Dear Martin Landa sup p is mistyped and its correct form would be Kp that you can find it in page 585 adjacent to fig.19.61 and it is coeff. of passive earth pressure.(Kp=(tan(45+fi/2))^2 according to Rankin theory) As you know Broms calculated lateral load capacity from internal moment diagram related to soil reaction diagram (which in turn is related to estimated deformation diagram) and Kp enter to the equations of equilibrium due to soil reaction in zones that have passive conditions. yours sincerely ========================================== Saman Zargarbashie Student of Geotechnical Eng.(M.Sc) Iran University of Science and Technology Civil Engineering Department. Tehran-Iran e_mail: [log in to unmask] ========================================== %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%