Week 1 Challenge

Q.1. Truss Type Reasoning:

Answer : The most efficient type of truss system that carry gravity load efficiently is Truss A.

Discription of Truss A:

• In Truss A all the vertical members are in compression.
• Diagonal members are in tension.
• In this truss vertical and diagonal members are slopping towards center.

Discription of Truss B:

• In truss B vertical members are in tension.
• Diagonal members are in compression.
• In this truss vertical and diagonal members are slopping towards edge and not center.

Reason :

As the gravity load acts downword direction, vertical members in Truss A take the gravity load and resist it effectively. Hence the arrangement of the vertical and diagonal members of Truss A is such that, the vertical members carry gravity load which acts downwords and diagonal members carry tesion loads.

Q.2. Deflection shape and Bending Moment Daigram :

Answer : The Bending Moment Diagram and Deflection is uploaded in the attached file below.

Q.3. Determination of MOI Weight and C/S : Calculations are attached in word file below.

Answer : MOI Along Iz= 14841333.334 mm⁴

MOI Along Iy = 1843253.332 mm⁴

Weight per meter = 23.84 kg/m.

MOI Along Ix = 906.06 x 10⁶mm⁴

MOI Along Iy = 135.042 x 10⁶ mm⁴

weight = 204.1 kg/m

b. MOI Ix = 183396320mm⁴ c. MOI Iz = 668329931.698mm⁴

Weight = 76.145 Kg/m weight = 123.4805 Kg/m

Q.4. For given Figure to Calculate load coming on Interior and exterior Beam and Girder:

Answer: Given Floor load = 10KN/m2

Load coming on Interior Beam = 10KN/m2 x 2m

= 20KN/m.

The load of floor is taken by flooring and then transfered to interior beam as UDL. This UDL will be transfered to girder beam as point load and then to column and footing as point load.

Load coimng on Exterior Beam= 10KN/m2 x 1m

= 10KN/m.

Interior Beam will carry double the load on exterior beam.

Load coimg on Interior Girder = (10KN/m2 x 8/2 m)x2 + (10KN/m2 x 8/2 m)x2

= 80+80

= 160KN.

In the given figure the interior beam will transfer the half UDL to interior Girder and half the UDL load to exterior girder.

Load coimg on Exterior Girder = (10KN/m2 x 8/2 m)x2

= 80KN.

Q.5. Expansion Joint Determination for temparature stated problem.

Answer : Given initial length is 2000m and initial temparature is -20C, final temparature is 40C and co-efficient of temperature is 12x10^-6.

Change in length = co-efficient of temperature x initial length x change in temparature

change in temparature = Final - Initial

= 40-(-20)

= 60

change in length = 12x10^-6 x 2000 x 60

= 1.44

So total length of bridge at 40C = 2000+1.44

= 2001.44m

Hence the expansion joint should be given is 1.44m.