围海造陆工程泄水口吹填土流失不仅影响周边海域生态环境,而且降低企业效益.选取天津市南港吹填造陆工程为观测对象,探索与流失量相关因素之间的关系.吹填土以淤泥、淤泥质土、粉质粘土为主.现场观测主要包括吹填量、泄水口的流速、过水断面面积、浓度、流失量以及闸箱式泄水口的挡板上过水厚度.结果表明在吹填施工的中后期疏浚泥浆通过泄水口的流失率相当严重,流失土的颗粒平均粒径均较小.日吹填量不是影响流失量和流失率的主要因素,流失率对闸箱式泄水口的挡板顶标高的变化较为敏感,适时的增大泄水口的挡板顶标高,延长水力停留时间,提高泥沙落淤沉降效率,能显著降低流失率.
Land reclamation has become the most common way for expansion of land in coastal areas. The dred- ger fill loss in drain opening of land reclamation project not only has an adverse effect on ecological environment in surrounding waters, but also reduces the benefit of dredging companies. The field observational research was carried out in land reclamation project of Tianjin Nangang Industrial Zone to investigate the relationship between dredger fill loss and factors of influence. The dredger fill was mainly composed of sludge, mucky soil and silty clay. The daily amount of dredgers, flow velocity, discharge section area and concentration in drain opening, sediment loss, water depth at top of baffle were measured. The results show that the dredger fill loss is quite severe in the mid-to final stages of construction. The mean grain size of dredger fill loss is small. The daily amount of dredgers is not the major factor influencing the daily amount of dredgers loss and loss rate. The elevation of baffle in drain opening has an effect on loss rate. The increased elevation of baffle would extend hy- draulic retention time and improve settling efficiency and decrease loss rate considerably.