

STRUCTURAL ENGINEERS' HANDBOOK 



Introduction. The book is divided into two parts which are self contained. Part I include* 

 a discussion of the design of structures and gives data and details for the design of steel bridges 

 and buildings. Part II contains tables for structural design and include* table* giving the proper- 

 ties of rolled sections, properties of built-up sections for chords, columns, struts, plate girders, 

 etc., and data for standard structural details. 



PART I. 



DATA AND DETAILS FOR THE DESIGN AND CONSTRUCTION OP STEEL BRIDGES 



AND BUILDINGS. 



Introduction. The discussion in Part I has been limited to steel bridges and buildings and 

 other simple steel structures; no reference being made to swing and movable bridges, cantilever 

 and suspension bridges. The design of a bridge includes the design of the substructure as well as 

 the superstructure, so that the design of retaining walls and bridge abutments has been briefly 

 discussed. Timber trestles and bridges are required for temporary structures and for the erection 

 of steel structures, and a brief discussion of timber trestles and bridges is therefore properly 

 included. 



The design of a structure requires not only a knowledge of the properties of materials and the 

 ability to calculate the stresses, but also a knowledge of local conditions and requirements, of 

 economic design, of details of construction, of methods of erection, methods of fabrication and 

 their effect on cost, and of many other matters which limit the design. The most economical 

 structure for any given conditions is the one which will give the greatest service for the least 

 money, quality of service and the life of the structure being given proper consideration. Financial 

 limitations often limit the design and the problem then is to design a structure that will give 

 satisfactory service with the money available. 



To design a satisfactory structure when limited by financial considerations is a problem that 

 requires the exercise of the highest possible skill on the part of the m^im-fr. H- must be able to 

 select an economical type of structure; he must make an accurate estimate of the loads to be carried 

 by the structure; he must be able to calculate the stresses with accuracy; he must make the de- 

 tailed design with due reference to ease of obtaining the material, the cost of shop work, and the 

 cost of erection. 



The shop cost of steel structures varies with the type of structure, the sue and weight of the 

 members and upon the make-up of the members and the details. By using fewer and larger mem- 

 bers, by using rolled beams and columns in the place of built-up plate girders and columns, and by 

 using tie plates in the place of lacing, the shop cost per pound of a railroad bridge may be materially 

 reduced. If the simplification of the design is carried too far the reduction in shop cost will result 

 in a material increase in the weight of the bridge, and in an increase in the cost of the bridge. 

 with a. decrease in efficiency. The details of the design of a structure should be worked out with 

 reference to ease and economy of erection as well as ease and low cost of fabrication. While the 

 standardizing of connections so that multiple punches may be used may result in a considerable 



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