| Glass fiber reinforced polymer(Glass Fiber Reinforced Polymer,GFRP)compared with the traditional steel anchor anti floating anchor has high tensile strength,good corrosion resistance,the advantages of low relaxation and strong anti-interference Ability,has drawn more and more attention in anti floating Engineering,Its application in the field of anti floating engineering has good applicability and certain progress significance.Through the pull-out tests designed by the anti floating anchor,based on displacement testing device stress test method and the improved model,through the selection of different adhesive and steel casing,analyzes the influence of anchoring force between the steel sleeve and the binder to protect the GFRP anti floating anchor rod body of the anti floating anchor anchorage performance of GFRP.Study on the influence of different wall thickness,steel tube of different length of test result in the testing process at the same time,through the contrast test of indoor design of anti float anchor,analyzed the creep phenomenon of anti floating anchor GFRP in constant time,the creep regularity of GFRP anti floating anchor rod inside and outside the room test.The experimental results provide a reference for GFRP anti floating anchor engineering application.The main work and research results are as follows:1,Based on the different diameter,different bond length of steel casing and different kinds of bonding agent and GFRP anti floating anchor in the weathered granite,the field destructive pullout test was carried out,The influence of binder and steel casing on the anchoring performance of GFRP anti floating anchor rod during drawing process was studied.The types of anchor failure were analyzed,and a set of suit ABle GFRP anti floating anchor rod test device was developed.(1)The test of anti floating anchor GFRP destructive pull-out test based on epoxy resin are filled between the anchor rod and steel casing,AB glue and adhesive binder for three different tests,compared with epoxy resin and AB adhesive,structural adhesive has little influence of temperature,curing time,the advantages of bond strong.More suitABle for GFRP anti floating anchor pullout test.(2)A kind of structural glue filling process is invented,which solves the problem of filling difficulty caused by the small fluidity of structural glue and the uneven filling,thus affecting the cohesive force.(3)The failure mode of the steel casing with different sizes and thicknesses was analyzed by field GFRP anti floating anchor pullout test,(1)If the wall thickness of the steel casing is not enough,the steel bushing will be broken due to the low tensile strength,(2)When the length of the steel bushing is 140 mm,the brittle section will be damaged because of the failure to bear the clamping force of the loading segment anchorage,(3)When the length of the steel sleeve is 280 mm,the anchor rod will fall off the steel bushing because of the lack of friction between the steel pipe and the anchor rod.2,An outer anchoring section with concrete floor inversion simulation of anti floating anchor,creep test through indoor and field GFRP anti floating anchor,the creep characteristics of anti floating anchor GFRP analysis,study the influence of different anchorage length on the bearing capacity of the creep characteristics and limits.At the same time and comparing with the indoor and field test results,determine the feasibility the creep properties of GFRP anti float anchor test in the room.(1)The three stages of creep of GFRP anti floating anchor rod are determined,and the creep characteristics of each stage are analyzed.(2)Through the analysis of the load displacement curve,the results show that the creep resistance of GFRP anti floating anchor under the limit load of 40% can be observed.The indoor and field tests show similar laws(3)The creep characteristics of the anchorage length of GFRP anchor is roughly the same,but the ultimate pullout capacity of different anchorage length limit of anti floating anchor 15 d GFRP pullout capacity is ABout half the length of rock bolt is 30 d.(4)comparative analysis of the creep characteristics of indoor GFRP anti floating anchor and field GFRP anti floating anchor,and the results of indoor GFRP anti floating anchor have high similarity compared with field test.It is considered that the indoor test can be replaced by laboratory test to save the manpower and material resources when studying the creep characteristics of GFRP anti floating anchor. |
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