水平反力系数 - Matlock/Reese法
此方法适用于无黏性土。土的水平反力系数由下式计算得到：
其中： | nh | - | 水平压缩模量 [MN/m3] |
d | - | 桩径 [m] | |
z | 深度 [m] |
无黏性土水平压缩模量nh的建议值如下表：
土体类型 - 密实度 | nh [MN/m3] |
干砂和干砾石 - 松散 - 中密 - 密实 | 1.8 – 2.2 5.5 – 7.0 15.0 – 18.0 |
湿砂和湿砾石 - 松散 - 中密 - 密实 | 1.0 – 1.4 3.5 – 4.5 9.0 – 12.0 |
参考文献：
Reese, L. C. et. Matlock, H.: Non-Dimensional Solutions for Laterally Loaded Piles with Soil Modulus Assumed Proportional to Depth. University of Texas, Austin, 1956.
Reese, L. C. et. Matlock, H.: Generalized Solutions for Laterally Loaded Piles. Journal of the Soil Mechanics and Foundations Division, ASCE 86, No. 5, 1960, pp. 63 - 91.
Reese, L. C. et. Matlock, H.: Foundation analysis of offshore pile-supported structures. Proceedings of the 5th International Conference, ISSMFE, Paris, Vol. 2, 1961, pp. 91–7.