Pretensioned prestressed concrete bridge decks generally comprise pretensioned units used in conjunction with cast in situ concrete, resulting in composite bridge decks which are ideally suited for small and medium spans in range of 20 to 30m and in general pretensioned girders are provided with straight tendons and to use of seven wire strands has been found to be advantageous in comparison with plain or indented wires.

L = 2.11m, A = 650mm² = 0.65m²
Effective length = L_c = (0.65�2.11) = 1.37m.

A comparative study also indicates that a suspension bridge requires a stiffening girder with a flexural stiffness which must be about ten times larger than that required for a cable stayed bridge covering same span and suspension bridge requires additional heavy anchor blocks which can be prohibitively costly if navigation clearance is high and foundation conditions poor.

It is important to note that re is no single form of design which would be most economical in a given situation and to arrive at an economical design, several alternatives using different materials and structural configurations should be examined and a comparative analysis made which will lead to an optimal design.

f_c is 415, v_cw = 1900kn, balance shear = 934kn, using 12mm diameter two legged stirrups spacing,
s_v = (0.87x415x2x113x1900/934�10³) = 165mm.

Critical path method of project evaluation review techniques (PERT) are widely used in management of project work and with advent of computers, data processing, preparation of working drawings, work scheduling, materials management, controlling various activities of project and upgrading various tasks have become more simpler and y can be efficiently handled with less paper works.

For spans in range of 18-24m, trusses are made in one piece but when spans run from 24-30m, y are made in two pieces with a joint at mid span and beyond m y are divided into equal spans and joints are made.

The reinforcements consists of mild steel or HYSD bars toger with high tensile steel wires or cables use in tie members and material requirements per truss varies with span and spans of trusses.

Permissible stresses compressive stresses in concrete at transfer and working loads, as recommended f_ct = 15n/mm² < 0.4f_ci = (0.45�35) = 15.75n/mm², f_st ratio, ? = 0.80, f_cw = 12n/mm² < 0.33f_ck = (0.33�40) = 13.2n/mm², f_u = f_tw = 0.

Based on oretical and experimental investigations, it well established that forces in various members of truss are analyzed on assumption that joint are hinged in case os steel, reinforced concrete and prestressed concrete trusses.