Concrete Structure Anchor Of Planting-bar Theory And Pull Out The Experimental Research

In recent years,anchorage technique of the concrete is increasingly wide applicated inconstruction and municipal engineering, especially in building renovation, building USES ofchange, building seismic strengthening and equipment installation, of bridge reinforcementand tunnels, ports, docks, underground structure, curtain wall construction projects, concreteanchorage techniques to its high efficiency, flexible, economic and other properties, highlyengineering's favour, so fully understand the anchor system dynamic mechanism forengineering design is very important. At present the studies of planting-bar anchor mostly inengineering application for the purpose, the stress of planting-bar mechanism, the bond-slipbehavior and failure modes, less attention, need of its scientific system research. This articlethrough theoretical analysis and experimental research, this paper studies the anchor systemof planting-bar bond-slip behavior, of the interface stress transfer laws and ultimate bearingcapacity and pull resistance than reasonable aperture. Obtain the following importantachievements:Based on the established concrete reinforced surface morphology of planting-bar boltload transfer dilatancy sliding model, adopts load transfer function method, establishelastic-plastic theory space model, got planting-bar anchor axial force and shear stress alonganchor length distribution, the theoretical solution,and the factors affecting anchoring effectthe system analysis.According to pull out tests the failure process of round and rebar steel are analyzed,and application of acoustic emission testing technology, pointed out the changing relations insync between the acoustic emission energy slippage with the load characteristics of slippage,validation planting-bar anchor analyzed drawing failure process. Through rebar and roundsteel pull out tests,the stress distribution of along anchorage length was obtained, and a comparative analysis of the theoretical results and a good coincidence. According to thecalculation formulas of the theory, the factors influencing anchoring effect for: reinforced thesurface roughness, anchor diameter, the surrounding media strength etc, and with the test data,using the least squares on the curve fitting, obtained respectively the specific equationbetween bonding strength and affecting factors.The test site appear bonding destruction and cone - bond destruction two differentforms, are given respectively limit resistance formula of bearing capacity of pull. Accordingto the destruction cone - bond failure surface condition characteristic and limit equilibriumtheory, deduced to comprehensive consideration of the fracture surface shape, matrix tensilestrength and the lateral pressure and grouting pressure the limits of such factors as drawingresistance, the calculation formulas of the bearing capacity and test results and analyzed, agood coincidence.With dilatancy sliding theory as a foundation, by using elastic mechanicsaxisymmetric problems stress given the anchorage layer crack criterion, and maked atheoretical analysis to the reasonable aperture, obtained the reasonable scope than aperture.