Study On Load Transfer Mechanism And Principle Of Design For Prestressed Bond-type Anchor

Prestessed anchorage technology has been one of the most effective and the most economic methods to resolve complex problem in geotechnical engineering, as it is to utilize subtly the higher tensile strength of steel and can transfer or enhance intensity and steady ability of rock and soil,what's more,it decreases the cost of engineering and is beneficial to the safety of construction.It is of pivotal importance to obtain the transmission regularity of anchoring force for design of prestessed anchorage in geotechnical engineering.Therefore, to study deeply load transfer mechanism of anchor has very important theoretic and engneering value.The main points are as following:1 .Based on the collection of research data both at home and abroad, the research present about the anchor's load transfer mechanism is summarized,and the main problems are indicated.2.Some failure models of anchor are expatiated. Bond property among bolt, grout body and ground is discussed. A model of load transfer from anchoring body to ground is foundede,and by this model,the influence of elastical module of rock or soil to the distribution of shear stress along the anchoring segment and the change of stress among the anchoring body in the process of applying load to the anchor are analyzed .Gauss distribution model for anchoring body's axial force is put forward,the method of determination of parameter called 'n' from the test data is also achieved.3.According to test data of Gabazhou Multipurpose Project,the property of anchor's load-transfer is analyzed,and make use of the theory ahead to explain the results of test.In the light of some data come from Northeast Research Institute of China Railway Engineering Corporation, the relation between carrying capacity and the length of anchoring section is discussed. further.4.Based on the results ahead,some problems about anchorage design are discussed in order to provide some consult for the design and construction of prestressed anchor.The discussion is concentrated on theanchoring body's design such as the choose of anchorage type, determination of the length of anchorage section, the design method of technology which can improve carrying capacity of anchor.