DESIGN PACKAGE ON REINFORCED EARTH AND SHELF RETAINING WALLS

Abstract

Retaining wall is a very important and widely used structure in construction and maintenance of highways, railway tracks and other engineering works. Conventional walls like gravity walls, cantilever walls and conterfort walls are used for these purposes since a long time. But when height of wall is more than about 8 m, they become uneconomical. In the recent past, new techniques in the field of retaining walls have been developed, which are economical and also have the advantage of ease in construction. In this thesis work, two such techniques viz. 1. Shelf retaining walls, and 2. Reinforced earth walls are described in detail and software packages 'SHELF' and `REWALL' for their design and drafting have been developed. Both the packages are user friendly and interactive and use graphics facility of Turbo C + + to display full details of retaining walls. Different soil and loading conditions that are usually encountered in practice are accounted. Earth pressure due to backfill, point load, line load, strip load, earthquake, uniform surcharge and water table are accounted for in the design. The structural design of elements of shelf type cantilever wall is carried out by the limit state method as per IS: 456 - 1978. Tie Back Wedge method is adopted for design of reinforced earth walls. In `REWALL', provision is made that either geogrids or strips may be used as reinforcement element. Main features of the packages developed includes, knowledge base which flashes on the user's screen enabling the user to make a right decision and graphical outputs of loading conditions, tentative and design dimensions, reinforcement details and drainage arrangements give clear picture to the user.