为评估多源固废固化湖泊底泥在冻融循环条件下的微结构劣化特征以及强度衰减规律，针对粒化高炉矿渣、脱硫石膏、建筑垃圾协同固化底泥试样，通过多次反复冻融循环试验，观察固化底泥材料在冻融循环条件下的无侧限抗压强度、体积变形、渗透系数等宏观工程特征的演变规律。结合X射线衍射试验、傅里叶红外光谱、扫描电镜和能谱分析等微观测试手段，系统地分析了冻融循环过程中固化底泥材料的矿物组构、官能团、表面形貌和元素构成，揭示了冻融循环作用下固化底泥结构劣化微观机理。结果表明，随冻融循环次数的增多，纤维状的钙矾石和柱状石膏等胶凝产物发生断裂，且相互交叠成网络状，内部孔隙增多，这可能是造成固化底泥强度减少、渗透系数增大的原因。获取的固化底泥在冻融循环过程中的力学特征及劣化规律，可为该种材料在西北、东北等具有显著冻融循环特征地区的应用与推广提供基础数据。

To evaluate the micro-structural degradation characteristics and strength attenuation law of multi source solid waste solidified lake sediment under freeze-thaw cycle conditions, the macroscopic engineering characteristics of the solidified sediment material under freeze-thaw cycle conditions, such as unconfined compressive strength, volume deformation and permeability coefficient were observed through multiple repeated freeze-thaw cycle tests on samples of granulated blast furnace slag, desulfurization gypsum, and construction waste co solidified sediment. By combining micro testing methods such as X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy spectrum analysis, then the mineral composition, functional groups, surface morphology and elemental composition of solidified sediment materials during freeze-thaw cycles were systematically analyzed, revealing the micro mechanism of structural degradation of solidified sediment under freeze-thaw cycles. The results show that with the increase of freeze-thaw cycles, fibrous ettringite and columnar gypsum and other cementitious products fracture and overlapped with each other to form a network, and the internal pores increased. This may be the reason for the decrease in strength and increase in permeability coefficient of the solidified sediment. The obtained mechanical characteristics and degradation patterns of solidified sediment during freeze-thaw cycles can provide basic data for the application and promotion of this material in regions with significant freeze-thaw cycle characteristics such as northwest and northeast of China.