DEVELOPMENT OF SOFTWARE FOR DESIGN OF REINFORCED EARTH` SLOPES AND WALLS

Abstract

The advent of geosynthetic-reinforcement materials has brought a new dimension of efficiency to design and construction of reinforced slopes, retaining walls, etc., due to their corrosive resistance and long-term stability. The overall process of engineering design can be considered as a sequence of problem definition, data acquisition, conceptual design and detailed design. While the initial stages require most of engineering judgement, the detailed design stage is usually most time consuming when it requires optimization & repetition of straight forward calculations and presentation of the design to a high standard. A computer program was written which embodied the entire detailed design process from raw data to presentation of the design in the form of graphical output. Here, a user friendly interactive software on design of reinforced earth walls/slopes is presented and the software is highly versatile. The design package has been used to solve a few typical design problems and the results are analysed to identify critical factors governing the design. A few typical cases of geogrid reinforced slopes from literature have been briefly illustrated. These cases suggest that Reinforced Earth Slopes of very large heights can be constructed successfully. The Design procedure and charts suggested by Jewell (1991) are incorporated in the package. The charts provide convenient input on proportioning of Reinforced Earth slopes and walls with slope angle up to 90°. Further a quasi-static analysis suggested by Michalowski (1998), where seismic influence is substituted with a static force, a method widely accepted in design, has been incorporated. The Software package has been developed using Visual Basic 6.0. The software provides user friendly input of design data, knowledge base as help information and the design outcome in the form of graphical output. Interactive mode of design scheme to achieve optimal design has been adopted. The results obtained for a few typical design examples have been presented to bring out the effect of various parameters such as allowable strength of reinforcement, pore water pressure, slope angle, reinforcement spacing, and surcharge loads, etc., on the design.