Performance-Based Sesimic Design Of Gravity Earth-Retaining Wall Based On Large Shaking Table Test

Gravity retaining wall is key structure in geotechnical engineering, developing large scale shaking table tests and performance-based seismic design not only can reveal failure mechanism and laws of gravity retaining walls under seismic loads, perfect the seismic design theory and method, but also improve seismic competence and ability, and is of great significance to the development of seismic code. Therefore, the mainly works we have done in this paper are as follows:1. According to intensity, structure form, damage types, site condition, masonry type and the relationship between line alignment and fault zone, seismic damage of retaining structures in WenChuan earthquake are classified and analysis. The distribution law of seismic damage affected by the above factors is summarized, in the perspective of seismic damage survey and analysis, the revising suggestions of seismic codes are proposed.2. Seismic earth pressure calculation flows of seismic codes among China, European countries, Japanese and New Zealand are introduced. Combined with an example of a retaining wall, the differences of the above seismic codes and the gap between China seismic code and the others are discussed. By analyzing the calculation results, some suggestions for modifying seismic earth pressure calculation method in Chinese code are proposed.3. Experimental designs, implementations and the main test results of large scale shaking table tests are firstly described in detail, variation law of displacement and earth pressure are summarized later. After carrying out comparative studies of earth pressure calculated by seismic codes and measured values, the seismic performance differences of retaining walls lying in different site conditions are systematically investigated. Finally, some relative design criteria of current seismic code are affirmed and extended, the reasonable revising suggestions for seismic code are also proposed.4. Based on the survey and analysis of retaining structures seismic damage in WenChuan earthquake and large scale shaking table tests, a seismic performance-based design method for gravity retaining walls is established, which firstly introduces the graded protection design idea into the seismic design of retaining walls, and the transformation from force-based to displacement-based of seismic design ideas for subgrads retaining structure is also realized. By comparing the design method of seismic code and performance-based design, the superiority of performance design has been revealed. Finally, a standard flow of performance-based seismic design for gravity retaining walls is formed, which improves the feasibility of performance-based design in engineering applications.5. By refining the main research results of the whole paper, the key technique problems of seismic design are discussed in two perspectives which are extension and updating of current seismic technique formwork, the gap of current seismic code are also filled based on the above works. Lastly, we put forward revising suggestions for seismic code.