在干湿循环和施工振动共同作用下，残积土的强度和变形参数将发生显著劣化，对基坑工程的安全产生影响和威胁。借助直剪和固结试验获得残积土在干湿循环和施工振动作用下强度和变形的规律及劣化后参数预测模型，并将其应用于某地铁基坑开挖精细化数值模拟。试验分析发现：黏聚力c随干湿循环次数n和振动时间t的增加呈非线性衰减，内摩擦角φ随n增加呈波动上升，振动作用对φ的影响随n增加而减小；未经历振动时随n增加，压缩系数a_v1-2呈线性增长，参考切线模量E_{\mathrm{o}\mathrm{e}\mathrm{d}}^{\mathrm{r}\mathrm{e}\mathrm{f}}缓慢减小；经历振动后a_v1-2呈波动变化，E_{\mathrm{o}\mathrm{e}\mathrm{d}}^{\mathrm{r}\mathrm{e}\mathrm{f}}先快速减小、再缓慢减小、最后逐渐增大。考虑干湿循环和施工振动影响将基坑划分为6个影响区：干湿循环充分影响区、干湿循环影响过渡区、干湿循环和振动共同强影响区、干湿循环和振动共同弱影响区、仅振动影响区和无影响区。在各个区采用劣化后对应的土体参数开展基坑开挖精细化数值模拟，结果表明：随基坑边缘距离增大，地表沉降呈“先减小后增大”的变化趋势。随基坑深度增加，地下连续墙水平位移呈“两头小、中间大”的变化趋势；对于地表沉降和地下连续墙水平位移，有建筑物一侧的变形均小于无建筑物一侧的变形。考虑干湿循环和施工振动共同作用后的地表沉降、地下连续墙水平位移模拟结果更接近现场监测值，可为残积土基坑设计施工提供有效技术指导。

Under the coupled effects of drying-wetting cycles and construction vibration, both strength and deformation parameters of residual soil undergo significant degradation, thereby compromising the safety of excavation support systems. Through direct shear tests and consolidation tests, this study characterizes the strength-deformation behavior of residual soil under drying-wetting cycles and construction vibration, develops predictive models for deteriorated parameters, and implements them in high-fidelity numerical simulations of a metro excavation project. The experimental results indicate that: cohesion c undergoes nonlinear decay with increasing drying-wetting cycles n and vibration duration t; internal friction angle φ exhibits oscillatory increase with n, while vibration effects on φ diminish progressively at higher n; without vibration, compression coefficient a_v1-2 increases linearly with n, whereas reference tangent modulus E_{\mathrm{o}\mathrm{e}\mathrm{d}}^{\mathrm{r}\mathrm{e}\mathrm{f}} decreases gradually; under vibration, a_v1-2 shows triphasic evolution: rapid initial decrease slow secondary decrease eventual increase. By considering the effects of drying-wetting cycle and construction vibration, the excavation is divided into 6 impact zones: fully drying-wetting-affected, over drying-wetting-affected, strongly coupled drying-wetting and vibration, weakly coupled drying-wetting-affected, vibration-only, and unaffected. Degraded soil parameters corresponding to each impact zone were implemented in high-fidelity numerical simulations of the excavation sequence. Results reveal that surface settlement first decreases then increases with horizontal distance from the excavation edge. As the excavation depth increases, diaphragm wall horizontal displacement exhibits a “small-large-small” profile along the wall height. Both ground settlement and wall horizontal displacement are consistently smaller on the side adjacent to an existing building than on the unobstructed side. Incorporating the coupled effects of drying and wetting cycling and construction vibration, the simulated surface settlements and wall horizontal displacements match the field measurements more closely, thus providing a practical guidance for the design and construction of the residual soil excavations.