Experimental Study On Uplift Capacity And Soil Deformation Around Multiplate Helical Type Anchors In Sand

Multiplate helical type anchor,As a unique form of foundation,with the advantages of convenient installation,higher bearing capacity,less disturbance to the environment and can withstand both tensile and compressive,has been widely used and played an irreplaceable role in many fields of geotechnical engineering,different from the important role in construction,at present,the theoretical research of multiplate helical type anchor on its bearing mechanism is still very backward.Limited to the traditional means of measurement,most researches on the multiplate helical type anchor are based on assumed failure plain,which leads to a large error in analyzing the deformation mechanism of the soil around the anchors.In order to reveal the true deformation mechanism of multiplate helical type anchor in sands,the undisturbed deformation measurement technology is used to study the soil deformation fields around the anchor.Based on the Strain Master image processing system,the deformation fields are calculated and compared and analyzed with the multiplate helical type anchor mode test,then the influencing factors of the bearing capacity of multiplate helical type anchor have been revealed.Based on these studies,this paper analyzed the efficiency of the bearing capacity of multiplate helical type anchor,and build a more suitable prediction mode for the bearing capacity of multiplate helical type anchor.Main conclusions are summarized below.(1)This paper designed a series of model test including different densities of sands,different burial rate and different anchor spacing in order to reveal the influencing factors of the bearing capacity of multiplate helical type anchor,so that can systematically analyze the true deformation mechanism of the soil around the anchors.(2)Based on the result of the model test,series of force-displacement curve have been drawn under different influencing factors,according to these curves,the influencing factors of the bearing capacity are analyzed,then the mechanical characteristics of multiplate helical type anchors in different bearing stages are obtained under different influencing factors.(3)Using the Strain Master image processing system,the displacement fields and the shear fields of the soil around multiplate helical type anchor have been calculated,through the comparative analysis of the deformation field under different influencing factors,the true mechanism of the deformation of the soil around the anchor is revealed,and the failure shape of the soil around the anchor is analyzed based on the shear theory.(4)Based on the theory of limit equilibrium and the efficiency of multiplate helical type anchor,a theoretical model of multiplate helical type anchor is proposed.Based on this model,the extensional bearing capacity of multiplate helical type anchor under the corresponding test conditions is estimated and compared with the result of the model test.The results are compared to test the accuracy and rationality of the theoretical model.