固结条件对海岸带花岗岩风化土强度指标的影响

Influence of consolidation conditions on strength indexes of granite weathered soil in coastal zone

对等向固结和K_(0)固结后的不同花岗岩风化土试样进行了不排水剪切试验,研究了固结条件对花岗岩风化土应力应变关系和强度指标的影响。研究结果表明:花岗岩风化土的应力应变关系曲线在等向固结不排水剪切试验中呈应变硬化型,在K_(0)固结不排水剪切试验中主要为应变软化型;固结方法对花岗岩风化土的不排水强度存在一定的影响,在不同的围压下,经过K_(0)固结后试样的最大主应力差值均大于等向固结试样;不同固结方法对不排水试验得出的强度指标也有一定的影响,K_(0)固结后花岗岩风化土试样的黏聚力和内摩擦角都大于等向固结后的试样。研究成果对工程设计有重要参考意义。

The undrained shear tests are carried out on granite weathered soil samples after the isotropic consolidation and K_(0) consolidation,and the influences of consolidation conditions on the stress-strain relationship and the strength indexes of granite weathered soil are studied.The study results show that the stress-strain relationship curves of granite weathered soil is the strain hardening type in the isotropic consolidation undrained tests and the strain softening type in the K_(0) consolidation undrained tests.The consolidation method has a certain impact on the undrained strength of granite weathered soil.Under different confining pressures,the maximum principal stress difference of the samples after K_(0) consolidation is greater than that of the isotropic consolidation samples.The different consolidation methods also have a certain influence on the strength indexes of undrained tests.The cohesion and the internal friction angle of granite weathered soil samples after the K_(0) consolidation are greater than those after the isotropic consolidation.The study results provide the important reference for engineering design.