Study On The Behavior Of Sinking Model Cutoff Wall Material And Deformation Characteristics In Levee Project

At present, a number of matured vertical cutoff techniques have been widely used in levee project,many rich experiences have been accumulated in the treatment of diseased levee project. The vertical cutoff technique has been widely used in levee project,such as grouting,preventing seepage wall,high pressure jetting,deep mixing cement pile,vertical spreading plastic technique,and so on.The vertical cutoff technique in levee project is a synthetic system engineering,the selection of vertical cutoff scheme is mainly concerned with behavior of embankment filling,dike subsoil,preventing seepage mixture and so on. Although a large number of research achievements on vertical cutoff techniques have been obtained, each has a certain suitability.But,the mechanism has not been understood thoroughly,the design theory and the project application are quite immature. At the same time,the mechanism,the site and the degree of destroy of each disease are different. Most of the existing construction ways are relatively backward,which hinders the further development of vertical cutoff technique. So,the selection of a scientific,economical and rational synthesize scheme is a key in the treatment of diseased levee project.The preventing seepage material is also accompanied by the development of vertical cutoff technique. Based on the research results of vertical cutoff techniques and their application and test results in levee project,the composite mortar of vibratory sink mold wall is mainly studied in this paper. According to the application of vibration sinking mould wall in Huai River entering sea channel,the mechanism of vibration sinking mould wall is first discussed. Based on the test results,the seepage,the pump,the fluidity,the segregability,the bleeding and the imperviousness of composite mortar of different mixing ratio are discussed. The mechanics characteristics of composite mortar and cutoff wall and their influencing factors are then analyzed,especially,the influence of the aging and the components are very notable. At the same time,the construction points of vertical cutoff techniques is also discussed. The main works is introduced in the following:(1) The cause of crash,the relation between the crash,the filtration failure and the kind of filtration failure in levee and dam project are summarized. The research results show that a large number of research achievements on vertical cutoff techniques and impervious materials and their application are conservative and relatively backward according to the seepage failure kinds in levee and dam project. At the same time,the problem of levee project in lower reaches of the Yangtze River is also analyzed.(2) According to the behavior of raw material,the optimal mix ratio of composite mortar is determined. At the same time,the amount of every raw material to be used is also determined by the mix ratio test of composite mortar.(3) The cement and the flying ash are mainly used as concretion agent in the composite mortar,the soil is mainly imbued with gap around the sand,the sand is mainly used as aggregate,and the additional dose is chiefly used as water-reducing and reinforcement. The behavior of the composite mortar is mainly concerned with the mix ratio,the water cement ratio,the cement sand ratio,the cement grade,the size of sand,the aging,the additional amount of cement and flying ash,the gradation of mixture,and so on.(4) Layering compression strength and layering degree of composite mortar is studied according to the layering model test. The layering properties and the effect regular to the compression strength of composite mortar are promulgated. The layering compression strength formula of the wall is then put forward.(5) According to the strength test results of composite mortar,the mechanical characteristics,the influence of the additional amount and the aging are analyzed. The behavior of impervious,pump,fluidity and bleeding of different composite ratio are discussed by the test results,the effects on the composite mortar behavior of different content of admixture are analyzed. The rational mixture ratio is then put forward. At the same time,the behavior of composite mortar is comparative analyzed with the flexible concrete and the plastic concrete.(6) The damage model,the microstructure,the solidification and the strength increasing mechanism of composite mortar are proclaimed by the result of the scanning electron microscope(SEM).(7) The failure characteristics of composite mortar are revealed from the tests. A new point of view of the critical stress state of tensile and shear for composite mortar is presented,and the failure criterion of cutoff wall is also presented. According to the failure criterion and mechanical analysis,the composite mortar wall would perform a good behavior,it has been verified by the cutoff wall in levee project.(8) The mechanical behavior of mortar vertical cutoff wall is analyzed by nonlinear elastoplastic FEM using Biot consideration theory. The effect regular of preventing seepage mixture,embankment filling and dike subsoil on the mechanical behavior and the concerted deformation is promulgated. At the same time,the behavior of contact plane of soil and vibratory sink mold vertical cutoff wall is analyzed by contact plane test.(9) The different particular treatment schemes is successfully proposed in the project application,such as the construction of conglomerate layer,change axial line joint seam,and so on. The result of field tests is used to certificate the impervious property and effect of vibratorysink mold vertical cutoff wall with the help of project application. The depth of the vibratory sink mold vertical cutoff wall is successfully realized to overtake 20m in the use of HuaiHo River Waterway to sea embankment project.(10) According to the mortar vertical cutoff wall of levee project,the problem,which need to further study and resolve,is put forward.