As the river with highest silt content in the world, the Yellow River is dredged annually to relieve the pressure of flood control. Prior studies indicated that the dredged Yellow River silt cannot be directly utilized as construction filling material because of the deficiency in strength and stability. In this study, soybean urease induced calcium carbonate precipitation (SICP) method was proposed to solidify the Yellow River silt for the purpose of promoting its mechanical properties. The influences of soybean powder concentration and pH value on the soybean urease activity were investigated. By estimating the urease activity of per unit mass, the soybean powder concentration with highest extraction efficiency were determined. The optimum bio-treatment recipe including cement solution concentration and grouting time of the biological solidification agent suitable for the Yellow River silt was characterized through unconfined compressive strength (UCS) test and CaCO3 content test. Meanwhile, scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis of the bio-treated Yellow River silt sample verified the effectiveness of solidification from microscopic viewpoint. The findings of this study suggest that soybean urease induced calcium carbonate precipitation (SICP) method can effectively improve the geotechnical engineering properties of Yellow River silt and provide a technical approach for the resource utilization of the Yellow River silt.

作为世界上泥沙含量最高的河流，黄河每年都进行疏浚，以缓解防洪压力。已有研究表明，由于疏浚后的黄河淤泥强度和稳定性不足，不能直接用作建筑填料。在这项研究中，提出了大豆脲酶诱导碳酸钙沉淀（SICP）方法固化黄河淤泥，以提高其力学性能。考察了大豆粉浓度和pH值对大豆脲酶活性的影响。通过估算每单位质量的脲酶活性，确定提取效率最高的豆粉浓度。抗压强度（UCS）测试和CaCO3含量测试。同时，对经过生物处理的黄河淤泥样品进行扫描电子显微镜（SEM）和X射线衍射（XRD）分析，从微观角度验证了固化的有效性。该研究结果表明，大豆脲酶诱导碳酸钙沉淀（SICP）法可有效改善黄河淤泥的岩土工程性能，为黄河淤泥的资源化利用提供技术途径。