Lugs, design base plate

Two or four lug systems are normally used however, more may be used if the situation warrants it. There is a wide variety of types of lugs, and each one will cause different stress distributions in the shell. Either one or two gussets can be used, with or without a compression plate. If a compression plate is used, it should be designed to be stiff enough to transmit the load uniformly along the shell. The base plate of the lug can be attached to the shell wall or unattached. Reinforcing pads can be used to reduce tbe shell stresses. In some cases, the shell course to which the lugs are attached can be made thicker to reduce the local stress. 

Design the weld between the plate shear lug and the base plate considering the shear and moment calculated is step 3. 

The guidelines for designing welded anchors for embedded plates presented herein are based on ACI 318 Appendix D, and the user should refer to that document for details not included herein. Shear lugs on embedded plates are similar to those discussed in 3.7 except without grout, and will not be discussed further. 

Design a shear lug pipe section for a 19-in. square base plate, subject to a factored axial dead load of 25 kips, a factored axial live load of 50 kips, and a factored horizontal shear load of 55 kips. The base plate and shear lug have Fy = 36 ksi and the concrete has a strength, f c = 4 ksi. The contact plane between the grout and base plate... 

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