浙江玉环漩门三期吹填淤泥的工程特性

围垦工程中各个区域吹填淤泥的成因、成分、物理力学特性相差较大。通过室内土工试验对吹填淤泥的物理性质进行研究,采用量筒沉积试验研究吹填淤泥的沉积规律,利用室内试验探索淤泥强度和渗透性随含水率和孔隙比变化的规律,采用现场试验对淤泥含水率和强度沿深度分布规律进行研究。结果表明:沉积试验中,初期(t118 h)淤泥沉降速度较快,以土颗粒自重沉积为主,沉降量、密度、含水率与孔隙比变化明显,海水吹填泥浆的沉积要快于淡水泥浆沉积,通过添加分散剂或絮凝剂来加快泥浆沉积速率效果不明显。采用半对数坐标表示淤泥强度或渗透性与淤泥含水率或孔隙比关系具有较好的相关性。含水率沿深度方向递减,而强度则沿深度方向递增。在不同自重固结历时下,吹填淤泥浅层含水率和强度变幅较小,深层变化较明显。

A study of engineering characteristics of hydraulic filled mud from Xuanmen third stage construction in Yuhuan of Zhejiang Province

The causes, composition, physical and mechanical characteristics of the hydraulicly filled mud are quite different for reclamation projects in various regions. The physical characteristics of the hydraulicly filled mud are studied by soil tests in laboratory, and studies of the sedimentation behavior of the hydraulicly filled mud are carried out by cylinder deposition tests, and the change behavior of strength and permeability of the hydraulicly filled mud with different water contents and void ratios are studied by laboratory tests, and the distribution behavior of water content and strength of the hydraulicly filled mud with different depths are studied by field tests. The analysis results show that: in the sedimentation experiments, the settlement speed is fast in the early (t＜118 h) sedimentation due to the soil self weight settlements, and the settlements, density, water content and void ratios change obviously. The hydraulicly filled mud in saline water settles faster than that in the fresh water, and the effect on accelerating settlement rate of the hydraulicly filled mud is not obvious by adding dispersant or flocculant. A good correlation relationship is obtained between mud strength or permeability and water contents or void ratios by semi-logarithmic ordinate representing mud strength and permeability. The water content decreases with depth, and the strength increases with depth. Change in water content and strength with depth is a little bit under different self-weight consolidation conditions in shallow layer, but more significant in deep layer.