Experimental Study On Design Of Basalt Fiber Reinforced Polymer Anchor Supporting Soil Slope

Basalt fiber reinforced polymer(BFRP)is a material of high strength,light weight,anticorrosive,and the thermal expansion coefficient is close to the concrete’ s.Once used as a steel replacement,the corrosion problem of steel anchor can be solved fundamentally.In recent years,BFRP bar has been applied in geotechnical anchorage engineering.In this thesis,the mechanical properties of BFRP bar are studied firstly by tensile test,shearing test,corrosion resistance test and bonding strength test between BFRP bar and cement-based materials.Secondly,Based on the design specifications of steel anchor and the equal strength principle,.the design parameters of non-prestressed BFRP anchor in supporting soil slope are suggested,and the design method is put forward.The method is used to design BFRP anchor in supporting slope of foundation pit.The slope is located in site of a project in Chengdu.In order to forecast support effect of BFRP anchor and steel anchor,a numerical simulation about two anchored slope was carried out using FLAC3D software.Finally,the validity of design method of BFRP anchor supporting soil slope is tested by contrast test and destruction test on site.In field test,the BFRP anchor is designed by the design method above to support a slope,and the other part of the slope of foundation pit was supported by steel anchor.In order to analyze reinforcement effect of BFRP anchor and steel anchor,and study failure mode of two anchored slopes.Slope surface displacement,deep deformation and force of anchors are monitored during the field test.Experimental studies in this thesis shows following conclusions.The tensile safety factor of non-prestressed BFRP anchor should not be less than 1.5(permanent)and 1.3(temporary).The tensile strength standard value is 75%of ultimate strength,and the value of BFRP bar(diameter≥12mm)is 680MPa.The design value of bonding strength between BFRP bar and mortar is equal to the allowable value divided by 1.2,which is equal to the average value of pull-out test divided by 2.1.So,the design value of bonding strength is 2.3MPa.The monitoring data of field test proved that the designed BFRP anchor can effectively strengthen soil slope and control displacement better.Moreover,the supporting effect of BFRP anchor is equivalent to steel anchor,and the slope failure mode of BFRP anchor reinforcement is the same as that of steel anchor.Therefore,the design is reasonable on BFRP anchor,using equal strength substitution method to design the BFRP anchor is feasible.