Research On Anti-Seismic Property For The Earth Dikes And Dams With Polymer Anti-Seepage Wall

Polymer anti-seepage wall is a new technology for the reinforcement of earth dikes and dams. It has advantages of quick, light, ductile, durable, minimally invasive and environment-friendly properties. It has been widely applied in the reinforcement of earth dikes and dams, which produces good social, economic and environmental effect and has the prodigious value of popularization and application. Aiming at the shadow area and application key point of the new technology—dynamic property and anti-seismic property, the study was carried out. Starting with laboratory experiment, model test, numerical modeling and theoretical analysis, seismic characteristics and anti-seismic property of earth dikes and dams with polymer anti-seepage wall was studied. The main research work is as follows:(1)Piezoceramic bender elements technology was used to research the dynamic property of polymer grouting materials. The problems which affect the accuracy of shear wave velocity determination were solved. The dynamic shear velocity and dynamic shear modulus of polymer grouting materials with different density were obtained. The quick judgment method for dynamic shear modulus of polymer anti-seepage wall in engineering was given. The dynamic shear modulus and static elastic modulus were contrasted and the quadratic polynomial function between them was given. The correlation of dynamic modulus of polymer grouting materials and damming clay was discussed.(2)The dynamic centrifugal tests of earth dikes and dams with anti-seepage wall using authentic materials were studied. The unequal stress model scaling law of earth dam and dike with anti-seepage wall was designed. Based on one-way analysis of variance, the dynamic centrifuge model of polymer anti-seepage wall was designed and manufactured. Based on the basic theory of the geotechnical centrifugal model test, a kind of micro-concrete specialized for dynamic centrifuge model was designed. After testing, the physical and mechanical properties of two anti-seepage walls met the experiment requirements.(3)Based on dynamic centrifuge test results, the seismic response characteristics between the earth dike and dam with polymer anti-seepage wall and the earth dike and dam with concrete anti-seepage wall were studied. Based on the analysis of dynamic stress of the wall, acceleration of the dam, settlement of the dam crest, excess pore pressure of the dam and the dynamic soil pressure increment of the dam, the difference of the seismic response of two walls and two dams was focused. In the test, the destructive phenomenon of concrete anti-seepage wall was observed and the unfavorable area of traditional anti-seepage wall under the seismic loads was found.(4)The anti-seismic property of the earth dike and dam with polymer anti-seepage wall was studied. Using finite element software ABAQUS and combining with the dynamic property of polymer grouting materials obtained from piezoceramic bender elements test, the three-dimentional numerical calculation model of earth dike and dam with polymer anti-seepage wall was established with consideration of the seismic wave input from viscous-spring artificial boundary and the viscoelastic property of soil. The correctness and reasonability of the model was verified through comparison with test results. Combined with test results, the seismic property of earth dike and dam with polymer anti-seepage wall was obtained, the anti-seismic property of earth dike and dam with polymer anti-seepage wall and related mechanism were defined.(5)The density optimization design of polymer anti-seepage wall based on multiple-objective functions under seismic loads was researched. The safety margin of anti-seismic property for polymer anti-seepage wall was proposed. The multiple-objective optimization methods based on graphic method was used in the optimization design of polymer anti-seepage wall. With the purpose of good anti-seismic property and low cost, the optimization model which combines seismic safety with economical efficiency was established and the density optimization design of polymer anti-seepage wall was conducted in the constraint conditions of seepage-proofing and technical feasibility requirements.