moment in a lateral loaded pile

huangyhg

moment in a lateral loaded pile
in the structural engineering handbook by gaylord & gaylord, there is a formula for moment in a lateral loaded pile, m=cm x qhg x t.  cm is defined, but i can't find a definition of t, other than z=x/t.  can anyone tell me a definition for z, x, and/or t.  this is found on page 5-84 of my old copy.  also, does anyone have any other good design methods.  i use enercalc to determine pole embedment, but it doesn't give design forces for the pole (auger cast pile).  
for some of the other old ways, go to my web site (link below) and download the out-of-print documents "how to determine lateral load capacity of piles" and "pole building design".