考虑非达西渗流的泥浆离心脱水分析

Analysis of centrifugal dewatering of slurry considering non-Darcian flow

摘要:

为深入探究离心脱水技术在处理主要由黏性土组成的建筑废弃泥浆时的内在机理及其影响因素,利用分段线性化方法,充分考虑黏性土中渗流的非达西特性以及土体变形的非线性特征,建立在离心作用下能够考虑其非达西渗流特性的泥浆脱水分析模型。通过与已有研究成果及室内试验结果的对比,证明了该模型的有效性。在此基础上,分析了模型参数对脱水过程的影响。研究结果表明:脱水速度和最终土水界面位移量随着电机转速的增大而增大；增加泥浆初始厚度会增大最终土水界面位移量,但会降低初期的土水界面移动速度；压缩指数在初期对土水界面位移的影响并不明显,但其增大会导致最终土水界面位移量的增加；非达西渗流参数的增大会导致土水界面位移的减少,但通过提升电机转速,可以有效地降低非达西渗流对脱水效果的不利影响。研究成果可为离心脱水技术在建筑废弃泥浆处理中的进一步优化与应用提供借鉴和参考。

Abstract:

In order to further explore the internal mechanisms and influencing factors of centrifugal dehydration technology in the treatment of construction waste mud mainly composed of cohesive soil. In this paper, the piecewise linearization method is used to fully consider the non-Darcian flow characteristics in cohesive soil and the nonlinear characteristics of soil deformation. A mud dehydration analysis model that can consider its non-Darcian flow characteristics under centrifugal action is established. The validity of the present model was proved by comparing it with the existing research results and laboratory model test results. On this basis, the influence of the model parameters on the dewatering process was investigated. The numerical results showed that the dewatering rate and the final displacement of the soil-water interface increased with the increase in motor speed. Increasing the initial thickness of mud will increase the final displacement of the soil-water interface but will reduce the initial soil-water interface movement speed. The influence of the compression index on the displacement of the soil-water interface is not obvious in the initial stage, but its increase will lead to an increase in the final displacement of the soil-water interface. The increase in non-Darcian flow parameters will lead to a decrease in soil-water interface displacement, but by increasing the motor speed, the adverse effect of non-Darcian flow on the dewatering effect can be effectively reduced. The research results can provide a reference for the further optimization and application of centrifugal dehydration technology in the treatment of construction waste mud.