The paper deals with the load distribution law and the development of side resistance and end resistance of single bored pile in loess under vertical load through a great number of tests in field on single pile employing some advanced equipments such as sliding micrometers . some examples are given to demonstrate the application of these laws into optimization design of piles 本文通过大量的单桩现场试验，利用瑞士滑动测微等先进测试手段，分析和研究了黄土地基中钻孔灌注桩单桩在竖向荷载作用下侧阻力和端阻力的发挥特征及荷载分布规律，并用实例说明了如何利用这些规律进行工程优化设计。
