UNIVERSITY OF NEWCASTLE UPON TYNE

DEPARTMENT OF CIVIL ENGINEERING

 BACHELOR OF ENGINEERING & MASTER OF ENGINEERING

IN

CIVIL ENGINEERING,

CIVIL & STRUCTURAL ENGINEERING,

CIVIL & ENVIRONMENTAL ENGINEERING

 Stage 1

 

CIV 131 - ELEMENTARY STRUCTURAL DESIGN

 PEDESTRIAN ARCH BRIDGE

Module Director: Prof. J. Knapton

e-mail:john.knapton@ncl.ac.uk

web page: www.staff.ncl.ac.uk/john.knapton/

 

Note: To comply with the Department's Quality Assurance procedures, you will need to complete 3 copies of the Coursework Quality Assurance Form. You will have been told how to obtain them. To see how to complete the form click here.

Description of assignment

Each Group is to design the main span of an arch bridge to allow pedestrians to cross Glasshouse Bridge Road between Sites 4 & 11 on the Integrated Design project site. The bridge is to comprise a three pinned timber arch supporting the pedestrian deck in a similar manner to the bridge in Bellevue, Washington State shown below. Each Group is to submit one common report which will have the following headings:

 Description of proposed bridge

Approximately 1000 words supported by sketches and material researched from the library and the internet. Note that the bridge includes the main span and two side spans comprising the ramps. Select a site for the bridge and show your proposed location. Pay particular attention to level changes.

Analysis and design of bridge deck

Develop a "free body diagram" of the main central span of the bridge structure and hence calculate the force in the main arch. Consider the deck structure to be pin-jointed at the intersection of the deck and the arch. The self-weight of the arch and the steel decking must be taken into account in addition to the imposed load. The load on the deck from pedestrians is 4.0kN/m2. Select appropriate member sizes from the tables below and present your calculations. Design a connexion between the arch and the deck. See the pictures of the Bellevue on this web site for ideas.

Details of bridge

Prepare about 1000 words and sketches based upon the following. The deck is to comprise steel plates supported by I -section steel cross beams in turn supported by I-section steel beams running between the arches. Assume that the ramps at each end of the main span are designed to a similar principle - as with the Bellevue bridge - but design only the main centre span. For the deck, steel sheets are available in thicknesses of 10mm, 20mm, 30mm, and 40mm. Assume that the timber is available in all sizes and that it can take stress in compression, bending and tension of 3N/mm2. The density of steel is 7800kg/m3 and the density of timber is 1100kg/m3. The steelwork can sustain stresses of 165N/mm2 in tension, compression or bending. Note that the bridge must provide clearance of 4.7m for traffic below and 2.6m for the pedestrians walking along the deck. Determine the span of the bridge by reference to your chosen site. The width of the deck is 2m.

General arrangement drawing

A general arrangement drawing showing an elevation, a plan and a cross section is to be produced by each student individually on an A1 sheet showing the entire bridge i.e. the main span and the two side spans. The drawing is to be at a scale of 1:50, except for the cross section which is to be 1:20. The drawing is to be on film and a folded print is to be submitted by each student.

Costings

Each Group is to keep a record of time spent on the project by each member of the Group. The report is to include a daily time sheet summary for each student. Assuming your time costs 55 per hour, calculate the cost of the exercise. Assuming structural steelwork (I-sections & plates) costs 1200 per ton, and timber costs 700 per ton, calculate the cost of the bridge.

 Peer assessment

Each Group is to agree a mark out of 20 for each individual within the Group. Use the following guideline:

Performance Mark

Did not contribute 0

Minor contribution, no responsibility taken 5

Diligent effort but little initiative 10

Major contribution appreciated by others 15

Outstanding in all respects 20

 

The peer assessment should be signed by each member of the Group. In case of dispute, the Group is to meet Prof. Knapton. When the report is marked, the total mark gained will be apportioned amongst Group members in proportion to the peer assessment scores. Note that assigning a high mark to each group member will not increase the total number of marks to be shared amongst the group members.

 

The report is to be handed in to Prof. Knapton by 2pm on Friday 10th May 2002.

 

Universal Beam & Rolled Steel Joist I-Sections available

Depth (mm)

Width (mm)

Area (mm2)

I(cm4)

Weight (kg/m)

305

165

6830

11686

54

254

146

5500

6546

43

203

133

3800

2880

30

178

102

2740

1519

22

152

89

2180

881

17

102

64

1230

217

10

76

51

850

83

7