Intro Doc
$\underline{Braced \space Wall \space TERS \space in \space Cohesionless \space Soil}$ $\\$ This app calculates the stability of a braced wall with three anchors/struts. The anchors/struts are added to increase the stability of the sheet piling. This app will determine the total length of sheet pile needed to reach a user-specified factor of safety. The loads carried by each strut are also computed. $\\$ The construction of a braced wall in cohesionless soil is completed in 4 stages: $\\$ $\bullet$Stage 1. Install Sheet Pile and Complete First Excavation $\\$ $\bullet$Stage 2. Install First Strut and Complete Second Excavation $\\$ $\bullet$Stage 3. Install Second Strut and Complete Second Excavation $\\$ $\bullet$Stage 4. Install Third Strut and Complete Final Excavation $\\$ Cases 1 and 4 must be used to calculate the excavation depths and strut depths for Stages 1-3 This app will calculate the stability of the braced wall based on values entered for Stage 4 $\\$ $\underline{Calculations}$ $\\$ The summation of moments are used in these calculations to find depths, such as sheet pile embedment depth, zero-shear location, and total sheet pile embedment depth The moments are calculated by: \begin{equation}\label{eq1} M=P \cdot L \end{equation} $\\$ where P is the pressure and L is distance $\\$ The active and passive forces used in moment summations are: $\bullet$Active Surcharge - rectangular distribution along length of wall $\\$ $\bullet$Active Sand Above Dredge Line - triangular distribution $\\$ $\bullet$Active Sand Below Dredge Line - rectangular distribution $\\$ $\bullet$Active Sand Below Dredge Line - triangular distribution $\\$ $\bullet$Active Water Pressure Below GWT - triangular distribution $\\$ $\bullet$Passive Sand Below Dredge Line - triangular distribution $\\$ $\bullet$Passive Water Pressure Below GWT - triangular distribution $\\$ The embedment depth, du, is found using the summation of the restoring moments divided by the disturbing moments With a factor of safety of 1, du is solved iteratively $\\$ The maximum moment location is found where the sum of the restoring pressure equals the sum of the disturbing pressures $\\$ The actual embedment depth is found by using a specified FOS, which equals the restoring moments divided by the disturbing moments The depth is solved for iteratively The actual embedment depth is added to the final excavation depth to find the total sheet pile length $\\$ Strut loads are found by multiplying the tributary area for the strut by the total pressure above the dredge line (Terzaghi-Peck Equations) $\\$ \begin{equation}\label{eq2} \sigma = 0.65 \cdot Ka \cdot \gamma \cdot h + Ka \cdot minimum \space surcharge \end{equation} $\\$ The strut load for 3 is solved assuming the restoring moment and disturbing moment are equal with a depth of embedment, D D is solved for iteratively, when the wall is assumed to be a single anchor wall The forces acting on the wall from the depth, D, to the dredge line is the strut load for 3 $\\$ $\underline{Potential \space Hydraulic \space Pumping}$ $\\$ The US STeel Sheet Pile Manual provides a graph to calculate the factor of safety for the excavation The chart is shown as the thumbnail picture for the app The D/Hu and B/Hu ratios are solved for in the app, and the results must be used in coordination with the graph to find the FOS