A_p = 7980mm², f_ck = 60n/mm², b = 800mm, f_p = 1862n/mm², b_w = 200mm, M_u(required) = 16865knm, D_t = 400mm, d = 1750mm, M_u = 0.9dA_pf_p = (0.9x1750x7980x1862) = 2340x 10⁶ nmm = 23402 knm.

Long span continuous prestressed concrete bridges are built of which type of box girders multi celled box girders segments of variable depth using post tensioning system, and typical cross sections of post tensioned prestressed concrete bridge decks and salient features of cantilever construction method using cast insitu segments and precast concrete elements.

Prestressed hollow inverted pyramids have been used as a transfer: Girder system to support four storey complex housing administration building for engineering construction corporation limited at manapakkam in madras and upper four storeys housing administrative complex rest on four hollow prestressed pyramids which in turn are supported on hollow core walls.

P_u = (1.5×395) = 592.5kn, b = 250mm, D = 200mm, f_ck = 35n/mm²
P_u/f_ckbD = (592.5×10³/35x200x200) = 0.338.

The use of concrete trusses will considerably reduce maintenance cost in comparison with steel trusses which require periodical painting at shorter intervals and trusses in structural member are of circular, cylindrical, hollow etc used for various heavy structures stress analysis is done by considering all factors which influence trusses.

The height of reinforced concrete truss at midspan is in range of 1/7 to 1/9 of its span length and span of trusses generally lies of range of 18-30m and se spans are commonly used for bridge decks.

When loads are applied to chords of a truss between panel points and bending moment developed are determined by assuming chord as a continuous beam with spans equal to distance between joints.

The use of concrete trusses with modular coordinates for spans of 6,9,12,15,18,24,30 and 36m with a base module of 30m is most common for industrial buildings of east European countries such as Russia, Poland, Slovakia, Germany, Branko zezelji has reported construction of reinforced concrete wit prestressed tie members for spans up to 60m in erstwhile Yugoslavia.

The precast prestressed I and inverted T beams have been standardized by cement and concrete association for use in construction of bridge decks of spans varying from 7 to 36m and standard I and T units are widely employed in highway bridge beams in USA.

At ends of trusses near supports, 10-12mm steel bearing plates are anchored and embedded while casting, which serve as bearing and for fixing trusses on neoprene pad bearings located on columns.