Experimental Study On Mechanical Properties Of The Slurry-soil Interface Of Earthen Sites Anchorage System

The study of interfacial mechanical properties is of great significance for revealing the anchoring mechanism of the anchor system in earthen sites.The mechanical properties of the second interface have a significant impact on the overall stability of the corresponding system when we analyze the failure mechanism of the anchor system.Researches have shown that the study of its failure mechanism is on preliminary stage.In order to explore failure mechanism of the second interface,we put forward to some experimental apparatus and method alone,i.e.,the testing device measuring second interfacial mechanical properties based on press,making specimen device and the method of preparing sample which includes interface.For four different materials widely used in anchoring engineering(calcined ginger nuts(CGN),soil(C),fly ash(F)and quartz sand(S)),we make anchoring slurry through mingling that four materials each other and research the influence of different slurry and roughness of wall of hole on the mechanical properties of the second interface by using the apparatus and method mentioned above,as well as obtain shear strength and the whole process curves of load-displacement.Based on above the research,this paper can draw these main conclusions as following:(1)Institute established anchorage laboratory test system can complete the a series of processes including making specimen,hole-making,applying push-out test and so on.It can truly reflect the characteristics of the interface between the slurry and the soil when the anchor system is destroyed.That system can provide a new method for revealing the mechanical behavior and obtaining the mechanical properties for slurry-soil interface,and then provides a new idea for the determination of interfacial shear stress-displacement relationship in geotechnical engineering.(2)The shear strength of the interface increases with the increase of pore wall roughness.When CGN+C is Used as the anchoring slurry and the anchorage length is 30 cm,the slurry-soil interface can provide shear strength of 0.08~0.21MPa(smooth hole wall)and 0.24~0.48MPa(thread hole wall).Accordingly,as the anchorage slurry,CGN+F can provide the shear strength of 0.11~0.41 MPa and 0.38~0.68 MPa,respectively;CGN+S can provide the shear strength of 0.08-0.33 MPa and 0.13-0.56 MPa respectively;and CGN+FS can provide shear strength of 0.07~0.15 MPa and 0.21~0.41 MPa respectively.(3)The failure form of slurry-soil interface is revealed,that is,the most interface failure of sample whose pore wall is smooth is bond failure,and the anchorage grouting is most completely pushed out.While the counterpart of threaded pore wall mainly appears the taper-bond composite failure and its interfacial bottom opposes obvious characteristics of cone failure.(4)The obtained fitting results are great well with the corresponding experimental results when we use the mode which applies the piecewise function to fit the shear stress-displacement relationship to analyze the mechanical properties of the second interface of anchorage system in earthen sites.