1. Lateral load tests on a number of steel model piles were carried out in saturated sand layer.
　Main findings are as follows:
(1) A new expression p=k・x・y0.5 for the relationship between soil reaction p and pile deflection y can far better explain the actual behaviours of piles than any other expression so far proposed.
(2) Soil resistance per unit area of pile surface decreases with increasing width of pile, but it becomes almost constant when pile width is larger than 20 cm.
(3) Effective length of embedment for a laterally loa
ded pile is considered to be 1.5 lm1, in which lm1 is the depth of the first zero point of the moment distribution curve for an infinitely long pile.
2. Conversion factors are obtained by introducing the expression p=k・x・y0.5 into the law of similarity. Also standard curves of the pile-top deflection, maximum bending moment, effective length, and pile inclination are established on the basis of the model test results. Conversion of the standard curves by means of the conversion factors gives the estimation of behaviours of a prototype pile. The necessary computation for the above mentioned conversion can easily be made with the aid of computation charts given in this paper.
3. Many field test date are collected and analyzed to show that an unique relationship exists between soil constant k and standard penetration value N both in sandy soil and in clayey soil.