基桩完整性检测中桩土相互作用参数的试验研究

通过模型桩室内试验模拟真实的桩土相互作用边界条件,应用低应变反射波法对桩土相互作用阻尼系数进行系统的研究。结果表明,桩土相互作用阻尼系数随着桩周土应力增大而增大,而且还与土质和土体的含水状态有关。对于砂土、粉土、粉质粘土,在相同应力状态下,粉质粘土的阻尼作用最大,粉土次之,砂土最小;对于同一类土,饱和土体阻尼作用大于非饱和土体。最后通过对试验结果的拟合分析建立阻尼系数与桩周土应力的相关关系。

Experimental study on pile-soil interaction parameter in pile integrity test

Damping coefficient of pile-soil interaction was systematically researched by laboratory test.In the test practical boundary condition was simulated and low-strain reflected wave method was used.It was shown that damping coefficient increased with increasing stress of soil around pile and was influenced by soil property and water content.Among three typical soils: sand,silt and silty clay,damp in silty clay was maximum,that in sand was minimum and that in silt was between the former two under the same soil stress.And damp in saturated soil was larger than that in unsaturated one.Finally,dependency relation between damping coefficient and stress of soil was established by fitting.