新型压缩摩擦组合分散型锚索锚固机制及效应研究

STUDY OF REINFORCEMENT MECHANISM AND EFFECT OF NEW PRESSURE-FRICTION-TYPE PRESTRESSED ANCHORAGE CABLE

预应力锚固技术广泛应用于水利水电、交通运输及地下采矿等工程领域。由于常规压力集中型锚索具有前端应力集中、剪应力分布不均匀等现象,研究、设计新型压缩摩擦组合分散型锚索。在介绍该技术要点的基础上,通过室内张拉试验以及数值仿真模拟试验,对该种锚固技术的锚固机制及效应进行系统地研究。结果表明,新型压缩摩擦组合分散型锚索内锚头应力集中量值较小,注浆体轴向压应力及剪应力叠加不明显,应力分布较为均匀,可有效克服现有压力集中型锚索所存在的缺陷,达到改善内锚头应力、提高锚固可靠性要求。在总张拉力确定的情况下,利用所设计的新型压缩摩擦组合分散型锚索技术可实现总张拉力要求,达到锚固岩体的目的。研究结果可为岩土体锚固系统设置提供一定的借鉴及参考。

At present,the prestressed anchoring technology is applied extensively to the construction of projects,such as water resources and hydropower engineering,transportation engineering,underground mining engineering,and so on.Due to the limitations of conventional prestressed anchorage cable,such as stress concentration on the head of anchor-root and nonuniformity of shear stress distribution,a new pressure-friction-type prestressed anchorage cable（PFPAC） is proposed.A number of laboratory tension tests and numerical simulations are conducted to understand the reinforcement mechanism and its effect systematically.The results show that the compressive stress concentrated on anchor-root is low;the superposition of axial compressive stress and shear stress in grouting are not obvious;and the stress distribution is uniform.PFPAC can overcome the defects of conventional prestressed anchorage cable effectively.The stress distribution in the anchor-root and the reliability of cable can be significantly improved,and the total tension stress can be effectively provided by the PFPAC if the total tension stress is already determined in the project.The results can provide an alternative in selecting anchorage system in geotechnical engineering.