疏浚吹填粉土固化室内试验

Laboratory experiment on dredging reclaimed silt solidification

基于北方港口疏浚吹填粉土振动液化和土体稳定性差的特性,开展室内固化试验。研究吹填粉土固化后的物理力学性质变化及规律,分析固化粉土作为围埝、人工岛和路基填筑材料可行性,为疏浚吹填粉土资源化利用提供技术支撑。结果表明:水泥掺量为3%~12%时,吹填粉土固化后塑性指数为10. 4~15. 5,黏性和密实程度增大,抵抗变形能力增强,渗透性减小,转变为典型的黏性土;水泥掺量相同工况下,随着龄期的增加,吹填粉土固化强度不断增加,龄期14 d时平均强度可增加到28 d龄期的76%;疏浚吹填粉土的水泥掺量为3%~12%固化后,28 d龄期后再经水浸泡48 h的无侧限抗压强度为96~624 kPa,强度值相对变化≤16. 5%,水稳性能好,可作为水下围埝和人工岛等的填筑材料,具有重大实际应用价值。

Based on the characteristics of vibration liquefaction and poor stability of the dredging reclaimed silt in northern port area,we carry out laboratory experiments to study the changes of physical and mechanical properties of the dredged silt after curing.We analyze the feasibility of the solidified silt as the coffer,artificial island and roadbed filling material,and provide technical support for resource utilization of the dredging reclaimed silt.The results show that when the content of cement is from 3%to 12%,the plastic index of dusted silt after curing is from 10.4 to 15.5,the viscosity and compactness increase,the resistance to deformation increases and the permeability decreases,the silt becomes typical clay.Under the same working condition of cement content,the solidification strength of reclaimed silt increases continuously with the increase of age,and the average strength at 14 days increased to 76%at 28 days.When the cement content of dredging reclaimed silt is from 3%to 12%,the unconfined compressive strength is from 96 kPa to 624 kPa for 48 hours of water immersion after the age 28 days,relative change of intensity is less than or equal to 16.5%,water stable performance is good.It can be used as filling material for underwater coffer and artificial island and so on,which has great practical application value.