The document discusses the design of a circular composite footbridge at an intersection in Harare, Zimbabwe to address issues of high pedestrian and traffic volumes. It notes problems like congestion and pedestrian collisions due to lack of separation of pedestrian and vehicle traffic. The objectives are to design the footbridge to improve safety and reduce congestion according to standards. Methodology includes interviews, surveys and software analysis. Preliminary design considers geometry, loads, and sizing of bridge components. The soil study finds stable clay soils that can support pile foundations.

1. DESIGN OF A CIRCULAR COMPOSITE FOOTBRIDGE AT THE INTERSECTION OF JULIUS NYERERE AND KENETH KAUNDA IN HARARE
NAME:MARLON KACHUWA
REG #:R182902R

2. INTRODUCTION
 Although there has been a popularity discipline of walking, it remains as the most used mode of transport daily
 Walking inevitably involves crossing a road, where the desire line of the pedestrian conflicts with the higher speed
and lesser vulnerability of motor vehicles
 According to (Department for Transport, 2004), pedestrians still comprise around a quarter of those who die in
road collisions and statistics shows that in Great Britain in 2003 over 290,000 people were killed or injured in road
traffic collisions (36,405 were pedestrians)
 According to Traffic Safety Council of Zimbabwe (TSCZ), the rate of road crash fatality has increased from 1,836
in 2016 to an average of 2,000 deaths per year – over 5 deaths per day- from 2017 to 2019
 These problems were dealt with by introducing education programmes, physical interventions, signage, road
markings and construction of footbridges.

3. PROBLEM STATEMENT
 THERE IS HIGH TRAFFIC FLOW AND PEDESTRIAN FLOW AT THE INTERSECTION
WHICH RESULTS IN HIGH LEVEL OF CONGESTION AND PEDESTRIAN
COLLISIONS.
 POWERCUTS IN HARARE ALSO INCREASE CHANCES OF ACCIDENTS AND
PEDESTRIAN COLLISIONS AS TRAFFIC SIGNALS WON’T BE WORKING.
 AT THE INTERSECTION, PEDESTRIANS FACES CHALLENGE OF CROSSING THE
ROAD AS THE DRIVERS WONT BE GIVING THEM RIGHT OF WAY THIS RESULTS
IN PEDESTRIANS CROSSING THE ROAD WITHOUT PAYING ATTENTION TO
TRAFFIC SIGNALS.
 SUCH ACTIONS WILL ENDANGER THE SAFETY OF PEDESTRIANS USING THE
INTERSECTION.

4. PROBLEM
STATEMENT CONT
THE CAPTION
SHOWS
PEDESTRIANS
USING THE
INTERSECTION.

5. JUSTIFICATION
 AT THE INTERSECTION OF JULIUS NYERERE AND CHARTER, A LOT OF
PEOPLE USES THAT INTERSECTION SINCE IT IS THE MAIN ROAD THAT
LEADS TO CHITUNGWIZA WHICH IS ONE OF THE BIGGEST TOWNS IN
HARARE.
 A LARGE NUMBER OF PEOPLE IN CHITUNGWIZA WORK IN CITY OF
HARARE AND USES THIS INTERSECTION TO ACCESS OTHER PARTS OF
THE CBD, HENCE THERE IS NEED TO SEPARATE THE PEDESTRIAN AND
VEHICULAR TRAFFIC AS WELL AS TO IMPROVE THE TRAFFIC FLOW AND
SAFETY OF PEDESTRIANS, AND TO BUILD A LANDMARK STRUCTURE IN
THE CITY CENTRE BY CONSTRUCTING A FOOTBRIDGE.

6. OBJECTIVES
MAIN OBJECTIVE
 Design of a circular composite
footbridge so as to improve safety of
pedestrians and reduce traffic
congestion by pedestrians at the
intersection of Julius Nyerere and
Charter according to the specified
standards.
1. To carry out interviews with the
pedestrians and drivers using the
intersection.
2. To carry out a traffic, pedestrian
survey at the intersection.
3. To design and analyse the composite
footbridge manually and use of
software such as Sap2000.

7. LITERATURE REVIEW
 WHAT IS TRAFFIC CONGESTION
 CAUSES OF TRAFFIC CONGESTION
 CAUSES OF PEDESTRIAN COLLISIONS AT INTERSECTION
 PEDESTRIAN BEHAVIOUR AND ATTITUDE WHEN CROSSING
 CASE STUDIES
 DESIGN

8. METHODOLOGY
OBJECTIVE METHOD
To carry out interviews with the pedestrians using the
intersection to see if the structure would serve its purpose
and to assess the causes of pedestrian collisions at
intersections and how pedestrians cause traffic
congestion.
Questions were asked to pedestrians and drivers on how
they use the intersection and how they give each other
right of way.
To carry out a pedestrian survey at the intersection. Observations were done manually, observing how
pedestrians are crossing the intersection and how drivers
behave on the intersection.
To design and analyse the composite footbridge. Use of software(SAP2000)

9. STUDY AREA
The caption shows the map of
Harare.

10. LOCATION OF
PEDESTRIAN BRIDGE
The caption shows the
intersection of Julius Nyerere
and Charter.

11. RESULTS AND ANALYSIS
Behaviour of Drivers
(When a driver saw a pedestrian passing the road)
Vehicle Type Total Willing To Stop Don’t want to stop
(Slow down)
Overtake
Bus 100 24 53 23
Car 100 33 21 46
Motor Cycle 100 10 19 71
Mini-bus 100 8 35 67
Pick-Up 100 27 63 10
Truck 100 36 42 22

12. RESULTS AND ANALYSIS
 From survey it is clear that high speedy vehicle has a tendency of overtaking. On the other-hand the large vehicle
slows down when someone cross the road.

13. RESULTS AND ANALYSIS
Means of Crossing the Road Number of Pedestrians Crossing
Traffic Signal 31
Pass Directly 69

14. RESULTS AND ANALYSIS
 The survey shows that pedestrians are less interested in crossing in waiting for traffic signals to give them right of
way. Most of them pass the road directly which is risky and hamper their safety. When they were asked about why
they do not use safer means they replied that traffic signal consumes time while crossing the road directly is
quicker.

15. GEOTECHNICAL RESULTS FROM CITY OF HARARE
SOIL PROFILE
TRIAL HOLE NUMBER TESTED DEPTH (MM) DESCRIPTION OF MATERIAL
1 0 – 30 Spray and Chip
30 – 120 Crusher Run
120 – 330 Brown Iron Stone
330+ Light Grey Clay

16. SIEVE ANALYSIS TEST
SAMPLE
NUMBE
R
DESCRIPTIO
N OF
MATERIAL
TESTED
DEPTH
(MM)
BS SIEVE SIZES (MM) % PASSING
37,5 26,5 19,0 9,5 4.75 2,36 1,18 0,600 0,300 0,150 0,075
1. LIGHT
GREY
CLAY.
1 000 - - - - - 100 99 92 94 91 89

17. PLASTICITY INDEX
SAMPLE
NUMBER
DESCRIPTION
OF SAMPLE
TESTED
DEPTH
(mm)
WL WP IP IC IF PP
1. LIGHT GREY
CLAY.
1000 66 21,8 44,6 0 88,7 3 956

18. DCP TEST
SAMPLE NUMBER TESTED DEPTH
(MM)
PENETRATION
PER BLOW
(MM)
BEARING
CAPACITY
KN/M2
(KPa)
1. 1 065 65 Less than 50
1 115 50 45
1 150 35 67
1 190 40 57
1 225 35 57
1 245 20 120
1 275 30 80
1 300 25 97
1 320 20 120
1 340 20 120
1 360 20 120

19. CONCLUSIONS
 The soil found were light grey clay with high plasticity index. The plasticity index is 44.6. The soils are stable at
1320mm below ground level where the safe bearing capacity is 120kPa.
 Pile foundation is recommended since the structure is going to carry heavy loads .

20. PRELIMINARY DESIGN/SIZING
BRIDGE GEOMETRY
CLEAR SPAN 30.1M(DIAMETER)
CHS SECTIONS 60.3x3.5
CLEAR HEIGHT 5m
WIDTH OF FOOTBRIDGE 4m
COLUMN PIER SIZE 500MM
COMPOSITE SLAB DEPTH 200MM
LOADS APPLIED ON STRUCTURE
DEAD LOADS: Selfweight of concrete+selfweight of
steel+floor finishes
LIVE LOADS 5.0KNm-2 (BS 5400-2-1978 7.1.1)

21. PELIMINARY SIZING
PLAN VIEW OF THE
PEDESTRIAN BRIDGE

22. PRLIMINARY SIZING
SECTION VIEW OF THE
PEDESTRIAN BRIDGE

23. THANK YOU

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