压力型和拉力型锚索锚固作用的原位试验研究

Field Tests on the Anchor Effect of Pressure and Tensile Anchor Cable Structures

在泥岩地层中对比进行了4根压力型和拉力型锚索结构的原位试验．分析了各级荷载锚固作用下锚头位移随锚固力的变化情况，研究了两种锚索结构的锚固效应和加载性能。试验结果分析表明．压力分散型锚索通过承载板实现荷载的传递和扩散．可使其围岩因围压提高而表现出较高的抗压和抗剪能力．其破坏形式表现为渐近的塑性破坏．在加载后期还呈现出“加载能力强化”的特性。而拉力型锚索的破坏则表现为突然性和整体性破坏．其破坏荷载仅为压力型锚索塑性破坏荷载的69％～86％。因此．压力型锚索的受力结构比拉力型锚索更为合理，其承载力较高．也更加安全可靠．

The field test on 4 anchor cables of pressure and tensile structures was carried out on marlite layer. The displacement of the anchor caput varying with anchor forces was analyzed under the conditions of different loads. The anchor effect and beating capability of two kinds of anchor cable structures were studied. The test results showed that the plastic breaching progress is gradually and the characteristic of ＂aggrandizement of loading capacity＂ was revealed during the loading end for the pressure anchor cable structure, because the compressive and shear capacity of rock mass was improved with increasing of confining pressure in the layer, through transferred and diffused pressure by beating board. But for the tensile anchor cable, its destructive is abrupt and in whole breakdown. Its destructive load is only 69%- 86% of pressure anchor cable structure. Therefore compared to the tensile anchor cable, the pressure anchor cable structure is more reasonable, higher beating capacity and more safe and reliable.