Study Of Seismic Behaviors And Seismic Residualdisplacements Of Sheet-pile Quay Walls Under Earthquake

With simple structure, less raw material, lower cost and easy prefabrication for main members, sheet pile wharf is widely used in coastal areas and inland areas. However, because of the mechanical characteristics of the sheet pile wharf and sensitivity of its strength and stability to water depth, using range isn’t extended to deep-water field. Therefore, the intra-industry brought up a new type of structure for sheet pile wharf, blind sheet pile wharf, which could makes it applicable in deep-water field. In normal service state, the sheet pile wall not only bear common loads but also can suffer earthquakes. Great damage can be caused by inappropriate design in earthquakes. For example, the sheet pile wharf suffer great damage, such as abruption of the sheet piles, in Hyogo-ken earthquake in Kobe, Japan. Form the aspect of the structural earthquake resistance, it is the anti-displacement ability not the strength that determine the structural safety. At the present time, there is little achievement in the study of structural static and seismic design parameters, but no relative paper about the displacement and residual displacement is published.In this diploma, finite element software and current soil pressure theory are applied to investigate the structural static and seismic design parameters for traditional sheet pile wharf and blind sheet pile wharf, and calculating method of the displacement for the front wall is also brought up. Primary coverage is as follows.(1) By consulting the research results and design specification of the sheet pile wharf and blind sheet pile wharf at home and abroad and combining the cases about the damage of the wharf under earthquakes, importance of studying the structural seismic parameters of the sheet pile wharf and the residual displacement of the front wall is illustrated.(2) Based on finite element software ADINA, effect of the design parameters under static loads of the two types of wharfs, sheet pile wharf and blind sheet pile wharf, on the structural force and displacement of the front wall is investigated, and reasonable selection ranges of the structural design parameters for the two types of wharfs are given, respectively.(3) By using Kobe wave, effect design parameters under earthquakes of the two types of wharfs on the structural force and displacement of the front wall is studied, and earthquake acceleration amplitude’s impact on the front wall’s force and residual displacement for sheet pile wharf is discussed. Also, the reasonable selection ranges of the two types of wharfs are presented, respectively.(4) On the basis of the relatively consummate static soil pressure theory and soil arching effect theory, calculating equation of the front wall’s displacement for the two types of wharfs under static loads is derived, and comparisons are made between the calculating results and site observation data of the Jintang Harbor 10# berth wharf and 32# berth wharf, respectively, by which the correctness of the theoretical results is proved.(5) Based on the research conducted by Lin Yuliang from Central South University on graphical method in obtaining the dynamic soil pressure of clay soil and combining structural characteristics of sheet pile wharf and differential equation of deflection line, calculating formula of the front wall’s residual displacement for the sheet pile wharf is derived. Comparison is made between the theoretical results and the FEM simulation results, by which the correctness of the theoretical equation is proved.