Analysis of the Internal Mechanism of Huaiba Landslide in Sanmenxia, Henan—Self-Healing Characteristics Test of Sliding Zone Soil

滑坡作为典型渐进式地质灾害，其剪切带的强度演化规律直接影响灾害的复活机制与防控策略。本研究针对滑带土剪切破坏后呈现的抗剪强度自恢复现象，创新性地提出剪切带“损伤–愈合–再活化”的动态演化理论。以豫西黄土滑坡区典型的三门峡槐扒滑坡原状滑带土为研究对象，采用自主研发的环剪试验系统，设计多工况“剪切–停滞–再剪切”循环试验，系统揭示不同法向应力(100~300 kPa)和停滞时间(3~72 h)耦合作用下滑带土自愈合效应的时空演化规律。研究揭示：滑带土自愈合强度恢复率与停滞时间呈显著正相关，在300 kPa法向应力下停滞72 h后恢复率达42.3%；自愈效应具有显著的时间依赖性，但易受后期变形破坏影响，0.5 mm位移即可导致83%的愈合强度损失。法向应力的增大显著提升了强度恢复速率，而恢复幅度随停滞时间延长呈指数增长趋势，并在72小时后趋于稳定。基于微观结构分析和能量耗散理论，首次构建考虑黏土矿物重结晶和孔隙水膜重建的双机制愈合模型。研究成果突破了传统残余强度理论的局限性，为滑坡多级防控体系的构建提供科学依据，推动防灾工程从被动治理向主动调控转变。Landslide, as a typical progressive geological hazard, the shear zone strength evolution law directly influences the disaster reactivation mechanism and prevention strategies. This study innovatively proposes the dynamic evolution theory of “damage-healing-reactivation” for shear zones, targeting the self-recovery phenomenon of shear strength in post-failure sliding zone soils. Taking undisturbed sliding zone soils from the typical Sanmenxia Huaipa Landslide in the loess area of western Henan as research objects, self-developed ring shear testing systems were used to design multi-condition “shear-stagnation-re-shear” cyclic tests. The spatio-temporal evolution laws of self-healing effects in sliding zone soils under the combined action of different normal stresses (100~300 kPa) and stagnation times (3~72 h) were systematically revealed. Research findings show that: The self-healing strength recovery rate of sliding zone soils has a significant positive correlation with stagnation time, reaching 42.3% after 72 h of stagnation under 300 kPa normal stress; The self-healing effect exhibits significant time-dependence but is vulnerable to subsequent deformation and failure, with 0.5 mm displacement causing 83% loss of healed strength; Increasing normal stress significantly enhances the strength recovery rate, while the recovery amplitude shows an exponential growth trend with prolonged stagnation time, tending to stabilize after 72 hours. Based on microstructure analysis and energy dissipation theory, a dual-mechanism healing model considering clay mineral recrystallization and pore water film reconstruction was first established. These research results break through the limitations of traditional residual strength theory, providing scientific basis for constructing multi-level landslide prevention systems and promoting the transformation of disaster prevention engineering from passive treatment to active regulation.