Design of Steel Structures

7

Welded Plate Girder

7.1 Introduction

Beams of long span subjected to heavy loads are encountered in buildings and bridges. For these beams, ready-made I sections are not suitable since their depth is limited due to buckling of the web. In this situation, girders are to be fabricated using flange and web plates as per requirement. Usually, the flange and web plates are connected by welding (Figure 7.1). Girders fabricated in this manner are known as welded plate girders and their depth to web thickness ratio (d/t_w) may be up to 400. Because of higher d/t_w, the buckling of the web becomes the major problem with these girders. To overcome this problem, different types of stiffeners are provided as shown in Figure 7.1.

 

 

Figure 7.1 Welded plate ...