A model pile instrumented with miniature load cells has been jacked into a bed of dense sand and loaded horizontally in two directions. From the load cell readings taken and a consideration of force equilibrium, the approximate distribution of stress around the circumference of the pile on horizontal loading has been obtained. The resultant stress in the horizontal plane was non-uniform and directed approximately radially towards the pile around much of its circumference.
In the analysis of a pile under horizontal loading, it is generally assumed that the horizontal load is resisted solely by a stress uniform across the width of the pile and directed parallel to the horizontal load. The analysis takes no account of stresses not aligned with the horizontal load, which is found to underestimate the resistance of the pile/sand system to horizontal loading.