. 1. While all the following tasks are the responsibility of Civil Engineers, which task is NOT to be carried out by Structural Engineers? a. Determining the structural form of a bridge b. Design loads on a building c. Designing the type of foundations for a building d. Determining whether a structure would collapse after fire e. Determining the design life of a building 2. A person weighing 90 kg is moving at a speed of 50 km/hr and occupies a plan area of 0.4m x 0.4m . a. Express the weight of the person in kN: b. Express the weight of the person in kPa: c. Express the weight of the person in MPa: d. Express the speed of the person in m/s: 3. For a dead load G = 8kN/m and a live load Q = 5 kN/m, what is the ultimate limit state (ULS) design load? (Ans: 17.1kN/m) Ans :

The ULS loading is used when calculating; a) the strength of the system or b) the maximum deflection of the system?

4. For a dead load G = 8kN/m and a live load Q = 5 kN/m, what is the serviceability limit state (SLS) design load? (Ans: 11.5kN/m) Ans:

The SLS loading is used when calculating; a) the strength of the system or b) the maximum deflection of the system? Page 1

5. This question relates to the use of statistics to calculate live loads . The following data is collected from a survey of groups of people standing within 2 m2 of area. Calculate the characteristic live load Q and the SLS & ULS design live load in kPa. Assume the following data is representative of all the survey data collected and each person occupies the same space. Person

1

2

3

4

5

6

7

Weight, x (kg)

90

110

58

73

85

62

78

Step 1: Calculate the average weight of the people in kg =

∑x

kg

Calculate the average load the weight of the people equate to in kN/m2 = (Ans: 2.78 kPa)

kPa

Step 2: Calculate the standard deviation (σ) of the statistics by completing the following table - it is OK to use a calculator function, or else use the following formula

n

∑ 𝑥2

(∑ 𝑥)

2

 



n x2   x nn  1



2

7

σ

=

kg OR

kPa (Ans: 0.62kPa)

Step 3: Write down the formula for calculating the characteristic live load Q and calculate this value in kg and kN/m2

(Ans: 108.7kg, 3.8kPa)

Step 4: Calculate the ultimate limit state (ULS) and serviceability limit state (SLS) design live loads in kPa (by applying the appropriate load factor) (Ans: 5.7 kPa, 2.66 kPa)

6. A concrete ‘T’ beam is used as a pedestrian bridge between two supports as shown in Figure 1. The beam must support a live load of 5kPa. Calculate the dead and live load in kN/m and the ultimate limit state load acting. Take density of concrete = 24 kN/m3. beam ramp

8 metres pier

elevation 1000 mm

Figure 1 150 mm 250 mm 300 mm

Beam Cross-section a) Calculate the self-weight (dead load) of the beam in kN/m (Ans: 5.4kN/m). Method 1: Calculate the total weight of the entire beam and then divide by the beam length. Step

Task

1

Cross-sectional area (m2) =

2

Volume of beam (m3) =

3

Total weight (kN) =

4

Total weight (kN/m) =

Value

Method 2: Calculate the weight of the beam directly in kN/m. Step

Task

1

Cross-sectional area (m2) =

2

Total weight (kN/m) =

Value

Page 3

b) Calculate the live load acting on the beam in kN/m. (Ans: 5kN/m) Method 1: Calculate the total live load acting on the beam and then divide by the beam length. Step 1

2

Task

Value

Plan area of beam load acts on (m2) = Total live load acting (kN) =

3

Live load (kN/m) =

Method 2: Calculate the live load directly in kN/m. Step 1

c)

Task

Value

Live load (kN/m) =

Calculate the ultimate limit state (ULS) of these loads acting on the beam (kN/m) (Ans: 13.98kN/m)

d) If a ‘non-permanent’ fixture applies an additional point load of 20kN to the beam, 3m from the left pier, draw all ULS loads on the beam (noting all relevant dimensions).

Page 4

7. A concrete slab, 250 mm thick, 6 m wide and 8 m long, is used to support a live load of 4 kN/m2 on one half and 5kN/m2 on the other half of the slab as shown in Figure 2. The concrete slab is supported by three equally loaded steel 300 x 600 x 10RHS (rectangular hollow section) beams, each 8 m long. Assume the three beams carry equal load. Take density of concrete = 24 kN/m3, and density of steel = 7850kg/m3 Concrete slab

Live load = 4 kN/m2

300 mm

Live load = 5 kN/m2

6m

600 mm 250 mm steel beam Cross-section Wall thickness = 10mm

4m

4m

Figure 2 (a) Calculate the dead load (G) on each steel beam (including self-weight), in kN/m. (Ans: 13.38kN/m) Step 1

2

Task

Value

Cross-sectional area of concrete slab supported by single beam (m2) = Weight of concrete slab per beam (kN/m) =

Cross-sectional area of each steel 3

4

beam (m2) =

Self-weight of each steel beam (kN/m) =

5

Total weight on one beam (slab + beam self-weight) (kN/m) =

Page 5

(b) Calculate the live loads (Q) on each steel beam, in kN/m. (Ans: 8 & 10kN/m) Step 1

Task

Value

Width of load area acting on beam (m) =

2

Live load on beam LHS (kN/m) =

3

Live load on beam RHS (kN/m) =

(c) Calculate the ultimate limit state load each steel beam, in kN/m. (Ans: 28.06 & 31.16kN/m) Step

Task

1

ULS load on LHS of beam (kN/m) =

2

ULS load on RHS of beam (kN/m) =

Value

(d) Assume the lines below represents a single beam. Show the dead loads, live loads and ULS loads on the beam and all relevant dimensions.

Dead Loads

Live Loads

ULS Loads

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