Review of Studies on Retaining Wall's Behavior on Dynamic / Seismic Condition
Current theories, experimental investigations and numerical findings for retaining walls subject to dynamic excitations are reviewed. Brief features of each method, and experimental and numerical methods are introduced and compared. Tables are listed after each section for a clear and brief view of methods in a categorized manner. Conclusive comments plus current concerns and future expectations of this area are made at last. This review aims at shedding light on the development and concepts of different researches in dynamic retaining wall design and analysis.
Seismic Response and Evaluation of Cantilever Retaining Wall
A Cantilever retaining wall is one of the most important types of retaining structures. It is extensively used in variety of situations such as highway engineering, railway engineering, bridge engineering and irrigation engineering. Reinforced concrete retaining walls have a vertical or inclined stem cast with base slab. For greater heights earth pressure due to retained fill will be higher due to lever arm effect, higher moments are produced at base, which leads to higher section for stability design as well as structural design. This studies the stability and performance for seismic response and evaluation of cantilever retaining wall with the help of a finite element method, STAAD.pro. While the following provisions of the Indian Standard Code, IS 456:2000 and IS 1893: 1984/2002 for the sections.
Threshold Accelerations for Rotation or Sliding of Bridge Abutments
An analytic procedure for predicting threshold accelerations for movement of gravity-wall bridge abutments due to earthquake loading is first described in this paper. This method combines the well-known previous work related to the sliding mode of intermittent failure with a new theory on seismic reduction of bearing capacity leading to periodic vertical movement and consequent rotation of bridge abutments. Since the critical or threshold accelerations at which horizontal and vertical equilibrium are lost are different, mixed modes of seismic movement are also possible. The major emphasis of this paper is to then present laboratory observations on small-scale, retaining-wall bridge abutments subjected to seismic excitation to verify the critical acceleration levels predicted by this analytic analysis for the various modes of wall movement. Three different test series were performed on a shaking table on walls with different interface conditions between the wall and the foundation, backfill, and bridge deck. The abutment models were general in the sense that, while a particular mode of progressive failure could be anticipated, it was not forced.