stiffness.

The paper presents only some problems of design and constraction of the bridge. The active provides the results of the research out composite muilti-span prestressed reinforced concrete beam for time building bridges. Comparison of experimental and theoretical sizes. Values of crack resisting, deformation property and strength index are received, work stages and studied slabe collapse odes are also described. The characteristic stage of the tensely deformed state are selected. State and practic making of multi-span iron concrete constractions by high productive modern technology.

The active provides the results of experimental reseach abtain in investigation of the testing multi – span prestresset reinforced concrete bridges. For the first time in the laboratory conditions were held experimental researches of prefabricated monolithic precast spans to check accepted methods of calculating the direct determination of efforts elements during the action of static load. Tests showed sufficient stiffness and strength of prefabricated monolithic spans working in an elastic phase, almost in the estimated load.