| The reinforced cemented soil pile(anchor)structure is widely used for foundation pit support in soft soil areas.With good corrosion resistance,Glass Fiber Reinforced Polymer(GFRP)bars can replace steel bars as reinforcements and be used in engineering applications in coastal soft soil areas with extreme salt content.In addition,to improve the tensile and flexural strength of cement soil,adding fiber into cemented soil becomes an effectively methods.The interface bond behavior of the reinforced body in cemented soil has an important influence on the bearing performance of the supporting structure.In order to realize the waste utilization of construction waste and provide a basis for the calculation theory of bearing capacity of GFRP bars in cemented soil retaining structure,an experimental study is investigated in this research.The experiments illustrate the bond behavior of GFRP bars embedded in cemented soil mixed with glass fiber and construction waste under various maintenance conditions.Theoretical analysis of the forced deformation characteristics of the whole length of the GFRP bars has also been carried out.The common outcomes of the research are as follows:Firstly,the scheme was determined by the uniform experiment design principle considering four experimental factors: sampling/curing environment,cement mixing ratio,glass fiber mixing ratio,and construction waste mixing ratio.Then,36 groups of GFRP bars pull-out experiments and unconfined compressive tests of cemented soil cubes were employed to obtain the interface bond-slip curves of GFRP bars in cemented soil.To analyze the influence of each factor on the ultimate bond strength(UBS),the Kriging model was established based on the UBS data acquired from the previous experiments and was utilized in fitting the UBS with different combinations of experimental factors.Secondly,analyzing the morphological characteristics of the bond-slip curve based on the test results,which also showed that the UBS presented a linear correlation with the unconfined compressive strength(UCS)and bond strength of the other characteristic points(the 1st valley point,the 2nd peak point and the 2nd valley point)in the interface bond-slip curve,respectively.The relationship between the rib spacing of GFRP bars and the displacement of each characteristic point were also studied.The rid effect represents the common phenomenon of undulant attenuation in the residual softening section of the bond-slip curve caused by the ribs of the tendons.Regarding the rib effect,the interface bond-slip model for the GFRP-Fiber Cemented Soil was developed on the basis of the strength and displacement values of the 4characteristic points in the bond-slip curve.Thirdly,a theoretical method was proposed,which could yield the interface bond-slip model for the GFRP-Cemented Soil indirectly only with UCS of the cemented soil and the rib spacing of the GFRP bars.The reliability of this pattern was confirmed by some sets of tset results,exhibiting a considerable fitting precision degree.The results show that the interface bond-slip model has good performance in fitting and prediction of the interface bond-slip curves of GFRP bars in fiber cemented soil.Finaly,according to the established bond-slip model,the forced deformation analysis of the whole length of the GFRP bars is carried out based on the load transfer method.Meanwhile,the pull-out discrete element model of GFRP bars in fiber cemented soil has been established to obtain the load-displacement curve of the top of reinforced body.Furthermore,this paper discusses the influence of unconfined compressive strength and rib spacing on the pull-out bearing capacity of the reinforced body.The results show that increasing the unconfined compressive strength of fiber cement-soil can effectively enhance the bearing capacity of the reinforced cemented soil pile-anchor structure,and increasing the rib spacing of GFRP bars appropriately can reduce the relative displacement of the reinforced body effectively. |
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