T Chart to evaluate consolidation test results

Using Terzaghi's degree of consolidation, U, and the time factor, T, relationship, if M<SUB>U1</SUB> and M<SUB>U2</SUB> (M<SUB>U1</SUB> ≠ M<SUB>U2</SUB>) are slopes of the U-√T curve at any two time factors T<SUB>U1</SUB> and T<SUB>U2</SUB>, then it can be shown that a unique relationship exists between T<SUB>U2</SUB>/T<SUB>U1</SUB>, M<SUB>U1</SUB>/M<SUB>U2</SUB>, and T<SUB>U1</SUB> (or T<SUB>U2</SUB>), and knowing any two of these, the third can be uniquely determined. A chart, called the T chart, has been plotted using these three variables for quickly determining T and U at any experimental time, t, to determine the coefficient of consolidation, c<SUB>ν</SUB>, corrected zero settlement, δ<SUB>0</SUB>, and ultimate primary settlement, δ<SUB>100</SUB>. The chart can be used even in those cases where settlement and time, at the instant of load increment, are not known