Mid Exam 2018, questions PDF

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Summary

Mid-sem Sample...

Description

School of Civil, Mining and Environmental Engineering Student to complete: Family name Other names Student number Table number

CIVL314 Structural Design 2 Wollongong Campus

Sample Mid-Session Examination Paper Spring 2018

Exam duration

2 hours

Items permitted by examiner

UOW approved calculator Open book

Aids supplied

None

Directions to students

2 questions to be answered. Marks for each question are indicated on the question. Begin each question on a new page.

This exam paper must not be removed from the exam venue

2018 August 17

CIVL314 Woll Autumn 2018

Page 1 of 4

Note: Only 2 questions will be set in the mid-session examination. This sample examination paper contains 3 questions to demonstrate probable patterns of mid-session examination questions. Method, layout and accurate referencing to AS/NZS 1170 and AS 3600 clauses and or text books will be assessed in addition to answers obtained.

QUESTION 1 (a) Calculate the ultimate design wind speed Vdes,  and design wind pressure p for the following sites, assuming Ms=Mt=1, Cfig=1 (consider average recurrence interval, R= 1000 years for ultimate limit state) (According to National Construction Code, NCC 2016) (i) A 5m high building in a built up area on the Gold Coast (ii) At the roof level of a 25 m high building on the Gold Coast, which does not have significant shielding from adjacent structures. b) An office building in Wollongong of plan dimension 30 m x 25 m and height 24 m, constructed of ordinary moment resisting concrete frame, needs to be designed for earthquake action [Figure 1(a)]. Soil profile of the site is shown Figure 1(b). Calculate earthquake base shear force and base overturning moment for the building according to AS 1170.4. Consider that in this building more than 300 people can congregate in one area. [Assume thickness of the slab= 200 mm, concrete unit weigh= 25 kN/m3 and superimposed dead load= 1 kPa. Consider trafficking roof. Live load for office building should be considered according to AS /NZS 1170.1] 30 m

SPT N-Values 6m

7 12

8m

18

8m

32

12

6@4 m=24 m Width of the building = 25 m

Soil Profile of the site Elevation (a)

(b)

Figure 1: Calculation of Earthquake Action

2017 August 20

CIVL314 Woll Spring 2017

Page 2 of 4

QUESTION 2 A floor system for an office building consists of a grid of beams supported by columns as shown in Figure 2. Based on preliminary estimates, columns are chosen as 400 mm x 400 mm and beams are chosen as 400 mm (width) x 600 mm (depth). Also, the total thickness of the slab (Ds) is chosen as 220 mm. For the corner slab A: (a) Check whether the slab thickness satisfies the deemed to comply span-to-depth ratio specified in AS 3600 for a limiting incremental deflection, /Lef= 1/500. (b) Design the slab (reinforcement in the primary and the secondary direction). Consider that the thickness of the slab is 220 mm. (c) Check the shear capacity of the slab and comment on its adequacy.

Columns 400 mm sq.

6000mm

6000mm

A

6000mm

Design Data: Compressive strength of concrete, f'c=32 MPa Unit weight of concrete= 25 kN/m3 Yield strength of steel, fsy=500 MPa Slab thickness, Ds=220 mm; concrete cover= 25 mm Superimposed dead load = 1.0 kPa; live load = 3.0 kPa Use N12 reinforcing bars

Beams 400 mm x 600 mm

7500mm

7500mm

7500mm

7500mm

Note: Dimensions are from column centrelines Dimensions are not in true scale

Figure 2: Floor layout of an office building

2017 August 20

CIVL314 Woll Spring 2017

Page 3 of 4

QUESTION 3 For the flat plate floor shown in Figure 3, (i) (ii) (iii)

Determine bending moment distributions for the interior design strips in the X- and Ydirections. Check the interior column A for punching shear strength in the critical direction using the provisions of AS3600. Consider that the thickness of the slab is 280 mm. What measures should be taken if punching shear capacity of the flat plate floor is not sufficient?

Design Data Compressive strength of concrete, f'c=32 MPa Unit weight of concrete= 25 kN/m3 Yield strength of steel, fsy=500 MPa Slab thickness, Ds=280 mm; Concrete Cover= 30 mm Superimposed dead load = 1 kPa; Live load = 3.0 kPa Perimeter columns: 500 × 500 mm Interior columns: 400 × 400 mm 

Figure 3: Flat plate floor and column locations

2017 August 20

CIVL314 Woll Spring 2017

Page 4 of 4...