Technical Guidelines and Tips on Popsicle Bridge Building Contest hosted by DLSU Civil Engineering Society (CES).

1. DLSU-CES BRIDGE Building Contest SY 2009-2010 Technical Guidelines

2. Truss Bridge Competition

4. TRUSS Bridge Specs Weight, W ≤ 1.50 kg H+D ≤150mm Length, L ≤ 770 mm Height H ≤ 100 mm Span Length, between UTM supports S = 560 mm UTM Support Provide a 60 mm minimum flat bearing surface at the supported points (see sample bridges) Bridge Deck Width B ≤ 140 mm Top of UTM Depth D ≤ 50 mm

5. Sample Bridge Design A H L S D

6. Sample Bridge Design A H+D ≤ 150 mm

7. Sample Bridge Design B H L S D

8. Sample Bridge Design B H+D ≤ 15 0 mm D ≤ 50 mm H ≤ 100 mm

11. Sample Bridge L = 700 mm, H = 200 mm, B = 130 mm, W = 1.26 kg

13. Weight , W <= 1500 g

15. Best Bridge Design Winnner: 2008-2009 (DHVCAT)

18. Bridge Testing Testing Results P = 30 kg,  = 5 mm, W = 1.26 kg S = 30 x 1000/(5 x 1.26) = 4761.90 (kg/m)/kg

21. TOP 4 STRENGTH CATEGORY 5 th Bridge Building Contest 2008-2009

22. W=0.492 kg, P=27 kg, D=8.7 mm, S=6308

23. W=0.541 kg, P=25 kg, D=8.6 mm, S=5375

24. W=1.205 kg, P=65 kg, D=13.4 mm, S=4025

26. TIP 1 : if you want to efficiently use the strength of popsicle sticks, design your bridge such that tensile forces not compressive forces are developed in most of the members. “ Popsicle sticks are stronger in tension than compression because of buckling.”

27. You can analyze the truss using A structural analysis software.

28. TIP 2 : If you want to increase the capacity of the members against buckling, then provide braces.

29. Before Loading After Loading: No Horizontal Braces at the top. Buckling occurred.

30. TIP 3 : A deep hollow box girder is relatively light and has a larger flexural capacity.

31. TIP 4 : Don’t make your bridge to heavy!

35. tHank yOu! Happy Bridge Building!