Centrifugal Model Test And Analysis On Seismic Response Of Landslide Mass Reinforced By Anti-slide Pile

Landslides triggered by earthquake are one of the most severe geologic hazards in the world, which can bring great damage to the safety of lifies and properties for people. The mechanism and laws of landslide under earthquake should be analyzed in order to reduce its harm. The anti-slide piles have been widely used tomitigate the landslide risk. Many researchers have nowdays focused on its static design for the anti-slide piles. However, the researches on seismic performance of colluvial landslide reinforced by anti-slide piles under earthquake are little, which could not meet the needs of the practice engineering. To improve the stability of colluvial landslide and make a reliable anti-slide measures, it is significant to study the seismic response and performant of colluvial landslide and its supporting systems. And it can reveal the mechanism and seismic performance of anti-slide pile under earthquake, which can provides important theoretical value and scientific significance for the seismic design of anti-slide piles. In this thesis, four centrifugal shaking table model tests of colluvial landslide and reinforced landslide with anti-slide piles were designed and carried out at 50 gravitational accelerations. Based on a typical colluvial landslide as the reference prototype, the centrifugal shaking table tests, numerical simulation and numerical analysis method have been used to study their sismic response. The main contents in thesis are summaried as follows:1. The technique of centrifugal shaking table test and the basic situations of the equipments used in centrifugal shaking table model tests were introduced. And then the design of centrifugal model tests on seismic response of colluvial landslide and reinforced landslide by anti-slide piles was introduced form the test models, the arrangement of sensors, the sensor calibrations, the preparation of model test, the inputted seismic motion and other aspects in details. The design and preparation of model test can provide a good reference for other centrifugal shaking table model tests.2. One centrifugal shaking table model test was carried out in order to understand the laws and characteristics of colluvial landslide under earthquake waves. The macro features of seismic response, the displacement response, the horizontal and vertical acceleration response at landslide surface, the horizontal acceleration response at landslide body and at bedrock, different types and different intensities of seismic wave effect on the dynamic response of colluvial landslide, and the influence of landslide body to the input seismic wave were all analyzed in details. The seismic response characteristic and regular of colluvial landslide were also given by inputting earthquake waves with different types and different intensities.3. Three centrifugal shaking table model tests of landslide mass reinforced by anti-slide piles were carried out to research their seismic response. The distributions of earth pressure and the bending moment along with the height under static and dynamic loads in the reinforced landslide mass were compared and analyzed. And results showed that the positions of the maximum earth pressure and the maximum bending moment were different under static and dynamic loads when the pile spacing was bigger. Centrifugal shaking table model tests on seismic response of the landslide mass reinforced by anti-slide piles were considering different pile spacing and different water content in landslide body. The distribution regularity of dynamic earth pressure and the dynamic bending moment of the pile under different parameters of the inputted seismic wave were analyzed. And the acceleration response characteristics and seismic wave propagation laws in stabilized landslide were known.4. A method was presented to realize viscoelastic artificial boundary in finite element software, and the results of numerical examples verified the effectiveness and stability of this method. The finite element numerical analysis model was built up based on the properties of indoor soil tests. The compared results between the numerical and the test were verified that the model had some reliability. Considering the effect on the anti-slide pile by various factors, such as pile space, embedded depth of pile, pile section size and elastic modulus of the pile, three-dimensional numerical model were used to study the supporting performances of anti-slide pile under earthquake. Influencing factors for the maximum dynamic bending moment of anti-slide pile were studied by grey correlation analysis method. And the results can be helpful for the seismic design of anti-slide pile.5. Based on the ultimate equilibrium theory, a general analytical expression for the factor of safety of slope was proposed. The method considered most parameters such as hydraulic condition, surcharge, depth of tension crack, horizontal and vertical seismic loads. A detailed parametric analysis was presented to study their effect on the stability of the slope. Grey support vector machines(SVM) model was proposed which can be used to forcaste slope displacements. Based on the centrifuge shaking table model test research on the dynamic response of colluvial landslide and the orthogonal design method, predictive model was established to analyze influence factors of the acceleration response of colluvial landslide. The main factors affected the dynamic response of colluvial landslide were researched.