对水平受荷单桩经典m法进行了数学简化分析，对一些需通过查表内插法选取的计算参数进行了高精度数值拟合，使得工程计算更方便快捷，并通过工程算例计算比较分析，认为拟合弹性解析解精度高、可靠快捷。另外，由于受较大水平荷载的单桩桩顶层土会出现塑性屈服变形，若仍采用经典m法计算，则桩顶水平位移明显偏小。基于提出的高精度拟合弹性解析解及塑性区平衡微分方程，通过待定系数法及理论计算，给出了考虑桩顶塑性屈服区影响下的桩顶变位半经验弹塑性解析解，最后通过算例计算比较分析，认为半经验弹塑性解析解成果与实测成果基本一致，满足工程实践要求。

The classic m-method for the calculation of laterally loaded single pile is mathematically simplified. A numerical fitting of high precision is given to the calculation parameters selected by looking up table and by interpolation with the classic m-method. Comparison of engineering examples shows that the elastic analytical solution by fitting is more accurate, reliable and efficient. In addition, since large horizontal load will lead to plastic yield in the top soil layer above the single pile, the horizontal displacement of the pile will be remarkably  smaller if the classic m-method is still employed. On the basis of the fitted elastic analytic solution proposed in this research and the equilibrium differential equation for plastic zone, as well as the method of undetermined coefficient, the nonlinear semi-empirical analytical solution of horizontal displacement on the pile head which takes the plastic yield of pile head into account is given. Calculation example verifies that the results by this semi-empirical plastic analytical solution is generally the same with observed results and meets the requirements of engineering practice.