预应力锚索地梁中合理锚固角的确定

A method for determining rational anchorage-angle of foundation beam with prestressed anchor-cable

在现有预应力锚索地梁设计中一般直接沿用预应力锚索的锚固角确定方法,而工程中时有因锚索锚固角设计不合理导致结构工程失效的事例。鉴于此,研究了预应力锚索地梁中合理确定锚固角的方法,提出以锚索地梁和坡面岩体间不发生相对滑动为初判条件;以锚索提供最大抗滑力为设计目标,定义了预应力的利用率,并建议以初判条件和预应力利用率为主,兼顾经济和施工因素合理确定锚固角。最后以实际工程算例说明了该方法的具体应用。

At present, the method for determining anchorage angle of foundation beam with prestressed anchor-cable is usually the same as that in the prestressed anchorages engineering. Therefore, some slopes cannot be reinforced efficiently by foundation beam with prestressed cable because of the unreasonable designed anchorage-angle. A new method for designing the reasonable anchorage-angle is proposed. Firstly, an initial criterion there is no slip between the beam and the slope surface is proposed. Secondly, the highest possible anchorage power must be obtained in the design, and it is the design objective. Prestressed utilization-ratio is defined as the ratio of the real anchorage stress to anchor-cable prestress. So, the anchorage angle can be determined rationally considering the initial criterion and the utilization-ratio and giving attention to the economic and construction factors. Finally, an engineering example is given to explain how to use this method in practice.