论文部分内容阅读
建立了一种考虑桩侧土应变软化的荷载传递函数,其参数的物理意义明确,取值简单,应用简便。并根据浙江地区的工程经验,给出不同土层中软化系数c的建议值。该应变软化函数的特征中,软化系数c越大,软化现象越显著,即残余强度越低;参数τu决定应变软化函数的极大值,即极限摩阻力;参数s u决定应变软化函数的驻点(临界点),即极限位移。该应变软化函数的特征:当相对位移小于极限位移时,桩侧摩阻力随着相对位移的增大而增大,且增大速度不断减小;当相对位移等于极限位移时,桩侧摩阻力达到最大值;当相对位移大于极限位移时,桩侧摩阻力随着相对位移的增大而减小。应用应变软化函数和双曲线荷载传递函数对所收集的工程桩实测资料及离心试验资料进行拟合,结果表明此应变软化传递函数比双曲线荷载传递函数更适合于反映桩侧土软化的应力应变关系。
A load transfer function considering the strain softening of pile side soil is established. The physical meaning of the parameters is clear, the value is simple and the application is simple. Based on the engineering experience in Zhejiang Province, the recommended values of softening coefficient c in different soil layers are given. In the characteristics of the strain softening function, the larger the softening coefficient c, the more significant the softening phenomenon, that is, the lower the residual strength. The parameter τu determines the maximum value of the strain softening function, that is, the ultimate frictional resistance. The parameter su determines the stationary point of the strain softening function (Critical point), that is, extreme displacement. The characteristics of the strain softening function: when the relative displacement is less than the limit displacement, the pile friction increases with the relative displacement, and the increasing speed decreases. When the relative displacement is equal to the limit displacement, Reaching the maximum; when the relative displacement is greater than the limit displacement, the friction of pile side decreases with the increase of relative displacement. The strain softening function and hyperbolic load transfer function are used to fit the measured data and the centrifugal test data. The results show that the strain softening transfer function is more suitable than the hyperbolic load transfer function to reflect the softening stress and strain relationship.