Study On Construction Quality Control Of Full Section Asphalt Concrete Core Wall

In recent years,with the national attention to water conservancy and hydropower projects,asphalt concrete core wall seepage control body has been widely used in each dam body,because of its strong adaptability,reasonable cost,convenient construction and other advantages by domestic and foreign engineers praise.In sichuan area,especially the soil is red layer area,sand,mudstone and mixture belong to soft rock,that is,non-clay,also different from the usual rockfill,the use of asphalt concrete core wall as impervious body,is very consistent with China's sustainable development of resources and economic development.With the introduction of the 13 th five-year plan and the gradual development of the western region,the construction of earth-rock DAMS in China has become more and more important.In this paper a lot of reading at home and abroad about the document of earth and rockfill dam and asphalt concrete core wall as the foundation,paving and rolling through the field test,the site construction quality control of caxa reservoir bitumen concrete core wall of corresponding parameters,such as: the optimal mixture ratio,material selection,construction equipment optimization,temperature control,site layout,personnel transfer,mixing ingredients,etc.Field test also verified that the actual quality of the core wall is in line with the requirements.The stability of asphalt concrete core rockfill dam is studied by three dimensional finite element method.The field test mainly includes spreading test,rolling test,physical mechanics and deformation performance test,penetration test and so on.Three-dimensional finite element research mainly includes calculation parameter selection,monomer dispersion and simulation method,calculation result analysis,stability analysis,etc.,and the following conclusions are obtained:(1)The asphalt mortar,asphalt concrete mix ratio and construction process parameters which can be used for reference for similar projects are obtained(2)after considering the rheological(wetting)of dam shell material,the maximum settlement of dam body during the completion period,water storage period and 6 years after water storage operation are respectively 169.3cm,185.9cm and 190.5cm,and the final settlement is about 2.16% of the height of dam.Due to the low modulus of filling stone and slag material,the settlement of dam body is obviously higher than that of similar projects.(3)after 4 years of storage and operation,the deformation of the dam basically tends to be stable.The maximum post-construction settlement of the dam is 7.1cm,which is about0.08% of the height of the dam.(4)the maximum values of vertical compressive strain and axial tensile strain of the asphalt core wall are 8.35% and 1.13% respectively;The tensile strain is less than the allowable strain of asphalt concrete,and the asphalt core wall will not suffer from tensile failure.For compressive strain,it has exceeded the operating compressive strain of asphalt concrete uniaxial compression test.Considering that the lateral direction of asphalt core wall is limited,its compressive strain is still within the allowable compressive strain range of the triaxial test results,the asphalt core wall is safe from compressive damage.(5)the scope of sandy gravel horizontal drainage with layout optimization analysis showed that the reducing sand gravel horizontal drainage with the layout of scope of asphalt core wall dam of axial strain,minimal impact on the vertical strain,for control of asphalt concrete damage index is perpendicular to the strain,so the appropriate cutting sandy gravel horizontal drainage with the layout of the range is feasible,after considering the asphalt core wall damage downstream of the saturation line will have a certain degree of rise,proposed to sandy gravel horizontal drainage with reduced to 410 m,the elevation of the bottom up to397 m.(6)the parameter sensitivity analysis of dam shell material shows that increasing the compaction degree of dam shell material can significantly reduce the deformation of dam body and the strain of asphalt core wall,so the compaction degree of dam shell material should be increased as far as possible.(7)the stability analysis of the dam slope shows that the anti-sliding stability safety factors of the upper and lower dam slope meet the requirements of the code and have a high safety reserve,without instability failure.In this paper,combined with the actual project "sichuan caxa reservoir" study of asphalt concrete core wall,the conducted field of roller compaction and paving test,and choose the appropriate constitutive model for three dimensional finite element analysis,but because of the limitation of the author practical ability,for the purpose of this article is still in the study of comparative basis some of the problems,needs in the future study and work for further research and improvement.