碱渣固化疏浚淤泥的动变形特性研究

Dynamic deformation for dredged soil solidified with soda residue

以碱渣为主固化剂,结合矿渣和电石渣对疏浚淤泥进行固化处理,开展不同固化剂掺量、含水率、围压和固结比等条件下固化淤泥的动三轴试验,研究动应力-应变关系、动弹性模量及阻尼比的变化规律及经验公式。研究表明:固化剂掺量增加和含水率降低可改善固化淤泥动力性质,增大动弹性模量、减小阻尼比,但当碱渣掺量高于40%时动弹性模量减小、阻尼比增大;围压和固结比增加使动弹性模量增大、阻尼比减小;从固化淤泥的动力性质和经济性来看,碱渣35%,矿渣10%,电石渣4%是较优的固化剂掺量。固化淤泥动应力-应变关系符合Hardin-Drnevich模型。基于Darendeli模型得到适合描述固化淤泥动弹性模量与应变关系的归一化曲线。在Hardin经验公式基础上,提出反映固化淤泥相对结构度的修正最大动剪切模量经验公式。固化淤泥最大动弹性模量为86.96~157.23 MPa,接近或超过了一般固化土的下限值,用作工程填料时具有良好的动变形性质。

The dredged soil was solidified with soda residue,ground granulated blast furnace slag and carbide slag.Dynamic triaxial tests were conducted under different solidifier contents,water contents,confining pressures and consolidation ratios.The dynamic stress-strain relationship,dynamic elastic modulus,damping ratio and empirical formula were studied.The results show that the increase in solidifier content and the decrease in water content contribute to increase the dynamic elastic modulus and decrease the damping ratio,but when soda residue content is higher than 40%,the dynamic elastic modulus decreases and the damping ratio increases.The increase in confining pressure and consolidation ratio help to increase the dynamic elastic modulus and decrease the damping ratio.From the viewpoint of dynamic properties and economy,the appropriate contents of soda residue,ground granulated blast furnace slag and carbide slag are 35%,10%and 4%,respectively.The dynamic stress-strain relationship of solidified soil is in accordance with the Hardin-Drnevich model.The Darendeli model can be used to describe the dynamic elastic modulus and stain relationship for solidified soil.On the basis of Hardin's maximum dynamic shear modulus formula,the modified empirical formula for solidified soil is proposed.The maximum dynamic elastic modulus of the solidified dredged soil is 86.96-157.23 MPa,which is close to or exceeds the lower limit of general solidified soil.The solidified soil can be used as general engineering filler and exhibits good dynamic deformation properties.