土钉加固黏性土坡动力离心模型试验研究

 很多滑坡是由地震引发的，为了防止或减轻地震造成的边坡灾害，目前在边坡的加固治理方面已经发展并形成一些较好的方法，而土钉是边坡抗震加固的一种简便有效的方法。采用动力离心模型试验方法，再现地震条件下土钉加固黏性土坡和素土坡的响应；测量了试验过程中边坡的位移场和加速度响应的变化过程。基于试验结果，通过对比素土坡和土钉加固土坡的动力响应，探讨土钉加固土坡的变形规律和加固机制。试验结果表明，地震过程中土坡产生不可恢复的累积变形，其大小与输入的地震加速度峰值有关。通过比较土钉加固土坡和素土坡的位移分布，研究土钉加固土坡的机制。引入土单元应变进行分析，结果表明，土钉加固措施能显著地改变边坡的位移场分布，限制土坡的剪切变形，避免滑裂面的产生，从而提高了边坡的稳定性。

DYNAMIC CENTRIFUGE MODELING TEST OF COHESIVE SOIL SLOPES REINFORCED WITH SOIL NAILING

In order to prevent earthquake-induced hazards，many countermeasures are developed to improve the stability of slopes，among which the soil nailing reinforcement is widely used. The behaviors of the cohesive soil slopes reinforced with soil nailing during earthquake are investigated using centrifuge modeling tests；and the unreinforced slope is also investigated for comparison. The responses of the slope reinforced with soil nailing are measured during the test，including the time-history curves of displacements and accelerations of the slope. On the basis of the responses of the slope reinforced with soil nailing and the unreinforced slope by the comparison，the deformation rules and reinforcement mechanisms are discussed. The test results show that the nailing arrests a landslide that occurs in the unreinforced slope during earthquake. The displacement of the slope exhibits an evidently irreversible deformation accumulation that is dependent on the magnitude of seismic input amplitudes. The soil nailing reinforcement mechanism is analyzed based on the comparison of displacement distribution of the lateral sides of both slopes with introducing strain analysis of a soil element within the slope. It can be concluded that the soil nailing can significantly change the displacement distribution and reduce the shear deformation of the slope. Thus，the possible sliding can be prevented in the reinforced slope during the earthquake and the slope stability can be increased significantly.