Scheme On Widening Dam Crest And Driving Dynamic Response Of Existing Concrete Facing Rockfill Dam

As Wanzhou City's traffic jam is becoming increasingly serious,relevant department presented that Tianxian Lake sand shelter dam crest should be widened to relieve the traffic pressure on the road and original dam crest.Due to the design as supporting projects of Zhuxi River environmental governance without considering the crest widened and traffic function,different widening scheme has different influence on stress deformation and stability on dam slope.Although dam crest traffic had little effect on riverbed and left bank dam,may lead to the damage on impervious core wall that rockfill dam section with grouting reinforcement and slope stability.In order to understand stress deformation of widening facing rockfill dam under the traffic,the article selected widening concrete facing rockfill dam and used finite element simulation analysis method to study bearing property of concrete facing rockfill dam under vehicle load.The main research contents and results in this thesis include following aspects:(1)Putting forward vehicle load static value method through the research on dam crest traffic simulation method of vehicle load which was uniform static load;in the vehicle load dynamic simulation method,the value is taken as sine distributed load;in the moving vehicle load simulation method,the vehicle load was applied by VDLOAD program and the road load simulated real vehicle.Load magnitude had relevance to weight and speed.(2)Using the nonlinear elastic model to carry out the static finite element analysis and calculation.Researching deformation characteristics and stability of dam under the crest vehicle load with different widening scheme and selecting optimal one by comparative analysis.(3)Regarding maximum cross section as analyzed transect,analysising the dam crest traffic under optimal widening scheme by means of finite element dynamic analysis.Researching the stress and deformation under the different vehicle dynamic load including the action of driving speed and different water level.Getting characteristics of horizontal and vertical displacement,dynamic principal tensile stress as well as dangerous water level in the dam and grouting area and stress concentration zone.The result shows that the maximum value of dynamic principal tensile stressresponse of the grouting zone appears at the top of it and no pull cracks will be occurred.But the stress concentration area appears at the bottom of the grouting area;the maximum dynamic stress of the dam is in the middle of the retaining wall and no tension crack will be occurred in it.Due to the long distance from retaining wall to grouting area,the effect on the grouting area is very small.(4)Regarding axial longitudinal section as analyzed transect,analysising the dam crest traffic under optimal widening scheme by means of finite element dynamic analysis.Studying the stress and deformation in single vehicle load under the effect of vehicle speed and weight.Results show that under the effect of typical vehicle speed and weight the article selected,stress concentration formed at the bottom of filling area and no pull crack and effect will be appeared in the grouting area as well as dam crest.