How to Use Newmark's Chart
- 1). Verify the depth below the soil where the stress increase should reach to. Plot a plan of the uniformly loaded soil area with a scale where any given point (z) is equal to the unit length between the concentric circles on Newmark's chart.
- 2). Add the points (z) to a copy of Newmark's chart with a pencil. Position a point deeper than the spot that the stress increase reaches to in the center of the chart.
- 3). Count the number of elements on Newmark's chart which are located inside of your plotted soil area, understanding that the chart contains 200 elements on it but that not all 200 will fall within your plotted area.
- 4). Use the information on Newmark's chart, which you plotted to solve an equation that yields the increase in pressure at the soil depth you're examining (" [?σ]_z"). Plug your values into the equation on a piece of paper that says: [?σ]_z=(IV)qM where IV = influence value, q = pressure on the loaded area and M = the number of elements enclosed by the loaded area.