摘要
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 new load transfer model considering friction resistance softening of soils is proposed.Its parameters have clear physical significance,their values are easy to obtain,and the proposed value of softening coefficient c is given in accordance with the engineering experience in Zhejiang province.In this load transfer model,the softening coefficient c decides the degree of softening,the parameter s u decides the ultimate friction resistance,and the parameter τ u decides the ultimate relative displacement.When the relative displacement is smaller than the ultimate displacement,the friction resistance increases with relative displacement nonlinearly.When the relative displacement is equal to the ultimate displacement,the friction resistance reaches the peak value;when the relative displacement is larger than the ultimate displacement,friction resistance begins to decrease gradually.The normalized analysis of data from case histories and the comparison with the hyperbolic load transfer model indicate that the load transfer model considering strain softening of soils is better than the hyperbolic load transfer model in simulating the stress-strain curve of softening soils.
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2010年第7期1109-1113,共5页
Chinese Journal of Geotechnical Engineering
关键词
侧摩阻力
应变软化
传递函数
friction resistance
strain softening
load transfer function
