考虑桩土相对位移的超长单桩沉降计算研究

Study on Settlement Calculation of Super-Long Single Pile Considering Pile-Soil Relative Displacement

在单桩沉降计算所采用的荷载传递函数法中,引入描述桩土相对位移与桩土间剪应力之间关系的Boxlucasl函数。接着通过推导得出在改进的荷载传递函数法下的基本微分方程与边界条件,并运用数值计算方法对该微分方程的具体算例进行求解,得到桩身位移、桩周土体位移与桩土相对位移沿桩身的变化。结合具体算例将数值解与传统线性荷载传递函数法得到的解析解进行对比分析,验证了数值解的合理性,分析了Boxlucasl函数中的参数变化对有效桩长与桩顶荷载关系曲线的影响。

In the load transfer function method used in single pile settlement calculation,the Boxlucasl function is introduced to describe the r elationship between the r elative displacement and the shear str ess at the pile-soil interface.Then the basic differential equation and boundary conditions under the improved load transfer function method ar e derived.Accor ding the numerical solution of a numerical example,the variations along the pile including the displacement of pile,the displacement of soil around the pile and the r elative displacement between the pile and soil are r evealed.Subsequently,u sing the same example,the result obtained by this numerical solution was compared with the one obtained by the analytical solution based on the traditional linear load transfer function method to verify the rationality of the numerical solution.Finally,the influence of parameter variations in Boxlucasl function on the relation ship curve between effective pile length and pile top load is analyzed.