Study On Strength And Creep Deformation Of Red Clay At Loading And Unloading Yard Of Anning Refinery

The red clay is widely distributed in our country.It is exposed on the surface of carbonate rock in hot and humid environment in the Pleistocene,after a series of complex physical and chemical weathering,especially laterization,formed and covered in bedrock,a high plastic clay brown or yellowish brown.The strength characteristics and creep deformation of red clay is an important factor affecting the quality of the project.The study of this problem has important theoretical and engineering significance.Because of the great difference of the material composition of red clay with different regions,the regional differences of its engineering properties are larger.In this paper,a series of experiments are carried out to study the strength and creep deformation of the red clay,which is used for the deep artificial filling of the Anning refinery of CNPC Yunnan petrochemical factory in Kunming area.The main research results are summarized as follows.(1)According to the difference of engineering properties of red clay in different regions,the basic physical and chemical parameters of red clay in Yunnan petrochemical field of PetroChina are analyzed by the basic physical and mechanical tests.The results show that the characteristics of the red clay is high liquid limit and plastic limit,medium compressibility,and so on.(2)The strength characteristics of remolded red clay of different compaction degree,different water content and different confining pressure were studied by unconsolidated undrained test with Model SLB-1 Three axis Tester Apparatus.The main results are as follows.When the degree of compaction is more than 92%,the shear strength increases slowly with the increase of the degree of compaction,and the degree of compaction has little effect on the shear strength.The cohesion with the compaction degree of linear increase slowly,and the internal friction angle with essentially the same.The shear strength of red clay decreases quickly with the increase of water content,and then decreases slowly.The water content has a great influence on the shear strength.The cohesion decreases linearly with the increase of water content.However,the internal friction angle decreases slowly with the increase of water content,and then decreases quickly.Under the same compaction,the shear strength of red clay increases linearly with the increase of confining pressure.With the increase of water content,the shear strength curve tends to be a spot under different confining pressures,And the greater the water content,the influence of confining pressure on shear strength is smaller.(3)The creep properties of remolded red clay of different compaction degree,different initial water content and different vertical load were studied by the confined single-axis creep test with Triple medium pressure consolidation apparatus.The main results are as follows.When the puddlability is greater than 92%,the puddlability has little effect on creep.In the same degree of compaction,when the water content is lower than 21.26%,the creep deformation of red clay decreases with the increase of water content.When the water content exceeds this value,the creep deformation increases with the increase of water content in the same degree of compaction.The vertical load has great influence on the creep of red clay.