破碎岩质边坡预应力锚固机制数值模拟研究

NUMERICAL SIMULATION STUDY ON PRESTRESSED ANCHORAGE MECHANISM IN A CRUSHED ROCK SLOPE

以金华—丽水—温州高速公路破碎岩质边坡预应力锚固工程为例,对破碎岩质边坡的预应力锚固机制开展系统的数值模拟分析。首先,依据现场实测预应力锚索张拉吨位与岩体变形的关系曲线,通过数值反分析,确定边坡岩体的力学参数,建立岩体力学计算分析模型。结合现场监测数据和室内试验研究成果,重点分析锚索预应力的扩散方式,探讨岩体质量、锚索张拉吨位以及外锚固结构对加固坡体应力和变形分布的影响规律,揭示预应力锚索体系的应力传递规律和坡体变形响应规律,从力学机制上揭示预应力锚索加固该类破碎岩质边坡的机制。

Based on a case of crush rock slope reinforced by prestressed cables in Jinhua--Lishui--Wenzhou Expressway, the prestressed anchorage mechanism in crush rock slope were systematically analyzed by FEM. First, according to the in-situ tested relational curves of cable tension forces and rock deformation, the physico-mechanical properties of rock mass were evaluated using numerical back-analysis method. Then, an analytic mechanical model was developed. Combined with in-situ tested data and laboratory research result, the stress dispersion manner of cable＇s prestress was analyzed; the distributions of slope stress and deformation varied with influence of rock mass properties, cable tension tonnage as well as different anchorage structures were discussed; the rule of slope stress and deformation response under prestressed anchorage forces was studied. As a result, the anchorage mechanism of prestressed cables in crush rock slope was discovered by the way of numerical simulation.