水平梯形分布荷载桩双参数法的数值解

为提高现有水平梯形分布荷载桩设计计算水平，提出了地基系数按双参数抗力模式表达下的水平梯形分布荷载桩位移和内力计算的有限差分数值分析方法，并详细推导了桩身位移的差分格式。基于这些公式，编制了全桩位移、内力及侧土抗力的计算和图形处理程序，可适用于滑坡抗滑桩和深基坑悬臂支护桩的设计计算。算例表明，该方法方便可靠，当有限差分段划分得足够小时，可使数值解接近于真实解。通过调整地基系数进行试算．可实现桩身位移和内力计算结果与实测或实际值较好吻合，从而为有试桩资料的条件下反算地基抗力系数提供了一种验算方法。计算程序的自动图形处理有助于桩身结构设计的优化和经济效益的提高。

NUMERICAL SOLUTION OF PILES UNDER LATERAL LOAD OF TRAPEZOID-DISTRIBUTION BY BIPARAMETER METHOD

In order to improve the design and calculation of laterally loaded piles,numerical analytical method of finite difference is proposed which can calculate displacements and internal forces of piles under lateral load of trapezoid distribution based on biparameter mode of foundation coefficient. The finite difference formulations of displacements of piles are deduced in details. Based on these formulations,computation and visualization programs of displacements,internal forces of piles and soil reaction are developed for design calculations of anti-sliding piles and cantilever soil retaining piles for deep foundation pits. The examples show that this method is convenient and reliable. Numerical solutions are close to real solutions when differential segments are small enough. Calculation results of displacements and internal forces can perfectly coincide with measurements and practical values by trial computations with foundation coefficients adjusted. This method is used to obtain the foundation resistant coefficients by back-calculation with the data of testing piles given. The automatic visualization by the computer program is helpful to the optimization of structural design and hence the economic benefits.