Study On The Interfacial Mechanical Behavior Of BFRP Soilanchor Bolt

Basalt fiber reinforced Polymer(BFRP)bars have a series of excellent properties such as lightweight and high strength,corrosion resistance,environmental protection,and can solve the defects on the corrosion of traditional steel rockbolt using as anchor bolt.As a representative of the new composite materials,BFRP bars have broad application prospects and huge economic benefit in geotechnical engineering.In view of the special talus mixed soil in the Western Sichuan mountainous area of China,the interfacial mechanical behaviour of BFRP soil anchor bolt is investigated by means of literature research,laboratory test and numerical simulation.In the laboratory test,four variables of 12 groups of tests including the type of anchor rod,diameter,anchorage length and grouting body diameter are compared and analyzed.Meanwhile,the failure modes of anchorage body,influencing factors,the axial distribution law of normal stress and shear stress at the first and second interface are analysed,and the bond-slip curve of the second interface is obtained.The results show that the normal stress of the anchor bolt decrease non-uniformly along the axial direction,while the shear stress,which increase and then decrease,shows a form of unimodal curve.The point of peak normal stress in grouting body moves back with the increase of the load.The existence of circumferential cracks in grouting body is observed,and has an important influence on the pullout mechanical properties of BFRP bolt,that is,decreases the value of the axial stress in anchor bolt and makes it present a single-peak or multi-peak distribution along the axis.The numerical analysis of pullout test is carried out based on ABAQUS FEM softwar.And cohesion elements is adopted to simulate the second interface failure,and bilinear constitutive model is used to describe the traction-separation laws(TSL).Finally,the load-displacement curve,the axial distribution law of stress in the BFRP bolt and anchorage body are obtained.By comparing with the test results,the validity of the CZM method is verified at simulating the pullout failure of BFRP bolt,and the existing problems are also analyzed.