引黄济青渠首沉砂池黄河砂理化特性研究

Study on Physical and Chemical Properties of Sediment in the Head Silt Basin of Yellow River Diversion to Qingdao Project

摘要:

针对引黄济青渠首沉砂池存在年均淤积量大、清淤成本高、占地广等问题,提出"取样-试验测定-特性量化"的技术方法,开展砂的筛分、土的液塑限、土的击实及土的承载比(CBR)四大核心试验。结果表明:该区域黄河砂细度模数介于0.74~0.81之间,属特细砂,含泥量占比17%~22.32%,级配不良;液限32.4%~33.4%、塑限18.0%~19.0%、塑性指数14.3~14.5,判定为低液限粉质黏土;最佳含水率8.8%~9.2%,最大干密度1.74~1.77 g/cm3,击实特性与低液限粉质黏土契合;纯砂掺入5%生石灰后,贯入量2.5 mm时CBR值达16.9%,符合公路路基填料标准。

Abstract:

The head silt basin of the Yellow River Diversion to Qingdao Project features large annual siltation volume, high dredging cost and extensive land occupation. Adopting the technical route of sampling experimental determination property quantification, this study carries out four core tests including sediment sieve analysis, liquid and plastic limit test, compaction test and California Bearing Ratio (CBR) test. The results show that the fineness modulus of local Yellow River sediment ranges from 0.74 to 0.81, belonging to superfine sand with a silt content of 17%~22.32% and poor gradation. The liquid limit is 32.4%~33.4%, plastic limit 18.0%~19.0%, and plasticity index 14.3~14.5, which is classified as low-liquid-limit silty clay. The optimum moisture content is 8.8%~9.2% and the maximum dry density is 1.74~1.77 g/cm3, with compaction characteristics consistent with low-liquid-limit silty clay. After mixing 5% quicklime into pure sediment, the CBR value reaches 16.9% at a penetration of 2.5 mm, complying with the specification requirements for highway subgrade filling materials.