In this study the effect of having semelIs connecting the twofootings of a frame was studied experimentally and numerically since it wasexpected to affect seriously the behaviour of such frames.Many variables were considered in tills study such as the rigidity ofthe tie-beam and its location weather directly on the soil; at the level ofplane concrete; or at the footing level; at the level ofR.C. footing; or at avariable distance above the footing. The effect of varying the soil type andThe location of load, was also considered, two cases of loading werestudied.a) Two vertical loads 50 tones each acting on tile frame girder at adistance equal one third the girder span from each side. ~.b) One lateral horizontal load 5t acting at the column-girder joint.and photoelesticity methods were used to investigate.,.tnti’oned variables on the mechanical behaviour ofeach other showing a reasonableand recommendations concerning thertance of usmg semells, its rigidity, location under differentCir4N1llstance hich may be of great use for designers were arised.