COST OPTIMIZATION OF USING GEOGRIDS VS PILES IN THE FOUNDATION OF INTERCHANGE BRIDGES

The use of soil reinforcement has become widely ado pted due to successive development of different types of geosynthetics. Although soil reinforcement had gained wide acceptance in other countries, Iraq is still hesitated to adopt the system. This paper is an economic study to investigate the feasibility of using geogrids in the foundation of interchange bridges, resting on sandy soils, instead of piles. The design restrictions are imposed as design constraints in the analysis of both cases (geogrids and piles). Choice of the design parameters are made in a way that fit local circumstances in middle and south Iraq considering common safety factors.