岩质边坡预应力锚固的力学行为及群锚效应

MECHANICAL BEHAVIOUR AND EFFECTS OF PRESTRESSED ANCHORAGE FOR ROCK SLOPE

预应力锚固技术是现代岩土工程加固的重要手段 ,针对预应力锚固体在张拉和运营过程中所实测到的资料 ,详细分析了锚固体的剪应力、轴力的传递特征 ,得到了不同预应力值下的应力变化规律 ,提出了岩质高边坡预应力锚固的群锚第一效应和第二效应的概念。通过大量资料分析 ,分别提出了内锚固段轴力、剪应力分布的经验公式 ,为合理施锚和优化布锚提供了设计依据。后续试验进一步表明 ,针对不同岩体结构类型的岩锚锚固端应力传递规律具有广泛的应用范围 ,工程实践证明了所提公式应用的可靠性和经济性。

Prestressed anchorage technique is an important method to reinforcing high rock slope. Based on the monitoring data of prestressed cables, the mechanical characteristics of both shear stress and tendon force within the fixed part of cables are analyzed.Empirical formulas of stress distribution between the interface of grouted body and drilling wall are proposed. Moreover, the new concepts, termed as the first and second effectiveness of anchorage, are also put forward. It is concluded that the structural properties of rockmass is the main factor to affect anchorage stress distribution, which can be obtaind by in situ testing of cables. The suggested methods could be widely used for practical engineering.