【作者】 赵亮；

【导师】 陈锐； 毛宗原；

【作者基本信息】 哈尔滨工业大学 ， 土木水利（专业学位）， 2025， 硕士

【摘要】 随着我国海洋经济的全面发展,海洋工程建设活动方兴未艾。我国沿海软土区域分布广泛,其高含水率、高压缩性及低抗剪强度的物理特性,需进一步处理后才能为工程使用。传统水泥固化剂一般用来提高土体强度,但其生产能耗高且存在早期强度不足的问题。鉴于此,本研究利用以工业固废为原料的新型固废基固化剂,通过系列室内土工试验,以不同含水率、固化剂掺量及养护龄期作为控制变量,说明了固废基固化剂优于水泥固化剂对于固化海相淤泥的综合力学性能,并进一步揭示了固废基固化海相淤泥的静动力特性,一定程度为解决海相淤泥固化与固废资源化两大难题提供试验支撑。基于室内土工试验,系统对比了固废基固化剂与水泥固化剂固化海相淤泥的基本物理力学性能。其中无侧限抗压试验表明,在相同水固比条件下,固废基固化土不仅保持与水泥固化土相当的施工和易性,展现出更优的抗压强度增长特性。当固化剂掺量由10%递增至25%时,固废基固化土试样无侧限抗压强度呈现非线性增长规律,其中25%掺量对比10%低掺量时抗压强度增幅均在300%以上。并且通过建立水固比-养护龄期无侧限抗压强度预测模型,实现了对固废基固化土无侧限抗压强度的有效预测,为工程配比设计提供了量化依据。直剪试验揭示出固废基固化土的抗剪特性呈现双阶段演化特征:初始应变硬化阶段(养护龄期低于1 d)抗剪强度受含水率与固化剂掺量影响较小;当进入应变软化阶段后,抗剪强度随含水率降低或固化剂掺量增加而明显提升,且其对海相淤泥的黏聚力提升能力要优于水泥固化剂。扫描电镜结果显示出固废基固化剂更强的土颗粒联接及孔隙填充作用。循环荷载作用下,随着加载次数的增加,固废基固化土饱和试样的动弹性模量与阻尼比逐渐降低,试样进入新“平衡”状态。循环后固废基固化土饱和试样三轴抗压峰值强度明显降低,而低含水率试样降幅最大。值得注意的是,该固废基固化土试样在循环荷载作用下表现出不同于未经循环加载固废基固化土饱和试样的孔压响应机制——加载初期负孔压增长现象。这与土颗粒间通过胶凝物质形成的封闭孔隙结构密切相关,并且通过微观试验基本证实了这一点。更多还原

【Abstract】 With the comprehensive development of China’s marine economy,marine engineering construction activities are on the rise.China’s coastal soft soil area is widely distributed,its high water content,high compressibility and low shear strength of physical properties,need to be further processed for engineering use.Traditional cement curing agents are generally used to improve the strength of soils,but their production is energy intensive and suffers from insufficient early strength.In view of this,this study utilizes a new type of solid waste-based curing agent with industrial solid waste as raw material,and through a series of indoor geotechnical tests with different water content,curing agent dosage and curing age as the control variables,it illustrates that solid waste-based curing agent is better than cementitious curing agent for the curing of marine silt in terms of comprehensive mechanical properties,and further reveals the static-dynamic properties of cured marine silt with solid waste-based curing agent,which provides an opportunity to solve the two major problems of curing and resource utilization of waste in the sea phase.It also further reveals the hydrostatic properties of solid waste-based cured marine silt,which to a certain extent provides experimental support for solving the two major problems of marine silt curing and waste resource utilization.Based on the indoor geotechnical tests,the basic physical and mechanical properties of the cured marine silt were systematically compared between the waste-based curing agent and the cement curing agent.The unconfined compressive test shows that under the same water-solid ratio,the solid waste-based cured soil not only maintains the same construction ease as the cement-cured soil,but also shows better compressive strength growth characteristics.When the dosage of curing agent was increased from 10%to 25%,the unconfined compressive strength of cured soil samples showed a non-linear growth pattern,in which the increase of compressive strength was more than 300%when 25%dosage was compared with 10%low dosage.And through the establishment of water-solid ratio-maintenance age unconfined compressive strength prediction model,the effective prediction of the unconfined compressive strength of solid waste-based cured soil was realized,which provides a quantitative basis for the design of engineering proportioning.The direct shear test reveals that the shear characteristics of solid waste-based cured soil show a two-stage evolution:the shear strength of the initial strain-hardening stage(the age of maintenance is less than one day)is less affected by the water content and the amount of curing agent;when it enters into the strain-softening stage,the shear strength is significantly increased with the decrease of water content or the increase of curing agent,and its ability to improve the adhesion to the sea-phase silt is better than that of the cement curing agent.Scanning electron microscopy results showed stronger soil particle association and pore filling effect of solid waste-based curing agent.Under cyclic loading,the dynamic modulus of elasticity and damping ratio of the saturated specimens of solid waste-based cured soil gradually decreased with the increase of loading times,and the specimens entered into a new“equilibrium”state.The peak triaxial compressive strength of the solid waste-based cured soil saturated specimens decreased significantly after the cycle,and the decrease was the largest in the low moisture content specimens.It is worth noting that the solidified soil specimens showed a different pore pressure response mechanism under cyclic loading than the saturated solidified soil specimens without cyclic loading—the negative pore pressure growth phenomenon at the beginning of loading.This is closely related to the closed pore structure formed between soil particles through the cementing material,and was largely confirmed by microscopic tests.更多还原