Indian Journal of Science and Technology

Abstract

Objectives: The present study discuss estimation of active and passive earth pressure behind a smooth vertical retaining wall with horizontal backfill under linearly varying geotechnical properties, i.e., cohesion (c), angle of internal friction (φ) and unit weight (γ) of backfill vary linearly with depth.It is noted that the earth pressure behind the retaining wall is nonlinear and its variation can be established through regression analysis that follows 2nd order polynomial in the form of pa = -az2 +bz+c; where z is the depth below the backfill surface, a, b & c are constants. Methods/Statistical Analysis: Regression analysis incorporating least square error approach option is available in Microsoft excel in data analysis tool pack. The total amount of thrust (active or passive ) estimated through non-linear distribution of earth pressure behind retaining wall is compared with the corresponding values computed through most widely used Rankine’s earth pressure theory in which average values of geotechnical parameters are taken. Findings: It is noted that there is 5-7% reduction in the active earth thrust although not much reduction is achieved in the moment. In passive case, the increase in passive thrust is almost 20%. Application/Improvements: Consideration of non-linear earth pressure distribution is useful in situations where base width of the retaining wall is controlled with respect to base shear. It will ultimately lead to reduction in the total cost of construction of the retaining wall and will help in achieving economy when the length of the retaining wall is large.
Keywords: Earth Pressure, Geotechnical, Regression,Retaining Wall