| Based on the fan foundation project of Yanzi Mountain wind power station in Jiangyong County,Yongzhou City,Hunan Province,the performance of the contact surface between concrete and steel ring in fan foundation was studied in this paper.The load of fan foundation was complex,and the load was transferred to fan foundation through the foundation ring between fan tower and concrete foundation.Therefore,the research on anchorage performance of foundation ring concrete and steel ring was the key problem to explore the bearing capacity of fan foundation.The connection between steel ring and concrete of fan foundation was simplified into the model of section steel and concrete in laboratory test.The anchoring performance of the model was studied by drawing test,and the conclusion was drawn:(1)Increasing the strength grade of concrete and the length of anchoring between steel and concrete could increase the bond strength.The larger the buried depth and the greater the load,the greater the micro-strain in the steel plate,and the bond stress between the steel plate and concrete interface degenerates when the buried depth and load value were reached.The pull-out force of steel bar with lower flange and upper and lower flange was 138.6 KN and 152.3 KN,and the bond stress between strain measuring point 7 and strain measuring point 9 was the largest,which was in agreement with the calculated data.(2)With lower flange,the maximum bond stress was 2.3287 MPa,when there were upper and lower flanges the stress was 2.404 MPa.The existence of upper and lower flange was beneficial to the bond between steel and concrete.Plaxis finite element numerical simulation was used to simulate and analyze the steel ring and concrete force of fan foundation of Yanzishan wind farm.The results are as follows:(1)The maximum vertical displacement at the leading edge of the horizontal force was 1.3 mm,and the maximum horizontal displacement was 0.64 mm for the steel ring with the lower flange.When slip occurs,the stress on the contact surface of steel ring and concrete was concentrated at the lower flange,and when the flange was supreme,the concrete displacement of the front edge of the force was basically through from top to bottom.The maximum stress occurs at the top and bottom of the steel ring.(2)compared with the foundation with lower flange,the maximum compressive stress of concrete increases by 122.5 KPA compared with the foundation with upper and lower flange.It showed that the upper flange reduced the compressive stress of concrete,and this kind of design could be used in practical design under the consideration of economic and reasonable conditions. |
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