沉积泥沙自重固结系数测试方法研究

Terzaghi理论中的固结系数为定值,应用于沉积泥沙大变形固结计算时存在较大误差,而沉积泥沙固结系数的试验测定仍存在一定困难。沉降柱试验能完整的模拟低浓度泥沙的沉积固结过程,准确获取泥沙沉降过程曲线和沉积层体积分数分布曲线。在此基础上,基于不同阶段泥沙沉降过程控制方程,通过作图方法得到沉降控制方程的拟合参数,得到了随固结过程连续变化的沉积泥沙自重固结系数。根据固结过程中的沉积泥沙渗透系数和体积压缩系数变化规律,同样得到四种不同的固结系数求解方法,并讨论了各影响因素对沉积泥沙自重固结系数的影响趋势。

Test methods for self-weight consolidation coefficient of deposited sediment

The consolidation coefficient in the Terzaghi theory is constant. It will cause significant errors if it is directly applied in the calculation of large strain consolidation of deposited sediment. Meanwhile, it is still extremely difficult to obtain the self-weight consolidation coefficient of deposited sediment. Especially, the sediment deposition and consolidation process can be simulated using the sediment settlement experiment with realtively row initial concentration, and the curves of sediment settlement and deposited layer particle volume fraction also can be obtained accordingly. Based on the sediment settlemen control equations for different settlement stages, the fitted sediment settlment parameters can be determined through the mapping method, and then the self-weight consolidation coefficient of deposited sediment at different consolidation stages can be calculated. According to the change laws of hydraulic conductivity and volumetric compression coefficient, four methods for the consolidation coefficient are discussed, and the the trends and main influence factors are studied.